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• 61. [Article] AI - Fish Habitat Assessment in The Oregon Department Of Forestry Miamii Study Area

  Abstract -- A collaborative project between the Oregon Department of Forestry (ODF) and the Oregon Department of Fish and Wildlife (ODFW) was initiated to synthesize aquatic habitat and fisheries information ...

  Citation × Citation Citation Abstract Copy Title: AI - Fish Habitat Assessment in The Oregon Department Of Forestry Miamii Study Area Abstract -- A collaborative project between the Oregon Department of Forestry (ODF) and the Oregon Department of Fish and Wildlife (ODFW) was initiated to synthesize aquatic habitat and fisheries information for the Miami River drainage to assist in the development of operational management plans, stream habitat restoration projects, habitat conservation planning, and watershed analysis. The project summarizes the condition of stream habitat, the distribution and abundance of salmonid fishes, and the potential for restoration. The ODFW Aquatic Inventories Project has conducted stream habitat surveys as part of its basin survey project and habitat assessment project under the Oregon Plan for Salmon and Watersheds. The goal of these surveys was to document the status and trends of stream conditions in coastal drainages. These surveys in conjunction with fish distribution, fish presence, potential barriers to passage, and past restoration activities will be the basis of the analyses. Title: AI - Fish Habitat Assessment in The Oregon Department Of Forestry Miamii Study Area Abstract -- A collaborative project between the Oregon Department of Forestry (ODF) and the Oregon Department of Fish and Wildlife (ODFW) was initiated to synthesize aquatic habitat and fisheries information for the Miami River drainage to assist in the development of operational management plans, stream habitat restoration projects, habitat conservation planning, and watershed analysis. The project summarizes the condition of stream habitat, the distribution and abundance of salmonid fishes, and the potential for restoration. The ODFW Aquatic Inventories Project has conducted stream habitat surveys as part of its basin survey project and habitat assessment project under the Oregon Plan for Salmon and Watersheds. The goal of these surveys was to document the status and trends of stream conditions in coastal drainages. These surveys in conjunction with fish distribution, fish presence, potential barriers to passage, and past restoration activities will be the basis of the analyses. Close

• 62. [Article] Mass erosion occurrence and debris torrent impacts on some streams in the Willamette National Forest

  This study focused on extensive soil mass movement occurrence in the Willamette National Forest of western Oregon and on intensive measurements of some physical and biological changes in streams following ...

