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• 8451. [Article] Status of Winter Rearing Habitat In Four Coho Population Units, 2007 Report Number: OPSW-ODFW-2008-7

  Abstract -- In a recent assessment of coastal coho salmon by the Oregon Department of Fish and Wildlife (2005), the authors concluded that productivity in 21 of 21 coastal coho populations was limited ...

  Citation × Citation Citation Abstract Copy Title: Status of Winter Rearing Habitat In Four Coho Population Units, 2007 Report Number: OPSW-ODFW-2008-7 Abstract -- In a recent assessment of coastal coho salmon by the Oregon Department of Fish and Wildlife (2005), the authors concluded that productivity in 21 of 21 coastal coho populations was limited primarily (13) or secondarily (8) by the complexity of stream habitat used by juvenile coho during their first winter of freshwater residence. The Oregon Coast Coho Conservation Plan (Nicholas 2006), written in response to the assessment, concluded that recovery of coho populations will depend largely on improvement of freshwater habitat. The Conservation Plan (Nicholas 2006) presents population specific goals for the amount and quality of winter habitat needed to achieve desired status of coho populations. Monitoring objectives in the Plan are 1) describe the status of freshwater habitat in each population unit with a focus on features important to overwinter survival of juvenile coho, 2) estimate carrying capacity in each population unit with + 30% confidence, and 3) measure progress towards meeting the habitat goals of the Conservation Plan. This report describes the first two monitoring objectives for winter habitat in four population units: the Coquille, South Umpqua, Siuslaw, and Nehalem. Winter habitat surveys are conducted to describe the freshwater habitat conditions that may limit the survival of juvenile coho during the season at which the conditions are limiting. The Habitat Limiting Factors Model (Nickelson et al. 1992a, Nickelson et al. 1992b, Nickelson 1998) estimates the capacity of streams to support juvenile salmon based on quantitative descriptions of summer and winter habitat. The model assigns value to the size, type and complexity of habitat units, giving highest value to slow water pools such as alcoves and beaver ponds, and pools with large wood. Because winter habitat limits the capacity of most coastal streams to support juvenile coho (Rodgers et al. 2005), accurate estimates of winter habitat are essential to life cycle modeling and to meet objectives of the Conservation Plan. Rodgers et al. (2005) estimated potential carrying capacity of stream habitat within each coastal coho population unit, but statistical confidence was limited by the source and manipulation of the data. Although the data set was extensive, most of the reaches were not randomly selected, and a regression model was used to extrapolate conditions from summer to winter (Rodgers et al. 2005). Summer surveys provide applicable information, but at low flow conditions. Summer weather and stream flows are predictable and conducive to field work; study sites are more accessible, work days are longer and warmer, lower water levels enable walking in the channel more easily, and water clarity is high. However, while more difficult logistically, winter surveys provide estimates during high flow conditions thought to be most important to juvenile coho survival. The winter surveys are conducted during “base flow” when off-channel habitats and secondary channels are inundated, but not over floodplain. The winter 2007 survey sites were selected using the Generalized Random Tessellation Stratified (GRTS) sample design (Stevens 2002) from a pool of sites previously surveyed during summer. This provided an opportunity to describe status within coho population units and refine the summer to winter conversion regression model. More sites are visited during summer than winter, and the sample pool will expand if we can use summer surveys to predict winter conditions. A thorough description of seasonal habitat variation will determine the appropriateness of using summer habitat data to assess habitat conditions during the winter. The objectives of this report are to provide the status of winter habitat surveyed in 2007 in four Oregon coastal coho salmon (Oncorhynchus kisutch) population units (Nehalem, Siuslaw, Coquille, South Umpqua), estimate the potential winter capacity of streams within those population units, and describe the differences observed in stream habitat between winter and summer with emphasis on slow water and secondary channel habitats. We also performed a sensitivity analysis to determine the number of survey sites necessary to represent each population unit within the desired confidence recommended in the Conservation Plan (Nicholas 2006). Title: Status of Winter Rearing Habitat In Four Coho Population Units, 2007 Report Number: OPSW-ODFW-2008-7 Abstract -- In a recent assessment of coastal coho salmon by the Oregon Department of Fish and Wildlife (2005), the authors concluded that productivity in 21 of 21 coastal coho populations was limited primarily (13) or secondarily (8) by the complexity of stream habitat used by juvenile coho during their first winter of freshwater residence. The Oregon Coast Coho Conservation Plan (Nicholas 2006), written in response to the assessment, concluded that recovery of coho populations will depend largely on improvement of freshwater habitat. The Conservation Plan (Nicholas 2006) presents population specific goals for the amount and quality of winter habitat needed to achieve desired status of coho populations. Monitoring objectives in the Plan are 1) describe the status of freshwater habitat in each population unit with a focus on features important to overwinter survival of juvenile coho, 2) estimate carrying capacity in each population unit with + 30% confidence, and 3) measure progress towards meeting the habitat goals of the Conservation Plan. This report describes the first two monitoring objectives for winter habitat in four population units: the Coquille, South Umpqua, Siuslaw, and Nehalem. Winter habitat surveys are conducted to describe the freshwater habitat conditions that may limit the survival of juvenile coho during the season at which the conditions are limiting. The Habitat Limiting Factors Model (Nickelson et al. 1992a, Nickelson et al. 1992b, Nickelson 1998) estimates the capacity of streams to support juvenile salmon based on quantitative descriptions of summer and winter habitat. The model assigns value to the size, type and complexity of habitat units, giving highest value to slow water pools such as alcoves and beaver ponds, and pools with large wood. Because winter habitat limits the capacity of most coastal streams to support juvenile coho (Rodgers et al. 2005), accurate estimates of winter habitat are essential to life cycle modeling and to meet objectives of the Conservation Plan. Rodgers et al. (2005) estimated potential carrying capacity of stream habitat within each coastal coho population unit, but statistical confidence was limited by the source and manipulation of the data. Although the data set was extensive, most of the reaches were not randomly selected, and a regression model was used to extrapolate conditions from summer to winter (Rodgers et al. 2005). Summer surveys provide applicable information, but at low flow conditions. Summer weather and stream flows are predictable and conducive to field work; study sites are more accessible, work days are longer and warmer, lower water levels enable walking in the channel more easily, and water clarity is high. However, while more difficult logistically, winter surveys provide estimates during high flow conditions thought to be most important to juvenile coho survival. The winter surveys are conducted during “base flow” when off-channel habitats and secondary channels are inundated, but not over floodplain. The winter 2007 survey sites were selected using the Generalized Random Tessellation Stratified (GRTS) sample design (Stevens 2002) from a pool of sites previously surveyed during summer. This provided an opportunity to describe status within coho population units and refine the summer to winter conversion regression model. More sites are visited during summer than winter, and the sample pool will expand if we can use summer surveys to predict winter conditions. A thorough description of seasonal habitat variation will determine the appropriateness of using summer habitat data to assess habitat conditions during the winter. The objectives of this report are to provide the status of winter habitat surveyed in 2007 in four Oregon coastal coho salmon (Oncorhynchus kisutch) population units (Nehalem, Siuslaw, Coquille, South Umpqua), estimate the potential winter capacity of streams within those population units, and describe the differences observed in stream habitat between winter and summer with emphasis on slow water and secondary channel habitats. We also performed a sensitivity analysis to determine the number of survey sites necessary to represent each population unit within the desired confidence recommended in the Conservation Plan (Nicholas 2006). Close

• 8452. [Article] Recovery of Wild Coho Salmon in Salmon River Basin, 2008 Report Number: OPSW-ODFW-2009-10

  Abstract -- Recovery and conservation of naturally self-sustaining salmon populations is a central goal of the Oregon Plan for Salmon and Watersheds. In 1998, the Oregon Department of Fish and Wildlife ...

