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• 3581. [Article] Science basis for changing forest structure to modify wildfire behavior and severity

  Fire, other disturbances, physical setting, weather, and climate shape the structure and function of forests throughout the Western United States. More than 80 years of fire research have shown that physical ...

  Citation × Citation Citation Abstract Copy Title: Science basis for changing forest structure to modify wildfire behavior and severity Author: Graham, Russell T., McCaffrey, Sarah, Jain, Theresa B. Fire, other disturbances, physical setting, weather, and climate shape the structure and function of forests throughout the Western United States. More than 80 years of fire research have shown that physical setting, fuels, and weather combine to determine wildfire intensity (the rate at which it consumes fuel) and severity (the effect fire has on vegetation, soils, buildings, watersheds, and so forth). Millions of acres of forestlands (mainly in dry forests dominated by ponderosa pine and/or Douglas-fir) contain a high accumulation of flammable fuels compared to conditions prior to the 20th century. Forests with high stem density and fuel loading combined with extreme fire weather conditions have led to severe and large wildfires (such as those seen in the summers of 2000, 2002, and 2003) that have put a number of important values at risk. Although homes in the path of a wildfire are perhaps the most immediately recognized value, these wildfires also put numerous other human and ecological values at risk, such as power grids, drinking water supplies, firefighter safety, critical habitat, soil productivity, and air quality. For a given set of weather conditions, fire behavior is strongly influenced by stand and fuel structure. Crown fires in the dry forest types represent an increasing challenge for fire management as well as a general threat to the ecology of these forests and the closely associated human values. Crown fires are dependent on the sequence of available fuels starting from the ground surface to the canopy. Limiting crown fire in these forests can be accomplished by actions that manage in concert the surface, ladder, and crown fuels. Reducing crown fire and wildland fire growth across landscapes decreases the chances of developing large wildfires that affect human values adjacent to forested areas. However, a narrow focus on minimizing crown fire potential will not necessarily reduce the damage to homes and ecosystems when fires do occur. Homes are often ignited by embers flying far from the fire front, and by surface fires. Fire effects on ecosystems can also occur during surface fires where surface and understory fuels and deep organic layers are sufficient to generate high temperatures for long periods. Fuel treatments can help produce forest structures and fuel characteristics that then reduce the likelihood that wildfires will cause large, rapid changes in biophysical conditions. Fuel treatments can also help modify fire behavior sufficiently so that some wildfires can be suppressed more easily. Subsequent, sustained fuel treatments can maintain these conditions. Different fuel reduction methods target different components of the fuel bed. Thinning mainly affects standing vegetation, and other types of fuel treatments such as prescribed fire and pile burning woody fuels are needed to modify the combustion environment of surface fuels. In forests that have not experienced fire for many decades, multiple fuel treatments—that is, thinning and surface fuel reduction—may be required to significantly affect crown fire and surface fire hazard. Fuel treatments cannot guarantee benign fire behavior but can reduce the probability that extreme fire behavior will occur. Fuel treatments can be designed to restore forest conditions to a more resilient and resistant condition than now exists in many forests, and subsequent management could maintain these conditions, particularly in dry forests (ponderosa pine and Douglas-fir) where crown fires were historically infrequent. The degree of risk reduction will depend to some degree on the level of investment, social and economic acceptability of treatments, and concurrent consideration of other resource values (for example, wildlife). This report describes the kinds, quality, amount, and gaps of scientific knowledge for making informed decisions on fuel treatments used to modify wildfire behavior and effects in dry forests of the interior Western United States (especially forests dominated by ponderosa pine and Douglas-fir). A review of scientific principles and applications relevant to fuel treatment primarily for the dry forests is provided for the following topics: fuels, fire hazard, fire behavior, fire effects, forest structure, treatment effects and longevity, landscape fuel patterns, and scientific tools useful for management and planning. Title: Science basis for changing forest structure to modify wildfire behavior and severity Author: Graham, Russell T., McCaffrey, Sarah, Jain, Theresa B. Fire, other disturbances, physical setting, weather, and climate shape the structure and function of forests throughout the Western United States. More than 80 years of fire research have shown that physical setting, fuels, and weather combine to determine wildfire intensity (the rate at which it consumes fuel) and severity (the effect fire has on vegetation, soils, buildings, watersheds, and so forth). Millions of acres of forestlands (mainly in dry forests dominated by ponderosa pine and/or Douglas-fir) contain a high accumulation of flammable fuels compared to conditions prior to the 20th century. Forests with high stem density and fuel loading combined with extreme fire weather conditions have led to severe and large wildfires (such as those seen in the summers of 2000, 2002, and 2003) that have put a number of important values at risk. Although homes in the path of a wildfire are perhaps the most immediately recognized value, these wildfires also put numerous other human and ecological values at risk, such as power grids, drinking water supplies, firefighter safety, critical habitat, soil productivity, and air quality. For a given set of weather conditions, fire behavior is strongly influenced by stand and fuel structure. Crown fires in the dry forest types represent an increasing challenge for fire management as well as a general threat to the ecology of these forests and the closely associated human values. Crown fires are dependent on the sequence of available fuels starting from the ground surface to the canopy. Limiting crown fire in these forests can be accomplished by actions that manage in concert the surface, ladder, and crown fuels. Reducing crown fire and wildland fire growth across landscapes decreases the chances of developing large wildfires that affect human values adjacent to forested areas. However, a narrow focus on minimizing crown fire potential will not necessarily reduce the damage to homes and ecosystems when fires do occur. Homes are often ignited by embers flying far from the fire front, and by surface fires. Fire effects on ecosystems can also occur during surface fires where surface and understory fuels and deep organic layers are sufficient to generate high temperatures for long periods. Fuel treatments can help produce forest structures and fuel characteristics that then reduce the likelihood that wildfires will cause large, rapid changes in biophysical conditions. Fuel treatments can also help modify fire behavior sufficiently so that some wildfires can be suppressed more easily. Subsequent, sustained fuel treatments can maintain these conditions. Different fuel reduction methods target different components of the fuel bed. Thinning mainly affects standing vegetation, and other types of fuel treatments such as prescribed fire and pile burning woody fuels are needed to modify the combustion environment of surface fuels. In forests that have not experienced fire for many decades, multiple fuel treatments—that is, thinning and surface fuel reduction—may be required to significantly affect crown fire and surface fire hazard. Fuel treatments cannot guarantee benign fire behavior but can reduce the probability that extreme fire behavior will occur. Fuel treatments can be designed to restore forest conditions to a more resilient and resistant condition than now exists in many forests, and subsequent management could maintain these conditions, particularly in dry forests (ponderosa pine and Douglas-fir) where crown fires were historically infrequent. The degree of risk reduction will depend to some degree on the level of investment, social and economic acceptability of treatments, and concurrent consideration of other resource values (for example, wildlife). This report describes the kinds, quality, amount, and gaps of scientific knowledge for making informed decisions on fuel treatments used to modify wildfire behavior and effects in dry forests of the interior Western United States (especially forests dominated by ponderosa pine and Douglas-fir). A review of scientific principles and applications relevant to fuel treatment primarily for the dry forests is provided for the following topics: fuels, fire hazard, fire behavior, fire effects, forest structure, treatment effects and longevity, landscape fuel patterns, and scientific tools useful for management and planning. Close

• 3582. [Article] Quantification of Ecological Change Using Repeat Photography and Ground Based Lidar

  Remote sensing techniques have long been useful in quantifying changes in ecosystems and the field of remote sensing is constantly evolving to better assess and describe changes, both spatially and temporally. ...

  Citation × Citation Citation Abstract Copy Title: Quantification of Ecological Change Using Repeat Photography and Ground Based Lidar Author: Batchelor, Jonathan L. Remote sensing techniques have long been useful in quantifying changes in ecosystems and the field of remote sensing is constantly evolving to better assess and describe changes, both spatially and temporally. In this thesis I explored the novel use of two remote sensing methods to quantify ecosystems; repeat photograph to describe change over time, and ground based lidar to describe change spatially. Using repeat photography, I assessed the effects of the removal of livestock in riparian systems at Hart Mountain National Antelope Refuge in southeastern Oregon, 23 years after the cessation of cattle grazing. I compared photos taken before grazing was ended with later retake photos. Two methods were used for this assessment: 1) a qualitative visual method comparing seven cover types and processes and 2) a new quantitative method of inserting digital line transects into photos. Results indicated that channel widths and eroding banks decreased in 64% and 73% of sites, respectively. I found a 90% decrease in the amount of bare soil (p<0.001) and a 63 % decrease in exposed channel (p<0.001) as, well as a significant increase in the cover of grasses/sedges/forbs (15% increase, p=0.037), rushes (389% increase, p=0.014) and willow (388% increase, P<0.001). I also assessed the accuracy of the new method of inserting digital line transects into photo pairs. An overall accuracy of 91% (kappa 83%) suggests digital line transects can be a useful tool for quantifying vegetation cover from photos. My results indicate that the removal of cattle can result in dramatic changes in riparian vegetation, even in semi-arid landscapes and without active restoration treatments. I used ground based lidar to quantify forest structure in a spatially explicit manner. The structural complexity of a forest has profound influences on its ecological functioning and overall health. The arrangement and amount of aboveground biomass are two important components of this structural complexity that influence the biodiversity in a forest ecosystem. In this paper, I explored and develop novel depth and openness metrics derived from single point ground-based lidar scans, which can quantify this complexity to a higher level of detail. Depth is a 3D, radial measure of the visible distance in all directions from a location (e.g., at the scanner origin). Openness is the percent of scan pulses in the near-omnidirectional view without a return,. To derive these metrics, I collected 243 scans at 27 forested stands in the Pacific Northwest region of the United States, representing a broad range of forest structure types. I created structural signatures using depth and openness for each stand and determined that our metrics could reliably differentiate forests. These metrics were compared to several traditional metrics: diameter at breast height (DBH), basal area, and diameter diversity index (DDI). The mean and variance in DBH of trees, basal area, and DDI of each stand were determined by generating isovists (polygons measuring visible space from a location) derived from point cloud cross sections. Interestingly, there was only weak to moderate correlation observed between depth or openness metrics when compared with the mean and variance in DBH, basal area, and DDI, suggesting that our new metrics (depth and openness) quantify a wider range of aspects of structure at the stand and plot level that are not captured by those traditional metrics. The proposed metrics can quantify forest structure at a high level of precision, reduce observer bias, and preserve a level of complexity lost in simple indices. The proposed metrics have great potential for quantifying change in forested systems, and describing habitat for organisms. Title: Quantification of Ecological Change Using Repeat Photography and Ground Based Lidar Author: Batchelor, Jonathan L. Remote sensing techniques have long been useful in quantifying changes in ecosystems and the field of remote sensing is constantly evolving to better assess and describe changes, both spatially and temporally. In this thesis I explored the novel use of two remote sensing methods to quantify ecosystems; repeat photograph to describe change over time, and ground based lidar to describe change spatially. Using repeat photography, I assessed the effects of the removal of livestock in riparian systems at Hart Mountain National Antelope Refuge in southeastern Oregon, 23 years after the cessation of cattle grazing. I compared photos taken before grazing was ended with later retake photos. Two methods were used for this assessment: 1) a qualitative visual method comparing seven cover types and processes and 2) a new quantitative method of inserting digital line transects into photos. Results indicated that channel widths and eroding banks decreased in 64% and 73% of sites, respectively. I found a 90% decrease in the amount of bare soil (p<0.001) and a 63 % decrease in exposed channel (p<0.001) as, well as a significant increase in the cover of grasses/sedges/forbs (15% increase, p=0.037), rushes (389% increase, p=0.014) and willow (388% increase, P<0.001). I also assessed the accuracy of the new method of inserting digital line transects into photo pairs. An overall accuracy of 91% (kappa 83%) suggests digital line transects can be a useful tool for quantifying vegetation cover from photos. My results indicate that the removal of cattle can result in dramatic changes in riparian vegetation, even in semi-arid landscapes and without active restoration treatments. I used ground based lidar to quantify forest structure in a spatially explicit manner. The structural complexity of a forest has profound influences on its ecological functioning and overall health. The arrangement and amount of aboveground biomass are two important components of this structural complexity that influence the biodiversity in a forest ecosystem. In this paper, I explored and develop novel depth and openness metrics derived from single point ground-based lidar scans, which can quantify this complexity to a higher level of detail. Depth is a 3D, radial measure of the visible distance in all directions from a location (e.g., at the scanner origin). Openness is the percent of scan pulses in the near-omnidirectional view without a return,. To derive these metrics, I collected 243 scans at 27 forested stands in the Pacific Northwest region of the United States, representing a broad range of forest structure types. I created structural signatures using depth and openness for each stand and determined that our metrics could reliably differentiate forests. These metrics were compared to several traditional metrics: diameter at breast height (DBH), basal area, and diameter diversity index (DDI). The mean and variance in DBH of trees, basal area, and DDI of each stand were determined by generating isovists (polygons measuring visible space from a location) derived from point cloud cross sections. Interestingly, there was only weak to moderate correlation observed between depth or openness metrics when compared with the mean and variance in DBH, basal area, and DDI, suggesting that our new metrics (depth and openness) quantify a wider range of aspects of structure at the stand and plot level that are not captured by those traditional metrics. The proposed metrics can quantify forest structure at a high level of precision, reduce observer bias, and preserve a level of complexity lost in simple indices. The proposed metrics have great potential for quantifying change in forested systems, and describing habitat for organisms. Close

• 3583. [Article] Modeling Transport, Retention, and Growth of Early Life Stages of Small Pelagic Fishes in the Southern Humboldt System

  Small pelagic fishes (SPF), such as anchovies and sardines, are ecologically important due to their large abundance and intermediate trophic position that links plankton production to upper trophic levels. ...

  Citation × Citation Citation Abstract Copy Title: Modeling Transport, Retention, and Growth of Early Life Stages of Small Pelagic Fishes in the Southern Humboldt System Author: Gomez, Fabian A. Small pelagic fishes (SPF), such as anchovies and sardines, are ecologically important due to their large abundance and intermediate trophic position that links plankton production to upper trophic levels. They are also economically important, supporting large fisheries that contribute to one fourth of the world fish landings. Reproductive success in SPF strongly depends on environmental factors acting on early life stages (ELS). Among these factors are ocean circulation, habitat temperature, prey and predators. Understanding the coupling between ocean circulation and ELS is relevant to obtain insights on the processes that control SPF abundance. Using a numerical modeling approach, this dissertation examines spatiotemporal patterns in dispersal, growth and survival of ELS of anchovy (Engraulis ringens) and common sardine (Strangomera bentincki) in the southern Humboldt System (off central Chile). Three model components are integrated: 1) a realistically driven three-dimensional high-resolution ocean circulation model, coupled to an eight-component lower trophic level model (LTLM), which reproduces the main physics and plankton dynamics experienced by fish ELS; 2) a particle-tracking model (PTM) to simulate ELS dispersal; and 3) an Individual Based Model (IBM) of bioenergetics to simulate ELS development, growth, and survival. A combination of remotely sensed observations and the outputs of the ocean model are used in Chapter 2 to document the impact of intraseasonal upwelling variability on plankton abundance and structure. Intraseasonal changes in phytoplankton are consistent with alongshore wind disturbances due to Madden-Julian oscillations. The phytoplankton intraseasonal variability exhibits largest amplitude in spring-summer, a feature related to the background seasonal conditions in ocean stratification and light. Chapter 3 documents variability in ELS dispersal using the PTM. We examine if patterns in anchovy and sardine spawning promote shelf retention and prey availability for ELS. We show that the timing of spawning (Aug-Oct) is only partially linked to high retention, but also demonstrate that the main spawning locations along the coast favor high coastal retention year-round. Experiments with ontogenetic diel vertical migration (ODVM) schemes increase retention and spawning-to-nursery connectivity. We suggest that the main spawning period is mostly explained by enhanced prey availability and connectivity, whereas inner shelf spawning and ODVM are the main strategies to increase retention of larvae nearshore. Chapter 4 examines anchovy ELS development, growth, and survival derived from an IBM. Mortality rate is assumed to decline with individual development and size, and increases with temperature. Dispersal patterns strongly determine individual growth and survival. Passive individuals initialized at 5 m depth growth fast near the coast, but they experience strong food limitation when advected far offshore. Passive individuals initialized at 20 m depth have the largest nearshore retention, but slow growth and survival due to low temperature and prey abundance. A favorable trade-off between high retention and growth was derived from individuals initialized at 10 m. Ontogenetic and diel vertical migration increased retention and survival over the shelf, but decreased larval growth. This study advances understanding of the interplay of multiple processes that modulate the timing and intensity of spawning, distribution, growth and survival of small pelagic fish in coastal upwelling ecosystems. It also documents the need for more and better field studies to represent better crucial early life stage traits and processes, such as vertical distribution, larval foraging, mortality, and bioenergetics. Title: Modeling Transport, Retention, and Growth of Early Life Stages of Small Pelagic Fishes in the Southern Humboldt System Author: Gomez, Fabian A. Small pelagic fishes (SPF), such as anchovies and sardines, are ecologically important due to their large abundance and intermediate trophic position that links plankton production to upper trophic levels. They are also economically important, supporting large fisheries that contribute to one fourth of the world fish landings. Reproductive success in SPF strongly depends on environmental factors acting on early life stages (ELS). Among these factors are ocean circulation, habitat temperature, prey and predators. Understanding the coupling between ocean circulation and ELS is relevant to obtain insights on the processes that control SPF abundance. Using a numerical modeling approach, this dissertation examines spatiotemporal patterns in dispersal, growth and survival of ELS of anchovy (Engraulis ringens) and common sardine (Strangomera bentincki) in the southern Humboldt System (off central Chile). Three model components are integrated: 1) a realistically driven three-dimensional high-resolution ocean circulation model, coupled to an eight-component lower trophic level model (LTLM), which reproduces the main physics and plankton dynamics experienced by fish ELS; 2) a particle-tracking model (PTM) to simulate ELS dispersal; and 3) an Individual Based Model (IBM) of bioenergetics to simulate ELS development, growth, and survival. A combination of remotely sensed observations and the outputs of the ocean model are used in Chapter 2 to document the impact of intraseasonal upwelling variability on plankton abundance and structure. Intraseasonal changes in phytoplankton are consistent with alongshore wind disturbances due to Madden-Julian oscillations. The phytoplankton intraseasonal variability exhibits largest amplitude in spring-summer, a feature related to the background seasonal conditions in ocean stratification and light. Chapter 3 documents variability in ELS dispersal using the PTM. We examine if patterns in anchovy and sardine spawning promote shelf retention and prey availability for ELS. We show that the timing of spawning (Aug-Oct) is only partially linked to high retention, but also demonstrate that the main spawning locations along the coast favor high coastal retention year-round. Experiments with ontogenetic diel vertical migration (ODVM) schemes increase retention and spawning-to-nursery connectivity. We suggest that the main spawning period is mostly explained by enhanced prey availability and connectivity, whereas inner shelf spawning and ODVM are the main strategies to increase retention of larvae nearshore. Chapter 4 examines anchovy ELS development, growth, and survival derived from an IBM. Mortality rate is assumed to decline with individual development and size, and increases with temperature. Dispersal patterns strongly determine individual growth and survival. Passive individuals initialized at 5 m depth growth fast near the coast, but they experience strong food limitation when advected far offshore. Passive individuals initialized at 20 m depth have the largest nearshore retention, but slow growth and survival due to low temperature and prey abundance. A favorable trade-off between high retention and growth was derived from individuals initialized at 10 m. Ontogenetic and diel vertical migration increased retention and survival over the shelf, but decreased larval growth. This study advances understanding of the interplay of multiple processes that modulate the timing and intensity of spawning, distribution, growth and survival of small pelagic fish in coastal upwelling ecosystems. It also documents the need for more and better field studies to represent better crucial early life stage traits and processes, such as vertical distribution, larval foraging, mortality, and bioenergetics. Close

• 3584. [Article] Dispersal Behavior in African Buffalo (Syncerus caffer) : Tradeoffs Between Nutritional Resources and Disease Exposure

  Dispersal facilitates population health and maintains resilience in species via gene flow. Adult dispersal occurs in some species, is often facultative, and is poorly understood, but has important management ...