  Citation × Citation Citation Abstract Copy Title: Mass erosion occurrence and debris torrent impacts on some streams in the Willamette National Forest Author: Chesney, Charles J. This study focused on extensive soil mass movement occurrence in the Willamette National Forest of western Oregon and on intensive measurements of some physical and biological changes in streams following debris torrents. Debris torrents are a rapid movement of water-charged debris confined to steep headwater channels. The frequency (events/ha/yr) of mass failures identified from aerial photos increased in the presence of clearcuts and roads relative to forest conditions. Approximately 71% of hillslope mass failures entered the stream channel, and an estimated 43% of hillslope mass failures resulted in debris torrents. Standing crop of large organic debris and annual input to streams affected by debris torrents were highly variable. Silvicultural conditions of upslope vegetation and morphological features of debris torrent tracks influenced woody loading and input. Old-growth streams and depositional stream sites contained higher amounts of large organic debris and received higher inputs of large organic debris than streams in clearcuts and erosional stream sites. Depositional sites along debris torrent tracks have higher pool area and depth relative to erosional stream sites. Stream channel gradient and channel cross-sectional form influence the character of erosional or depositional sites sluiced by a debris torrent. Higher total pool ratings in depositional stream sites indicate spatial complexity of channel form that is related to the availability, transport, and stability of particulate bed materials. Herbs produced the majority of foliar biomass (> 50% of total) in one-fifth of all stream sites. Shrubs produced the majority of foliar biomass in one-third of all stream sites. Stream sites where estimated foliar biomass of post-torrent plant strata exceeded estimated foliar biomass of residual plant strata were more numerous. Successional changes in clearcut riparian zones included a shift to intolerant deciduous overstory species and more numerous shrub species than in old-growth riparian zones. The diameter growth of tolerant late successional overstory species in these riparian zones was inconsistent, whereas diameter growth of early successional species was rapid. Case studies of two streams permitted analysis of riparian recovery relative to that of an undisturbed stream site upstream of the debris torrent track. Warfield Creek is a stream where a high energy debris torrent remarkably altered stream conditions. Simmonds Creek is a stream where a low energy debris torrent imperceptibly changed stream conditions. Channel slope, channel cross-sectional form, severity of debris torrent, position of stream segment within the drainage, and presence of channel obstructions all affect stream response to debris torrents, as do riparian vegetation and litterfall inputs to the stream. Riparian recovery remains difficult to quantify because of physical and biological structures of stream ecosystems that vary in space and time. Title: Mass erosion occurrence and debris torrent impacts on some streams in the Willamette National Forest Author: Chesney, Charles J. This study focused on extensive soil mass movement occurrence in the Willamette National Forest of western Oregon and on intensive measurements of some physical and biological changes in streams following debris torrents. Debris torrents are a rapid movement of water-charged debris confined to steep headwater channels. The frequency (events/ha/yr) of mass failures identified from aerial photos increased in the presence of clearcuts and roads relative to forest conditions. Approximately 71% of hillslope mass failures entered the stream channel, and an estimated 43% of hillslope mass failures resulted in debris torrents. Standing crop of large organic debris and annual input to streams affected by debris torrents were highly variable. Silvicultural conditions of upslope vegetation and morphological features of debris torrent tracks influenced woody loading and input. Old-growth streams and depositional stream sites contained higher amounts of large organic debris and received higher inputs of large organic debris than streams in clearcuts and erosional stream sites. Depositional sites along debris torrent tracks have higher pool area and depth relative to erosional stream sites. Stream channel gradient and channel cross-sectional form influence the character of erosional or depositional sites sluiced by a debris torrent. Higher total pool ratings in depositional stream sites indicate spatial complexity of channel form that is related to the availability, transport, and stability of particulate bed materials. Herbs produced the majority of foliar biomass (> 50% of total) in one-fifth of all stream sites. Shrubs produced the majority of foliar biomass in one-third of all stream sites. Stream sites where estimated foliar biomass of post-torrent plant strata exceeded estimated foliar biomass of residual plant strata were more numerous. Successional changes in clearcut riparian zones included a shift to intolerant deciduous overstory species and more numerous shrub species than in old-growth riparian zones. The diameter growth of tolerant late successional overstory species in these riparian zones was inconsistent, whereas diameter growth of early successional species was rapid. Case studies of two streams permitted analysis of riparian recovery relative to that of an undisturbed stream site upstream of the debris torrent track. Warfield Creek is a stream where a high energy debris torrent remarkably altered stream conditions. Simmonds Creek is a stream where a low energy debris torrent imperceptibly changed stream conditions. Channel slope, channel cross-sectional form, severity of debris torrent, position of stream segment within the drainage, and presence of channel obstructions all affect stream response to debris torrents, as do riparian vegetation and litterfall inputs to the stream. Riparian recovery remains difficult to quantify because of physical and biological structures of stream ecosystems that vary in space and time. Close

• 63. [Article] Potential for dispersal of the non-native parasite Myxobolus cerebralis : qualitative risk assessments for the state of Alaska and the Willamette River Basin, Oregon

  First introduced to the USA in 1958, Myxobolus cerebralis, the parasite responsible for whirling disease in salmonids, has since spread across the country causing severe declines in wild trout populations ...