  Citation × Citation Citation Abstract Copy Title: Recovery of Wild Coho Salmon in Salmon River Basin, 2008 Report Number: OPSW-ODFW-2009-10 Abstract -- Recovery and conservation of naturally self-sustaining salmon populations is a central goal of the Oregon Plan for Salmon and Watersheds. In 1998, the Oregon Department of Fish and Wildlife (ODFW) initiated a comprehensive program to monitor the status of coho salmon (Oncorhynchus kisutch) populations and aquatic habitat in coastal drainages of Oregon (OWEB 2003). A 2005 assessment by ODFW concluded that Oregon coastal coho were viable at the scale of the Evolutionary Significant Unit (ESU) and demonstrated resilience in response to improving ocean conditions. Yet 7 of 21 (33%) individual populations within the ESU failed one or more of five criteria used to assess viability (Chilcote et al. 2005), and it is uncertain whether productivity levels across the ESU will recover sufficiently to withstand future periods of poor ocean conditions. The coho population in Salmon River was the only population in the ESU to fail all five viability criteria. Uncertainty remains about the response of Oregon coastal coho salmon to different combinations of freshwater and marine limiting factors, complicating recovery efforts (Lawson 1993; Lawson et al. 2004; IMST 2006). Such uncertainty cannot be resolved entirely by existing Oregon Plan monitoring programs, which target only a portion of the habitats and coho salmon life stages in large river basins, and with few exceptions (e.g., Johnson et al. 2005), were not designed to test population responses to individual management manipulations. In 2007, in response to the failure of viability criteria, ODFW managers discontinued releases of hatchery coho salmon into Salmon River as one of the primary management actions under the Oregon Conservation Plan for the Oregon Coast Coho Evolutionarily Significant Unit (hereafter “coho plan,” Nicholas 2006). This change affords the first opportunity in Oregon to monitor the results of a large scale experiment in removing hatchery coho salmon from a basin for at least four generations (twelve years). Hatchery production has been a centerpiece of salmon management for decades, but rarely has full recovery from hatchery influence been given a chance to succeed. Salmon River offers a test basin to explore whether an independent population of coho salmon can recover from a prolonged period of very low abundance following removal of the primary factor limiting productivity. Here we describe the first year of a study to monitor the dynamics of the coho salmon population in the Salmon River basin on the central Oregon coast and to determine whether management changes targeting both hatchery influence and stream habitat complexity improve population viability. This research will validate assumptions about factors limiting coho recovery and determine whether recovery measures proposed by the Coho Plan have been effective. Our research is designed to document changes in population abundance, distribution, and life history structure of coho salmon following the removal of hatchery coho salmon from the watershed. It integrates adult, juvenile, and habitat components to establish links and describe variability between juvenile performance and adult recovery. It also monitors the coho salmon population across habitat types and life history stages to identify population responses at a landscape scale. We will establish the link between productivity and survival at each salmon life stage and recovery of the adult population. From these indicators, we will determine the potential resiliency of coho salmon, detail the biological benefits/tradeoffs of returning the ecosystem to natural salmon production, and assess whether supplementation should remain an option in Salmon River. As a conceptual framework, our research design and analyses are guided by the “viable salmonid population” criteria identified by McElhany (2000) and modified by Chilcote et al. (2005) and Nicholas (2006), including abundance, productivity, distribution, diversity, and habitat quality. The results of our new research will be integrated with habitat survey and adult population data collected under the existing Oregon Plan monitoring program and coho salmon population and life history data available from previous Salmon River surveys (Mullen 1978, 1979; Cornwell et al. 2001; Bottom et al 2005; Volk et al. in review). Together these data will address four principal objectives: 1. Quantify viability of the coho salmon population before and after hatchery coho salmon are removed from Salmon River. 2. Assess whether viability of the Salmon River coho population is limited by quantity and complexity of stream habitat. 3. Describe the diversity of juvenile and adult life histories of coho salmon in the Salmon River basin and estimate the relative contributions of alternate juvenile life history to adult returns. 4. Determine salmonid use and benefits of restored tidal wetlands before and after hatchery coho salmon are removed from Salmon River. By synthesizing historic data with new information for the Salmon River basin, we will compare population structure during three distinct periods – pre-hatchery (1974-77), hatchery (1990-2008), and post-hatchery (2009-2013). This annual report discusses the activities and findings from 2008, the first year of the multi-year project, including coho salmon distribution and abundance on the Salmon River spawning grounds, juvenile abundance and distribution in the watershed and estuary, migration timing, and life history diversity. Title: Recovery of Wild Coho Salmon in Salmon River Basin, 2008 Report Number: OPSW-ODFW-2009-10 Abstract -- Recovery and conservation of naturally self-sustaining salmon populations is a central goal of the Oregon Plan for Salmon and Watersheds. In 1998, the Oregon Department of Fish and Wildlife (ODFW) initiated a comprehensive program to monitor the status of coho salmon (Oncorhynchus kisutch) populations and aquatic habitat in coastal drainages of Oregon (OWEB 2003). A 2005 assessment by ODFW concluded that Oregon coastal coho were viable at the scale of the Evolutionary Significant Unit (ESU) and demonstrated resilience in response to improving ocean conditions. Yet 7 of 21 (33%) individual populations within the ESU failed one or more of five criteria used to assess viability (Chilcote et al. 2005), and it is uncertain whether productivity levels across the ESU will recover sufficiently to withstand future periods of poor ocean conditions. The coho population in Salmon River was the only population in the ESU to fail all five viability criteria. Uncertainty remains about the response of Oregon coastal coho salmon to different combinations of freshwater and marine limiting factors, complicating recovery efforts (Lawson 1993; Lawson et al. 2004; IMST 2006). Such uncertainty cannot be resolved entirely by existing Oregon Plan monitoring programs, which target only a portion of the habitats and coho salmon life stages in large river basins, and with few exceptions (e.g., Johnson et al. 2005), were not designed to test population responses to individual management manipulations. In 2007, in response to the failure of viability criteria, ODFW managers discontinued releases of hatchery coho salmon into Salmon River as one of the primary management actions under the Oregon Conservation Plan for the Oregon Coast Coho Evolutionarily Significant Unit (hereafter “coho plan,” Nicholas 2006). This change affords the first opportunity in Oregon to monitor the results of a large scale experiment in removing hatchery coho salmon from a basin for at least four generations (twelve years). Hatchery production has been a centerpiece of salmon management for decades, but rarely has full recovery from hatchery influence been given a chance to succeed. Salmon River offers a test basin to explore whether an independent population of coho salmon can recover from a prolonged period of very low abundance following removal of the primary factor limiting productivity. Here we describe the first year of a study to monitor the dynamics of the coho salmon population in the Salmon River basin on the central Oregon coast and to determine whether management changes targeting both hatchery influence and stream habitat complexity improve population viability. This research will validate assumptions about factors limiting coho recovery and determine whether recovery measures proposed by the Coho Plan have been effective. Our research is designed to document changes in population abundance, distribution, and life history structure of coho salmon following the removal of hatchery coho salmon from the watershed. It integrates adult, juvenile, and habitat components to establish links and describe variability between juvenile performance and adult recovery. It also monitors the coho salmon population across habitat types and life history stages to identify population responses at a landscape scale. We will establish the link between productivity and survival at each salmon life stage and recovery of the adult population. From these indicators, we will determine the potential resiliency of coho salmon, detail the biological benefits/tradeoffs of returning the ecosystem to natural salmon production, and assess whether supplementation should remain an option in Salmon River. As a conceptual framework, our research design and analyses are guided by the “viable salmonid population” criteria identified by McElhany (2000) and modified by Chilcote et al. (2005) and Nicholas (2006), including abundance, productivity, distribution, diversity, and habitat quality. The results of our new research will be integrated with habitat survey and adult population data collected under the existing Oregon Plan monitoring program and coho salmon population and life history data available from previous Salmon River surveys (Mullen 1978, 1979; Cornwell et al. 2001; Bottom et al 2005; Volk et al. in review). Together these data will address four principal objectives: 1. Quantify viability of the coho salmon population before and after hatchery coho salmon are removed from Salmon River. 2. Assess whether viability of the Salmon River coho population is limited by quantity and complexity of stream habitat. 3. Describe the diversity of juvenile and adult life histories of coho salmon in the Salmon River basin and estimate the relative contributions of alternate juvenile life history to adult returns. 4. Determine salmonid use and benefits of restored tidal wetlands before and after hatchery coho salmon are removed from Salmon River. By synthesizing historic data with new information for the Salmon River basin, we will compare population structure during three distinct periods – pre-hatchery (1974-77), hatchery (1990-2008), and post-hatchery (2009-2013). This annual report discusses the activities and findings from 2008, the first year of the multi-year project, including coho salmon distribution and abundance on the Salmon River spawning grounds, juvenile abundance and distribution in the watershed and estuary, migration timing, and life history diversity. Close

• 8453. [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

• 8454. [Article] Water and Soil Management Practices to Enhance Plant Growth, Berry Development, and Fruit Quality of Northern Highbush Blueberry (Vaccinium corymbosum L.)