  Citation × Citation Citation Abstract Copy Title: Dispersal Behavior in African Buffalo (Syncerus caffer) : Tradeoffs Between Nutritional Resources and Disease Exposure Author: Spaan, Robert Steven Dispersal facilitates population health and maintains resilience in species via gene flow. Adult dispersal occurs in some species, is often facultative, and is poorly understood, but has important management implications, particularly with respect to disease spread. Although the role of adult dispersal in spreading disease has been documented, the potential influence of disease on dispersal has received little attention. African buffalo (Syncerus caffer) are wide ranging and harbor many pathogens that can affect nearby livestock. Dispersal of adult buffalo has been well documented, but ecological and social drivers of buffalo dispersal are poorly understood. At the individual level, animals must balance the potential benefits of dispersal against its costs. Costs may be incurred in the form of risk, such as mortality or potential injury while dispersing, energetic and time costs associated with the energy and time invested in dispersing, and costs associated with lost opportunities, e.g. reduced fecundity due to unfamiliar surroundings and social groups. Disease in particular is another poorly-understood but potentially important factor influencing costs and benefits of dispersal. Dispersal from a crowded habitat may offer an escape from high pathogen and parasite exposure risk, conversely dispersing individuals in this stressful period may have reduced immunity and consequently be more susceptible to infections. In addition, if pathogen exposure profiles differ among social groups, dispersing animals may face new pathogen challenges to which they are immunologically naïve to, when they arrive at a new social group. However, few studies have estimated dispersal costs of large mammals, particularly those with facultative adult dispersal. First, we investigated drivers of adult buffalo dispersal to determine whether likelihood of dispersal for individual female buffalo was influenced by (1) animal traits, including age, condition, and reproductive status (2) herd membership, (3) environmental variables - season and year, (4) gastro-intestinal parasites - strongyles, coccidia and schistosomes and (5) microparasite infections - bovine tuberculosis (Mycobacterium bovis) and brucellosis (Brucella abortus). The likelihood and drivers of buffalo dispersal varied by herd, area and year. In the Lower Sabie herd younger individuals were more likely to disperse, with most dispersal occurring in the early wet season and during an unusually dry year, 2009. In the Crocodile Bridge area buffalo in poor condition were most likely to disperse. Our findings suggest that dispersal of female buffalo is driven by either seasonal (Lower Sabie), or perhaps social (Crocodile Bridge) resource restriction. We found no direct effects of infections on buffalo dispersal, assuaging fears that highly infectious individuals might be more prone to dispersing, which could accelerate the spatial spread of infectious diseases. Second, we investigated: (1) effects of dispersal on fitness, by comparing survival, and fecundity of dispersing and philopatric (control) buffalo, as well as comparing the difference in pre and post dispersal body condition of dispersers with the change of body condition of philopatric control animals for the same period; (2) disease risks associated with dispersal, by determining whether burdens of gastro-intestinal parasites and the incidence of bacterial and viral infections changed during dispersal. No significant difference in mortality risk or fecundity was observed between dispersing and philopatric control animals, nor did change in body condition differ. However, we detected disease consequences of dispersal that varied by location. Dispersers from the resource-limited herd suffered more bovine tuberculosis and brucellosis infections after dispersal, both of which are chronic infections with clear, long term effects on survival and fecundity, when compared to controls from the same location. Dispersers from the less resource-limited herds had increases in schistosome burdens. Schistosomes are parasitic worms with relatively minor health effects; relatively long-lived but not as long as the life of the host (i.e., buffalo can reduce their burdens). Previous work has shown that adult buffalo disperse in response to resource limitation due to seasonal forage shortages or density dependent Title: Dispersal Behavior in African Buffalo (Syncerus caffer) : Tradeoffs Between Nutritional Resources and Disease Exposure Author: Spaan, Robert Steven Dispersal facilitates population health and maintains resilience in species via gene flow. Adult dispersal occurs in some species, is often facultative, and is poorly understood, but has important management implications, particularly with respect to disease spread. Although the role of adult dispersal in spreading disease has been documented, the potential influence of disease on dispersal has received little attention. African buffalo (Syncerus caffer) are wide ranging and harbor many pathogens that can affect nearby livestock. Dispersal of adult buffalo has been well documented, but ecological and social drivers of buffalo dispersal are poorly understood. At the individual level, animals must balance the potential benefits of dispersal against its costs. Costs may be incurred in the form of risk, such as mortality or potential injury while dispersing, energetic and time costs associated with the energy and time invested in dispersing, and costs associated with lost opportunities, e.g. reduced fecundity due to unfamiliar surroundings and social groups. Disease in particular is another poorly-understood but potentially important factor influencing costs and benefits of dispersal. Dispersal from a crowded habitat may offer an escape from high pathogen and parasite exposure risk, conversely dispersing individuals in this stressful period may have reduced immunity and consequently be more susceptible to infections. In addition, if pathogen exposure profiles differ among social groups, dispersing animals may face new pathogen challenges to which they are immunologically naïve to, when they arrive at a new social group. However, few studies have estimated dispersal costs of large mammals, particularly those with facultative adult dispersal. First, we investigated drivers of adult buffalo dispersal to determine whether likelihood of dispersal for individual female buffalo was influenced by (1) animal traits, including age, condition, and reproductive status (2) herd membership, (3) environmental variables - season and year, (4) gastro-intestinal parasites - strongyles, coccidia and schistosomes and (5) microparasite infections - bovine tuberculosis (Mycobacterium bovis) and brucellosis (Brucella abortus). The likelihood and drivers of buffalo dispersal varied by herd, area and year. In the Lower Sabie herd younger individuals were more likely to disperse, with most dispersal occurring in the early wet season and during an unusually dry year, 2009. In the Crocodile Bridge area buffalo in poor condition were most likely to disperse. Our findings suggest that dispersal of female buffalo is driven by either seasonal (Lower Sabie), or perhaps social (Crocodile Bridge) resource restriction. We found no direct effects of infections on buffalo dispersal, assuaging fears that highly infectious individuals might be more prone to dispersing, which could accelerate the spatial spread of infectious diseases. Second, we investigated: (1) effects of dispersal on fitness, by comparing survival, and fecundity of dispersing and philopatric (control) buffalo, as well as comparing the difference in pre and post dispersal body condition of dispersers with the change of body condition of philopatric control animals for the same period; (2) disease risks associated with dispersal, by determining whether burdens of gastro-intestinal parasites and the incidence of bacterial and viral infections changed during dispersal. No significant difference in mortality risk or fecundity was observed between dispersing and philopatric control animals, nor did change in body condition differ. However, we detected disease consequences of dispersal that varied by location. Dispersers from the resource-limited herd suffered more bovine tuberculosis and brucellosis infections after dispersal, both of which are chronic infections with clear, long term effects on survival and fecundity, when compared to controls from the same location. Dispersers from the less resource-limited herds had increases in schistosome burdens. Schistosomes are parasitic worms with relatively minor health effects; relatively long-lived but not as long as the life of the host (i.e., buffalo can reduce their burdens). Previous work has shown that adult buffalo disperse in response to resource limitation due to seasonal forage shortages or density dependent Close

• 3585. [Article] The ecology of riparian ecosystems of Northeast Oregon : shrub recovery at Meadow Creek and the structure and biomass of headwater Upper Grande Ronde ecosystems

  Riparian ecosystems play numerous and essential roles related to the quality and flow of water, and food/habitat for fish, and varieties of wildlife. Due to lateral and linear linkages throughout the landscape, ...

  Citation × Citation Citation Abstract Copy Title: The ecology of riparian ecosystems of Northeast Oregon : shrub recovery at Meadow Creek and the structure and biomass of headwater Upper Grande Ronde ecosystems Author: Case, Richard L. Riparian ecosystems play numerous and essential roles related to the quality and flow of water, and food/habitat for fish, and varieties of wildlife. Due to lateral and linear linkages throughout the landscape, these zones influence the integrity of the terrestrial as well as the entire aquatic-riverine ecosystem. Since Euro-American settlement in the West, the structure and condition of many riparian ecosystems has been significantly altered. To provide tools and an ecological perspective related to riparian restoration and management, and to document late 20th century headwater riparian structure and biomass in the Upper Grande Ronde Basin, this research project was undertaken. At Meadow Creek, the response of riparian hardwood species to the termination of livestock grazing was quantified. Regression equations were developed to predict shrub biomass. Permanently marked hardwood plants were measured annually to quantify parameters of growth (height, crown area, mainstem diameter, number of stems, biomass). Permanent belt transects on gravel bars were utilized to quantify rates of shrub establishment. Elk/deer-proof exclosures allowed the quantification of the browsing influence of wild ungulates. In 1991, initial shrub heights and densities reflected decades of grazing pressure. Mean heights of515 woody plants (14 species) was 47 cm and densities on gravel bars averaged 10.7 plants/100m². After two seasons without livestock grazing, mean crown volumes of willows (Salix spp.) increased 550% inside of wild ungulate exclosures and 195% outside, black cottonwood (Populus trichocarpa) 773% inside and 808% outside, and thin-leaf alder (Almis incana) 1046% inside and 198% outside, respectively. Willows were significantly impeded (p<0.Ol) mule deer and Rocky Mountain elk, alder samples were too small to statistically test, and cottonwood was not significantly impeded. However, impacts by deer and elk may be exaggerated due to high densities and the ungulate density-dynamics unique within the 77 km² Starkey Experimental Forest big-game enclosure surrounding the study site. Establishment rates are low at this time, i.e., only 10% of previously suppressed willows produced catkins. Although in transects densities increased by 5 new woody plants/lOOm² (50m of streambank). Other non-anthropogenic factors influencing the recovery of shrubs, included beaver which removed mainstems from 20% of willows, 11% of thin-leaf alder, and 4% of black cottonwood, and active insect defoliation which was noted on 16% of willows, 7% of thin-leaf alder, and 0% of black cottonwood. Crude protein levels measured in willow and alder leaves was relatively high (16.1 to 16.3%) helping to explain their palatability and use by wild and domestic herbivores. Few studies have quantified biomass, structure and composition of headwater riparian ecosystems. Data such as this are important given their dominant roles in ecosystem biodiversity, and aquatic function. To document relatively intact forested headwater ripanan conditions in the Upper Grande Ronde Basin, the biomass, structure and composition along six headwater reaches was quantified. Sampling was done using a nested belt transect/plot arrangement along 500 meter reaches. Total aboveground biomass (TAGB) ranged from 203 to 261 Mg/ha, with overstory conifers contributing 101 to 177 Mg/ha. Living understory components (saplings, seedlings, shrubs, and herbs) comprised 5 to 18 Mg/ha (2 to 9% of TAGB), while forest floor detrital accumulations comprised 65 to 101 Mg/ha (29 to 42% of TAGB). Average shade per day for July, 1993 ranged between 53% and 75%, reducing the unshaded solar energy potential of 2390 Mj/day to between 680 and 1280 Mj/day striking each m² of stream surface. This baseline reference information can serve in multi-disciplined research, as well as, be a basis for long term studies of natural systems responding to changing climate and different resource management scenarios. Title: The ecology of riparian ecosystems of Northeast Oregon : shrub recovery at Meadow Creek and the structure and biomass of headwater Upper Grande Ronde ecosystems Author: Case, Richard L. Riparian ecosystems play numerous and essential roles related to the quality and flow of water, and food/habitat for fish, and varieties of wildlife. Due to lateral and linear linkages throughout the landscape, these zones influence the integrity of the terrestrial as well as the entire aquatic-riverine ecosystem. Since Euro-American settlement in the West, the structure and condition of many riparian ecosystems has been significantly altered. To provide tools and an ecological perspective related to riparian restoration and management, and to document late 20th century headwater riparian structure and biomass in the Upper Grande Ronde Basin, this research project was undertaken. At Meadow Creek, the response of riparian hardwood species to the termination of livestock grazing was quantified. Regression equations were developed to predict shrub biomass. Permanently marked hardwood plants were measured annually to quantify parameters of growth (height, crown area, mainstem diameter, number of stems, biomass). Permanent belt transects on gravel bars were utilized to quantify rates of shrub establishment. Elk/deer-proof exclosures allowed the quantification of the browsing influence of wild ungulates. In 1991, initial shrub heights and densities reflected decades of grazing pressure. Mean heights of515 woody plants (14 species) was 47 cm and densities on gravel bars averaged 10.7 plants/100m². After two seasons without livestock grazing, mean crown volumes of willows (Salix spp.) increased 550% inside of wild ungulate exclosures and 195% outside, black cottonwood (Populus trichocarpa) 773% inside and 808% outside, and thin-leaf alder (Almis incana) 1046% inside and 198% outside, respectively. Willows were significantly impeded (p<0.Ol) mule deer and Rocky Mountain elk, alder samples were too small to statistically test, and cottonwood was not significantly impeded. However, impacts by deer and elk may be exaggerated due to high densities and the ungulate density-dynamics unique within the 77 km² Starkey Experimental Forest big-game enclosure surrounding the study site. Establishment rates are low at this time, i.e., only 10% of previously suppressed willows produced catkins. Although in transects densities increased by 5 new woody plants/lOOm² (50m of streambank). Other non-anthropogenic factors influencing the recovery of shrubs, included beaver which removed mainstems from 20% of willows, 11% of thin-leaf alder, and 4% of black cottonwood, and active insect defoliation which was noted on 16% of willows, 7% of thin-leaf alder, and 0% of black cottonwood. Crude protein levels measured in willow and alder leaves was relatively high (16.1 to 16.3%) helping to explain their palatability and use by wild and domestic herbivores. Few studies have quantified biomass, structure and composition of headwater riparian ecosystems. Data such as this are important given their dominant roles in ecosystem biodiversity, and aquatic function. To document relatively intact forested headwater ripanan conditions in the Upper Grande Ronde Basin, the biomass, structure and composition along six headwater reaches was quantified. Sampling was done using a nested belt transect/plot arrangement along 500 meter reaches. Total aboveground biomass (TAGB) ranged from 203 to 261 Mg/ha, with overstory conifers contributing 101 to 177 Mg/ha. Living understory components (saplings, seedlings, shrubs, and herbs) comprised 5 to 18 Mg/ha (2 to 9% of TAGB), while forest floor detrital accumulations comprised 65 to 101 Mg/ha (29 to 42% of TAGB). Average shade per day for July, 1993 ranged between 53% and 75%, reducing the unshaded solar energy potential of 2390 Mj/day to between 680 and 1280 Mj/day striking each m² of stream surface. This baseline reference information can serve in multi-disciplined research, as well as, be a basis for long term studies of natural systems responding to changing climate and different resource management scenarios. Close

• 3586. [Article] Willamette Biological Opinion Hatchery Research 2010 Annual Report

  Abstract -- Task 1.1: Distribution, Abundance, and Proportion of Hatchery and Natural-Origin Chinook Salmon: Counts of spring Chinook redds were similar in 2010 compared to the 2002–2009 averages for the ...