  Citation × Citation Citation Abstract Copy Title: Potential for dispersal of the non-native parasite Myxobolus cerebralis : qualitative risk assessments for the state of Alaska and the Willamette River Basin, Oregon Author: Arsan, E. Leyla First introduced to the USA in 1958, Myxobolus cerebralis, the parasite responsible for whirling disease in salmonids, has since spread across the country causing severe declines in wild trout populations in the intermountain west. Recent development of risk assessment models used to assess the likelihood and consequences of exotic parasite introduction, have strengthened the process of science-based decision-making in aquatic animal health. In the case of M. cerebralis, it is necessary to use a risk assessment model with two unique segments that clearly address the distinct life stages and respective hosts of the parasite separately. The studies described examine the probability of M. cerebralis introduction and establishment for two regions: the state of Alaska, and the Willamette River basin, Oregon. The Alaska risk assessment was based on the assumption that the parasite did not already occur in the state. However, in the process of validating this assumption, we documented the first polymerase chain reaction (PCR) detection of the parasite in the state. The pathogen was identified in hatchery rainbow trout (Oncorhynchus mykiss) from the Anchorage area. Although this is the first detection of the parasite in Alaska, clinical whirling disease has never been documented in the state. To qualitatively assess the risk of further spread of M. cerebralis in Alaska, four potential routes of dissemination were examined: movement of fish by humans, natural dispersal (via migratory birds and stray anadromous salmon), recreational activities, and commercial seafood processing. This research indicates the most likely pathway for M. cerebralis transport in Alaska is human movement of fish. In the Willamette River basin, Oregon, introduction of M. cerebralis has already occurred, though establishment appears limited to a single private hatchery. Introduction in this region was considered the most likely to occur as a result of human movements of fish. Straying anadromous salmonids were also assessed and were present in higher numbers than predicted. However, they were not infected with the parasite, and thus the probability for introduction by this route is low. The probability of introduction of the parasite varies throughout the Willamette River basin. Areas with the highest probability for M. cerebralis introduction were identified as the Clackamas and Santiam River subbasins. The Clackamas River has already experienced an introduction of the parasite, has the largest concentration of hatcheries (state, federal, and private), has a popular sport fishery, and is the closest major tributary to the enormous piscivorous bird-populations in the Columbia River estuary. The Santiam subbasin has a popular sport fishery, received the highest number of stray fish in the Willamette River basin, and has the second largest concentration of hatcheries in the Willamette River basin. Unique from introduction, establishment of the parasite is dependent upon several environmental and biological factors including: water temperatures, spatial/temporal overlap of hosts, and the distribution and genetic composition of the parasite’s invertebrate host, Tubifex tubifex. The distribution, genetic composition and susceptibility of T. tubifex, were considered the most important factor in the ability of M. cerebralis to establish in both systems. Surveys of oligochaete populations were conducted in both study regions. In Alaska, T. tubifex was not detected from the southeast region and the apparent lack of appropriate tubificid hosts may prevent establishment in that part of the state. However, 4 lineages (I, III, IV, and VI) of the species were identified from southcentral Alaska. Lineage IV has not been previously been described in North America and its susceptibility to M. cerebralis was unknown. When lineage IV T. tubifex and 3 mixed-lineage (I, III, IV and VI) groups were exposed to M. cerebralis, only lineage III became infected under our experimental conditions. Thus, if the parasite were dispersed, conditions are appropriate for establishment and propagation of the parasite life cycle in southcentral Alaska, although detrimental effects on fish populations may be reduced as a result of the presence of non-susceptible lineages of T. tubifex. The probability of further establishment in this area is greatest in Ship Creek, where the abundance of susceptible T. tubifex, the presence of susceptible rainbow trout (Oncorhynchus mykiss), and the proximity to the known area of infection make conditions particularly appropriate. Similar to findings in Alaska, the Willamette River basin, Oregon also supports populations of susceptible T. tubifex. If the pathogen were introduced, probability of establishment is high in certain areas of the basin as all conditions are appropriate for propagation of the parasite life cycle. Tributaries to the mainstem Willamette River have the highest probability of establishment as these areas have the greatest numbers of susceptible T. tubifex. However, the abundance of resistant strains of T. tubifex could mitigate the effects of M. cerebralis if introduced. Management recommendations to reduce the likelihood of parasite dissemination are similar for Oregon and Alaska since human movement of fish and angler activities were considered the most likely routes of introduction for both regions. Based on this research, steps should also be taken to limit human movement of fish, whether by restricting carcass planting for stream enrichment in Oregon, or by prohibiting use of fish heads as bait in southcentral Alaska. The states should also allot resources to angler education and awareness of the effects of angler activity and recreation on dispersal of M. cerebralis. This could be done using a combination of brochures and signage at boat ramps describing how to prevent spread of aquatic nuisance species. Title: Potential for dispersal of the non-native parasite Myxobolus cerebralis : qualitative risk assessments for the state of Alaska and the Willamette River Basin, Oregon Author: Arsan, E. Leyla First introduced to the USA in 1958, Myxobolus cerebralis, the parasite responsible for whirling disease in salmonids, has since spread across the country causing severe declines in wild trout populations in the intermountain west. Recent development of risk assessment models used to assess the likelihood and consequences of exotic parasite introduction, have strengthened the process of science-based decision-making in aquatic animal health. In the case of M. cerebralis, it is necessary to use a risk assessment model with two unique segments that clearly address the distinct life stages and respective hosts of the parasite separately. The studies described examine the probability of M. cerebralis introduction and establishment for two regions: the state of Alaska, and the Willamette River basin, Oregon. The Alaska risk assessment was based on the assumption that the parasite did not already occur in the state. However, in the process of validating this assumption, we documented the first polymerase chain reaction (PCR) detection of the parasite in the state. The pathogen was identified in hatchery rainbow trout (Oncorhynchus mykiss) from the Anchorage area. Although this is the first detection of the parasite in Alaska, clinical whirling disease has never been documented in the state. To qualitatively assess the risk of further spread of M. cerebralis in Alaska, four potential routes of dissemination were examined: movement of fish by humans, natural dispersal (via migratory birds and stray anadromous salmon), recreational activities, and commercial seafood processing. This research indicates the most likely pathway for M. cerebralis transport in Alaska is human movement of fish. In the Willamette River basin, Oregon, introduction of M. cerebralis has already occurred, though establishment appears limited to a single private hatchery. Introduction in this region was considered the most likely to occur as a result of human movements of fish. Straying anadromous salmonids were also assessed and were present in higher numbers than predicted. However, they were not infected with the parasite, and thus the probability for introduction by this route is low. The probability of introduction of the parasite varies throughout the Willamette River basin. Areas with the highest probability for M. cerebralis introduction were identified as the Clackamas and Santiam River subbasins. The Clackamas River has already experienced an introduction of the parasite, has the largest concentration of hatcheries (state, federal, and private), has a popular sport fishery, and is the closest major tributary to the enormous piscivorous bird-populations in the Columbia River estuary. The Santiam subbasin has a popular sport fishery, received the highest number of stray fish in the Willamette River basin, and has the second largest concentration of hatcheries in the Willamette River basin. Unique from introduction, establishment of the parasite is dependent upon several environmental and biological factors including: water temperatures, spatial/temporal overlap of hosts, and the distribution and genetic composition of the parasite’s invertebrate host, Tubifex tubifex. The distribution, genetic composition and susceptibility of T. tubifex, were considered the most important factor in the ability of M. cerebralis to establish in both systems. Surveys of oligochaete populations were conducted in both study regions. In Alaska, T. tubifex was not detected from the southeast region and the apparent lack of appropriate tubificid hosts may prevent establishment in that part of the state. However, 4 lineages (I, III, IV, and VI) of the species were identified from southcentral Alaska. Lineage IV has not been previously been described in North America and its susceptibility to M. cerebralis was unknown. When lineage IV T. tubifex and 3 mixed-lineage (I, III, IV and VI) groups were exposed to M. cerebralis, only lineage III became infected under our experimental conditions. Thus, if the parasite were dispersed, conditions are appropriate for establishment and propagation of the parasite life cycle in southcentral Alaska, although detrimental effects on fish populations may be reduced as a result of the presence of non-susceptible lineages of T. tubifex. The probability of further establishment in this area is greatest in Ship Creek, where the abundance of susceptible T. tubifex, the presence of susceptible rainbow trout (Oncorhynchus mykiss), and the proximity to the known area of infection make conditions particularly appropriate. Similar to findings in Alaska, the Willamette River basin, Oregon also supports populations of susceptible T. tubifex. If the pathogen were introduced, probability of establishment is high in certain areas of the basin as all conditions are appropriate for propagation of the parasite life cycle. Tributaries to the mainstem Willamette River have the highest probability of establishment as these areas have the greatest numbers of susceptible T. tubifex. However, the abundance of resistant strains of T. tubifex could mitigate the effects of M. cerebralis if introduced. Management recommendations to reduce the likelihood of parasite dissemination are similar for Oregon and Alaska since human movement of fish and angler activities were considered the most likely routes of introduction for both regions. Based on this research, steps should also be taken to limit human movement of fish, whether by restricting carcass planting for stream enrichment in Oregon, or by prohibiting use of fish heads as bait in southcentral Alaska. The states should also allot resources to angler education and awareness of the effects of angler activity and recreation on dispersal of M. cerebralis. This could be done using a combination of brochures and signage at boat ramps describing how to prevent spread of aquatic nuisance species. Close