  Drought and mandatory water restrictions are limiting the availability of irrigation water in many important blueberry growing regions and new strategies are needed to maintain yield and fruit quality ...

  Citation × Citation Citation Abstract Copy Title: Water and Soil Management Practices to Enhance Plant Growth, Berry Development, and Fruit Quality of Northern Highbush Blueberry (Vaccinium corymbosum L.) Author: Almutairi, Khalid F. Drought and mandatory water restrictions are limiting the availability of irrigation water in many important blueberry growing regions and new strategies are needed to maintain yield and fruit quality with less water. Three potential options for reducing water use, including deficit irrigation, irrigation cut-offs, and crop thinning, were evaluated for 2 years in a mature planting of northern highbush blueberry (Vaccinium corymbosum L. ‘Elliott’). Treatments consisted of no thinning and 50% crop removal in combination with either full irrigation at 100% of estimated crop evapotranspiration (ETsubscript c]), deficit irrigation at 50% ET[subscript c] (applied for the entire growing season), or full irrigation with irrigation cut-off for 4–6 weeks during early or late stages of fruit development. Stem water potential was similar with full and deficit irrigation but, regardless of crop thinning, declined by 0.5–0.6 MPa when irrigation was cut-off early and by > 2.0 MPa when irrigation was cut-off late. In one or both years, the fruiting season was advanced with either deficit irrigation or late cut-off, whereas cutting off irrigation early delayed the season. Yield was not affected by deficit irrigation in plants with a full crop load but was reduced by an average of 35% when irrigation was cut-off late each year. Cutting off irrigation early likewise reduced yield, but only in the second year when the plants were not thinned; however, early cut-off also reduced fruit soluble solids and berry weight by 7% to 24%compared to full irrigation. Cutting off irrigation late produced the smallest and firmest fruit with the highest soluble solids and total acidity among the treatments, as well as the slowest rate of fruit loss in cold storage. Deficit irrigation had the least effect on fruit quality and, based on these results, appears to be the most viable option for maintaining yield with less water (2.5 ML·ha⁻¹ less water per season). A second study was conducted in a 7-year-old field of certified organic highbush blueberry. Two cultivars (‘Duke’ and ‘Liberty’) mulched with either porous polyethylene ground cover (“weed mat”) or yard debris compost topped with sawdust (sawdust+compost) and each fertilized with either feather meal or fish emulsion were evaluated. One-year-old fruiting laterals were randomly-selected at three heights (top, middle, and bottom) on the east and west side of the plants. Bud, flower, and fruit development were monitored through fruit harvest. There was relatively little effect of mulch type or fertilizer source on the measured variables. Fruit harvest occurred ≈8 d after the fruit were fully blue and ranged from 2-25 July 2012 and 26 June-3 July 2013 in ‘Duke’ and from 1-20 Aug. 2012 and 17 July-7 Aug. 2013 in ‘Liberty’. Proportionally more fruit buds occurred on middle laterals than upper and lower laterals. The dates of bud swell and bud break were not affected by cultivar or lateral position. ‘Duke’ and ‘Liberty’ produced 6-8 and 7-9 flowers/bud, respectively. Fruit set was high in both cultivars, averaging ≈95%. However, 13-18% and 29-38 % of the initial set fruit dropped in ’Duke’ and ‘Liberty’ in late May to early June. Fruit ripening was more uniform within clusters in ‘Duke’ than in ‘Liberty’, and average fruit size was similar among harvests in ‘Duke’ but decreased by 25-40% between the first and last harvest in ‘Liberty’. Fruit matured 3−5 d earlier on the east side of the canopy than on the west side. The results suggest that pruning proportionally more on the lower part of the canopy than on the upper part will result in larger fruit at harvest than uniform pruning throughout the bush. The final study was conducted to determine the potential of applying micronized elemental sulfur (S°) by chemigation through the drip system to reduce high soil pH in a new planting of ‘Duke’ blueberry. The S° was mixed with water and injected weekly for 2 months prior to planting, as well as 2 years after planting, atrates of 0, 50, 100 and 150 kg·ha⁻¹ per year, and was compared to the conventional practice of incorporating prilled S° into the soil prior to planting (two applications of 750 kg·ha⁻¹ each). Chemigation quickly reduced soil pH (0-10 cm) within a month from 6.6 with no S° to 6.1 with 50 kg·ha-1 S° and 5.8 with 100 or 150 kg·ha⁻¹ S°. The change was short-term, however, and by May of the following year, soil pH averaged 6.7, 6.5, 6.2, and 6.1 with each increasing rate of S° chemigation, respectively. The conventional treatment, in comparison, averaged 6.6 on the first date and 6.3 on the second date. In July of the following year, soil pH ranged from an average of 6.4 with no S° to 6.2 with 150 kg·ha⁻¹ S° and 5.5 with prilled S°. Soil pH declined thereafter to as low as 5.9 with additional S° chemigation and at lower depths (10-30 cm) was similar to the conventional treatment. None of the treatments had any effect on winter pruning weight in year 1 or on yield, berry weight, and plant dry weight in year 2. Chemigation with S° can be used to quickly reduce soil pH following planting and, therefore, may be a useful practice to correct high pH problems in established blueberry fields. However, it was less effective and more time consuming than applying prilled S° prior to planting. Title: Water and Soil Management Practices to Enhance Plant Growth, Berry Development, and Fruit Quality of Northern Highbush Blueberry (Vaccinium corymbosum L.) Author: Almutairi, Khalid F. Drought and mandatory water restrictions are limiting the availability of irrigation water in many important blueberry growing regions and new strategies are needed to maintain yield and fruit quality with less water. Three potential options for reducing water use, including deficit irrigation, irrigation cut-offs, and crop thinning, were evaluated for 2 years in a mature planting of northern highbush blueberry (Vaccinium corymbosum L. ‘Elliott’). Treatments consisted of no thinning and 50% crop removal in combination with either full irrigation at 100% of estimated crop evapotranspiration (ETsubscript c]), deficit irrigation at 50% ET[subscript c] (applied for the entire growing season), or full irrigation with irrigation cut-off for 4–6 weeks during early or late stages of fruit development. Stem water potential was similar with full and deficit irrigation but, regardless of crop thinning, declined by 0.5–0.6 MPa when irrigation was cut-off early and by > 2.0 MPa when irrigation was cut-off late. In one or both years, the fruiting season was advanced with either deficit irrigation or late cut-off, whereas cutting off irrigation early delayed the season. Yield was not affected by deficit irrigation in plants with a full crop load but was reduced by an average of 35% when irrigation was cut-off late each year. Cutting off irrigation early likewise reduced yield, but only in the second year when the plants were not thinned; however, early cut-off also reduced fruit soluble solids and berry weight by 7% to 24%compared to full irrigation. Cutting off irrigation late produced the smallest and firmest fruit with the highest soluble solids and total acidity among the treatments, as well as the slowest rate of fruit loss in cold storage. Deficit irrigation had the least effect on fruit quality and, based on these results, appears to be the most viable option for maintaining yield with less water (2.5 ML·ha⁻¹ less water per season). A second study was conducted in a 7-year-old field of certified organic highbush blueberry. Two cultivars (‘Duke’ and ‘Liberty’) mulched with either porous polyethylene ground cover (“weed mat”) or yard debris compost topped with sawdust (sawdust+compost) and each fertilized with either feather meal or fish emulsion were evaluated. One-year-old fruiting laterals were randomly-selected at three heights (top, middle, and bottom) on the east and west side of the plants. Bud, flower, and fruit development were monitored through fruit harvest. There was relatively little effect of mulch type or fertilizer source on the measured variables. Fruit harvest occurred ≈8 d after the fruit were fully blue and ranged from 2-25 July 2012 and 26 June-3 July 2013 in ‘Duke’ and from 1-20 Aug. 2012 and 17 July-7 Aug. 2013 in ‘Liberty’. Proportionally more fruit buds occurred on middle laterals than upper and lower laterals. The dates of bud swell and bud break were not affected by cultivar or lateral position. ‘Duke’ and ‘Liberty’ produced 6-8 and 7-9 flowers/bud, respectively. Fruit set was high in both cultivars, averaging ≈95%. However, 13-18% and 29-38 % of the initial set fruit dropped in ’Duke’ and ‘Liberty’ in late May to early June. Fruit ripening was more uniform within clusters in ‘Duke’ than in ‘Liberty’, and average fruit size was similar among harvests in ‘Duke’ but decreased by 25-40% between the first and last harvest in ‘Liberty’. Fruit matured 3−5 d earlier on the east side of the canopy than on the west side. The results suggest that pruning proportionally more on the lower part of the canopy than on the upper part will result in larger fruit at harvest than uniform pruning throughout the bush. The final study was conducted to determine the potential of applying micronized elemental sulfur (S°) by chemigation through the drip system to reduce high soil pH in a new planting of ‘Duke’ blueberry. The S° was mixed with water and injected weekly for 2 months prior to planting, as well as 2 years after planting, atrates of 0, 50, 100 and 150 kg·ha⁻¹ per year, and was compared to the conventional practice of incorporating prilled S° into the soil prior to planting (two applications of 750 kg·ha⁻¹ each). Chemigation quickly reduced soil pH (0-10 cm) within a month from 6.6 with no S° to 6.1 with 50 kg·ha-1 S° and 5.8 with 100 or 150 kg·ha⁻¹ S°. The change was short-term, however, and by May of the following year, soil pH averaged 6.7, 6.5, 6.2, and 6.1 with each increasing rate of S° chemigation, respectively. The conventional treatment, in comparison, averaged 6.6 on the first date and 6.3 on the second date. In July of the following year, soil pH ranged from an average of 6.4 with no S° to 6.2 with 150 kg·ha⁻¹ S° and 5.5 with prilled S°. Soil pH declined thereafter to as low as 5.9 with additional S° chemigation and at lower depths (10-30 cm) was similar to the conventional treatment. None of the treatments had any effect on winter pruning weight in year 1 or on yield, berry weight, and plant dry weight in year 2. Chemigation with S° can be used to quickly reduce soil pH following planting and, therefore, may be a useful practice to correct high pH problems in established blueberry fields. However, it was less effective and more time consuming than applying prilled S° prior to planting. Close