  Citation × Citation Citation Abstract Copy Title: Willamette Biological Opinion Hatchery Research 2010 Annual Report Abstract -- Task 1.1: Distribution, Abundance, and Proportion of Hatchery and Natural-Origin Chinook Salmon: Counts of spring Chinook redds were similar in 2010 compared to the 2002–2009 averages for the Middle Fork Willamette, McKenzie and the North Santiam rivers and significantly higher in the South Santiam River Preliminary analyses indicate that the proportions of hatchery fish recovered as carcasses from the spawning grounds varied significantly among all four surveyed sub-basins (South Santiam > M. Fork Willamette > North Santiam > McKenzie) Task 1.2: Monitor fin-clipped & unclipped fish passing Leaburg and Upper Bennett dams. Adult fish passage at Leaburg and Upper Bennett dams was continuously monitored in 2010. We estimated that 2,696 spring Chinook (52% unclipped) passed above Leaburg Dam and 5,956 passed above upper Bennett Dam (14% unclipped). Passage at Leaburg Dam of fin-clipped fish was strongly bimodal with peaks in June (coincident with passage of the majority of unclipped fish) and September (coincident with a smaller proportion of unclipped fish). This bimodal peak suggests that hatchery fish might be removed in September to reduce the proportion of hatchery origin spawners while simultaneously reducing the impacts of handling wild fish. Task 2.1: Collection, spawn timing, and Hatchery/Wild (H/W ) composition for broodstock management. Collection, spawn timing, and H/W composition for broodstock management were successfully monitored at all facilities in 2010. Task 2.2: Determine Survival of Outplanted Fish and Abundance of Spawners. Patterns of pre-spawning mortality were similar to results in 2009 with mortality below project dams significantly higher than that above project dams. We did not detect significant differences in mortality between clipped and unclipped spring Chinook. In comparisons of pre-spawning mortality among sub-basins above project dams, pre-spawning mortality was uniformly low in the Breitenbush and N. Santiam above Detroit, S. Santiam above Foster, and in the S. Fork McKenzie. Pre-spawning mortality was uniformly higher above project dams in the N. Fork Mid. Fork Willamette, Fall Creek and the Little N. Fork Santiam. No comprehensive surveys were conducted in the Middle Fork Willamette. Task 3.1: Determine the extent of summer steelhead reproduction in the wild: We developed a formal study plan to analyze and interpret genetic results from a collection of 299 tissue samples from unclipped juvenile steelhead at Willamette Falls, five from the mainstem Willamette River, and two from the South Santiam River in 2010 in addition to a single sample from an unclipped adult steelhead at the Minto fish collection facility. Samples were preserved 7 and cataloged and then shipped to the NOAA Fisheries Manchester, Washington (WA) laboratory for analysis. Task 3.2: Evaluate release strategies for summer steelhead to increase migration and reduce impacts on wild fish. Study plans to evaluate advantages and disadvantages of volitional release strategies were completed and presented in the 2009 annual report to USACE (Cannon et al. 2010). Funding to process the tissue samples was not available in 2010, and no progress was made in executing the proposed work. Title: Willamette Biological Opinion Hatchery Research 2010 Annual Report Abstract -- Task 1.1: Distribution, Abundance, and Proportion of Hatchery and Natural-Origin Chinook Salmon: Counts of spring Chinook redds were similar in 2010 compared to the 2002–2009 averages for the Middle Fork Willamette, McKenzie and the North Santiam rivers and significantly higher in the South Santiam River Preliminary analyses indicate that the proportions of hatchery fish recovered as carcasses from the spawning grounds varied significantly among all four surveyed sub-basins (South Santiam > M. Fork Willamette > North Santiam > McKenzie) Task 1.2: Monitor fin-clipped & unclipped fish passing Leaburg and Upper Bennett dams. Adult fish passage at Leaburg and Upper Bennett dams was continuously monitored in 2010. We estimated that 2,696 spring Chinook (52% unclipped) passed above Leaburg Dam and 5,956 passed above upper Bennett Dam (14% unclipped). Passage at Leaburg Dam of fin-clipped fish was strongly bimodal with peaks in June (coincident with passage of the majority of unclipped fish) and September (coincident with a smaller proportion of unclipped fish). This bimodal peak suggests that hatchery fish might be removed in September to reduce the proportion of hatchery origin spawners while simultaneously reducing the impacts of handling wild fish. Task 2.1: Collection, spawn timing, and Hatchery/Wild (H/W ) composition for broodstock management. Collection, spawn timing, and H/W composition for broodstock management were successfully monitored at all facilities in 2010. Task 2.2: Determine Survival of Outplanted Fish and Abundance of Spawners. Patterns of pre-spawning mortality were similar to results in 2009 with mortality below project dams significantly higher than that above project dams. We did not detect significant differences in mortality between clipped and unclipped spring Chinook. In comparisons of pre-spawning mortality among sub-basins above project dams, pre-spawning mortality was uniformly low in the Breitenbush and N. Santiam above Detroit, S. Santiam above Foster, and in the S. Fork McKenzie. Pre-spawning mortality was uniformly higher above project dams in the N. Fork Mid. Fork Willamette, Fall Creek and the Little N. Fork Santiam. No comprehensive surveys were conducted in the Middle Fork Willamette. Task 3.1: Determine the extent of summer steelhead reproduction in the wild: We developed a formal study plan to analyze and interpret genetic results from a collection of 299 tissue samples from unclipped juvenile steelhead at Willamette Falls, five from the mainstem Willamette River, and two from the South Santiam River in 2010 in addition to a single sample from an unclipped adult steelhead at the Minto fish collection facility. Samples were preserved 7 and cataloged and then shipped to the NOAA Fisheries Manchester, Washington (WA) laboratory for analysis. Task 3.2: Evaluate release strategies for summer steelhead to increase migration and reduce impacts on wild fish. Study plans to evaluate advantages and disadvantages of volitional release strategies were completed and presented in the 2009 annual report to USACE (Cannon et al. 2010). Funding to process the tissue samples was not available in 2010, and no progress was made in executing the proposed work. Close

• 3587. [Article] Tenmile Lake Basin Partnership - OWEB Final Report: Grant 217-2051

  Abstract -- Pacific Lamprey are native to the Tenmile Watershed and culturally important to the local Native American Tribes. Likewise, Salmon and Steelhead have both an economic and cultural significance ...

  Citation × Citation Citation Abstract Copy Title: Tenmile Lake Basin Partnership - OWEB Final Report: Grant 217-2051 Abstract -- Pacific Lamprey are native to the Tenmile Watershed and culturally important to the local Native American Tribes. Likewise, Salmon and Steelhead have both an economic and cultural significance to the local citizens and Tribes. Pacific Lamprey were historically harvested by the people of the Confederated Tribes of the Coos, Lower Umpqua and Siuslaw Indians (CTCLUSI), but it was unknown if Pacific Lamprey were still present in the Tenmile Watershed. A fish trap was built on Eel Lake by the Oregon Department of Fish and Wildlife (ODFW) in 1989 for the purpose of fish capture and rearing. The trap is effective in capturing Salmon and Steelhead but may act as a barrier to the passage of Pacific Lamprey. This monitoring effort was designed to assess the presence/absence of Pacific Lamprey in the Tenmile Watershed, identify migration timing, potential lamprey passage barriers and rearing/spawning habitats, and collect and organize data from Eel Lake Trap on native Coho, Cutthroat, and native/hatchery Steelhead returns and trends. Lamprey larvae (ammocoete) monitoring was conducted in the summer of 2017 using electro-shockers. Shocking occurred on 3 tributaries of Tenmile Lakes (Big Creek, Johnson Creek, and Shutter Creek), and 3 creeks within the Eel Lake basin (Eel Creek, Clear Creek, and Winters Arm Creek). Two species of lamprey were identified, Western Brook (Lampetra richardsoni) and Pacific (Entosphenus tridentatus). Western Brook were found in all sampled Tenmile Lakes Basin streams, but only in the streams above Eel Lake Trap in the Eel Lake Basin. No Western Brook were identified in Eel Creek below the Trap. Pacific Lamprey were found in Johnson Creek and Big Creek in the Tenmile Lakes Basin, and in Eel Creek in the Eel Lake Basin. No Pacific Lamprey were identified above the Eel Lake Trap, suggesting that it may act as a complete passage barrier to that species. In addition, over 200 adult Pacific Lamprey were salvaged from an ODOT culvert enhancement project on Eel Creek near Hwy 101. Pacific Lamprey larvae were identified upstream of this project, but it is likely that it was a partial barrier. Two other ODOT culverts were identified as potential partial lamprey barriers on Eel Cr. Spawning areas for Pacific and Western Brook Lamprey are similar to spawning areas for salmon. Upper reaches of all the Tenmile Lake tributaries have appropriate spawning gravel. Lower stream areas are often high in sediment which is conducive to rearing lamprey larvae. This was confirmed in Johnson creek with high numbers of Pacific Lamprey larvae found at the mouth as it enters South Tenmile Lake. Farther upstream in the Johnson Creek system, larvae were abundant, but much smaller with many being too small to identify (<65mm). Western Brook larvae were found, but no Pacific Lamprey larvae were identified, perhaps amongst those unidentified specimens. Western Brook ammocoetes were also found at the lower site on Johnson Creek, and in Big Creek and Shutter Creek. Pacific Lamprey migration into the watershed is difficult to determine due to the elusive nature of the species and their life cycle trait of migrating in from the ocean in the spring of one year, then holding over until the next spring before spawning. When specimens are captured, it is difficult to determine whether it is a fresh migrant or last year’s holdover. Even if it can be determined which year it is from, it is still difficult to know how long it has been in the system before it was captured. In Phase 2 of this project, we will capture Pacific Lamprey either in traps near the mouth of Eel Cr, or at the lower culverts. This should give us a better sense of migration timing. Native Coho salmon counts at Eel Lake Trap were down significantly from the recorded high at the Trap of 441 in 2012, with only 66 native Coho returning in 2018 (the winter of 2017-2018). The previous 2 years were also low with 2016 and 2017 showing returns of only 53 and 118 respectively. The Coho numbers for most of the Oregon Coast also showed low returns. Hatchery Winter Steelhead counts were 502 for 2018. This compares to a record high of 828 in 2007, 595 in 2016, and 226 in 2017. Returning native Steelhead only numbered 10 for the 2018 season. The average return for Native Steelhead is 24. In 2018, 60 Steelhead were spawned including 2 native males, but no native females. 252 hatchery Steelhead were recycled into Saunders Lake, and 148 into Butterfield Lake. ODFW allocated 25,000 smolts for the Tenmile Watershed, which were acclimated and then released in April 2018. Title: Tenmile Lake Basin Partnership - OWEB Final Report: Grant 217-2051 Abstract -- Pacific Lamprey are native to the Tenmile Watershed and culturally important to the local Native American Tribes. Likewise, Salmon and Steelhead have both an economic and cultural significance to the local citizens and Tribes. Pacific Lamprey were historically harvested by the people of the Confederated Tribes of the Coos, Lower Umpqua and Siuslaw Indians (CTCLUSI), but it was unknown if Pacific Lamprey were still present in the Tenmile Watershed. A fish trap was built on Eel Lake by the Oregon Department of Fish and Wildlife (ODFW) in 1989 for the purpose of fish capture and rearing. The trap is effective in capturing Salmon and Steelhead but may act as a barrier to the passage of Pacific Lamprey. This monitoring effort was designed to assess the presence/absence of Pacific Lamprey in the Tenmile Watershed, identify migration timing, potential lamprey passage barriers and rearing/spawning habitats, and collect and organize data from Eel Lake Trap on native Coho, Cutthroat, and native/hatchery Steelhead returns and trends. Lamprey larvae (ammocoete) monitoring was conducted in the summer of 2017 using electro-shockers. Shocking occurred on 3 tributaries of Tenmile Lakes (Big Creek, Johnson Creek, and Shutter Creek), and 3 creeks within the Eel Lake basin (Eel Creek, Clear Creek, and Winters Arm Creek). Two species of lamprey were identified, Western Brook (Lampetra richardsoni) and Pacific (Entosphenus tridentatus). Western Brook were found in all sampled Tenmile Lakes Basin streams, but only in the streams above Eel Lake Trap in the Eel Lake Basin. No Western Brook were identified in Eel Creek below the Trap. Pacific Lamprey were found in Johnson Creek and Big Creek in the Tenmile Lakes Basin, and in Eel Creek in the Eel Lake Basin. No Pacific Lamprey were identified above the Eel Lake Trap, suggesting that it may act as a complete passage barrier to that species. In addition, over 200 adult Pacific Lamprey were salvaged from an ODOT culvert enhancement project on Eel Creek near Hwy 101. Pacific Lamprey larvae were identified upstream of this project, but it is likely that it was a partial barrier. Two other ODOT culverts were identified as potential partial lamprey barriers on Eel Cr. Spawning areas for Pacific and Western Brook Lamprey are similar to spawning areas for salmon. Upper reaches of all the Tenmile Lake tributaries have appropriate spawning gravel. Lower stream areas are often high in sediment which is conducive to rearing lamprey larvae. This was confirmed in Johnson creek with high numbers of Pacific Lamprey larvae found at the mouth as it enters South Tenmile Lake. Farther upstream in the Johnson Creek system, larvae were abundant, but much smaller with many being too small to identify (<65mm). Western Brook larvae were found, but no Pacific Lamprey larvae were identified, perhaps amongst those unidentified specimens. Western Brook ammocoetes were also found at the lower site on Johnson Creek, and in Big Creek and Shutter Creek. Pacific Lamprey migration into the watershed is difficult to determine due to the elusive nature of the species and their life cycle trait of migrating in from the ocean in the spring of one year, then holding over until the next spring before spawning. When specimens are captured, it is difficult to determine whether it is a fresh migrant or last year’s holdover. Even if it can be determined which year it is from, it is still difficult to know how long it has been in the system before it was captured. In Phase 2 of this project, we will capture Pacific Lamprey either in traps near the mouth of Eel Cr, or at the lower culverts. This should give us a better sense of migration timing. Native Coho salmon counts at Eel Lake Trap were down significantly from the recorded high at the Trap of 441 in 2012, with only 66 native Coho returning in 2018 (the winter of 2017-2018). The previous 2 years were also low with 2016 and 2017 showing returns of only 53 and 118 respectively. The Coho numbers for most of the Oregon Coast also showed low returns. Hatchery Winter Steelhead counts were 502 for 2018. This compares to a record high of 828 in 2007, 595 in 2016, and 226 in 2017. Returning native Steelhead only numbered 10 for the 2018 season. The average return for Native Steelhead is 24. In 2018, 60 Steelhead were spawned including 2 native males, but no native females. 252 hatchery Steelhead were recycled into Saunders Lake, and 148 into Butterfield Lake. ODFW allocated 25,000 smolts for the Tenmile Watershed, which were acclimated and then released in April 2018. Close

• 3588. [Article] Applying GPS and Accelerometers to the Study of African Savanna (Loxodonta africana) and Asian Elephant (Elephas maximus) Welfare in Zoos

  African savanna elephants (Loxodonta africana) and Asian elephants (Elephas maximus) are a focus of welfare research in zoos due to their high intelligence, complex social structure, and sheer size. Due ...

  Citation × Citation Citation Abstract Copy Title: Applying GPS and Accelerometers to the Study of African Savanna (Loxodonta africana) and Asian Elephant (Elephas maximus) Welfare in Zoos Author: Holdgate, Matthew Robert Year: 2015 African savanna elephants (Loxodonta africana) and Asian elephants (Elephas maximus) are a focus of welfare research in zoos due to their high intelligence, complex social structure, and sheer size. Due to these challenges, some argue that zoos are inherently incapable of providing appropriate care for elephants, while others believe that zoos can fulfill the needs of these species with improved husbandry. There is a general consensus from both within and outside of zoos, however, that zoos must improve their elephant programs or cease exhibiting these animals altogether. Now more than ever, applied research on zoo elephant welfare is needed to provide context for this debate. Researchers are interested in how far zoo elephants walk due to the potential health and welfare benefits of walking in these highly mobile species. Zoo researchers recently adopted GPS technology to study elephant walking, and preliminary evidence suggests that African elephants in large zoo exhibits walk distances that correspond with wild elephants under non-extreme conditions. However, data are limited from Asian elephants and from elephants in more typically-sized exhibits. In Chapter Two, I discuss important methodological considerations of utilizing GPS in a zoo environment, including an introduction to the technology, sources of error and mitigation, methods to improve GPS performance, and possible effects of GPS device attachment on animal behavior. This review shows GPS performance is adequate for tracking zoo elephant walking when proper methodological techniques are applied, and should serve as a useful reference for zoo researchers considering using GPS. In Chapter Three, I used GPS anklets to measure outdoor daily walking distance in 56 adult female African (n = 33) and Asian (n = 23) elephants housed in 30 zoos. I collected 259 days of data and found that elephants walked an average of 5.34 km/day with no significant difference between species. Multivariate regression models predicted that elephants with more dynamic feeding regimens (more diverse feeding types and frequencies; unscheduled feeding times) will walk more. Distance walked was also predicted to be higher in elephants that spend time in a greater number of different social groups. Distance walked was predicted to decline with age. Finally, I found a significant negative correlation between distance walked and nighttime space experience. The results of the analysis suggest that zoos that want to increase walking in their elephants need not rely solely on larger exhibits, but can increase walking by adding quality and complexity to exhibits. However, my results failed to establish a definitive link between walking distance and other validated measures of elephant welfare. Thus, the direct health and welfare benefits of walking in zoo elephants remain unresolved. Resting behaviors are an essential component of animal welfare, but have received little attention in zoological research. In Chapter Four, I used accelerometers in anklets to complete the first large-scale multi-species investigation of zoo elephant recumbence. I collected 344 days of data from 72 adult female African (n = 44) and Asian (n = 28) elephants at 40 zoos. I found that African elephants are recumbent an average of 2.14 hours/day, which is significantly less than Asian elephants at 3.22 hours/day. Multivariate regression models predicted that African elephant recumbence increases when they experience more space at night, and Asian elephant recumbence increases when they spend time housed alone. Both species showed a similar response to substrate, such that African elephants spending time on all-hard substrates are predicted to be recumbent less, while Asian elephants spending time on all-soft substrates are predicted to be recumbent more. The discovery that occasional non-recumbence is a common behavior in zoo elephants also introduces a new area of research that may have important animal welfare consequences. Finally, this study established that zoos should continue their efforts to replace hard substrate with soft substrate in order to provide zoo elephants with environments that facilitate recumbence. Overall, this work assessed walking and recumbence in zoo elephants, which will allow zoos to gauge the prevalence of these behaviors in their elephants as compared to the sub-population studied here. A variety of factors that are associated with these behaviors were also identified. With this information, zoos can prioritize modifications to their facilities and animal management programs to create an environment that encourages zoo elephants to express walking and recumbence behavior, should they choose to do so. This work is one component of the Elephant Welfare Project, the largest zoo animal welfare project ever undertaken, and is unprecedented in both scope and scale. The project was funded by the Institute of Museum and Library Services (IMLS), an independent, U.S., federal, grant-making agency that supports libraries, museums, and zoos. At the time of this writing, the first manuscripts from this project are being submitted to academic journals. These papers will describe the prevalence and distribution of a variety of elephant behaviors and welfare indicators, serve as a benchmark for future elephant welfare studies, and aid in decision making with regard to best practices in elephant management. Title: Applying GPS and Accelerometers to the Study of African Savanna (Loxodonta africana) and Asian Elephant (Elephas maximus) Welfare in Zoos Author: Holdgate, Matthew Robert Year: 2015 African savanna elephants (Loxodonta africana) and Asian elephants (Elephas maximus) are a focus of welfare research in zoos due to their high intelligence, complex social structure, and sheer size. Due to these challenges, some argue that zoos are inherently incapable of providing appropriate care for elephants, while others believe that zoos can fulfill the needs of these species with improved husbandry. There is a general consensus from both within and outside of zoos, however, that zoos must improve their elephant programs or cease exhibiting these animals altogether. Now more than ever, applied research on zoo elephant welfare is needed to provide context for this debate. Researchers are interested in how far zoo elephants walk due to the potential health and welfare benefits of walking in these highly mobile species. Zoo researchers recently adopted GPS technology to study elephant walking, and preliminary evidence suggests that African elephants in large zoo exhibits walk distances that correspond with wild elephants under non-extreme conditions. However, data are limited from Asian elephants and from elephants in more typically-sized exhibits. In Chapter Two, I discuss important methodological considerations of utilizing GPS in a zoo environment, including an introduction to the technology, sources of error and mitigation, methods to improve GPS performance, and possible effects of GPS device attachment on animal behavior. This review shows GPS performance is adequate for tracking zoo elephant walking when proper methodological techniques are applied, and should serve as a useful reference for zoo researchers considering using GPS. In Chapter Three, I used GPS anklets to measure outdoor daily walking distance in 56 adult female African (n = 33) and Asian (n = 23) elephants housed in 30 zoos. I collected 259 days of data and found that elephants walked an average of 5.34 km/day with no significant difference between species. Multivariate regression models predicted that elephants with more dynamic feeding regimens (more diverse feeding types and frequencies; unscheduled feeding times) will walk more. Distance walked was also predicted to be higher in elephants that spend time in a greater number of different social groups. Distance walked was predicted to decline with age. Finally, I found a significant negative correlation between distance walked and nighttime space experience. The results of the analysis suggest that zoos that want to increase walking in their elephants need not rely solely on larger exhibits, but can increase walking by adding quality and complexity to exhibits. However, my results failed to establish a definitive link between walking distance and other validated measures of elephant welfare. Thus, the direct health and welfare benefits of walking in zoo elephants remain unresolved. Resting behaviors are an essential component of animal welfare, but have received little attention in zoological research. In Chapter Four, I used accelerometers in anklets to complete the first large-scale multi-species investigation of zoo elephant recumbence. I collected 344 days of data from 72 adult female African (n = 44) and Asian (n = 28) elephants at 40 zoos. I found that African elephants are recumbent an average of 2.14 hours/day, which is significantly less than Asian elephants at 3.22 hours/day. Multivariate regression models predicted that African elephant recumbence increases when they experience more space at night, and Asian elephant recumbence increases when they spend time housed alone. Both species showed a similar response to substrate, such that African elephants spending time on all-hard substrates are predicted to be recumbent less, while Asian elephants spending time on all-soft substrates are predicted to be recumbent more. The discovery that occasional non-recumbence is a common behavior in zoo elephants also introduces a new area of research that may have important animal welfare consequences. Finally, this study established that zoos should continue their efforts to replace hard substrate with soft substrate in order to provide zoo elephants with environments that facilitate recumbence. Overall, this work assessed walking and recumbence in zoo elephants, which will allow zoos to gauge the prevalence of these behaviors in their elephants as compared to the sub-population studied here. A variety of factors that are associated with these behaviors were also identified. With this information, zoos can prioritize modifications to their facilities and animal management programs to create an environment that encourages zoo elephants to express walking and recumbence behavior, should they choose to do so. This work is one component of the Elephant Welfare Project, the largest zoo animal welfare project ever undertaken, and is unprecedented in both scope and scale. The project was funded by the Institute of Museum and Library Services (IMLS), an independent, U.S., federal, grant-making agency that supports libraries, museums, and zoos. At the time of this writing, the first manuscripts from this project are being submitted to academic journals. These papers will describe the prevalence and distribution of a variety of elephant behaviors and welfare indicators, serve as a benchmark for future elephant welfare studies, and aid in decision making with regard to best practices in elephant management. Close

• 3589. [Article] Population Structure of Island-Associated Pantropical Spotted Dolphins (Stenella attenuata) in Hawaiian Waters

  Understanding gene flow, diversity, and dispersal patterns is important for predicting effects of natural events and anthropogenic activities on dolphin populations. With the very recent exceptions of ...