• 64. [Article] Review of Appraisal of the archeological resources of twelve reservoirs in the Willamette Valley, Oregon

  1 p. Review produced for HC 441: Science Colloquium: Willamette River Environmental Health, Robert D. Clark Honors College, University of Oregon, Spring term, 2004.

  Citation × Citation Citation Abstract Copy Title: Review of Appraisal of the archeological resources of twelve reservoirs in the Willamette Valley, Oregon Author: Gordon, Eleanor, River Basin Surveys, Columbia Basin Project Year: 2006, 2004 1 p. Review produced for HC 441: Science Colloquium: Willamette River Environmental Health, Robert D. Clark Honors College, University of Oregon, Spring term, 2004. Title: Review of Appraisal of the archeological resources of twelve reservoirs in the Willamette Valley, Oregon Author: Gordon, Eleanor, River Basin Surveys, Columbia Basin Project Year: 2006, 2004 1 p. Review produced for HC 441: Science Colloquium: Willamette River Environmental Health, Robert D. Clark Honors College, University of Oregon, Spring term, 2004. Close

• 65. [Article] ODFW Rogue Adult Fish Presence Survey Final Report

  Abstract -- The report contains field season information for 2001-2003. The specific objectives of this project are 1) to determine the upper limits of fish distribution in previously unsurveyed streams ...