• 8455. [Article] Effect of dietary fatty acids, time of feeding and immune response in poultry

  In the presence of internal or external stressors, the body requires sources of energy that aide cells to combat inflammation. Fatty acids are an important source of energy and are vital components of ...

  Citation × Citation Citation Abstract Copy Title: Effect of dietary fatty acids, time of feeding and immune response in poultry Author: Gonzalez, Dulmelis In the presence of internal or external stressors, the body requires sources of energy that aide cells to combat inflammation. Fatty acids are an important source of energy and are vital components of cell membranes. Dietary fatty acids (n-6 and n-3) are of importance in immune function because they are precursors to metabolites that are potent mediators of inflammation. Poultry diets are high in n-6 fatty acids, which exert pro-inflammatory effects, and low in n-3 fatty acids, which tend to be less inflammatory. Delayed access to feed after hatching has been reported to impact the development of organs associated with immunity. Based on this information, two experiments were conducted in broiler chickens to determine the effect of dietary polyunsaturated fatty acid (PUFA) and the influence of time of feeding on bird performance, tissue lipid status, immune responses and expression of cyclooxygenase 2 (COX-2) upon challenge. In experiment 1, birds were fed diets that contained 3.5% oxidized yellow grease (low n-3) or 3.5% canola oil (high n-3). Birds were fed early (<5 hrs post-hatch) or late (>24 hrs post-hatch). Intramuscular injection of lipopolysaccharide (LPS) or phosphate buffered saline (control) was used as the immune challenge. Feeding high n-3 diets resulted in an increase in n-3 fatty acids in the liver in all treatment groups upon LPS challenge (P<0.05). LPS injection led to a decrease in total n-6 fatty acids in the liver when compared with control birds (P<0.05) fed early high n-3 and late low n-3. However, in spleen tissue, upon LPS challenge, increase in total n-3 fatty acids was observed only in birds fed early high n-3 and birds fed late high n-3. Plasma non-esterified fatty acids were lowest in high n-3 birds fed early (P<0.05). The spleen tissue total fat content was lowest in early high and late high n-3 birds (P<0.05). Breast muscle thiobarbituric acid reactive substances (TBARS) were higher in birds fed high n-3 compared to birds fed diets low in n-3 (P< 0.05). The delayed type hypersensitivity response was higher in birds fed high n-3 diet when compared to all other treatments (P<0.05). Thigh muscle of LPS challenged birds from early low n-3 and late high n-3 was significantly higher in TBARS when compared to control birds (P<0.05). There was no difference in final body weight, cut-up yield and organ weight of birds (P>0.05) except liver and thigh muscle weight percents were lowest in birds fed low n-3 (P<0.05). In the second experiment, birds were fed diets containing 3.5% sunflower oil (low n-3) or 3.5% fish oil (high n-3). The birds were either fed early (<5 hrs post hatch) or late (>48 hrs post-hatch). No effect due to time of feeding was observed (P>0.05). Birds fed high n-3 diets had higher C20:5n-3, C22:5n-3, C22:6n-3 and total n-3 fatty acids and birds that were fed a low n-3 diet had higher levels of total n-6 PUFAs (P<0.05). LPS challenged led to a decrease in spleen C22:5n-3 of birds fed late high n-3 when compared to control birds within the same treatment group (P<0.05). LPS challenged birds showed an increase in C20:4n-6, total polyunsaturated fats and total n-6 fatty acids in birds that were late fed low n-3 compared to control birds within the same treatment group (P<0.05). LPS challenged birds from early and late high n-3 had higher liver total saturated fats when compared to control birds of the same diet (P<0.05). LPS challenge led to an increase in liver total n-6 fatty acids in birds fed late low n-3 when compared to control birds within the same treatment (P<0.05). LPS birds from early and late high n-3 diets were higher in total liver n-3 fatty acid content when compared to birds fed low n-3 diets (P<0.05). Plasma isoprostanes showed no difference among treatment groups (P>0.05). Liver vitamin E was higher in control birds from early high n-3 groups when compared to the other treatments (P<0.05). Plasma vitamin E was highest in early low n-3 upon challenge when compared to the other treatments (P<0.05). LPS challenge resulted in an increase in vitamin E in the lung, small intestine and plasma of low n-3 birds. COX-2 expression in the spleen tissue increased due to LPS challenge. Time of feeding and diet had a significant effect on COX-2 protein expression (P<0.05). These results indicate that type of dietary fat and time of feeding may alter the inflammatory response upon challenge in broiler birds. During inflammation, lipid substrates for the activated immune system are provided by fatty acids. Therefore, dietary management strategies directed at attenuating immune tissue lipid content may prove to be beneficial in enhancing bird health and in increasing production performance in broiler chickens. Title: Effect of dietary fatty acids, time of feeding and immune response in poultry Author: Gonzalez, Dulmelis In the presence of internal or external stressors, the body requires sources of energy that aide cells to combat inflammation. Fatty acids are an important source of energy and are vital components of cell membranes. Dietary fatty acids (n-6 and n-3) are of importance in immune function because they are precursors to metabolites that are potent mediators of inflammation. Poultry diets are high in n-6 fatty acids, which exert pro-inflammatory effects, and low in n-3 fatty acids, which tend to be less inflammatory. Delayed access to feed after hatching has been reported to impact the development of organs associated with immunity. Based on this information, two experiments were conducted in broiler chickens to determine the effect of dietary polyunsaturated fatty acid (PUFA) and the influence of time of feeding on bird performance, tissue lipid status, immune responses and expression of cyclooxygenase 2 (COX-2) upon challenge. In experiment 1, birds were fed diets that contained 3.5% oxidized yellow grease (low n-3) or 3.5% canola oil (high n-3). Birds were fed early (<5 hrs post-hatch) or late (>24 hrs post-hatch). Intramuscular injection of lipopolysaccharide (LPS) or phosphate buffered saline (control) was used as the immune challenge. Feeding high n-3 diets resulted in an increase in n-3 fatty acids in the liver in all treatment groups upon LPS challenge (P<0.05). LPS injection led to a decrease in total n-6 fatty acids in the liver when compared with control birds (P<0.05) fed early high n-3 and late low n-3. However, in spleen tissue, upon LPS challenge, increase in total n-3 fatty acids was observed only in birds fed early high n-3 and birds fed late high n-3. Plasma non-esterified fatty acids were lowest in high n-3 birds fed early (P<0.05). The spleen tissue total fat content was lowest in early high and late high n-3 birds (P<0.05). Breast muscle thiobarbituric acid reactive substances (TBARS) were higher in birds fed high n-3 compared to birds fed diets low in n-3 (P< 0.05). The delayed type hypersensitivity response was higher in birds fed high n-3 diet when compared to all other treatments (P<0.05). Thigh muscle of LPS challenged birds from early low n-3 and late high n-3 was significantly higher in TBARS when compared to control birds (P<0.05). There was no difference in final body weight, cut-up yield and organ weight of birds (P>0.05) except liver and thigh muscle weight percents were lowest in birds fed low n-3 (P<0.05). In the second experiment, birds were fed diets containing 3.5% sunflower oil (low n-3) or 3.5% fish oil (high n-3). The birds were either fed early (<5 hrs post hatch) or late (>48 hrs post-hatch). No effect due to time of feeding was observed (P>0.05). Birds fed high n-3 diets had higher C20:5n-3, C22:5n-3, C22:6n-3 and total n-3 fatty acids and birds that were fed a low n-3 diet had higher levels of total n-6 PUFAs (P<0.05). LPS challenged led to a decrease in spleen C22:5n-3 of birds fed late high n-3 when compared to control birds within the same treatment group (P<0.05). LPS challenged birds showed an increase in C20:4n-6, total polyunsaturated fats and total n-6 fatty acids in birds that were late fed low n-3 compared to control birds within the same treatment group (P<0.05). LPS challenged birds from early and late high n-3 had higher liver total saturated fats when compared to control birds of the same diet (P<0.05). LPS challenge led to an increase in liver total n-6 fatty acids in birds fed late low n-3 when compared to control birds within the same treatment (P<0.05). LPS birds from early and late high n-3 diets were higher in total liver n-3 fatty acid content when compared to birds fed low n-3 diets (P<0.05). Plasma isoprostanes showed no difference among treatment groups (P>0.05). Liver vitamin E was higher in control birds from early high n-3 groups when compared to the other treatments (P<0.05). Plasma vitamin E was highest in early low n-3 upon challenge when compared to the other treatments (P<0.05). LPS challenge resulted in an increase in vitamin E in the lung, small intestine and plasma of low n-3 birds. COX-2 expression in the spleen tissue increased due to LPS challenge. Time of feeding and diet had a significant effect on COX-2 protein expression (P<0.05). These results indicate that type of dietary fat and time of feeding may alter the inflammatory response upon challenge in broiler birds. During inflammation, lipid substrates for the activated immune system are provided by fatty acids. Therefore, dietary management strategies directed at attenuating immune tissue lipid content may prove to be beneficial in enhancing bird health and in increasing production performance in broiler chickens. Close