  Citation × Citation Citation Abstract Copy Title: Population Structure of Island-Associated Pantropical Spotted Dolphins (Stenella attenuata) in Hawaiian Waters Author: Courbis, Sarah Shelby Year: 2011 Understanding gene flow, diversity, and dispersal patterns is important for predicting effects of natural events and anthropogenic activities on dolphin populations. With the very recent exceptions of false killer whales (Pseudorca crassidens), spinner dolphins (Stenella longirostris), and common bottlenose dolphins (Tursiops truncatus), Hawaiian odontocete species are managed as single stocks within the U.S. Hawaiian Exclusive Economic Zone. These exceptions are a result of recent studies that have indicated that some species have populations that show fidelity to individual islands or groups of islands, resulting in genetic differentiation, often with management implications. The first part of my study (following the introductory chapter) focused on population structure of pantropical spotted dolphins (Stenella attenuata) near the Hawaiian Islands. Because of the level of human interaction, pantropical spotted dolphin populations need to be defined accurately to be managed in a way that will avoid local population losses, especially given that the commercial and recreational troll fisheries near the islands "fish on dolphins" to catch tuna. I analyzed genetic samples for mtDNA and microsatellite loci from four island regions: Hawai'i, the 4-islands area, O'ahu, and Kaua'i/Ni'ihau. My results support genetic differentiation among the regions of Hawai'i, the 4-islands area, and O'ahu and suggest that pantropical spotted dolphins near Kaua'i/Ni'ihau are likely transient and in very low numbers. There was no strong evidence to support sex-biased dispersal or group fidelity. Possibly, differentiation is mediated by behavior adapted to differing habitat types. From a management perspective, spinner and bottlenose dolphin populations near the Hawaiian Islands have been split into separate stocks for management based on levels of genetic differentiation similar to those found for pantropical spotted dolphins. These precedents suggest that comparable action should be taken to split pantropical spotted dolphin stocks near the Hawaiian Islands. Most population studies rely heavily upon fixation indicies like FST to determine whether populations are genetically differentiated. When FST values are low but significantly different from zero, it can be difficult to interpret the biological significance of these values. As part of my study, I suggest that one way to evaluate whether small FST values indicate significant differentiation is to compare FST values with other populations considered to be separate based on factors such as extreme distance or morphological differences. I examined pantropical spotted dolphins from the coastal and offshore Eastern Tropical Pacificm (ETP), Hawaiian Islands, and China/Taiwan to examine the utility of comparing FST values across separate populations. Among Hawaiian Island regions, FST values are significantly different from zero but small. The comparison of these FST values with more distant populations in the ETP and China/Taiwan indicated that differences among Hawaiian Island regions were similar in magnitude to those found between the offshore and coastal ETP sub-species, but smaller than between the Hawaiian Island regions and the other regions examined. This suggests a level of reproductive isolation among the Hawaiian Islands regions that is comparable to that of offshore and coastal ETP populations, and supports the value of fixation index comparisons in evaluating differentiation among putative populations. My results suggest that assigning specific numerical baseline FST values may not always be biologically meaningful but that determining whether related populations with geographic or other separation show a preponderance of similar, lower, or higher fixation index values can help evaluate whether genetic differences among sympatric or parapatric groups warrants designating them as separate populations for management. Lastly, I explore whether the fast evolving mtDNA control region may be more suited to phylogenetic comparisons among the Stenella than slower evolving gene regions and whether the small number of haplotypes generally used in phylogenetic analyses is adequate for defining relationships among dolphins. Usually, slow evolving regions, such as gene regions, are used in phylogenetic analyses because species and genera have been isolated long enough for variation to have accumulated in such regions but not so long that many reversals (i.e. a mutational change in sequence that later changes back to the original sequence) have occured. The mtDNA control region is typically used for population genetic comparisons rather than phylogenetic comparisons because it is considered to be a fast evolving region. Historically, dolphin phylogeny has been examined using gene regions, which have resulted in ambiguous and unexpected relationships. However, the lack of variation in the mtDNA control region for pantropical spotted dolphin populations and the fact that recent studies have found that the mtDNA control region in cetaceans evolves at about one quarter the rate of other mammals, raises the question as to whether this region would be better suited to phylogenetic studies for the Stenella (and potentially other dolphin species). In comparing 346 haplotypes from five species of Stenella world-wide, I found that the mtDNA control region is probably not a good region to use for phylogenetic analyses, and that even faster evolving regions might perform better. The differences in the mtDNA control region were not sufficient to distinguish clear relationships among the Stenella. I also found that when subsets of haplotypes chosen at random were compared, the results differed among comparisons, suggesting that there is value in using more than the usual one or two haplotypes when making phylogentic comparisons. Given the recent increases in sequence availability (e.g. GenBank) and computing power, researchers should strongly consider using many haplotypes from a variety of populations in their phylogenetic comparisons. Title: Population Structure of Island-Associated Pantropical Spotted Dolphins (Stenella attenuata) in Hawaiian Waters Author: Courbis, Sarah Shelby Year: 2011 Understanding gene flow, diversity, and dispersal patterns is important for predicting effects of natural events and anthropogenic activities on dolphin populations. With the very recent exceptions of false killer whales (Pseudorca crassidens), spinner dolphins (Stenella longirostris), and common bottlenose dolphins (Tursiops truncatus), Hawaiian odontocete species are managed as single stocks within the U.S. Hawaiian Exclusive Economic Zone. These exceptions are a result of recent studies that have indicated that some species have populations that show fidelity to individual islands or groups of islands, resulting in genetic differentiation, often with management implications. The first part of my study (following the introductory chapter) focused on population structure of pantropical spotted dolphins (Stenella attenuata) near the Hawaiian Islands. Because of the level of human interaction, pantropical spotted dolphin populations need to be defined accurately to be managed in a way that will avoid local population losses, especially given that the commercial and recreational troll fisheries near the islands "fish on dolphins" to catch tuna. I analyzed genetic samples for mtDNA and microsatellite loci from four island regions: Hawai'i, the 4-islands area, O'ahu, and Kaua'i/Ni'ihau. My results support genetic differentiation among the regions of Hawai'i, the 4-islands area, and O'ahu and suggest that pantropical spotted dolphins near Kaua'i/Ni'ihau are likely transient and in very low numbers. There was no strong evidence to support sex-biased dispersal or group fidelity. Possibly, differentiation is mediated by behavior adapted to differing habitat types. From a management perspective, spinner and bottlenose dolphin populations near the Hawaiian Islands have been split into separate stocks for management based on levels of genetic differentiation similar to those found for pantropical spotted dolphins. These precedents suggest that comparable action should be taken to split pantropical spotted dolphin stocks near the Hawaiian Islands. Most population studies rely heavily upon fixation indicies like FST to determine whether populations are genetically differentiated. When FST values are low but significantly different from zero, it can be difficult to interpret the biological significance of these values. As part of my study, I suggest that one way to evaluate whether small FST values indicate significant differentiation is to compare FST values with other populations considered to be separate based on factors such as extreme distance or morphological differences. I examined pantropical spotted dolphins from the coastal and offshore Eastern Tropical Pacificm (ETP), Hawaiian Islands, and China/Taiwan to examine the utility of comparing FST values across separate populations. Among Hawaiian Island regions, FST values are significantly different from zero but small. The comparison of these FST values with more distant populations in the ETP and China/Taiwan indicated that differences among Hawaiian Island regions were similar in magnitude to those found between the offshore and coastal ETP sub-species, but smaller than between the Hawaiian Island regions and the other regions examined. This suggests a level of reproductive isolation among the Hawaiian Islands regions that is comparable to that of offshore and coastal ETP populations, and supports the value of fixation index comparisons in evaluating differentiation among putative populations. My results suggest that assigning specific numerical baseline FST values may not always be biologically meaningful but that determining whether related populations with geographic or other separation show a preponderance of similar, lower, or higher fixation index values can help evaluate whether genetic differences among sympatric or parapatric groups warrants designating them as separate populations for management. Lastly, I explore whether the fast evolving mtDNA control region may be more suited to phylogenetic comparisons among the Stenella than slower evolving gene regions and whether the small number of haplotypes generally used in phylogenetic analyses is adequate for defining relationships among dolphins. Usually, slow evolving regions, such as gene regions, are used in phylogenetic analyses because species and genera have been isolated long enough for variation to have accumulated in such regions but not so long that many reversals (i.e. a mutational change in sequence that later changes back to the original sequence) have occured. The mtDNA control region is typically used for population genetic comparisons rather than phylogenetic comparisons because it is considered to be a fast evolving region. Historically, dolphin phylogeny has been examined using gene regions, which have resulted in ambiguous and unexpected relationships. However, the lack of variation in the mtDNA control region for pantropical spotted dolphin populations and the fact that recent studies have found that the mtDNA control region in cetaceans evolves at about one quarter the rate of other mammals, raises the question as to whether this region would be better suited to phylogenetic studies for the Stenella (and potentially other dolphin species). In comparing 346 haplotypes from five species of Stenella world-wide, I found that the mtDNA control region is probably not a good region to use for phylogenetic analyses, and that even faster evolving regions might perform better. The differences in the mtDNA control region were not sufficient to distinguish clear relationships among the Stenella. I also found that when subsets of haplotypes chosen at random were compared, the results differed among comparisons, suggesting that there is value in using more than the usual one or two haplotypes when making phylogentic comparisons. Given the recent increases in sequence availability (e.g. GenBank) and computing power, researchers should strongly consider using many haplotypes from a variety of populations in their phylogenetic comparisons. Close

• 3590. [Article] Direct and indirect effects of livestock grazing intensity on processes regulating grassland bird populations

  In grasslands, grazing by large ungulates can influence vegetation structure, composition, primary productivity, and ultimately, ecosystem functioning. While grazing represents a complex disturbance, grazing ...

  Citation × Citation Citation Abstract Copy Title: Direct and indirect effects of livestock grazing intensity on processes regulating grassland bird populations Author: Johnson, Tracey N. In grasslands, grazing by large ungulates can influence vegetation structure, composition, primary productivity, and ultimately, ecosystem functioning. While grazing represents a complex disturbance, grazing intensity largely determines the effects of grazing on vegetation. Structural and compositional changes in the plant community caused by grazing could have bottom-up effects on species and interactions at higher trophic levels. Thus, particular management strategies for domestic livestock in rangeland systems could exert a strong affect on grassland wildlife. Grassland-dependent songbirds may be particularly susceptible to the effects of domestic grazers because they depend on grassland vegetation for foraging and nesting. Domestic livestock may influence grassland-breeding bird populations by affecting settlement decisions, resource availability, or reproductive success. We investigated the effects of grazing intensity on grassland vegetation structure and songbird demography in a northwestern bunchgrass prairie using paddocks with experimentally-manipulated cattle stocking rates. We compared effects of four stocking rates (0, 14.4, 28.8, and 43.2 animal unit months) on songbirds using a randomized complete block design with four replicates of each stocking rate to address hypotheses regarding demography of grassland songbirds. Overall paddock-level vegetation structure decreased and structural heterogeneity of vegetation increased with higher stocking rates, and those effects carried over one-year post-grazing. However, most bird species were able to locate nesting sites with similar vegetation structure regardless of paddock-level effects of stocking rate. The exceptions were western meadowlarks and vesper sparrows; nests of these species in paddocks with higher stocking rates had less vegetative cover. Apparent nest density for grasshopper sparrows was negatively affected by higher stocking rates. Grazing treatment effects on songbird population density were restricted to negative effects of higher stocking rates on savannah sparrows, but this relationship was not observed until the post-treatment year. Songbird community composition differed between control and heavily-grazed paddocks, but diversity was not affected by stocking rate. Nest fates were evaluated to determine whether stocking rate influenced nest survival or cause-specific nest failure. Other variables such as vegetation structure and predator community, date, year, and nest age were included to help clarify which mechanisms might be responsible for differences in nest survival or failure rates among treatments. For our analysis, we introduce the use of a novel software package, McNestimate, to estimate the daily probability of nest survival and failure from specific causes. McNestimate estimates the probability of nest failure from competing causes when the exact dates of failure are unknown using a Markov Chain framework, and incorporates a model selection approach which allows the use of covariates to help identify variables important in explaining variation in the daily probability of nest failure. Nest predation rates increased with the age of the nest and throughout the breeding season, but were not affected by stocking rate. The probability of nest failure from adverse weather declined throughout the season, but the rate of decline depended on year. Nest failure rates due to trampling were higher in paddocks with higher stocking rates, but also depended on the number of days cattle were present during the nesting period. Patterns of overall probability of nest success were driven by predation patterns in the first year, but in the second year were strongly influenced by the chances of weather-related nest failure. Although starvation was not identified as a significant source of nest failure, grazing-induced changes to vegetation structure and composition could influence food availability for breeding songbirds, ultimately affecting the composition of nestling diets and nestling condition. To better understand the relationship between grazing intensity, nestling diet composition, and subsequent effects on nestling condition, we examined the invertebrate composition of nestling fecal samples. All species showed strong preferences for Lepidoptera (moths and butterflies) larvae, and partial preferences for Coleoptera (beetles) and Araneae (spiders). The proportion of preferred prey items was not affected by stocking rate. There were effects of bird species on the proportion of Araneae and Coleoptera and the proportion of Acrididae (short-horned grasshoppers) in the diet of western meadowlark nestlings decreased with high stocking rates. Growth rates for western meadowlarks and vesper sparrows were negatively affected by higher stocking rates. These results suggest that stocking rates can have variable effects on grassland songbird population and nest density depending on each species' habitat requirements. However, negative effects of high stocking rates on nest survival and nestling condition could have consequences for juvenile survival and recruitment. Overall, low-to-moderate stocking rates are likely compatible with many grassland bird species in northwest bunchgrass prairie, and although heavier livestock grazing may help create suitable vegetation structure for some songbird species, high stocking rates may influence grassland songbird diet quality, or have negative effects on nestling condition. We hypothesized that grazing intensity could influence the grassland songbird community through "bottom-up" effects on vegetation, but effects of grazing at different intensities did not translate directly through the food web to influence songbird populations as strongly as lower trophic levels. Processes responsible for changes in community composition such as immigration or emigration may not have had time to ensue during our short-term experiment; alternatively, sufficient spatial or temporal heterogeneity remained in the system, even at the highest grazing intensity, such that grazing-induced changes in lower trophic levels were irrelevant for most songbird species. Our results contribute to understanding grassland songbird demographic responses to different grazing intensities and identify specific mechanisms by which conservation measures for declining grassland bird populations can be improved. Title: Direct and indirect effects of livestock grazing intensity on processes regulating grassland bird populations Author: Johnson, Tracey N. In grasslands, grazing by large ungulates can influence vegetation structure, composition, primary productivity, and ultimately, ecosystem functioning. While grazing represents a complex disturbance, grazing intensity largely determines the effects of grazing on vegetation. Structural and compositional changes in the plant community caused by grazing could have bottom-up effects on species and interactions at higher trophic levels. Thus, particular management strategies for domestic livestock in rangeland systems could exert a strong affect on grassland wildlife. Grassland-dependent songbirds may be particularly susceptible to the effects of domestic grazers because they depend on grassland vegetation for foraging and nesting. Domestic livestock may influence grassland-breeding bird populations by affecting settlement decisions, resource availability, or reproductive success. We investigated the effects of grazing intensity on grassland vegetation structure and songbird demography in a northwestern bunchgrass prairie using paddocks with experimentally-manipulated cattle stocking rates. We compared effects of four stocking rates (0, 14.4, 28.8, and 43.2 animal unit months) on songbirds using a randomized complete block design with four replicates of each stocking rate to address hypotheses regarding demography of grassland songbirds. Overall paddock-level vegetation structure decreased and structural heterogeneity of vegetation increased with higher stocking rates, and those effects carried over one-year post-grazing. However, most bird species were able to locate nesting sites with similar vegetation structure regardless of paddock-level effects of stocking rate. The exceptions were western meadowlarks and vesper sparrows; nests of these species in paddocks with higher stocking rates had less vegetative cover. Apparent nest density for grasshopper sparrows was negatively affected by higher stocking rates. Grazing treatment effects on songbird population density were restricted to negative effects of higher stocking rates on savannah sparrows, but this relationship was not observed until the post-treatment year. Songbird community composition differed between control and heavily-grazed paddocks, but diversity was not affected by stocking rate. Nest fates were evaluated to determine whether stocking rate influenced nest survival or cause-specific nest failure. Other variables such as vegetation structure and predator community, date, year, and nest age were included to help clarify which mechanisms might be responsible for differences in nest survival or failure rates among treatments. For our analysis, we introduce the use of a novel software package, McNestimate, to estimate the daily probability of nest survival and failure from specific causes. McNestimate estimates the probability of nest failure from competing causes when the exact dates of failure are unknown using a Markov Chain framework, and incorporates a model selection approach which allows the use of covariates to help identify variables important in explaining variation in the daily probability of nest failure. Nest predation rates increased with the age of the nest and throughout the breeding season, but were not affected by stocking rate. The probability of nest failure from adverse weather declined throughout the season, but the rate of decline depended on year. Nest failure rates due to trampling were higher in paddocks with higher stocking rates, but also depended on the number of days cattle were present during the nesting period. Patterns of overall probability of nest success were driven by predation patterns in the first year, but in the second year were strongly influenced by the chances of weather-related nest failure. Although starvation was not identified as a significant source of nest failure, grazing-induced changes to vegetation structure and composition could influence food availability for breeding songbirds, ultimately affecting the composition of nestling diets and nestling condition. To better understand the relationship between grazing intensity, nestling diet composition, and subsequent effects on nestling condition, we examined the invertebrate composition of nestling fecal samples. All species showed strong preferences for Lepidoptera (moths and butterflies) larvae, and partial preferences for Coleoptera (beetles) and Araneae (spiders). The proportion of preferred prey items was not affected by stocking rate. There were effects of bird species on the proportion of Araneae and Coleoptera and the proportion of Acrididae (short-horned grasshoppers) in the diet of western meadowlark nestlings decreased with high stocking rates. Growth rates for western meadowlarks and vesper sparrows were negatively affected by higher stocking rates. These results suggest that stocking rates can have variable effects on grassland songbird population and nest density depending on each species' habitat requirements. However, negative effects of high stocking rates on nest survival and nestling condition could have consequences for juvenile survival and recruitment. Overall, low-to-moderate stocking rates are likely compatible with many grassland bird species in northwest bunchgrass prairie, and although heavier livestock grazing may help create suitable vegetation structure for some songbird species, high stocking rates may influence grassland songbird diet quality, or have negative effects on nestling condition. We hypothesized that grazing intensity could influence the grassland songbird community through "bottom-up" effects on vegetation, but effects of grazing at different intensities did not translate directly through the food web to influence songbird populations as strongly as lower trophic levels. Processes responsible for changes in community composition such as immigration or emigration may not have had time to ensue during our short-term experiment; alternatively, sufficient spatial or temporal heterogeneity remained in the system, even at the highest grazing intensity, such that grazing-induced changes in lower trophic levels were irrelevant for most songbird species. Our results contribute to understanding grassland songbird demographic responses to different grazing intensities and identify specific mechanisms by which conservation measures for declining grassland bird populations can be improved. Close

• 3591. [Article] The physiology ecology and run diversity of adult Pacific lamprey, Entosphenus tridentatus, during the freshwater spawning migration

  Pacific lamprey, Entosphenus tridentatus, have shown recent and rapid declines in abundance. These anadromous fish return to streams where they mature, spawn and die. It has been inferred that Pacific ...