  Citation × Citation Citation Abstract Copy Title: ODFW Rogue Adult Fish Presence Survey Final Report Abstract -- The report contains field season information for 2001-2003. The specific objectives of this project are 1) to determine the upper limits of fish distribution in previously unsurveyed streams in the Rogue Basin and 2) to locate and describe artificial barriers to fish passage. The report contains methods, results, discussion, and summary tables. Title: ODFW Rogue Adult Fish Presence Survey Final Report Abstract -- The report contains field season information for 2001-2003. The specific objectives of this project are 1) to determine the upper limits of fish distribution in previously unsurveyed streams in the Rogue Basin and 2) to locate and describe artificial barriers to fish passage. The report contains methods, results, discussion, and summary tables. Close

• 66. [Article] The Shade Credit Incentive Landscapes of the McKenzie/Willamette Confluence

  Increasing population and land use decisions have had a negative effect on the aquatic ecosystems in the Willamette River Basin. One result is elevated temperatures in many of the Basin’s streams, which ...

  Citation × Citation Citation Abstract Copy Title: The Shade Credit Incentive Landscapes of the McKenzie/Willamette Confluence Author: Shaub, Nathan C. Increasing population and land use decisions have had a negative effect on the aquatic ecosystems in the Willamette River Basin. One result is elevated temperatures in many of the Basin’s streams, which adversely affect the fish that live in these streams. There are several regulatory mechanisms in place to improve water quality; however, recent attention has been focused on market-based pollution credit trading systems as an alternative approach. Clean Water Services, the public water utility in the Tualatin Watershed near Portland recently began the first program in the country to trade temperature pollution credits for creating shade. This project explores the distribution of high and low shade credit potential in the landscape around the confluence of the Willamette and McKenzie Rivers using the peer reviewed WET_Temp stream temperature model. The intent of this project is to provide a tool for land use planners to explore the geographic characteristics of high incentive areas (high shade potential) and target these areas with shade credit programs. Also, this project explores the effects of management decisions on the changing shade credit incentive landscape. Title: The Shade Credit Incentive Landscapes of the McKenzie/Willamette Confluence Author: Shaub, Nathan C. Increasing population and land use decisions have had a negative effect on the aquatic ecosystems in the Willamette River Basin. One result is elevated temperatures in many of the Basin’s streams, which adversely affect the fish that live in these streams. There are several regulatory mechanisms in place to improve water quality; however, recent attention has been focused on market-based pollution credit trading systems as an alternative approach. Clean Water Services, the public water utility in the Tualatin Watershed near Portland recently began the first program in the country to trade temperature pollution credits for creating shade. This project explores the distribution of high and low shade credit potential in the landscape around the confluence of the Willamette and McKenzie Rivers using the peer reviewed WET_Temp stream temperature model. The intent of this project is to provide a tool for land use planners to explore the geographic characteristics of high incentive areas (high shade potential) and target these areas with shade credit programs. Also, this project explores the effects of management decisions on the changing shade credit incentive landscape. Close

• 67. [Article] Historical changes in stream habitats in the Columbia River basin

  Knowledge of how stream habitats change over time in natural and human-influenced ecosystems at large, regional scales is currently limited. A historical stream survey (1934-1945) was compared to current ...