• 8456. [Article] Surface Water and Groundwater Interactions in the Walla Walla River, Northeast Oregon, USA : A Multi-Method Field-Based Approach

  Surface water and groundwater interactions are a key component in the functioning of stream ecosystems. Exchange of water between the stream and the hyporheic zone creates habitat for aquatic organisms ...

  Citation × Citation Citation Abstract Copy Title: Surface Water and Groundwater Interactions in the Walla Walla River, Northeast Oregon, USA : A Multi-Method Field-Based Approach Author: Gryczkowski, Landon Surface water and groundwater interactions are a key component in the functioning of stream ecosystems. Exchange of water between the stream and the hyporheic zone creates habitat for aquatic organisms and serves as a control for stream biogeochemical, thermal, and flow processes. This study takes a multi-method field-based approach to gain a better understanding of exchange processes in the Walla Walla River, Northeast Oregon, USA, with focus on advancing methodologies, spatial and temporal exchange dynamics, fish ecology and habitat, and geomorphic controls on hyporheic exchange. Fiber-optic distributed temperature sensing (DTS) was used to identify, quantify, and map cold-water inflows at the meter scale. Analysis of the maximum and minimum daily temperature traces separated each cold-water inflow into either hyporheic or groundwater-derived. DTS identified a very active hyporheic zone in this system, with a near-equal importance of hyporheic and groundwater inflows. Approximately one-third of the 2-km study reach was influence by cold-water inflows, providing significant cooling in certain areas. Using piezometers in conjunction with DTS provided validation and supplementation of DTS results, increased the reliability of conclusions, and helped to identify and understand specific exchange processes. Piezometer data showed downwelling conditions (negative head differential) except immediately downstream of riffles, with head differentials becoming increasingly negative farther downstream from a riffle. Furthermore, head differentials increased in the negative direction from left bank to right bank, indicating lateral movement of groundwater and more loss of river water from the right bank. Nearest to riffles and river bends, head differentials remained more stable over time, which may indicate that geomorphic structures influence head variations locally, while aquifer levels and dynamics have an increasing influence farther from these structures. Seasonally, head differentials became increasingly negative through the summer into fall as aquifer levels decreased, and areas of the river that lost the most water to the subsurface tended to lose more water at a faster rate as the summer progressed. However, the seasonal trend of head differentials may be counteracted by decreasing bed permeability, yielding little or no temporal change in vertical flux of water through the streambed. During high-flow events, river losses to the subsurface decreased overall; in particular, areas with the greatest water loss at low flows showed reduced losses during high flows. High variability and lack of patterns in the response to high flow events suggests complexity in this process. Temperature-related variables from DTS data were combined with habitat-related variables to determine which variables best explain pool-scale salmonid abundance. Two snorkel surveys of 23 pools within the study reach were performed. The change in temperature across the pool showed the strongest overall relationship to salmonid abundance, particularly Chinook salmon. Chinook salmon showed a stronger preference for specific pools compared to steelhead/rainbow trout. The magnitude of cold-water inflows appears more important than the presence or proportion of the pool receiving cold-water inflows, and salmonid abundance was more strongly explained by hyporheic inflows compared to groundwater. Temperature variables increased in importance relative to habitat variables in the second snorkel sample compared to sample one. The highest river temperatures of the summer occurred between the two sample dates, and this may suggest that salmonids’ affinity for cold-water refuge was enhanced through behavioral adaptation following periods of high temperature approaching the lethal threshold. The combined use of DTS, continuous electrical resistivity/induced polarization profiling, LiDAR, aerial imagery analysis, and field surveys allowed for the quantification of many geomorphic and hydraulic variables known or hypothesized to contribute to surface water and groundwater exchange processes. Regression analysis was used to determine which of these variables best explain the presence and magnitude of both groundwater and hyporheic inflows. For the first time, the cross-sectional area of the hyporheic zone was estimated at high resolution at the reach scale, and decreasing hyporheic cross-sectional area best explained both the presence and magnitude of cold-water inflows of either type. Higher water surface slope and sinuosity/curvature were next in order of importance. The presence of hyporheic inflows was also explained by higher water surface slope, sinuosity, and Reynolds number, while the magnitude of hyporheic inflows was best explained by higher sinuosity. Groundwater inflows were also explained by higher width-to-depth ratio, higher water surface slope, decreasing distance from a stream bank to the bankfull or floodplain extent, and decreasing flow velocity. Lateral processes (e.g. sinuosity) and vertical processes (e.g. water surface slope) were found to be of comparable importance, but lateral processes better explained larger decreases in stream temperature, possibly because lateral subsurface flow paths are longer in distance and duration. Hydraulic conductivity variables did not show up among the most important variables likely because of the difficulty in estimating hydraulic conductivity at the meter scale using electrical geophysical tools. Title: Surface Water and Groundwater Interactions in the Walla Walla River, Northeast Oregon, USA : A Multi-Method Field-Based Approach Author: Gryczkowski, Landon Surface water and groundwater interactions are a key component in the functioning of stream ecosystems. Exchange of water between the stream and the hyporheic zone creates habitat for aquatic organisms and serves as a control for stream biogeochemical, thermal, and flow processes. This study takes a multi-method field-based approach to gain a better understanding of exchange processes in the Walla Walla River, Northeast Oregon, USA, with focus on advancing methodologies, spatial and temporal exchange dynamics, fish ecology and habitat, and geomorphic controls on hyporheic exchange. Fiber-optic distributed temperature sensing (DTS) was used to identify, quantify, and map cold-water inflows at the meter scale. Analysis of the maximum and minimum daily temperature traces separated each cold-water inflow into either hyporheic or groundwater-derived. DTS identified a very active hyporheic zone in this system, with a near-equal importance of hyporheic and groundwater inflows. Approximately one-third of the 2-km study reach was influence by cold-water inflows, providing significant cooling in certain areas. Using piezometers in conjunction with DTS provided validation and supplementation of DTS results, increased the reliability of conclusions, and helped to identify and understand specific exchange processes. Piezometer data showed downwelling conditions (negative head differential) except immediately downstream of riffles, with head differentials becoming increasingly negative farther downstream from a riffle. Furthermore, head differentials increased in the negative direction from left bank to right bank, indicating lateral movement of groundwater and more loss of river water from the right bank. Nearest to riffles and river bends, head differentials remained more stable over time, which may indicate that geomorphic structures influence head variations locally, while aquifer levels and dynamics have an increasing influence farther from these structures. Seasonally, head differentials became increasingly negative through the summer into fall as aquifer levels decreased, and areas of the river that lost the most water to the subsurface tended to lose more water at a faster rate as the summer progressed. However, the seasonal trend of head differentials may be counteracted by decreasing bed permeability, yielding little or no temporal change in vertical flux of water through the streambed. During high-flow events, river losses to the subsurface decreased overall; in particular, areas with the greatest water loss at low flows showed reduced losses during high flows. High variability and lack of patterns in the response to high flow events suggests complexity in this process. Temperature-related variables from DTS data were combined with habitat-related variables to determine which variables best explain pool-scale salmonid abundance. Two snorkel surveys of 23 pools within the study reach were performed. The change in temperature across the pool showed the strongest overall relationship to salmonid abundance, particularly Chinook salmon. Chinook salmon showed a stronger preference for specific pools compared to steelhead/rainbow trout. The magnitude of cold-water inflows appears more important than the presence or proportion of the pool receiving cold-water inflows, and salmonid abundance was more strongly explained by hyporheic inflows compared to groundwater. Temperature variables increased in importance relative to habitat variables in the second snorkel sample compared to sample one. The highest river temperatures of the summer occurred between the two sample dates, and this may suggest that salmonids’ affinity for cold-water refuge was enhanced through behavioral adaptation following periods of high temperature approaching the lethal threshold. The combined use of DTS, continuous electrical resistivity/induced polarization profiling, LiDAR, aerial imagery analysis, and field surveys allowed for the quantification of many geomorphic and hydraulic variables known or hypothesized to contribute to surface water and groundwater exchange processes. Regression analysis was used to determine which of these variables best explain the presence and magnitude of both groundwater and hyporheic inflows. For the first time, the cross-sectional area of the hyporheic zone was estimated at high resolution at the reach scale, and decreasing hyporheic cross-sectional area best explained both the presence and magnitude of cold-water inflows of either type. Higher water surface slope and sinuosity/curvature were next in order of importance. The presence of hyporheic inflows was also explained by higher water surface slope, sinuosity, and Reynolds number, while the magnitude of hyporheic inflows was best explained by higher sinuosity. Groundwater inflows were also explained by higher width-to-depth ratio, higher water surface slope, decreasing distance from a stream bank to the bankfull or floodplain extent, and decreasing flow velocity. Lateral processes (e.g. sinuosity) and vertical processes (e.g. water surface slope) were found to be of comparable importance, but lateral processes better explained larger decreases in stream temperature, possibly because lateral subsurface flow paths are longer in distance and duration. Hydraulic conductivity variables did not show up among the most important variables likely because of the difficulty in estimating hydraulic conductivity at the meter scale using electrical geophysical tools. Close