  Citation × Citation Citation Abstract Copy Title: The physiology ecology and run diversity of adult Pacific lamprey, Entosphenus tridentatus, during the freshwater spawning migration Author: Clemens, Benjamin Jacob, 1976- Pacific lamprey, Entosphenus tridentatus, have shown recent and rapid declines in abundance. These anadromous fish return to streams where they mature, spawn and die. It has been inferred that Pacific lamprey enter freshwater and reside for ~ 1 year before spawning. This long exposure to the freshwater environment may affect the plasticity of the maturation process and the migration timing of Pacific lamprey. Diversity in run times and body size has been observed for Pacific lamprey, yet it is unknown if this diversity is induced by the freshwater environment or if it is genetic. My first goal was to describe the maturation and migration characteristics of adult Pacific lamprey during their freshwater migration. My second goal was to use these data to make an estimation of the run diversity in Pacific lamprey. I conducted three complementary studies, in the laboratory and the field, to achieve these goals. I held immature adult lamprey (non-ripe fish that had ceased parasitic feeding in the ocean and had returned to freshwater) in the laboratory at temperatures that mimicked what these fish would experience in the wild, during the summer (mean: 21.8 °C), and another group of lamprey at cooler temperature (mean: 13.6 °C) to compare maturation timing and characteristics. The warm water group of lamprey showed significantly greater proportional decreases in body mass following temperature exposure than fish in the cooler water. All fish exposed to the warm water matured the following spring (8-10 months later) whereas only about half of the fish from the cool water exposure matured. To understand the migration distances and timing of adult Pacific lamprey, I tracked radio-tagged fish throughout the Willamette Basin above Willamette Falls, Oregon, by airplane and recorded their location. Fish migrated primarily during the spring to early summer period before stopping during the remainder of summer, when peak river temperatures (≥ 20°C) occurred. These fish tended to remain stationary through the fall and winter. However, at least a few fish continued to migrate upstream after September. I monitored maturation characteristics of adult Pacific lamprey, over time at Willamette Falls, Oregon and compared these fish with recent migrants collected from the Pacific Ocean as they entered freshwater. The results suggest a unimodal spawn timing between April and June, at water temperatures < 20 °C. Between July and mid-September, as water temperatures peaked at ~ 25 °C, relatively immature fish for both sexes prevailed. Warm summer temperatures coincided with an increase and prevalence of testicular atrophy in males, and I also observed a large die-off of lamprey during this time. The immature fish had maturation stages and phenotypic characteristics similar to recent migrants collected at the mouth of the Klamath River, suggesting that the immature fish at Willamette Falls would spawn the following year, and spawners in any given year may have been recent migrants during the previous year. However there is a temporal overlap in the spring of immature and mature fish, and I found evidence from gonad histology of maturing fish as they entered the river from the ocean, suggesting that a cohort is comprised of recent migrants that spawn within several weeks of entering freshwater, and another cohort is comprised of recent migrants that mature and spawn at least 1 year later. I hypothesize that the recent migrants that would likely spawn shortly after entering freshwater are akin to a winter or "ocean maturing" steelhead, Oncorhynchus mykiss, that optimizes feeding and growth in the open ocean for a few years before entering freshwater to spawn low in the river system shortly afterwards. Alternatively, these lamprey may be similar to coastal cutthroat trout, O. clarki clarki, that feed and grow in the coastal areas of the ocean for a few months before entering freshwater to spawn. There could be other less apparent explanations as well. I also hypothesize that the lamprey that would likely spawn within ~ 1 year of entering freshwater are akin to a "stream maturing" steelhead that foregoes feeding and growth opportunities, enters freshwater during the summer – fall, and accesses spawning grounds to spawn at temperatures that promote evolutionary fitness via successful spawning the following spring. Based on the results of my research, I hypothesize that warm summer temperatures (> 20 °C) can act as a strong selection factor against stream maturing Pacific lamprey in two ways. First, these temperatures may expedite their maturation, while at the same time slowing their migration. If these hypotheses are true, then I predict an uncoupling of spawn timing with optimal habitat characteristics, that would promote fitness, in the upper watershed. Second, summer temperatures may cause gonad atrophy and death prior to spawning. This scenario may select for ocean maturing Pacific lamprey. Title: The physiology ecology and run diversity of adult Pacific lamprey, Entosphenus tridentatus, during the freshwater spawning migration Author: Clemens, Benjamin Jacob, 1976- Pacific lamprey, Entosphenus tridentatus, have shown recent and rapid declines in abundance. These anadromous fish return to streams where they mature, spawn and die. It has been inferred that Pacific lamprey enter freshwater and reside for ~ 1 year before spawning. This long exposure to the freshwater environment may affect the plasticity of the maturation process and the migration timing of Pacific lamprey. Diversity in run times and body size has been observed for Pacific lamprey, yet it is unknown if this diversity is induced by the freshwater environment or if it is genetic. My first goal was to describe the maturation and migration characteristics of adult Pacific lamprey during their freshwater migration. My second goal was to use these data to make an estimation of the run diversity in Pacific lamprey. I conducted three complementary studies, in the laboratory and the field, to achieve these goals. I held immature adult lamprey (non-ripe fish that had ceased parasitic feeding in the ocean and had returned to freshwater) in the laboratory at temperatures that mimicked what these fish would experience in the wild, during the summer (mean: 21.8 °C), and another group of lamprey at cooler temperature (mean: 13.6 °C) to compare maturation timing and characteristics. The warm water group of lamprey showed significantly greater proportional decreases in body mass following temperature exposure than fish in the cooler water. All fish exposed to the warm water matured the following spring (8-10 months later) whereas only about half of the fish from the cool water exposure matured. To understand the migration distances and timing of adult Pacific lamprey, I tracked radio-tagged fish throughout the Willamette Basin above Willamette Falls, Oregon, by airplane and recorded their location. Fish migrated primarily during the spring to early summer period before stopping during the remainder of summer, when peak river temperatures (≥ 20°C) occurred. These fish tended to remain stationary through the fall and winter. However, at least a few fish continued to migrate upstream after September. I monitored maturation characteristics of adult Pacific lamprey, over time at Willamette Falls, Oregon and compared these fish with recent migrants collected from the Pacific Ocean as they entered freshwater. The results suggest a unimodal spawn timing between April and June, at water temperatures < 20 °C. Between July and mid-September, as water temperatures peaked at ~ 25 °C, relatively immature fish for both sexes prevailed. Warm summer temperatures coincided with an increase and prevalence of testicular atrophy in males, and I also observed a large die-off of lamprey during this time. The immature fish had maturation stages and phenotypic characteristics similar to recent migrants collected at the mouth of the Klamath River, suggesting that the immature fish at Willamette Falls would spawn the following year, and spawners in any given year may have been recent migrants during the previous year. However there is a temporal overlap in the spring of immature and mature fish, and I found evidence from gonad histology of maturing fish as they entered the river from the ocean, suggesting that a cohort is comprised of recent migrants that spawn within several weeks of entering freshwater, and another cohort is comprised of recent migrants that mature and spawn at least 1 year later. I hypothesize that the recent migrants that would likely spawn shortly after entering freshwater are akin to a winter or "ocean maturing" steelhead, Oncorhynchus mykiss, that optimizes feeding and growth in the open ocean for a few years before entering freshwater to spawn low in the river system shortly afterwards. Alternatively, these lamprey may be similar to coastal cutthroat trout, O. clarki clarki, that feed and grow in the coastal areas of the ocean for a few months before entering freshwater to spawn. There could be other less apparent explanations as well. I also hypothesize that the lamprey that would likely spawn within ~ 1 year of entering freshwater are akin to a "stream maturing" steelhead that foregoes feeding and growth opportunities, enters freshwater during the summer – fall, and accesses spawning grounds to spawn at temperatures that promote evolutionary fitness via successful spawning the following spring. Based on the results of my research, I hypothesize that warm summer temperatures (> 20 °C) can act as a strong selection factor against stream maturing Pacific lamprey in two ways. First, these temperatures may expedite their maturation, while at the same time slowing their migration. If these hypotheses are true, then I predict an uncoupling of spawn timing with optimal habitat characteristics, that would promote fitness, in the upper watershed. Second, summer temperatures may cause gonad atrophy and death prior to spawning. This scenario may select for ocean maturing Pacific lamprey. Close

• 3592. [Article] Cruise ship disturbance to Kittlitz's murrelets (Brachyramphus brevirostris) in Glacier Bay National Park and Preserve, Alaska

  The Kittlitz's murrelet (Brachyramphus brevirostris), a small pursuit-diving seabird in the family Alcidae, occurs across much of coastal Alaska and parts of the Russian Far East. Glacier Bay National ...

  Citation × Citation Citation Abstract Copy Title: Cruise ship disturbance to Kittlitz's murrelets (Brachyramphus brevirostris) in Glacier Bay National Park and Preserve, Alaska Author: Marcella, Timothy K. The Kittlitz's murrelet (Brachyramphus brevirostris), a small pursuit-diving seabird in the family Alcidae, occurs across much of coastal Alaska and parts of the Russian Far East. Glacier Bay National Park, located in Southeast Alaska, is believed to support approximately 37% of the worldwide breeding population of Kittlitz's murrelets during the summer months. Recent concern over apparent population declines in Alaska, coupled with the Park's dual mandate of resource preservation and visitation, led to this study. Cruise ships, although not the most numerous vessel type operating in Glacier Bay, have previously been identified as the vessel type eliciting the greatest disturbance response from Kittlitz's murrelets. During the murrelet breeding seasons in 2011 and 2012, my field assistants and I collected focal observations of 4,251 Brachyramphus murrelets from the bow of cruise ships traveling through Glacier Bay. Identification of murrelets to species was hampered by both the distance at which murrelets responded to the approaching ship and the type of response to the ship (diving vs. flushing). For roughly 40% of focal observations of murrelets from cruise ships, the species of murrelet (Kittlitz's murrelet or marbled murrelet [B. marmoratus]) could not be identified. Apparent habitat partitioning by the two murrelet species in Glacier Bay resulted in 79% of identified murrelets in the upper section of the Bay (Upper Bay) being Kittlitz's murrelets, while 83% of identified murrelets in the lower section of the Bay (Lower Bay) were marbled murrelets. In the Upper Bay, cruise ships are predicted to disturb 61% of all murrelets within 850 m on either side of the cruise ship's course (i.e., elicited a flushing or diving response), whereas in the Lower Bay, cruise ships are predicted to disturb 72% of murrelets within 850 m of the ship's course. Using Cox multistate models, I demonstrated that murrelets in the Upper Bay (predominantly Kittlitz's murrelets) were more likely to dive than flush in response to approaching cruise ships, whereas murrelets in the Lower Bay (predominantly marbled murrelets) were more likely to flush than dive. Also, murrelets in the Upper Bay responded to cruise ships by flushing or diving at shorter distances from the ship compared to murrelets in the Lower Bay. Murrelets in both areas of Glacier Bay generally reacted to cruise ships at greater distances when the ship approached indirectly, presumably because of the larger profile presented by a passing ship as opposed to a directly advancing ship. Absolute distance of the cruise ship from a focal murrelet was a strong predictor of murrelet disturbance response; no other management-relevant covariates that were measured during this study (e.g., ship velocity, distance to shore, whether a cruise ship had entered the Bay earlier that day) explained a significant proportion of the variation in murrelet response. Inferences based on data collected on-board cruise ships were limited to murrelet disturbance responses that occurred within 1 km of the ship. This was because of limits to the distance from the ship at which behavioral responses could be observed and the a priori assumption that disturbance to murrelets by cruise ships was unlikely at distances greater than 1 km. Results from shipboard observations indicated that some proportion of murrelets encountered at the farthest distance we could make inferences were on occasion disturbed (point estimate at 850 m perpendicular distance from ship's course = 15-30% probability of flushing or diving). This suggests that disturbance of murrelets by cruise ships in Glacier Bay exceeded expected distance thresholds. In order to investigate the effects of cruise ships on murrelet behavior at distances greater than 1 km, my assistants and I collected a total of 643 focal observations of Kittlitz's murrelets during 181 hours of observation from land-based observation sites in the Upper Bay during the 2012 field season. By combining these data with AIS and GPS ship tracks, I was able to append distance to the nearest cruise ship to each focal murrelet observation and search for patterns in murrelet behavior. By collecting data in this manner, I was able to avoid biasing the study based on pre-conceived notions of what constituted a threshold distance for cruise ships to disturb Kittlitz's murrelets. Using a segmented regression model within a logistic regression framework, I found that Kittlitz's murrelets exhibited a disturbance threshold (defined as an increased incidence of flushing from the water) by cruise ships at distances of at least 1.6 km, and perhaps as great as 6.0 km, with a best estimate of threshold disturbance distance at 3.8 km from a cruise ship. When cruise ships were greater than 3.8 km from focal Kittlitz's murrelets, the baseline probability of murrelets flushing during a focal observation period was 12.5%. When cruise ships were less than 3.8 km from focal Kittlitz's murrelets, the probability of flushing increased logistically with decreasing distance to an estimated 48% for the closest approach distances. The unexpectedly long distances at which murrelet behavior was affected by cruise ships in Glacier Bay is most likely attributable to social facilitation by other disturbed murrelets, because similar numbers of murrelets flushed when cruise ships were approaching (n = 30) as when they were receding (n = 27). Once a Kittlitz's murrelet flushed from the water, the subsequent duration of flight did not vary with distance to the nearest cruise ship. Instead, the duration of Kittlitz's murrelet flight was associated with time of day. The strong association between the proximity of cruise ships and the probability of a murrelet flushing, even at distances of several kilometers, demonstrates that Kittlitz's murrelets in Glacier Bay are susceptible to disturbance from cruise ships at distances greater than has previously been published for any seabird. Title: Cruise ship disturbance to Kittlitz's murrelets (Brachyramphus brevirostris) in Glacier Bay National Park and Preserve, Alaska Author: Marcella, Timothy K. The Kittlitz's murrelet (Brachyramphus brevirostris), a small pursuit-diving seabird in the family Alcidae, occurs across much of coastal Alaska and parts of the Russian Far East. Glacier Bay National Park, located in Southeast Alaska, is believed to support approximately 37% of the worldwide breeding population of Kittlitz's murrelets during the summer months. Recent concern over apparent population declines in Alaska, coupled with the Park's dual mandate of resource preservation and visitation, led to this study. Cruise ships, although not the most numerous vessel type operating in Glacier Bay, have previously been identified as the vessel type eliciting the greatest disturbance response from Kittlitz's murrelets. During the murrelet breeding seasons in 2011 and 2012, my field assistants and I collected focal observations of 4,251 Brachyramphus murrelets from the bow of cruise ships traveling through Glacier Bay. Identification of murrelets to species was hampered by both the distance at which murrelets responded to the approaching ship and the type of response to the ship (diving vs. flushing). For roughly 40% of focal observations of murrelets from cruise ships, the species of murrelet (Kittlitz's murrelet or marbled murrelet [B. marmoratus]) could not be identified. Apparent habitat partitioning by the two murrelet species in Glacier Bay resulted in 79% of identified murrelets in the upper section of the Bay (Upper Bay) being Kittlitz's murrelets, while 83% of identified murrelets in the lower section of the Bay (Lower Bay) were marbled murrelets. In the Upper Bay, cruise ships are predicted to disturb 61% of all murrelets within 850 m on either side of the cruise ship's course (i.e., elicited a flushing or diving response), whereas in the Lower Bay, cruise ships are predicted to disturb 72% of murrelets within 850 m of the ship's course. Using Cox multistate models, I demonstrated that murrelets in the Upper Bay (predominantly Kittlitz's murrelets) were more likely to dive than flush in response to approaching cruise ships, whereas murrelets in the Lower Bay (predominantly marbled murrelets) were more likely to flush than dive. Also, murrelets in the Upper Bay responded to cruise ships by flushing or diving at shorter distances from the ship compared to murrelets in the Lower Bay. Murrelets in both areas of Glacier Bay generally reacted to cruise ships at greater distances when the ship approached indirectly, presumably because of the larger profile presented by a passing ship as opposed to a directly advancing ship. Absolute distance of the cruise ship from a focal murrelet was a strong predictor of murrelet disturbance response; no other management-relevant covariates that were measured during this study (e.g., ship velocity, distance to shore, whether a cruise ship had entered the Bay earlier that day) explained a significant proportion of the variation in murrelet response. Inferences based on data collected on-board cruise ships were limited to murrelet disturbance responses that occurred within 1 km of the ship. This was because of limits to the distance from the ship at which behavioral responses could be observed and the a priori assumption that disturbance to murrelets by cruise ships was unlikely at distances greater than 1 km. Results from shipboard observations indicated that some proportion of murrelets encountered at the farthest distance we could make inferences were on occasion disturbed (point estimate at 850 m perpendicular distance from ship's course = 15-30% probability of flushing or diving). This suggests that disturbance of murrelets by cruise ships in Glacier Bay exceeded expected distance thresholds. In order to investigate the effects of cruise ships on murrelet behavior at distances greater than 1 km, my assistants and I collected a total of 643 focal observations of Kittlitz's murrelets during 181 hours of observation from land-based observation sites in the Upper Bay during the 2012 field season. By combining these data with AIS and GPS ship tracks, I was able to append distance to the nearest cruise ship to each focal murrelet observation and search for patterns in murrelet behavior. By collecting data in this manner, I was able to avoid biasing the study based on pre-conceived notions of what constituted a threshold distance for cruise ships to disturb Kittlitz's murrelets. Using a segmented regression model within a logistic regression framework, I found that Kittlitz's murrelets exhibited a disturbance threshold (defined as an increased incidence of flushing from the water) by cruise ships at distances of at least 1.6 km, and perhaps as great as 6.0 km, with a best estimate of threshold disturbance distance at 3.8 km from a cruise ship. When cruise ships were greater than 3.8 km from focal Kittlitz's murrelets, the baseline probability of murrelets flushing during a focal observation period was 12.5%. When cruise ships were less than 3.8 km from focal Kittlitz's murrelets, the probability of flushing increased logistically with decreasing distance to an estimated 48% for the closest approach distances. The unexpectedly long distances at which murrelet behavior was affected by cruise ships in Glacier Bay is most likely attributable to social facilitation by other disturbed murrelets, because similar numbers of murrelets flushed when cruise ships were approaching (n = 30) as when they were receding (n = 27). Once a Kittlitz's murrelet flushed from the water, the subsequent duration of flight did not vary with distance to the nearest cruise ship. Instead, the duration of Kittlitz's murrelet flight was associated with time of day. The strong association between the proximity of cruise ships and the probability of a murrelet flushing, even at distances of several kilometers, demonstrates that Kittlitz's murrelets in Glacier Bay are susceptible to disturbance from cruise ships at distances greater than has previously been published for any seabird. Close

• 3593. [Article] Evaluating the data-poor fishery stock assessment method, DB-SRA

  Depletion-Based Stock Reduction Analysis (DB-SRA; Dick and MacCall, 2011) is a catch-only fisheries stock assessment model that has been developed to estimate an overfishing limit (OFL) in data-poor situations. ...