  Citation × Citation Citation Abstract Copy Title: Historical changes in stream habitats in the Columbia River basin Author: McIntosh, Bruce A. Knowledge of how stream habitats change over time in natural and human-influenced ecosystems at large, regional scales is currently limited. A historical stream survey (1934-1945) was compared to current surveys to assess changes in poo1 habitats in the Columbia River basin. Streams from across the basin, representing a wide range of geologies, stream sizes and land-use histories, were used to evaluate habitat change. We classified streams as managed or unmanaged, based on their land-use histories. Managed basins were watersheds managed predominantly for multiple-use (e.g., timber harvest, livestock grazing) and unmanaged basins were minimally affected by human disturbance (e.g., wilderness/roadless areas). The quantity and quality of pool habitats increased or remained the same in unmanaged streams, and decreased in managed streams since the 1930s. Despite differences in stream size and land-use history, the magnitude and direction of theses changes were consistent. In addition, the decrease in pool habitats did not differ between public and private lands. Ecoregions were used to assess regional patterns to these changes. Our analysis showed that pool habitats decreased in all Ecoregions except the North Cascades Ecoregion. Regional land-use histories were documented for the study streams. The overgrazing of most rangelands had been documented by 1900. Grazing practices began to change after 1930, but current information suggests that while uplands have improved, riparian areas have not. By World War II, stream habitats had been affected by the loss of riparian vegetation, large woody debris, and aquatic habitats due to splash dams, log drives, and riparian timber harvest. Timber harvest expanded to the uplands after World War II, as the demand for timber expanded. Rapidly developing road networks increased runoff and sedimentation, which continued the impact of timber harvest on already damaged stream ecosystems. Almost 90% of managed streams had roads along the channel or within the floodplain. "Stream improvements," such as channelization and stream cleaning, also affected stream ecosystems. We concluded that the chronic and persistent effects of land-use practices had simplified stream channels and reduced habitat complexity in most managed watersheds in the Columbia River basin. Title: Historical changes in stream habitats in the Columbia River basin Author: McIntosh, Bruce A. Knowledge of how stream habitats change over time in natural and human-influenced ecosystems at large, regional scales is currently limited. A historical stream survey (1934-1945) was compared to current surveys to assess changes in poo1 habitats in the Columbia River basin. Streams from across the basin, representing a wide range of geologies, stream sizes and land-use histories, were used to evaluate habitat change. We classified streams as managed or unmanaged, based on their land-use histories. Managed basins were watersheds managed predominantly for multiple-use (e.g., timber harvest, livestock grazing) and unmanaged basins were minimally affected by human disturbance (e.g., wilderness/roadless areas). The quantity and quality of pool habitats increased or remained the same in unmanaged streams, and decreased in managed streams since the 1930s. Despite differences in stream size and land-use history, the magnitude and direction of theses changes were consistent. In addition, the decrease in pool habitats did not differ between public and private lands. Ecoregions were used to assess regional patterns to these changes. Our analysis showed that pool habitats decreased in all Ecoregions except the North Cascades Ecoregion. Regional land-use histories were documented for the study streams. The overgrazing of most rangelands had been documented by 1900. Grazing practices began to change after 1930, but current information suggests that while uplands have improved, riparian areas have not. By World War II, stream habitats had been affected by the loss of riparian vegetation, large woody debris, and aquatic habitats due to splash dams, log drives, and riparian timber harvest. Timber harvest expanded to the uplands after World War II, as the demand for timber expanded. Rapidly developing road networks increased runoff and sedimentation, which continued the impact of timber harvest on already damaged stream ecosystems. Almost 90% of managed streams had roads along the channel or within the floodplain. "Stream improvements," such as channelization and stream cleaning, also affected stream ecosystems. We concluded that the chronic and persistent effects of land-use practices had simplified stream channels and reduced habitat complexity in most managed watersheds in the Columbia River basin. Close

• 68. [Image] Oregon lampreys : natural history, status, and analysis of management issues