• 8457. [Article] Historic Survival Rates and Cause-Specific Mortality for Columbian Black-Tailed Deer in Southwest Oregon

  In contrast with other Odocoileus species, Columbian black-tailed deer (Odocoileus hemionus columbianus) population dynamics are not well understood throughout the species’ range. Concerns over apparent ...

  Citation × Citation Citation Abstract Copy Title: Historic Survival Rates and Cause-Specific Mortality for Columbian Black-Tailed Deer in Southwest Oregon Author: Groot, Kevyn A. In contrast with other Odocoileus species, Columbian black-tailed deer (Odocoileus hemionus columbianus) population dynamics are not well understood throughout the species’ range. Concerns over apparent long-term population declines have prompted efforts to fill basic knowledge gaps including estimates of vital rates (fecundity, recruitment and survival) and cause-specific mortality. The Oregon Department of Fish and Wildlife completed an extensive Columbian black-tailed (black-tailed) deer radio-collaring study in Oregon's south Cascade range from 1994 - 2000, with the goal of better understanding and anticipating the effects of different harvest management strategies on deer herds in the region. I utilized this historical data to conduct an in-depth investigation of seasonal sex- and age-specific survival rates and cause-specific mortality rates for marked black-tailed deer. I used known-fate data for 293 male and female radio-collared black-tailed of 3 age classes (yearling, 2-year old, adult) to estimate seasonal survival and investigate a variety of explanatory factors including sex, age class, temporal effects (seasonal, annual and trends across season and year), and time-dependent large-scale regional climate covariates. Variation in survival rates for this population was best explained by an interaction between sex and age class, with decreased probability of survival with increasing age class. The age effect was most pronounced in males, and although female survival in the older age classes was higher compared to male survival as predicted, yearling males had higher survival rates than yearling females. There was strong support for temporal variation in survival between summer and winter seasons, with winter survival best modeled as constant across years and summer survival variable across years. Winter survival was generally higher than summer except in 1997 when winter and summer rates were similar. Despite annual variation in summer survival rates, large-scale climate indices (Southern Oscillation Index, Pacific Decadal Oscillation, and Palmer Drought Severity Index) did not explain any temporal variation in survival rates within seasons. Low survival rates during the summer season, particularly for older males, resulted in low estimates of annual survival in some years. Annual estimates for males ranged from 0.47 - 0.76 for yearlings, 0.29 - 0.60 for 2-year olds and 0.14 - 0.40 for adults across the 6 years of this study. Annual estimates for females were generally higher than for males but were some of the lowest documented for the species, ranging from 0.47 - 0.76 for yearlings, 0.46 - 0.75 for 2-year olds and 0.44 - 0.74 for adults. I used the nonparametric cumulative incidence function estimator (NPCIFE) to generate annual and seasonal cumulative incidence functions for four competing risks: harvest, predation, other low-incidence sources of anthropogenic or natural mortality, and mortality due to unknown sources. Annual and seasonal risk functions were pooled across all years of the study to maximize sample size. As predicted in this system with limited antlerless harvest, cumulative risk of harvest across the entire annual cycle (365 days) was significantly higher for males (0.16, 95% CI = 0.11 - 0.21); a 16% annual cumulative risk compared to just 3% for females (0.03, 95% CI = 0.01 - 0.05). In addition, cause-specific mortality by male age class during the period of highest hunting pressure (general Cascade rifle season) suggested that 2-year-old males had over twice the cumulative risk of legal harvest with 22% of this age class killed by hunters during the general rifle season (0.22, 95% CI = 0.12 - 0.33) compared to 10% of adults (0.10, 95% CI = 0.04 - 0.15). Most yearling males survived the harvest season as cumulative legal harvest risk for yearling males was low (0.02, 95% CI = -0.01 - 0.06) relative to 2-year-olds and adults. Cougars (Puma concolor) were the primary predator of marked black-tailed deer and there was no significant difference in annual cumulative predation risk between the sexes (males: 0.05, 95% CI = 0.02 - 0.08; females: 0.05, 95% CI = 0.03 - 0.08), with only 5% risk of predation each year for both males and females. There was strong evidence that cumulative predation risk for females was higher in winter (0.04, 95% CI = 0.02 - 0.06) compared to summer (0.01, 95% CI = -0.002 - 0.02), and an increase in cumulative risk from February to May provides supportive evidence that females are more susceptible to predation during these months. High survival rates of yearling males with dramatic declines in survival once many of these deer became 2-year olds or older suggest that harvest may have had an additive effect and been the primary cause of low survival rates observed for males. Observed variability in summer survival resulted in variable, and in some years very low, annual survival rates for adult females; a strong contrast to the generally stable annual survival rates reported for other populations of mule deer. The highest estimates of annual survival for yearling males and for females of all age classes (0.74) in 1997 are comparable to the low range of estimates observed in other populations, but in other years estimates are much lower than what has been previously reported for black-tailed deer. These low survival rates might suggest a mechanism resulting in population decline over time, but more information on other vital rates (fecundity, fawn survival, and recruitment), carrying capacity of the system and population size is necessary to understand the population dynamics of black-tailed deer in this region during the 1990's. Properties of the data relative to male age classes in particular (low sample sizes, high censoring rates) decreased precision of these estimates and might have resulted in biased estimates. Adult females had consistently sufficient sample sizes over the course of the study to generate more precise, reliable estimates of survival, particularly in the latter 3 years of the study; these estimates should therefore be viewed with more confidence. Cause-specific mortality rates should be viewed as minimums due to the high number of unknown mortalities (40% of total) in the study population, but they suggest that hunting is the primary source of mortality for adult males and predation has the highest impact on seasonal female mortality rates. Given the historical nature of these results, my estimates should be used as a baseline and foundation for comparison with results from current black-tailed deer research in Oregon. These results have raised potential questions regarding harvest levels on male black-tailed deer in addition to possible resource constraints affecting both sexes on seasonal ranges, and can therefore focus new research to address these concerns. Title: Historic Survival Rates