  Citation × Citation Citation Abstract Copy Title: Evaluating the data-poor fishery stock assessment method, DB-SRA Author: Owashi, Brandon R. Depletion-Based Stock Reduction Analysis (DB-SRA; Dick and MacCall, 2011) is a catch-only fisheries stock assessment model that has been developed to estimate an overfishing limit (OFL) in data-poor situations. DB-SRA projects the biomass trajectories of a stock by means of a catch time series and five parameters: the instantaneous, per annum, rate of natural mortality (M), age at 50% maturity, F[subscript MSY]/M, B[subscriptMSY]/B₀, and the predicted depletion of the stock from its unfished condition. F[subscriptMSY]/M is the rate of fishing mortality associated with the maximum sustainable yield (MSY) divided by the natural mortality rate, and B[subscriptMSY]/B₀ is the biomass level associated with the MSY divided by the unfished level of biomass. DB-SRA performs a Monte Carlo simulation where a large number of random parameter draws are made based on the input parameter’s prior distribution. Based on the catch time series, a biomass trajectory is produced to estimate a feasible set of input parameters and an OFL. The run and corresponding set of input parameters are not retained if the biomass trajectory goes below zero. In instances where the input parameter prior distributions are unknown, Dick and MacCall (2011) proposed a set of default values for two life history types (rockfish and flatfish). Although DB-SRA has been evaluated to some extent and is currently being used for management of data-poor species on the U.S. west coast, further evaluation is warranted. Like other fisheries assessment models, DB-SRA makes several assumptions that may have large influence on outputs and have largely gone untested. First, in essence DB-SRA assumes that only mature fish are caught in the fishery; this is rarely true on the U.S. West Coast and elsewhere, particularly for species with substantial recreational catch. Second, most stock assessment methods, including DB-SRA, are applied to large regions (e.g., U.S. west coast), assuming the population dynamics and fishing behavior remain consistent across the entire area. Market demands and habitat, among other factors, can lead to heterogeneity in population dynamics and fishing behavior. For instance, immature fish are often caught in recreational fisheries, but commercial fisheries tend to target larger fish, causing fishing impact to change across regions. I developed a two-region operating model that simulated data to generate input parameter expected values and a catch time series for each region, then conducted a factorial experiment to investigate the effect of four factors on DB-SRA (version 4) results: (1) different positions of the selectivity curve (the relative vulnerability to fishing of each age class) relative to the maturity curve; (2) spatial scale (separate by region versus combined); (3) exploitation history; and (4) life history type (rockfish and flatfish). The position of the selectivity curve influences the accuracy of the OFL estimates from DB-SRA, whereas the exploitation history has little effect. The OFL estimates are overestimated when the selectivity curve is to the right of the maturity curve and underestimated when the selectivity curve is to the left of the maturity curve. DB-SRA produces higher OFL estimates when two regions are used instead of one large region. Dividing the catch data into multiple regions resulted in higher OFL estimates than one combined region when the same input parameters and catch time series were used. An updated production function, for mimicking population dynamics, was implemented in DB-SRA (version 4), creating separate time lags for mortality and production (recruitment and growth). Instead of setting the time lags for mortality and production equal to the age at 50% maturity (version 3), the time lag for mortality has been changed to one year (version 4). Although the version 4 DB-SRA model has been used for fishery management, it has not been formally evaluated against version 3 to understand the impacts of this change on model results. To investigate the two versions, I looked at different positions of the selectivity curve relative to the maturity curve, different exploitation histories, and varying spatial scale for two life history types. The OFL estimates from version 3 of DB-SRA were larger than the OFL estimates from version 4, which is also evident in the biomass trajectories. The biomass trajectories from version 3 are always greater than the respective biomass trajectories from version 4. Although the OFL estimates from version 4 are not always less biased than those from version 3, the estimates from version 4 are always more precautionary and significantly reduce the chances for overestimating the OFL. The identification of factors that influence DB-SRA OFL estimates could demonstrate how DB-SRA can be adjusted to produce less biased OFL estimates in more situations. The change made in the production function between versions 3 and 4 of DB-SRA makes OFL estimates more precautionary; but does not always reduce the bias in the median OFL estimate. The results from this study could provide information to fisheries managers so that DB-SRA could be potentially improved and is applied in appropriate situations. Title: Evaluating the data-poor fishery stock assessment method, DB-SRA Author: Owashi, Brandon R. Depletion-Based Stock Reduction Analysis (DB-SRA; Dick and MacCall, 2011) is a catch-only fisheries stock assessment model that has been developed to estimate an overfishing limit (OFL) in data-poor situations. DB-SRA projects the biomass trajectories of a stock by means of a catch time series and five parameters: the instantaneous, per annum, rate of natural mortality (M), age at 50% maturity, F[subscript MSY]/M, B[subscriptMSY]/B₀, and the predicted depletion of the stock from its unfished condition. F[subscriptMSY]/M is the rate of fishing mortality associated with the maximum sustainable yield (MSY) divided by the natural mortality rate, and B[subscriptMSY]/B₀ is the biomass level associated with the MSY divided by the unfished level of biomass. DB-SRA performs a Monte Carlo simulation where a large number of random parameter draws are made based on the input parameter’s prior distribution. Based on the catch time series, a biomass trajectory is produced to estimate a feasible set of input parameters and an OFL. The run and corresponding set of input parameters are not retained if the biomass trajectory goes below zero. In instances where the input parameter prior distributions are unknown, Dick and MacCall (2011) proposed a set of default values for two life history types (rockfish and flatfish). Although DB-SRA has been evaluated to some extent and is currently being used for management of data-poor species on the U.S. west coast, further evaluation is warranted. Like other fisheries assessment models, DB-SRA makes several assumptions that may have large influence on outputs and have largely gone untested. First, in essence DB-SRA assumes that only mature fish are caught in the fishery; this is rarely true on the U.S. West Coast and elsewhere, particularly for species with substantial recreational catch. Second, most stock assessment methods, including DB-SRA, are applied to large regions (e.g., U.S. west coast), assuming the population dynamics and fishing behavior remain consistent across the entire area. Market demands and habitat, among other factors, can lead to heterogeneity in population dynamics and fishing behavior. For instance, immature fish are often caught in recreational fisheries, but commercial fisheries tend to target larger fish, causing fishing impact to change across regions. I developed a two-region operating model that simulated data to generate input parameter expected values and a catch time series for each region, then conducted a factorial experiment to investigate the effect of four factors on DB-SRA (version 4) results: (1) different positions of the selectivity curve (the relative vulnerability to fishing of each age class) relative to the maturity curve; (2) spatial scale (separate by region versus combined); (3) exploitation history; and (4) life history type (rockfish and flatfish). The position of the selectivity curve influences the accuracy of the OFL estimates from DB-SRA, whereas the exploitation history has little effect. The OFL estimates are overestimated when the selectivity curve is to the right of the maturity curve and underestimated when the selectivity curve is to the left of the maturity curve. DB-SRA produces higher OFL estimates when two regions are used instead of one large region. Dividing the catch data into multiple regions resulted in higher OFL estimates than one combined region when the same input parameters and catch time series were used. An updated production function, for mimicking population dynamics, was implemented in DB-SRA (version 4), creating separate time lags for mortality and production (recruitment and growth). Instead of setting the time lags for mortality and production equal to the age at 50% maturity (version 3), the time lag for mortality has been changed to one year (version 4). Although the version 4 DB-SRA model has been used for fishery management, it has not been formally evaluated against version 3 to understand the impacts of this change on model results. To investigate the two versions, I looked at different positions of the selectivity curve relative to the maturity curve, different exploitation histories, and varying spatial scale for two life history types. The OFL estimates from version 3 of DB-SRA were larger than the OFL estimates from version 4, which is also evident in the biomass trajectories. The biomass trajectories from version 3 are always greater than the respective biomass trajectories from version 4. Although the OFL estimates from version 4 are not always less biased than those from version 3, the estimates from version 4 are always more precautionary and significantly reduce the chances for overestimating the OFL. The identification of factors that influence DB-SRA OFL estimates could demonstrate how DB-SRA can be adjusted to produce less biased OFL estimates in more situations. The change made in the production function between versions 3 and 4 of DB-SRA makes OFL estimates more precautionary; but does not always reduce the bias in the median OFL estimate. The results from this study could provide information to fisheries managers so that DB-SRA could be potentially improved and is applied in appropriate situations. Close

• 3594. [Article] Effects of the invasive Pacific red lionfish Pterois volitans on native Atlantic coral-reef fish communities

  Predatory lionfishes (Pterois volitans and P. miles) were introduced to Florida waters during the mid to late 1980s, and eventually established self-sustaining breeding populations in the tropical western ...

  Citation × Citation Citation Abstract Copy Title: Effects of the invasive Pacific red lionfish Pterois volitans on native Atlantic coral-reef fish communities Author: Albins, Mark A. Predatory lionfishes (Pterois volitans and P. miles) were introduced to Florida waters during the mid to late 1980s, and eventually established self-sustaining breeding populations in the tropical western Atlantic. These invasive species are now widespread along the southeastern seaboard of the United States, across the Caribbean Sea, and in the Gulf of Mexico. In these regions, lionfish reach larger maximum sizes and higher abundances than they do in their native Pacific, suggesting that they have undergone ecological release. Invaded marine communities have thus far provided little if any biotic resistance. Lionfish are generalist predators with high consumption rates, inhabit a broad range of habitats, are defended from predation by venomous spines, and are capable of long-range larval dispersal. It is possible that lionfish have direct effects on native communities, through consumption of native fishes and competition with native predators, as well as indirect effects, such as overconsumption of herbivorous fishes that prevent seaweeds from outcompeting reef-building corals. There is also serious concern that invasive lionfish could act additively, or even synergistically, with existing stressors of coral-reef systems, such as overfishing and ocean warming, resulting in substantial negative consequences for native ecosystems and economically valuable fisheries. The primary goal of this dissertation was to conduct a set of controlled, replicated field experiments to rigorously examine and measure the effects of lionfish on native reef-fish communities across a range of spatial and temporal scales. In the first experiment (Chapter 2), the net recruitment of native fishes to twenty small patch reefs was compared in the presence (n = 10) and absence (n = 10) of lionfish. This study demonstrated that lionfish reduced net recruitment, or change in abundance of small native fishes, by an average (± SEM) of 78.9 ± 32.2 % over 5 weeks, affecting 23 of 38 species recruiting to reefs in both treatments. In a second experiment (Chapter 4), I examined the effects of lionfish on patch-reef communities of small native fishes relative to, and in combination with, those of a similarly sized native predator, the coney grouper (Cephalopholis fulva). Four different predator treatments were established by transplanting predators (n = 5 reefs each). Treatments included a single small invasive lionfish, a single small native grouper, a grouper and a lionfish together, and predator-free controls. Compared to controls, invasive lionfish caused reductions (mean ± SEM) in abundance (93.7 ± 17.8 %) and species richness (4.6 ± 1.6 species) of small native fishes. The negative effect of lionfish on abundance was 2.6 ± 0.5 times stronger than that of the native grouper. The greatest negative effects on abundance, species richness, evenness, and diversity of native fishes occurred when both lionfish and native grouper were present. Additionally, lionfish grew more than six times faster in both length and mass than did native grouper. A third experiment (Chapter 6) assessed the effects of lionfish on native reef-fish communities at spatial and temporal scales directly relevant to management and conservation efforts. Subsequent to baseline surveys, high- and low-density lionfish treatments were established on 10 large (1400 to 4000 m²) isolated coral reefs. After initiation of treatments, quarterly surveys of the native reef-fish communities were conducted for approximately 14 months. Lionfish caused significant reductions (mean ± SEM) in density (up to 3.22 ± 0.95 fish m⁻²), biomass (3.26 ± 1.10 g m⁻²), and species richness (4.92 ± 2.09 species) of small (<10 cm TL) native fishes. However, these negative effects on prey-sized fishes had not yet translated into declines in larger size classes during the first 14 months of this experiment. In addition to field experiments, this dissertation describes field and aquarium observations of a previously undocumented piscivorous behavior by invasive lionfish - blowing jets of water at prey fish - which may confer a high degree of predation efficiency, thus contributing to the dramatic success of the invasion (Chapter 5). Also provided is a review of the current state of knowledge about the lionfish invasion, with speculation on the long-term effects of the invasion on coral-reef communities, and a brief discussion of potential mitigation measures (Chapter 3). In sum, this research demonstrated that invasive lionfish have substantial negative effects on native communities of coral-reef fishes. In all cases, numerical reductions in small (prey-sized) native fishes caused by lionfish were substantial. Additionally, lionfish caused considerable reductions in native reef-fish species richness (via predation on rare species). These findings indicate that the lionfish invasion may have long-term, broad-scale impacts on the structure and function of coral-reef communities as a whole, potentially reducing the resilience of these systems to a myriad of existing stressors as well as their capacity to provide valuable ecosystem goods and services to humans. Title: Effects of the invasive Pacific red lionfish Pterois volitans on native Atlantic coral-reef fish communities Author: Albins, Mark A. Predatory lionfishes (Pterois volitans and P. miles) were introduced to Florida waters during the mid to late 1980s, and eventually established self-sustaining breeding populations in the tropical western Atlantic. These invasive species are now widespread along the southeastern seaboard of the United States, across the Caribbean Sea, and in the Gulf of Mexico. In these regions, lionfish reach larger maximum sizes and higher abundances than they do in their native Pacific, suggesting that they have undergone ecological release. Invaded marine communities have thus far provided little if any biotic resistance. Lionfish are generalist predators with high consumption rates, inhabit a broad range of habitats, are defended from predation by venomous spines, and are capable of long-range larval dispersal. It is possible that lionfish have direct effects on native communities, through consumption of native fishes and competition with native predators, as well as indirect effects, such as overconsumption of herbivorous fishes that prevent seaweeds from outcompeting reef-building corals. There is also serious concern that invasive lionfish could act additively, or even synergistically, with existing stressors of coral-reef systems, such as overfishing and ocean warming, resulting in substantial negative consequences for native ecosystems and economically valuable fisheries. The primary goal of this dissertation was to conduct a set of controlled, replicated field experiments to rigorously examine and measure the effects of lionfish on native reef-fish communities across a range of spatial and temporal scales. In the first experiment (Chapter 2), the net recruitment of native fishes to twenty small patch reefs was compared in the presence (n = 10) and absence (n = 10) of lionfish. This study demonstrated that lionfish reduced net recruitment, or change in abundance of small native fishes, by an average (± SEM) of 78.9 ± 32.2 % over 5 weeks, affecting 23 of 38 species recruiting to reefs in both treatments. In a second experiment (Chapter 4), I examined the effects of lionfish on patch-reef communities of small native fishes relative to, and in combination with, those of a similarly sized native predator, the coney grouper (Cephalopholis fulva). Four different predator treatments were established by transplanting predators (n = 5 reefs each). Treatments included a single small invasive lionfish, a single small native grouper, a grouper and a lionfish together, and predator-free controls. Compared to controls, invasive lionfish caused reductions (mean ± SEM) in abundance (93.7 ± 17.8 %) and species richness (4.6 ± 1.6 species) of small native fishes. The negative effect of lionfish on abundance was 2.6 ± 0.5 times stronger than that of the native grouper. The greatest negative effects on abundance, species richness, evenness, and diversity of native fishes occurred when both lionfish and native grouper were present. Additionally, lionfish grew more than six times faster in both length and mass than did native grouper. A third experiment (Chapter 6) assessed the effects of lionfish on native reef-fish communities at spatial and temporal scales directly relevant to management and conservation efforts. Subsequent to baseline surveys, high- and low-density lionfish treatments were established on 10 large (1400 to 4000 m²) isolated coral reefs. After initiation of treatments, quarterly surveys of the native reef-fish communities were conducted for approximately 14 months. Lionfish caused significant reductions (mean ± SEM) in density (up to 3.22 ± 0.95 fish m⁻²), biomass (3.26 ± 1.10 g m⁻²), and species richness (4.92 ± 2.09 species) of small (<10 cm TL) native fishes. However, these negative effects on prey-sized fishes had not yet translated into declines in larger size classes during the first 14 months of this experiment. In addition to field experiments, this dissertation describes field and aquarium observations of a previously undocumented piscivorous behavior by invasive lionfish - blowing jets of water at prey fish - which may confer a high degree of predation efficiency, thus contributing to the dramatic success of the invasion (Chapter 5). Also provided is a review of the current state of knowledge about the lionfish invasion, with speculation on the long-term effects of the invasion on coral-reef communities, and a brief discussion of potential mitigation measures (Chapter 3). In sum, this research demonstrated that invasive lionfish have substantial negative effects on native communities of coral-reef fishes. In all cases, numerical reductions in small (prey-sized) native fishes caused by lionfish were substantial. Additionally, lionfish caused considerable reductions in native reef-fish species richness (via predation on rare species). These findings indicate that the lionfish invasion may have long-term, broad-scale impacts on the structure and function of coral-reef communities as a whole, potentially reducing the resilience of these systems to a myriad of existing stressors as well as their capacity to provide valuable ecosystem goods and services to humans. Close

• 3595. [Article] Complexity of food web interactions in a large mammal system

  Food webs consist of a combination of bottom-up (resource-driven) and top-down (predator-driven) effects. The strength of these effects depends on the context in which they occur. I investigated food web ...