  	Executive Summary The jawless lampreys are remnants of the oldest vertebrates in the world. Oregon has somewhere between eight and a dozen species of these primitive fishes. Their taxonomy is obscure ...
  	Citation × Citation Citation Abstract Copy Title: Oregon lampreys : natural history, status, and analysis of management issues Author: Kostow, Kathryn Year: 2002, 2008, 2005 Executive Summary The jawless lampreys are remnants of the oldest vertebrates in the world. Oregon has somewhere between eight and a dozen species of these primitive fishes. Their taxonomy is obscure because different species tend to look very similar through most of their life cycle, and they have not been well-studied in Oregon. Lampreys occur in the Columbia Basin, including the lower Snake River, along the Oregon coast, in the upper Klamath Basin, and in Goose Lake Basin in southeastern Oregon. They all begin life in fresh water where juveniles burrow into silt and filter feed on algae. As some species approach adulthood they migrate to the ocean or to lakes where they briefly become ecto-parasites, feeding on other live fishes by attaching to them with sucker disc mouths. Other species remain non-parasitic. In addition to some enigmatic species identities, we generally have very little information about the detailed distributions, life histories and basic biology of lampreys. Lampreys became a conservation concern in the early 1990s when tribal co-managers and some Oregon Department of Fish and Wildlife (ODFW) staff noted that populations of Pacific Lampreys, Lampetra tridentata, were apparently declining to perilously low numbers. Pacific Lampreys were listed as an Oregon State sensitive species in 1993 and were given further legal protected status by the state in 1997 (OAR 635-044-0130). Lamprey status is difficult to assess for several reasons: 1) Most observations of lampreys in fresh water are of juveniles and it is difficult to tell the various species apart, even to the extent that the various species are currently clearly designated; 2) Data on lamprey is only collected incidental to monitoring of salmonids. The design and efficiency of the data collection effort is not always adequate for lampreys; and 3) We have very few historic data sets for lampreys. Therefore we often cannot determine how the abundances and distributions we see now compare with those in the past. The limited data that we have suggests that lampreys have declined through many parts of their ranges. The most precipitous declines appear to be in the upper Columbia and Snake basins where we have some historic data from mainstem dam counts. Pacific Lampreys have declined to only about 200 adults annually passing the Snake River dams. We also have evidence of declines of Pacific Lampreys in the lower Columbia and on the Oregon coast, although our data is quite limited. We have little to no information about any of the other species of lampreys. We are not even sure whether some of the recognized species, like the River Lamprey (L. ayresi), is still present in Oregon. This paper concludes with a Problem Analysis for Oregon lampreys. Our biggest problem is poor information, ranging from not knowing basic species identity to having inefficient or no systematic monitoring of lamprey abundance and distribution. ODFW continued an annual harvest on Pacific Lamprey in the Willamette Basin in 2001, but we lack the necessary information to assess the affects of the harvest on the population. Major habitat problems that affect lampreys include upstream passage over artificial barriers, a need for lamprey-friendly screening of water diversions, and urban and agricultural development of low-gradient flood plain habitats. Title: Oregon lampreys : natural history, status, and analysis of management issues Author: Kostow, Kathryn Year: 2002, 2008, 2005 Executive Summary The jawless lampreys are remnants of the oldest vertebrates in the world. Oregon has somewhere between eight and a dozen species of these primitive fishes. Their taxonomy is obscure because different species tend to look very similar through most of their life cycle, and they have not been well-studied in Oregon. Lampreys occur in the Columbia Basin, including the lower Snake River, along the Oregon coast, in the upper Klamath Basin, and in Goose Lake Basin in southeastern Oregon. They all begin life in fresh water where juveniles burrow into silt and filter feed on algae. As some species approach adulthood they migrate to the ocean or to lakes where they briefly become ecto-parasites, feeding on other live fishes by attaching to them with sucker disc mouths. Other species remain non-parasitic. In addition to some enigmatic species identities, we generally have very little information about the detailed distributions, life histories and basic biology of lampreys. Lampreys became a conservation concern in the early 1990s when tribal co-managers and some Oregon Department of Fish and Wildlife (ODFW) staff noted that populations of Pacific Lampreys, Lampetra tridentata, were apparently declining to perilously low numbers. Pacific Lampreys were listed as an Oregon State sensitive species in 1993 and were given further legal protected status by the state in 1997 (OAR 635-044-0130). Lamprey status is difficult to assess for several reasons: 1) Most observations of lampreys in fresh water are of juveniles and it is difficult to tell the various species apart, even to the extent that the various species are currently clearly designated; 2) Data on lamprey is only collected incidental to monitoring of salmonids. The design and efficiency of the data collection effort is not always adequate for lampreys; and 3) We have very few historic data sets for lampreys. Therefore we often cannot determine how the abundances and distributions we see now compare with those in the past. The limited data that we have suggests that lampreys have declined through many parts of their ranges. The most precipitous declines appear to be in the upper Columbia and Snake basins where we have some historic data from mainstem dam counts. Pacific Lampreys have declined to only about 200 adults annually passing the Snake River dams. We also have evidence of declines of Pacific Lampreys in the lower Columbia and on the Oregon coast, although our data is quite limited. We have little to no information about any of the other species of lampreys. We are not even sure whether some of the recognized species, like the River Lamprey (L. ayresi), is still present in Oregon. This paper concludes with a Problem Analysis for Oregon lampreys. Our biggest problem is poor information, ranging from not knowing basic species identity to having inefficient or no systematic monitoring of lamprey abundance and distribution. ODFW continued an annual harvest on Pacific Lamprey in the Willamette Basin in 2001, but we lack the necessary information to assess the affects of the harvest on the population. Major habitat problems that affect lampreys include upstream passage over artificial barriers, a need for lamprey-friendly screening of water diversions, and urban and agricultural development of low-gradient flood plain habitats. Close

• 69. [Article] Watershed and climate influences on flood frequency distributions in the Willamette River basin

  Problem areas identified are: The needs a) to develop curve fitting procedures to estimate flood flow distributions; b) to incorporate precipitation data into frequency analysis procedures; and c) to better ...