and Cause-Specific Mortality for Columbian Black-Tailed Deer in Southwest Oregon Author: Groot, Kevyn A. In contrast with other Odocoileus species, Columbian black-tailed deer (Odocoileus hemionus columbianus) population dynamics are not well understood throughout the species’ range. Concerns over apparent long-term population declines have prompted efforts to fill basic knowledge gaps including estimates of vital rates (fecundity, recruitment and survival) and cause-specific mortality. The Oregon Department of Fish and Wildlife completed an extensive Columbian black-tailed (black-tailed) deer radio-collaring study in Oregon's south Cascade range from 1994 - 2000, with the goal of better understanding and anticipating the effects of different harvest management strategies on deer herds in the region. I utilized this historical data to conduct an in-depth investigation of seasonal sex- and age-specific survival rates and cause-specific mortality rates for marked black-tailed deer. I used known-fate data for 293 male and female radio-collared black-tailed of 3 age classes (yearling, 2-year old, adult) to estimate seasonal survival and investigate a variety of explanatory factors including sex, age class, temporal effects (seasonal, annual and trends across season and year), and time-dependent large-scale regional climate covariates. Variation in survival rates for this population was best explained by an interaction between sex and age class, with decreased probability of survival with increasing age class. The age effect was most pronounced in males, and although female survival in the older age classes was higher compared to male survival as predicted, yearling males had higher survival rates than yearling females. There was strong support for temporal variation in survival between summer and winter seasons, with winter survival best modeled as constant across years and summer survival variable across years. Winter survival was generally higher than summer except in 1997 when winter and summer rates were similar. Despite annual variation in summer survival rates, large-scale climate indices (Southern Oscillation Index, Pacific Decadal Oscillation, and Palmer Drought Severity Index) did not explain any temporal variation in survival rates within seasons. Low survival rates during the summer season, particularly for older males, resulted in low estimates of annual survival in some years. Annual estimates for males ranged from 0.47 - 0.76 for yearlings, 0.29 - 0.60 for 2-year olds and 0.14 - 0.40 for adults across the 6 years of this study. Annual estimates for females were generally higher than for males but were some of the lowest documented for the species, ranging from 0.47 - 0.76 for yearlings, 0.46 - 0.75 for 2-year olds and 0.44 - 0.74 for adults. I used the nonparametric cumulative incidence function estimator (NPCIFE) to generate annual and seasonal cumulative incidence functions for four competing risks: harvest, predation, other low-incidence sources of anthropogenic or natural mortality, and mortality due to unknown sources. Annual and seasonal risk functions were pooled across all years of the study to maximize sample size. As predicted in this system with limited antlerless harvest, cumulative risk of harvest across the entire annual cycle (365 days) was significantly higher for males (0.16, 95% CI = 0.11 - 0.21); a 16% annual cumulative risk compared to just 3% for females (0.03, 95% CI = 0.01 - 0.05). In addition, cause-specific mortality by male age class during the period of highest hunting pressure (general Cascade rifle season) suggested that 2-year-old males had over twice the cumulative risk of legal harvest with 22% of this age class killed by hunters during the general rifle season (0.22, 95% CI = 0.12 - 0.33) compared to 10% of adults (0.10, 95% CI = 0.04 - 0.15). Most yearling males survived the harvest season as cumulative legal harvest risk for yearling males was low (0.02, 95% CI = -0.01 - 0.06) relative to 2-year-olds and adults. Cougars (Puma concolor) were the primary predator of marked black-tailed deer and there was no significant difference in annual cumulative predation risk between the sexes (males: 0.05, 95% CI = 0.02 - 0.08; females: 0.05, 95% CI = 0.03 - 0.08), with only 5% risk of predation each year for both males and females. There was strong evidence that cumulative predation risk for females was higher in winter (0.04, 95% CI = 0.02 - 0.06) compared to summer (0.01, 95% CI = -0.002 - 0.02), and an increase in cumulative risk from February to May provides supportive evidence that females are more susceptible to predation during these months. High survival rates of yearling males with dramatic declines in survival once many of these deer became 2-year olds or older suggest that harvest may have had an additive effect and been the primary cause of low survival rates observed for males. Observed variability in summer survival resulted in variable, and in some years very low, annual survival rates for adult females; a strong contrast to the generally stable annual survival rates reported for other populations of mule deer. The highest estimates of annual survival for yearling males and for females of all age classes (0.74) in 1997 are comparable to the low range of estimates observed in other populations, but in other years estimates are much lower than what has been previously reported for black-tailed deer. These low survival rates might suggest a mechanism resulting in population decline over time, but more information on other vital rates (fecundity, fawn survival, and recruitment), carrying capacity of the system and population size is necessary to understand the population dynamics of black-tailed deer in this region during the 1990's. Properties of the data relative to male age classes in particular (low sample sizes, high censoring rates) decreased precision of these estimates and might have resulted in biased estimates. Adult females had consistently sufficient sample sizes over the course of the study to generate more precise, reliable estimates of survival, particularly in the latter 3 years of the study; these estimates should therefore be viewed with more confidence. Cause-specific mortality rates should be viewed as minimums due to the high number of unknown mortalities (40% of total) in the study population, but they suggest that hunting is the primary source of mortality for adult males and predation has the highest impact on seasonal female mortality rates. Given the historical nature of these results, my estimates should be used as a baseline and foundation for comparison with results from current black-tailed deer research in Oregon. These results have raised potential questions regarding harvest levels on male black-tailed deer in addition to possible resource constraints affecting both sexes on seasonal ranges, and can therefore focus new research to address these concerns. Close

• 8458. [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

• 8459. [Article] Impacts of earlier emerging steelhead fry of hatchery origin on the social structure, distribution, and growth of wild steelhead fry

  Newly emerged steelhead fry (Oncorhynchus mvkiss) of hatchery and wild origins were studied in laboratory stream channels and natural streams. Objectives of the study were to determine if and how earlier emerging ...