  Citation × Citation Citation Abstract Copy Title: Complexity of food web interactions in a large mammal system Author: Eisenberg, Cristina Food webs consist of a combination of bottom-up (resource-driven) and top-down (predator-driven) effects. The strength of these effects depends on the context in which they occur. I investigated food web (trophic) relationships between wolf (Canis lupus) predation, elk (Cervus elaphus) herbivory, aspen (Populus tremuloides Michaux) recruitment, and fire. The study setting, in the central portion of the Crown of the Continent Ecosystem, spans the US/Canada border and encompasses Glacier National Park (GNP), Montana and Waterton Lakes National Park (WLNP), Alberta. I stratified my observations across three spatially distinct areas, the North Fork Valley, in the western portion of GNP; the Waterton Valley, in the eastern portion of WLNP; and the Saint Mary Valley, in the eastern portion of GNP. All valleys are elk winter range (low-lying grasslands with patches of aspen). The valleys have three different observed wolf population levels (Saint Mary: low; Waterton: moderate; North Fork: high), which represent three levels of long-term predation risk (the probability of an elk encountering a wolf). Ecological characteristics (e.g., climate, soils, elevation, plant associations) are comparable among valleys. Fire has occurred in 90% of the North Fork. My objective was to examine the relative influence of bottom-up (fire) and top-down (predation risk) factors and the context-dependence of these relationships via data gathered during a three-year time span. I found complex elk responses to bottom-up and top-down factors that could influence habitat use by elk. Pellet transect data demonstrated that elk exhibited the same risk reduction behavior at all wolf population levels, even at very low levels. Predation risk variables that provided impediments to detecting or escaping wolves had a similar and negative influence on occurrence of elk (pellet piles), regardless of wolf population density. Fire had a negative effect on elk density and a positive effect on wolf density (per scat piles) in aspen communities where a high wolf population existed. Aspen cover, which may be riskier than open grassland, also had a negative effect on elk density, except at very high wolf levels without fire. The risk of wolf predation alone did not drive elk behavior. Conversely, focal animal (elk vigilance behavior) data suggested a positive relationship between wolf population and elk vigilance. However, when I deconstructed vigilance, elk demonstrated complex, context-dependent adaptive behavior in response to the long-term risk of predation by wolves. Commonly identified drivers of elk vigilance (group size, impediments to wolf detection and escape) appeared to be important drivers at an intermediate level of long-term predation risk (e.g., Waterton). These drivers ceased to function in this manner when the long-term predation risk level increased (The North Fork). At high levels of long-term predation risk, vigilance was high, but not driven by these common factors. In some cases, the relationship between vigilance and risk factors was reversed (e.g., group size). And at a low level of long-term predation risk (Saint Mary), elk did not respond to these drivers of vigilance. When I measured aspen demography (browse, recruitment), browse was lower in the North Fork, where there was a high wolf population, suggesting a top-down effect. However, I found low aspen recruitment in the absence of fire in all valleys, which indicates a bottom-up effect in that aspen is highly fire-dependent. Top-down predictors of aspen recruitment (e.g., plot position and stand size, which are related to predation risk) had no effect on browse levels regardless of wolf population level. In sum, the risk of wolf predation alone did not drive the food web relationships I observed. Bottom-up and top-down forces worked together in valleys that contained well-established wolf populations, and to a lesser degree in a valley with a low wolf population. Commonly used measures of predation risk responses (e.g., vigilance) reversed their relationship as the wolf population increased. Low aspen recruitment in the absence of fire demonstrates the importance of bottom-up effects. Bottom-up and top-down effects may be important joint engineers of aspen communities. My findings invite deeper inquiry into the interaction between bottom-up and top-down effects in large mammal systems. Title: Complexity of food web interactions in a large mammal system Author: Eisenberg, Cristina Food webs consist of a combination of bottom-up (resource-driven) and top-down (predator-driven) effects. The strength of these effects depends on the context in which they occur. I investigated food web (trophic) relationships between wolf (Canis lupus) predation, elk (Cervus elaphus) herbivory, aspen (Populus tremuloides Michaux) recruitment, and fire. The study setting, in the central portion of the Crown of the Continent Ecosystem, spans the US/Canada border and encompasses Glacier National Park (GNP), Montana and Waterton Lakes National Park (WLNP), Alberta. I stratified my observations across three spatially distinct areas, the North Fork Valley, in the western portion of GNP; the Waterton Valley, in the eastern portion of WLNP; and the Saint Mary Valley, in the eastern portion of GNP. All valleys are elk winter range (low-lying grasslands with patches of aspen). The valleys have three different observed wolf population levels (Saint Mary: low; Waterton: moderate; North Fork: high), which represent three levels of long-term predation risk (the probability of an elk encountering a wolf). Ecological characteristics (e.g., climate, soils, elevation, plant associations) are comparable among valleys. Fire has occurred in 90% of the North Fork. My objective was to examine the relative influence of bottom-up (fire) and top-down (predation risk) factors and the context-dependence of these relationships via data gathered during a three-year time span. I found complex elk responses to bottom-up and top-down factors that could influence habitat use by elk. Pellet transect data demonstrated that elk exhibited the same risk reduction behavior at all wolf population levels, even at very low levels. Predation risk variables that provided impediments to detecting or escaping wolves had a similar and negative influence on occurrence of elk (pellet piles), regardless of wolf population density. Fire had a negative effect on elk density and a positive effect on wolf density (per scat piles) in aspen communities where a high wolf population existed. Aspen cover, which may be riskier than open grassland, also had a negative effect on elk density, except at very high wolf levels without fire. The risk of wolf predation alone did not drive elk behavior. Conversely, focal animal (elk vigilance behavior) data suggested a positive relationship between wolf population and elk vigilance. However, when I deconstructed vigilance, elk demonstrated complex, context-dependent adaptive behavior in response to the long-term risk of predation by wolves. Commonly identified drivers of elk vigilance (group size, impediments to wolf detection and escape) appeared to be important drivers at an intermediate level of long-term predation risk (e.g., Waterton). These drivers ceased to function in this manner when the long-term predation risk level increased (The North Fork). At high levels of long-term predation risk, vigilance was high, but not driven by these common factors. In some cases, the relationship between vigilance and risk factors was reversed (e.g., group size). And at a low level of long-term predation risk (Saint Mary), elk did not respond to these drivers of vigilance. When I measured aspen demography (browse, recruitment), browse was lower in the North Fork, where there was a high wolf population, suggesting a top-down effect. However, I found low aspen recruitment in the absence of fire in all valleys, which indicates a bottom-up effect in that aspen is highly fire-dependent. Top-down predictors of aspen recruitment (e.g., plot position and stand size, which are related to predation risk) had no effect on browse levels regardless of wolf population level. In sum, the risk of wolf predation alone did not drive the food web relationships I observed. Bottom-up and top-down forces worked together in valleys that contained well-established wolf populations, and to a lesser degree in a valley with a low wolf population. Commonly used measures of predation risk responses (e.g., vigilance) reversed their relationship as the wolf population increased. Low aspen recruitment in the absence of fire demonstrates the importance of bottom-up effects. Bottom-up and top-down effects may be important joint engineers of aspen communities. My findings invite deeper inquiry into the interaction between bottom-up and top-down effects in large mammal systems. Close

• 3596. [Article] A UK perspective on marine renewable energy environmental research: Keeping up with a ‘Deploy & Monitor’ philosophy

  There are many drivers for the pursuit of renewable energy extraction from coastal seas. In the United Kingdom these include moving away from fossil fuels to mitigate the impacts of climate change, improving ...

  Citation × Citation Citation Abstract Copy Title: A UK perspective on marine renewable energy environmental research: Keeping up with a ‘Deploy & Monitor’ philosophy Author: Wilson, Ben There are many drivers for the pursuit of renewable energy extraction from coastal seas. In the United Kingdom these include moving away from fossil fuels to mitigate the impacts of climate change, improving energy security by diversifying supply options, increasing wealth generation in outlying coastal communities, and seeking alternative sources of power as existing infrastructure (power stations) near the end of their useful lives. In Scotland these drivers are particularly strong because of the additional factors of decline of North Sea oil reserves; the political pressure not to re-develop nuclear power plants; and the abundant offshore wind, wave and tidal-stream resources. While these drivers are strong, and backed up by ambitious political targets, a variety of constraints currently limit development of a vibrant marine renewables sector in UK coastal waters. In addition to financial, technological and logistical issues, a diversity of environmental restrictions limitprogress of the renewables sector. Many of these environmental issues actually stem from a lack of basic knowledge of how marine renewable energy devices are likely to interact with the receiving environment and vulnerable species (particularly those protected by European legislation such as the Habitats and Species as well as the Birds Directives). Furthermore where negative interactions are known, there may be limited knowledge about, or options for, mitigating these impacts. Strictly applying precautionary principals to these new and diverse technologies with respect to their potential local negative environmental impacts threatens to halt development of these technologies despite their potential benefits for global climate and other environmental issues. This problem applies particularly to wave and tidal-stream technologies which are diverse, new, and without track-record. To overcome this issue, the Scottish government is implementing a staged introduction of these technologies under what has been termed a “Survey-Deploy-&-Monitor” policy. That is, commercial scale devices are being placed singly or in small arrays (< 10 MW) into areas of pre-determined and acceptable environmental sensitivity and then impacts are being quantified through a monitoring program. In parallel to this approach, The Crown Estate (the seabed owner) has performed a series of licensing rounds to lease preferred sites to specific wind, wave and tidal-stream developers. If consented, these sites will represent commercial-scale developments of all three technologies in Scottish and wider UK waters. Part of that consenting progress requires that developers provide evidence (through Environmental Impact Studies and the production of Environmental Statements) that their developments will not harm the surrounding environment. It is these consenting exercises and related fundamental questions about impacts that are currently driving most of the environmental research related to offshore wind and marine renewable technologies in the UK. Research tends to fall into three divisions based on the source of funding and the geographic scope of the issues. At the smallest scale are studies of individual sites of interest to individual developers seeking consents for a specific technology. More generic studies funded by government or industry consortia may be performed to understand environmental issues surrounding a particular group of technologies, installation methods, or operational parameters. In this case, the actual site may be less important. Finally, fundamental research (funded by Research Councils) may be carried out to understand how and why animals use renewable energy relevant sites. Because there are a large number of research studies currently underway at a wide range of scales, sites, and taxa in Scotland and the wider UK, it is not possible to summarize them all in this short talk. Instead, I will outline examples of the three broad areas of environmental research (site/device specific, technology generic and more basic ecology). These examples have also been chosen because they represent an ongoing project, a recently established group of research studies, and a potential new research program. Some of the perhaps less intuitive lessons that have arisen from some of such projects include : 1. The responses of organisms may not be tied to particular brands of device or energy extraction, whether wind, wave, tidal-stream or even oil platform. For fouling organisms the particulars of the substrate might be the important factor rather than the device’s method of energy extraction. Likewise for fish it may be the device complexity and position in the water column that is key to their interactions. 2. Conversely, particular, seemingly unimportant features of devices may have relevance to marine organisms. For example, the color of a turbine may be extremely important for animals maneuvering around the rotors, a duct or the pile. 3. Test centers used to assess full-scale devices may seem like excellent places to also perform environmental research; however care must be taken as the devices in test centers are typically early generation prototypes and may be swapped out frequently. Furthermore activities by other companies at neighboring berths may invalidate site or device specific experiments. 4. Inter-annual variability does not suit the current pace of marine renewables development and careful consideration of the use of control sites and BACI designs should be made. 5. Cumulative impacts of multiple renewable and other developments offer a massive challenge to determining environmental impact. This difficulty represents a significant area of uncertainty for developers seeking consent and may encourage a development race with companies not wanting to have to consider their development relative to all of the others that preceded them. 6. Finally, while much effort is currently being devoted to gathering sufficient data to permit consent and early stage deployments, the significant investments only come when developers set up arrays capable of producing commercially relevant power. At this point there may be a step change in the degree of monitoring required of any potential environmental interactions. Should intolerable impacts be found, then mitigation will be urgently required or an exit strategy implemented. Title: A UK perspective on marine renewable energy environmental research: Keeping up with a ‘Deploy & Monitor’ philosophy Author: Wilson, Ben There are many drivers for the pursuit of renewable energy extraction from coastal seas. In the United Kingdom these include moving away from fossil fuels to mitigate the impacts of climate change, improving energy security by diversifying supply options, increasing wealth generation in outlying coastal communities, and seeking alternative sources of power as existing infrastructure (power stations) near the end of their useful lives. In Scotland these drivers are particularly strong because of the additional factors of decline of North Sea oil reserves; the political pressure not to re-develop nuclear power plants; and the abundant offshore wind, wave and tidal-stream resources. While these drivers are strong, and backed up by ambitious political targets, a variety of constraints currently limit development of a vibrant marine renewables sector in UK coastal waters. In addition to financial, technological and logistical issues, a diversity of environmental restrictions limitprogress of the renewables sector. Many of these environmental issues actually stem from a lack of basic knowledge of how marine renewable energy devices are likely to interact with the receiving environment and vulnerable species (particularly those protected by European legislation such as the Habitats and Species as well as the Birds Directives). Furthermore where negative interactions are known, there may be limited knowledge about, or options for, mitigating these impacts. Strictly applying precautionary principals to these new and diverse technologies with respect to their potential local negative environmental impacts threatens to halt development of these technologies despite their potential benefits for global climate and other environmental issues. This problem applies particularly to wave and tidal-stream technologies which are diverse, new, and without track-record. To overcome this issue, the Scottish government is implementing a staged introduction of these technologies under what has been termed a “Survey-Deploy-&-Monitor” policy. That is, commercial scale devices are being placed singly or in small arrays (< 10 MW) into areas of pre-determined and acceptable environmental sensitivity and then impacts are being quantified through a monitoring program. In parallel to this approach, The Crown Estate (the seabed owner) has performed a series of licensing rounds to lease preferred sites to specific wind, wave and tidal-stream developers. If consented, these sites will represent commercial-scale developments of all three technologies in Scottish and wider UK waters. Part of that consenting progress requires that developers provide evidence (through Environmental Impact Studies and the production of Environmental Statements) that their developments will not harm the surrounding environment. It is these consenting exercises and related fundamental questions about impacts that are currently driving most of the environmental research related to offshore wind and marine renewable technologies in the UK. Research tends to fall into three divisions based on the source of funding and the geographic scope of the issues. At the smallest scale are studies of individual sites of interest to individual developers seeking consents for a specific technology. More generic studies funded by government or industry consortia may be performed to understand environmental issues surrounding a particular group of technologies, installation methods, or operational parameters. In this case, the actual site may be less important. Finally, fundamental research (funded by Research Councils) may be carried out to understand how and why animals use renewable energy relevant sites. Because there are a large number of research studies currently underway at a wide range of scales, sites, and taxa in Scotland and the wider UK, it is not possible to summarize them all in this short talk. Instead, I will outline examples of the three broad areas of environmental research (site/device specific, technology generic and more basic ecology). These examples have also been chosen because they represent an ongoing project, a recently established group of research studies, and a potential new research program. Some of the perhaps less intuitive lessons that have arisen from some of such projects include : 1. The responses of organisms may not be tied to particular brands of device or energy extraction, whether wind, wave, tidal-stream or even oil platform. For fouling organisms the particulars of the substrate might be the important factor rather than the device’s method of energy extraction. Likewise for fish it may be the device complexity and position in the water column that is key to their interactions. 2. Conversely, particular, seemingly unimportant features of devices may have relevance to marine organisms. For example, the color of a turbine may be extremely important for animals maneuvering around the rotors, a duct or the pile. 3. Test centers used to assess full-scale devices may seem like excellent places to also perform environmental research; however care must be taken as the devices in test centers are typically early generation prototypes and may be swapped out frequently. Furthermore activities by other companies at neighboring berths may invalidate site or device specific experiments. 4. Inter-annual variability does not suit the current pace of marine renewables development and careful consideration of the use of control sites and BACI designs should be made. 5. Cumulative impacts of multiple renewable and other developments offer a massive challenge to determining environmental impact. This difficulty represents a significant area of uncertainty for developers seeking consent and may encourage a development race with companies not wanting to have to consider their development relative to all of the others that preceded them. 6. Finally, while much effort is currently being devoted to gathering sufficient data to permit consent and early stage deployments, the significant investments only come when developers set up arrays capable of producing commercially relevant power. At this point there may be a step change in the degree of monitoring required of any potential environmental interactions. Should intolerable impacts be found, then mitigation will be urgently required or an exit strategy implemented. Close

• 3597. [Article] Forestry

  Posted by permission of Cambridge Scientific Abstracts (CSA). (c) CSA 2009. All rights reserved.

  Citation × Citation Citation Abstract Copy Title: Forestry Author: Avery, Bonnie E. Posted by permission of Cambridge Scientific Abstracts (CSA). (c) CSA 2009. All rights reserved. Title: Forestry Author: Avery, Bonnie E. Posted by permission of Cambridge Scientific Abstracts (CSA). (c) CSA 2009. All rights reserved. Close

• 3598. [Article] Forestry

  Posted by permission of Cambridge Scientific Abstracts (CSA). (c) CSA 2011. All rights reserved.

  Citation × Citation Citation Abstract Copy Title: Forestry Author: Avery, Bonnie E. Posted by permission of Cambridge Scientific Abstracts (CSA). (c) CSA 2011. All rights reserved. Title: Forestry Author: Avery, Bonnie E. Posted by permission of Cambridge Scientific Abstracts (CSA). (c) CSA 2011. All rights reserved. Close

• 3599. [Article] Plant selection, irrigation requirements and stormwater management of Pacific Northwest extensive green roofs

  An alternative to traditional roofing, extensive green roofs are contained ecosystems consisting of a drainage layer, a thin media profile which is planted with hardy plant species. Extensive green roof ...