  Citation × Citation Citation Abstract Copy Title: Watershed and climate influences on flood frequency distributions in the Willamette River basin Author: Tolle, Timothy Victor Problem areas identified are: The needs a) to develop curve fitting procedures to estimate flood flow distributions; b) to incorporate precipitation data into frequency analysis procedures; and c) to better define flood potentials for ungauged streams. Closely related to the above, it is noted that variables commonly used to estimate flood magnitudes usually do not serve as optimum predictors. Hydrophysical variables are shown to increase the ability to estimate flood magnitudes of all frequencies within the Willamette River basin of western Oregon. The major hypotheses tested show that the traditional "regionalization" procedure is not hydrologically sound. The objective herein is to regionalize flood distributions by basin parameters. These parameters include climatic variables that are hydrologically meaningful and easy to measure or estimate. Regression equations are developed to estimate the descriptive statistics of each stream's flood distribution. The mean of the logarithms of the annual peak flows describes numerically the position of a flood frequency curve. The standard deviation of the logarithms of the peak flows describes numerically the slope of the flood frequency curve assuming a log-normal or log Pearson type III distribution. Watershed relief is the strongest estimator of flood distributions for all but the low elevation streams (R² = 56%). Relief influences within-basin climatic variability. Large flood climatology differences yield desynchronized runoff from the various source areas. Only rarely do the different elevation areas synchronize and then they yield exceptionally large peak flows. Antecedent conditions are shown to be related to flood distributions. Those basins with large year-to-year differences in antecedent conditions have steeper flood frequency curves (R² = 76%). Precipitation zones, soil permeability, and forest cover all influence antecedent conditions. Drier basins with permeable soils and forest cover have steeper flood frequency curves. Lakes and ponds act as sinks on all peak flows, and streams which flow through them have less steep flood frequency curves. In combination with watershed relief and mean annual precipitation, these three variables explain 86% of the stream-to-stream differences in the slopes of flood frequency curves in the Willamette River basin. Drainage area, terrain roughness, forest cover, and precipitation explain over 95% of the stream-to-stream differences in average flood magnitudes. Steeper slopes yield larger flood peaks as does lesser forest cover. As elevation increases, average flood magnitudes decrease, but extreme peak flows are larger. Collectively these estimation equations reduce standard errors of 50-year floods from over 40% to less than 14%. They also reduce standard errors of ten-year and 25-year floods from 46% to 15%. Title: Watershed and climate influences on flood frequency distributions in the Willamette River basin Author: Tolle, Timothy Victor Problem areas identified are: The needs a) to develop curve fitting procedures to estimate flood flow distributions; b) to incorporate precipitation data into frequency analysis procedures; and c) to better define flood potentials for ungauged streams. Closely related to the above, it is noted that variables commonly used to estimate flood magnitudes usually do not serve as optimum predictors. Hydrophysical variables are shown to increase the ability to estimate flood magnitudes of all frequencies within the Willamette River basin of western Oregon. The major hypotheses tested show that the traditional "regionalization" procedure is not hydrologically sound. The objective herein is to regionalize flood distributions by basin parameters. These parameters include climatic variables that are hydrologically meaningful and easy to measure or estimate. Regression equations are developed to estimate the descriptive statistics of each stream's flood distribution. The mean of the logarithms of the annual peak flows describes numerically the position of a flood frequency curve. The standard deviation of the logarithms of the peak flows describes numerically the slope of the flood frequency curve assuming a log-normal or log Pearson type III distribution. Watershed relief is the strongest estimator of flood distributions for all but the low elevation streams (R² = 56%). Relief influences within-basin climatic variability. Large flood climatology differences yield desynchronized runoff from the various source areas. Only rarely do the different elevation areas synchronize and then they yield exceptionally large peak flows. Antecedent conditions are shown to be related to flood distributions. Those basins with large year-to-year differences in antecedent conditions have steeper flood frequency curves (R² = 76%). Precipitation zones, soil permeability, and forest cover all influence antecedent conditions. Drier basins with permeable soils and forest cover have steeper flood frequency curves. Lakes and ponds act as sinks on all peak flows, and streams which flow through them have less steep flood frequency curves. In combination with watershed relief and mean annual precipitation, these three variables explain 86% of the stream-to-stream differences in the slopes of flood frequency curves in the Willamette River basin. Drainage area, terrain roughness, forest cover, and precipitation explain over 95% of the stream-to-stream differences in average flood magnitudes. Steeper slopes yield larger flood peaks as does lesser forest cover. As elevation increases, average flood magnitudes decrease, but extreme peak flows are larger. Collectively these estimation equations reduce standard errors of 50-year floods from over 40% to less than 14%. They also reduce standard errors of ten-year and 25-year floods from 46% to 15%. Close

• 70. [Image] Water availability for Oregon's rivers and streams: Volume 1; Overview

  	Title from cover; "May 1991."; Includes bibliographical references (p. 19)
  	Citation × Citation Citation Abstract Copy Title: Water availability for Oregon's rivers and streams: Volume 1; Overview Author: Robison, E. George Year: 1991, 2004 Title from cover; "May 1991."; Includes bibliographical references (p. 19) Title: Water availability for Oregon's rivers and streams: Volume 1; Overview Author: Robison, E. George Year: 1991, 2004 Title from cover; "May 1991."; Includes bibliographical references (p. 19) Close