  Citation × Citation Citation Abstract Copy Title: Impacts of earlier emerging steelhead fry of hatchery origin on the social structure, distribution, and growth of wild steelhead fry Author: Noble, Sandra M. (Sandra Marie) Newly emerged steelhead fry (Oncorhynchus mvkiss) of hatchery and wild origins were studied in laboratory stream channels and natural streams. Objectives of the study were to determine if and how earlier emerging hatchery fry influence the emigration, realized densities, growth, habitat use, social structure, and activity patterns of localized populations of wild steelhead fry when the hatchery fry have a competitive advantage conferred by larger size and prior residence. During 1986 and 1987, the above variables were observed daily among hatchery and wild steelhead fry in laboratory stream channels for 8 weeks following emergence in June. The habitat use and social activities for fry of both origins were observed weekly in natural stream reaches from June through August in 1987 to corroborate lab findings. In lab channels, both hatchery and wild fry received 2 treatments: living alone (allopatry) and living together (sympatry). In the lab, fry of hatchery origin emerged 7 to 10 d prior to wild fry and remained larger in size during the 8 weeks of study both years. In natural stream reaches, fry of each origin were observed only in allopatric situations. Wild fry in the field emerged from natural redds while hatchery fry were released in stream reaches as unfed, newly emerged (swim-up) fry. Hatchery and wild fry in lab sections were found to be very similar in their emigration rates, distances to nearest neighbor, growth rates, and use of habitat. Both fry types, regardless of treatment or environment (lab or field), established similar stable social structure and used the same types of aggressive acts. Among all lab groups, once a fry became dominant, it retained that social status to the end of the study period. Significant differences (P<.05 both years) among comparison tests were: 1) in allopatric lab sections, wild fry maintained larger densities than hatchery fry, 2) in sympatry, hatchery fry had a greater tendency to establish stable focal points and social hierarchies more readily, defend larger areas, have better condition, prefer pools with overhead cover more frequently, be more aggressive, and reach stable densities more quickly than the wild fry, 3) fewer hatchery fry in sympatry maintained nomadic positions than wild fry in both treatments, 4) in sympatry, hatchery fry directed more acts of overt aggression toward wild fry than other hatchery fry, 5) wild fry in sympatry usually used defensive or less offensive acts of aggression when interacting with other fry, 6) fry of both origins in natural stream reaches maintained greater distances to their nearest neighbor than fry in allopatric lab sections, 7) dominant hatchery fry in both treatments maintained larger focal areas than subdominant fry, 8) hatchery fry maintained longer lengths than wild fry through the duration of the study, and 9) hatchery fry were more aggressive in sympatry than in allopatry. Potential differences (P<.05 in one year and P<.1 in the other year) were: 1) wild fry in sympatry had lower realized densities, maintained smaller focal areas, had greater proportions of nomadic individuals, and established stable social hierarchies slower than wild fry in allopatric lab sections, 2) wild fry in sympatry had poorer condition than all other fry groups in lab sections, 3) in sympatry, wild fry were the recipients of the majority of aggressive acts perpetrated by hatchery fry and other wild fry and usually assumed the subordinate positions within the social hierarchy, 4) all fry in the lab showed a high preference for pools with overhead cover and low preference for gravel and fines and run areas, and 5) wild fry in allopatric lab sections were more socially active than hatchery fry while the reverse was observed in the natural streams. Any influences that could be attributed to inherent differences between stock origins were probably masked by size differences between fry types. The study would have been more complete had I included sympatric lab sections where wild fry emerged first and where fry types emerged simultaneously, and sympatric reaches in natural streams. Results were further confounded by the limited number of wild adults used for broodstock in the lab segment of this study. Progeny produced from so few adults (5 adults of each sex each year) would have very limited genotypic variation compared to what occurs in natural streams. This may partially explain why some findings from lab sections and natural stream reaches differed. Likewise, genotypic expression among wild fry in lab sections may have varied greatly between years. This could explain differences found between years in behavior of wild fry in similar lab treatments. Although this study does not simulate all possible scenarios, results support suspicions that introductions of hatchery fry of larger size and earlier emergence into streams containing wild stocks could disrupt the social structure and negatively influence the realized densities, spatial distribution, growth, and behavior of wild juveniles in recipient streams. Title: Impacts of earlier emerging steelhead fry of hatchery origin on the social structure, distribution, and growth of wild steelhead fry Author: Noble, Sandra M. (Sandra Marie) Newly emerged steelhead fry (Oncorhynchus mvkiss) of hatchery and wild origins were studied in laboratory stream channels and natural streams. Objectives of the study were to determine if and how earlier emerging hatchery fry influence the emigration, realized densities, growth, habitat use, social structure, and activity patterns of localized populations of wild steelhead fry when the hatchery fry have a competitive advantage conferred by larger size and prior residence. During 1986 and 1987, the above variables were observed daily among hatchery and wild steelhead fry in laboratory stream channels for 8 weeks following emergence in June. The habitat use and social activities for fry of both origins were observed weekly in natural stream reaches from June through August in 1987 to corroborate lab findings. In lab channels, both hatchery and wild fry received 2 treatments: living alone (allopatry) and living together (sympatry). In the lab, fry of hatchery origin emerged 7 to 10 d prior to wild fry and remained larger in size during the 8 weeks of study both years. In natural stream reaches, fry of each origin were observed only in allopatric situations. Wild fry in the field emerged from natural redds while hatchery fry were released in stream reaches as unfed, newly emerged (swim-up) fry. Hatchery and wild fry in lab sections were found to be very similar in their emigration rates, distances to nearest neighbor, growth rates, and use of habitat. Both fry types, regardless of treatment or environment (lab or field), established similar stable social structure and used the same types of aggressive acts. Among all lab groups, once a fry became dominant, it retained that social status to the end of the study period. Significant differences (P<.05 both years) among comparison tests were: 1) in allopatric lab sections, wild fry maintained larger densities than hatchery fry, 2) in sympatry, hatchery fry had a greater tendency to establish stable focal points and social hierarchies more readily, defend larger areas, have better condition, prefer pools with overhead cover more frequently, be more aggressive, and reach stable densities more quickly than the wild fry, 3) fewer hatchery fry in sympatry maintained nomadic positions than wild fry in both treatments, 4) in sympatry, hatchery fry directed more acts of overt aggression toward wild fry than other hatchery fry, 5) wild fry in sympatry usually used defensive or less offensive acts of aggression when interacting with other fry, 6) fry of both origins in natural stream reaches maintained greater distances to their nearest neighbor than fry in allopatric lab sections, 7) dominant hatchery fry in both treatments maintained larger focal areas than subdominant fry, 8) hatchery fry maintained longer lengths than wild fry through the duration of the study, and 9) hatchery fry were more aggressive in sympatry than in allopatry. Potential differences (P<.05 in one year and P<.1 in the other year) were: 1) wild fry in sympatry had lower realized densities, maintained smaller focal areas, had greater proportions of nomadic individuals, and established stable social hierarchies slower than wild fry in allopatric lab sections, 2) wild fry in sympatry had poorer condition than all other fry groups in lab sections, 3) in sympatry, wild fry were the recipients of the majority of aggressive acts perpetrated by hatchery fry and other wild fry and usually assumed the subordinate positions within the social hierarchy, 4) all fry in the lab showed a high preference for pools with overhead cover and low preference for gravel and fines and run areas, and 5) wild fry in allopatric lab sections were more socially active than hatchery fry while the reverse was observed in the natural streams. Any influences that could be attributed to inherent differences between stock origins were probably masked by size differences between fry types. The study would have been more complete had I included sympatric lab sections where wild fry emerged first and where fry types emerged simultaneously, and sympatric reaches in natural streams. Results were further confounded by the limited number of wild adults used for broodstock in the lab segment of this study. Progeny produced from so few adults (5 adults of each sex each year) would have very limited genotypic variation compared to what occurs in natural streams. This may partially explain why some findings from lab sections and natural stream reaches differed. Likewise, genotypic expression among wild fry in lab sections may have varied greatly between years. This could explain differences found between years in behavior of wild fry in similar lab treatments. Although this study does not simulate all possible scenarios, results support suspicions that introductions of hatchery fry of larger size and earlier emergence into streams containing wild stocks could disrupt the social structure and negatively influence the realized densities, spatial distribution, growth, and behavior of wild juveniles in recipient streams. Close

• 8460. [Article] The legal and regulatory setting affecting timber supply on Oregon's public lands

  Graduation date:

  Citation × Citation Citation Abstract Copy Title: The legal and regulatory setting affecting timber supply on Oregon's public lands Author: Peckman, Nancy Graduation date: Title: The legal and regulatory setting affecting timber supply on Oregon's public lands Author: Peckman, Nancy Graduation date: Close