  Citation × Citation Citation Abstract Copy Title: Plant selection, irrigation requirements and stormwater management of Pacific Northwest extensive green roofs Author: Shroll, Erin An alternative to traditional roofing, extensive green roofs are contained ecosystems consisting of a drainage layer, a thin media profile which is planted with hardy plant species. Extensive green roof plants must maintain multiple functions while growing in a highly aggregate media at a depth of equal to or less than 15.25 cm. The shallow media depth weighs less and can often be used when retrofitting an existing building with a green roof. Maximizing functions such as stormwater mitigation requires designing for the purpose of the green roof goal and for the maintenance plan that will ensure plant health in extreme environments. However, our understanding of these complex and dynamic ecosystems on rooftops is still very limited and management of green roofs is often an afterthought, rarely taking into account regional differences in climate. The establishment period of an extensive green roof is a critical time to promote plant coverage, which often requires irrigation during dry periods. The Pacific Northwest (PNW) climate is challenging for green roof management because plants experience cool wet conditions for much of the year yet must survive warm, nearly rainless summers. However, extensive green roof maintenance is generally minimal unless aesthetics are the primary goal. Maintenance in the second year and the years following includes irrigation during dry periods to keep plants healthy or to enhance green roof function. The removal of competitive weeds and tree seedlings is also recommended throughout the life of the green roof. Extensive green roofs are increasingly being used to help improve stormwater management. The vegetative portion of an extensive green roof design is often steered by the structural load that a building can hold along with availability of local products and materials such as media and plants. A lightweight, high aggregate media planted with Sedum species and other succulents is often selected as these components have been successful and work well together. However, with the drive to increase the functional role of extensive green roofs, media and plant selection must be further investigated to fully understand how we can optimize green roof efficiency—in our case, stormwater management efficiency, the most requested function of commercial green roofs. In this study green roof plants were provided adequate irrigation in the first summer and throughout establishment. At the start of the second summer, we tested how the eight taxa performed under three different management regimes in the PNW: (i) non-irrigated, ii) irrigated in compliance with Portland, Oregon's floor area ratio (FAR) bonus requirement and iii) according to out horticultural decision resulting in the highest watering regime. We also measured weed pressure across the irrigation treatments. We selected plant taxa based on their potential functional attributes (habitat quality, aesthetic quality, stormwater management proficiency) as well as their availability through the regional nursery trade. Plants selected were Camassia quamash, Cistus creticus ssp creticus 'Lasithi', Delosperma cooperi, Eriophyllum lanatum var lanatum, Festuca idahoensis var roemeri, Iris chrysophylla, Sedum spathulifolium 'Cape Blanco' and Sisyrinchium idahoense. Within selected seasons the mean relative growth rate (MRGR) of each plant was analyzed and survivorship was recorded throughout this study. Throughout the first year of establishment, all plants grew and survival was high. Exceptions were that I. chrysophylla declined in mean relative growth rate (MRGR) and D. cooperi had a twenty five percent loss in survival during a cold winter spell. Plant growth and overall plant performance varied considerably among taxa throughout establishment and across the summer irrigation treatments. Weed pressure also varied across treatments. The highest watering regime provided the greatest plant survivorship and plants generally had a positive increase in MRGR. Exceptions were F. idahoensis var roemeri, which decreased in MRGR and S. spathulifolium 'Cape Blanco' which did not change in size. The irrigation regime compliant with the City of Portland provided increased plant survivorship over the non-irrigated regime, yet plant aesthetics were less for the same species compared to the highest watering regime. Plant survivorship in the non-irrigated regime included succulents, D. cooperi and S. spathulifolium 'Cape Blanco', and the summer-dormant bulb, C. quamash. Plant aesthetics within each irrigation regime varied considerably and mean aesthetic ratings declined as the summer season progressed. These results suggest that tailoring green roof management more precisely to plant choices and the regional environment will improve function and reduce overall costs. Maintenance costs are less (water costs and weeding labor) with a non-irrigated green roof however, plant aesthetics are compromised when plants experience three to five days without water. Overall the collected runoff from rainfall throughout this study, planted green roofs retained 45% of roof runoff verses 40.5 % retained by media only roofs (p< 0.001). Of the significantly different comparisons (α = 0.05), the vegetated plots had a higher mean retention of runoff over media only roofs nine times out of ten. Green roof runoff retention varied considerably throughout the collection period depending on season, rainfall amounts and saturation of media. Climatic variations and increased plant growth may explain these varying results of stormwater runoff retention of the green roofs. Results from this study suggest that we need to explicitly design green roofs to maximize the ecological goal, which in the case of this research is to mimic nature and allow for rainwater infiltration, retaining a percentage of runoff and detaining the rest so that it enters into stormwater systems at a manageable speed after the peak of the storm. The vegetative layer plays an important role in mitigating stormwater runoff; proper design influenced by regional climate, rooftop microclimates and plant needs as well as the subsequent maintenance regimes will optimize the intended green roof function while providing a suite of additional benefits. Title: Plant selection, irrigation requirements and stormwater management of Pacific Northwest extensive green roofs Author: Shroll, Erin An alternative to traditional roofing, extensive green roofs are contained ecosystems consisting of a drainage layer, a thin media profile which is planted with hardy plant species. Extensive green roof plants must maintain multiple functions while growing in a highly aggregate media at a depth of equal to or less than 15.25 cm. The shallow media depth weighs less and can often be used when retrofitting an existing building with a green roof. Maximizing functions such as stormwater mitigation requires designing for the purpose of the green roof goal and for the maintenance plan that will ensure plant health in extreme environments. However, our understanding of these complex and dynamic ecosystems on rooftops is still very limited and management of green roofs is often an afterthought, rarely taking into account regional differences in climate. The establishment period of an extensive green roof is a critical time to promote plant coverage, which often requires irrigation during dry periods. The Pacific Northwest (PNW) climate is challenging for green roof management because plants experience cool wet conditions for much of the year yet must survive warm, nearly rainless summers. However, extensive green roof maintenance is generally minimal unless aesthetics are the primary goal. Maintenance in the second year and the years following includes irrigation during dry periods to keep plants healthy or to enhance green roof function. The removal of competitive weeds and tree seedlings is also recommended throughout the life of the green roof. Extensive green roofs are increasingly being used to help improve stormwater management. The vegetative portion of an extensive green roof design is often steered by the structural load that a building can hold along with availability of local products and materials such as media and plants. A lightweight, high aggregate media planted with Sedum species and other succulents is often selected as these components have been successful and work well together. However, with the drive to increase the functional role of extensive green roofs, media and plant selection must be further investigated to fully understand how we can optimize green roof efficiency—in our case, stormwater management efficiency, the most requested function of commercial green roofs. In this study green roof plants were provided adequate irrigation in the first summer and throughout establishment. At the start of the second summer, we tested how the eight taxa performed under three different management regimes in the PNW: (i) non-irrigated, ii) irrigated in compliance with Portland, Oregon's floor area ratio (FAR) bonus requirement and iii) according to out horticultural decision resulting in the highest watering regime. We also measured weed pressure across the irrigation treatments. We selected plant taxa based on their potential functional attributes (habitat quality, aesthetic quality, stormwater management proficiency) as well as their availability through the regional nursery trade. Plants selected were Camassia quamash, Cistus creticus ssp creticus 'Lasithi', Delosperma cooperi, Eriophyllum lanatum var lanatum, Festuca idahoensis var roemeri, Iris chrysophylla, Sedum spathulifolium 'Cape Blanco' and Sisyrinchium idahoense. Within selected seasons the mean relative growth rate (MRGR) of each plant was analyzed and survivorship was recorded throughout this study. Throughout the first year of establishment, all plants grew and survival was high. Exceptions were that I. chrysophylla declined in mean relative growth rate (MRGR) and D. cooperi had a twenty five percent loss in survival during a cold winter spell. Plant growth and overall plant performance varied considerably among taxa throughout establishment and across the summer irrigation treatments. Weed pressure also varied across treatments. The highest watering regime provided the greatest plant survivorship and plants generally had a positive increase in MRGR. Exceptions were F. idahoensis var roemeri, which decreased in MRGR and S. spathulifolium 'Cape Blanco' which did not change in size. The irrigation regime compliant with the City of Portland provided increased plant survivorship over the non-irrigated regime, yet plant aesthetics were less for the same species compared to the highest watering regime. Plant survivorship in the non-irrigated regime included succulents, D. cooperi and S. spathulifolium 'Cape Blanco', and the summer-dormant bulb, C. quamash. Plant aesthetics within each irrigation regime varied considerably and mean aesthetic ratings declined as the summer season progressed. These results suggest that tailoring green roof management more precisely to plant choices and the regional environment will improve function and reduce overall costs. Maintenance costs are less (water costs and weeding labor) with a non-irrigated green roof however, plant aesthetics are compromised when plants experience three to five days without water. Overall the collected runoff from rainfall throughout this study, planted green roofs retained 45% of roof runoff verses 40.5 % retained by media only roofs (p< 0.001). Of the significantly different comparisons (α = 0.05), the vegetated plots had a higher mean retention of runoff over media only roofs nine times out of ten. Green roof runoff retention varied considerably throughout the collection period depending on season, rainfall amounts and saturation of media. Climatic variations and increased plant growth may explain these varying results of stormwater runoff retention of the green roofs. Results from this study suggest that we need to explicitly design green roofs to maximize the ecological goal, which in the case of this research is to mimic nature and allow for rainwater infiltration, retaining a percentage of runoff and detaining the rest so that it enters into stormwater systems at a manageable speed after the peak of the storm. The vegetative layer plays an important role in mitigating stormwater runoff; proper design influenced by regional climate, rooftop microclimates and plant needs as well as the subsequent maintenance regimes will optimize the intended green roof function while providing a suite of additional benefits. Close

• 3600. [Article] Pacific lamprey research and restoration project : annual report 1998

  This document is the 1998 annual progress report for studies of Pacific lampreys (Lampetra tridentata) conducted by the Confederated Tribes of the Umatilla Indian Reservation (CTUIR), Columbia River Inter-Tribal ...

  Citation × Citation Citation Abstract Copy Title: Pacific lamprey research and restoration project : annual report 1998 Author: Close, David A. This document is the 1998 annual progress report for studies of Pacific lampreys (Lampetra tridentata) conducted by the Confederated Tribes of the Umatilla Indian Reservation (CTUIR), Columbia River Inter-Tribal Fish Commission, and University of Minnesota (U of M). Bonneville Power Administration (BPA) funded activities through Project 94-026. The Pacific Lamprey Research and Restoration Project began after completion of a status report of Pacific lamprey in the Columbia River in 1995. The project started as a cooperative effort between the Confederated Tribes of the Umatilla Indian Reservation (CTUIR), Columbia River Inter-Tribal Fish Commission (CRITFC), and Oregon State University (OSU). Lamprey are a valuable subsistence food and cultural resource for Native Americans of the Pacific Northwest. The once abundant Pacific lampreys above Bonneville Dam are currently depressed (Close et al. 1995). Declines in Pacific lampreys have impacted treaty secured fishing opportunities by limiting tribal members catch and access to Pacific lampreys in the interior Columbia basin. Tribal members now harvest lampreys in lower Columbia River locations such as Willamette Falls near Oregon City, Oregon. Pacific lampreys are also an important part of the food web of North Pacific ecosystems, both as predator (Beamish 1980; Pike 1951; Roos and Gillohousin 1973), and prey (Semekula and Larkin 1968; Galbreath 1979; Roffe and Mate 1984; Merrell 1959; Wolf and Jones 1989) and as a vehicle for recruitment of marine nutrients. The decline of Pacific lampreys in the interior Columbia River basin has become a major concern. Effective recovery measures for Pacific lampreys can only be developed after we increase our knowledge of the biology and factors that are limiting the various life history stages. Prior to developing a restoration plan, we have carried out studies to review status, distribution, abundance, homing ability, and stock structure. These studies will culminate in the development and implementation of a restoration plan for the Umatilla River. Multiple pass electrofishing surveys to assess densities and distribution of lamprey larvae in the Umatilla River were conducted in 1998. Electrofishing surveys in the Umatilla River are useful for baseline comparison. Forty-two index sites were sampled from the mouth to river kilometer (RK) 124. Lamprey larvae were found in 4 of the 42 index plots. All sites with larvae were found at and below RK 9.3. Nine larvae were captured during the surveys. However, no larvae were caught on the second pass in each plot. Pacific lamprey larvae and adult lampreys were studied to determine their ability to produce and detect pheromones. Larval gall bladders were removed and gall bladder fluid was extracted and analyzed by high performance liquid chromatography (HPLC). Adult lampreys ability to detect pheromones were tested using electro-olfactogram (EOG) methods. Fifteen compounds including Petromyzonol sulfate (PS), a migratory pheromone found in sea lamprey larvae (Petromyzon marinus) (Li et al. 1995) were tested. Larval lampreys produced large amounts of (PS). Adult Pacific lamprey can detect PS and have an olfactory sensitivity to pheromones that is similar to sea lampreys. iv Pacific lamprey abundance, as indexed by fish ladder counts in 1998, was; Bonneville 37,478; The Dalles 7,665; John Day 12,579; McNary 3,393; Ice Harbor 763; Lower Monumental 69; Little Goose 90; Lower Granite 110; Rock Island 1,410; and Rock Reach 819 dams, respectively. Enumerating Pacific lamprey at counting stations remained extremely problematic, since excessive up- and downstream movement at the counting windows reduces the confidence in fish ladder passage estimates. This may be an indication of passage problems encountered by Pacific lampreys. In-season homing of Pacific lamprey was studied using radio telemetry. Pacific lampery were captured at Willamette Falls and Bonneville Dam, outfitted with radio transmitters and released approximately 26 km downstream of the Willamette River confluence. A total of 50 fish were instrumented. Results will be presented in next year’s report. Natal homing was also investigated using mtDNA analysis of fish captured at Bonneville Dam and from Willamette Falls. These results will also be presented next year. We collected lamprey tissues, from fish captured in several locations throughout the Columbia River Basin, to develop a genetic database for use in determining population structure. Additional samples for populations outside the Columbia River Basin were used to scale the results. Results from this investigation will be presented in next year’s annual report. Since the initiation of the CTUIR lamprey research and restoration project, additional lamprey studies have been proposed that have created uncertainties regarding the prioritization of projects and needs of lampreys. At the request of the Northwest Power Planning Council, a multi-agency Pacific lamprey technical workgroup (TWG) was established in 1996. Annual meetings are held to coordinate projects and prioritize research needs. The TWG identified critical uncertainties and needs to help in determining priorities of ongoing and proposed projects (Appendix A). Finally, an annotated bibliography of relevant lamprey literature was compiled (Appendix B). Title: Pacific lamprey research and restoration project : annual report 1998 Author: Close, David A. This document is the 1998 annual progress report for studies of Pacific lampreys (Lampetra tridentata) conducted by the Confederated Tribes of the Umatilla Indian Reservation (CTUIR), Columbia River Inter-Tribal Fish Commission, and University of Minnesota (U of M). Bonneville Power Administration (BPA) funded activities through Project 94-026. The Pacific Lamprey Research and Restoration Project began after completion of a status report of Pacific lamprey in the Columbia River in 1995. The project started as a cooperative effort between the Confederated Tribes of the Umatilla Indian Reservation (CTUIR), Columbia River Inter-Tribal Fish Commission (CRITFC), and Oregon State University (OSU). Lamprey are a valuable subsistence food and cultural resource for Native Americans of the Pacific Northwest. The once abundant Pacific lampreys above Bonneville Dam are currently depressed (Close et al. 1995). Declines in Pacific lampreys have impacted treaty secured fishing opportunities by limiting tribal members catch and access to Pacific lampreys in the interior Columbia basin. Tribal members now harvest lampreys in lower Columbia River locations such as Willamette Falls near Oregon City, Oregon. Pacific lampreys are also an important part of the food web of North Pacific ecosystems, both as predator (Beamish 1980; Pike 1951; Roos and Gillohousin 1973), and prey (Semekula and Larkin 1968; Galbreath 1979; Roffe and Mate 1984; Merrell 1959; Wolf and Jones 1989) and as a vehicle for recruitment of marine nutrients. The decline of Pacific lampreys in the interior Columbia River basin has become a major concern. Effective recovery measures for Pacific lampreys can only be developed after we increase our knowledge of the biology and factors that are limiting the various life history stages. Prior to developing a restoration plan, we have carried out studies to review status, distribution, abundance, homing ability, and stock structure. These studies will culminate in the development and implementation of a restoration plan for the Umatilla River. Multiple pass electrofishing surveys to assess densities and distribution of lamprey larvae in the Umatilla River were conducted in 1998. Electrofishing surveys in the Umatilla River are useful for baseline comparison. Forty-two index sites were sampled from the mouth to river kilometer (RK) 124. Lamprey larvae were found in 4 of the 42 index plots. All sites with larvae were found at and below RK 9.3. Nine larvae were captured during the surveys. However, no larvae were caught on the second pass in each plot. Pacific lamprey larvae and adult lampreys were studied to determine their ability to produce and detect pheromones. Larval gall bladders were removed and gall bladder fluid was extracted and analyzed by high performance liquid chromatography (HPLC). Adult lampreys ability to detect pheromones were tested using electro-olfactogram (EOG) methods. Fifteen compounds including Petromyzonol sulfate (PS), a migratory pheromone found in sea lamprey larvae (Petromyzon marinus) (Li et al. 1995) were tested. Larval lampreys produced large amounts of (PS). Adult Pacific lamprey can detect PS and have an olfactory sensitivity to pheromones that is similar to sea lampreys. iv Pacific lamprey abundance, as indexed by fish ladder counts in 1998, was; Bonneville 37,478; The Dalles 7,665; John Day 12,579; McNary 3,393; Ice Harbor 763; Lower Monumental 69; Little Goose 90; Lower Granite 110; Rock Island 1,410; and Rock Reach 819 dams, respectively. Enumerating Pacific lamprey at counting stations remained extremely problematic, since excessive up- and downstream movement at the counting windows reduces the confidence in fish ladder passage estimates. This may be an indication of passage problems encountered by Pacific lampreys. In-season homing of Pacific lamprey was studied using radio telemetry. Pacific lampery were captured at Willamette Falls and Bonneville Dam, outfitted with radio transmitters and released approximately 26 km downstream of the Willamette River confluence. A total of 50 fish were instrumented. Results will be presented in next year’s report. Natal homing was also investigated using mtDNA analysis of fish captured at Bonneville Dam and from Willamette Falls. These results will also be presented next year. We collected lamprey tissues, from fish captured in several locations throughout the Columbia River Basin, to develop a genetic database for use in determining population structure. Additional samples for populations outside the Columbia River Basin were used to scale the results. Results from this investigation will be presented in next year’s annual report. Since the initiation of the CTUIR lamprey research and restoration project, additional lamprey studies have been proposed that have created uncertainties regarding the prioritization of projects and needs of lampreys. At the request of the Northwest Power Planning Council, a multi-agency Pacific lamprey technical workgroup (TWG) was established in 1996. Annual meetings are held to coordinate projects and prioritize research needs. The TWG identified critical uncertainties and needs to help in determining priorities of ongoing and proposed projects (Appendix A). Finally, an annotated bibliography of relevant lamprey literature was compiled (Appendix B). Close