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• 1881. [Article] Length and age at maturity of female yelloweye rockfish (Sebastes rubberimus) and cabezon (Scorpaenichthys marmoratus) from Oregon waters based on histological evaluation of maturity Information Report number 2009-04

  Abstract -- Accurate estimates of female age or length at maturity are critical for the conservation of exploited fish stocks. Age at maturity is particularly important, as it strongly influences population ...

  Citation × Citation Citation Abstract Copy Title: Length and age at maturity of female yelloweye rockfish (Sebastes rubberimus) and cabezon (Scorpaenichthys marmoratus) from Oregon waters based on histological evaluation of maturity Information Report number 2009-04 Abstract -- Accurate estimates of female age or length at maturity are critical for the conservation of exploited fish stocks. Age at maturity is particularly important, as it strongly influences population model estimates of sustainable harvest rates (Clark 1991) and, along with mean body size, is an important predictor of the risk of overexploitation (Reynolds et al. 2005). For many U.S. west coast groundfish stocks, data on age and length at maturity is of poor quality. The age at maturity curves used in many stock assessments are currently based on macroscopic (visual) assessment of ovary condition. However, there is abundant evidence that histological evaluation of ovarian thin-sections, especially if combined with optimal seasonal sampling, is much more accurate (Gunderson et al. 1980, Wyllie Echeverria 1987, West 1990, Nichol and Pikitch 1994, Hannah and Parker 2007). The age data that have been used to develop curves of age at maturity for some species is also based on outdated ageing methods, such as surface aging of otoliths, as opposed to the more accurate “break and burn” technique (Barss 1989, Wyllie Echeverria 1987, Chilton and Beamish 1982). For other species, such as cabezon (Scorpaenichthys marmoratus), accurate age and growth data, based on thin-sectioning of otoliths, have just recently been developed (Grebel and Cailliet 2003). Information on age and length at maturity that is based on histological evaluation of maturity status and modern ageing techniques is therefore needed for many U.S. west coast groundfish species. Histology-based maturity data has been developed for some U.S. west coast groundfish species. These include darkblotched rockfish (Sebastes crameri, Nichol and Pikitch 1994), petrale sole (Eopsetta jordani, Hannah et al. 2002), greenstriped rockfish (Sebastes elongatus, Shaw and Gunderson 2006), Pacific ocean perch (Sebastes alutus, Hannah and Parker 2007) and rosethorn rockfish (Sebastes helvomaculatus, Shaw and Gunderson 2008). We report here on the development of similar data for female yelloweye rockfish (Sebastes rubberimus) and cabezon. Title: Length and age at maturity of female yelloweye rockfish (Sebastes rubberimus) and cabezon (Scorpaenichthys marmoratus) from Oregon waters based on histological evaluation of maturity Information Report number 2009-04 Abstract -- Accurate estimates of female age or length at maturity are critical for the conservation of exploited fish stocks. Age at maturity is particularly important, as it strongly influences population model estimates of sustainable harvest rates (Clark 1991) and, along with mean body size, is an important predictor of the risk of overexploitation (Reynolds et al. 2005). For many U.S. west coast groundfish stocks, data on age and length at maturity is of poor quality. The age at maturity curves used in many stock assessments are currently based on macroscopic (visual) assessment of ovary condition. However, there is abundant evidence that histological evaluation of ovarian thin-sections, especially if combined with optimal seasonal sampling, is much more accurate (Gunderson et al. 1980, Wyllie Echeverria 1987, West 1990, Nichol and Pikitch 1994, Hannah and Parker 2007). The age data that have been used to develop curves of age at maturity for some species is also based on outdated ageing methods, such as surface aging of otoliths, as opposed to the more accurate “break and burn” technique (Barss 1989, Wyllie Echeverria 1987, Chilton and Beamish 1982). For other species, such as cabezon (Scorpaenichthys marmoratus), accurate age and growth data, based on thin-sectioning of otoliths, have just recently been developed (Grebel and Cailliet 2003). Information on age and length at maturity that is based on histological evaluation of maturity status and modern ageing techniques is therefore needed for many U.S. west coast groundfish species. Histology-based maturity data has been developed for some U.S. west coast groundfish species. These include darkblotched rockfish (Sebastes crameri, Nichol and Pikitch 1994), petrale sole (Eopsetta jordani, Hannah et al. 2002), greenstriped rockfish (Sebastes elongatus, Shaw and Gunderson 2006), Pacific ocean perch (Sebastes alutus, Hannah and Parker 2007) and rosethorn rockfish (Sebastes helvomaculatus, Shaw and Gunderson 2008). We report here on the development of similar data for female yelloweye rockfish (Sebastes rubberimus) and cabezon. Close

• 1882. [Article] Abundance Monitoring of Juvenile Salmonids In Coastal Oregon and Lower Columbia Streams, 2008 Report Number: OPSW-ODFW-2009-1

  Abstract -- As part of the Oregon Plan for Salmon and Watersheds, the Oregon Department of Fish and Wildlife (ODFW) initiated this project in 1998 to monitor the status and trend in abundance and distribution ...

  Citation × Citation Citation Abstract Copy Title: Abundance Monitoring of Juvenile Salmonids In Coastal Oregon and Lower Columbia Streams, 2008 Report Number: OPSW-ODFW-2009-1 Abstract -- As part of the Oregon Plan for Salmon and Watersheds, the Oregon Department of Fish and Wildlife (ODFW) initiated this project in 1998 to monitor the status and trend in abundance and distribution of juvenile coho salmon (Oncorhynchus kisutch) in coastal Oregon streams. This report summarizes the data collected during the summer of 2008 and, for coho salmon, compares it to data previously collected. The project originally surveyed only 1st-3rd order (tributary) streams but was expanded in 2002 to include juvenile steelhead (Oncorhynchus mykiss) and 4th-6th order (mainstem) rearing areas and in 2006 to the Oregon portion of the Lower Columbia River coho evolutionarily significant unit (ESU) (Figure 1). The sampling frame is intended to encompass all non-tidal coho and steelhead rearing habitat. The original 100k stream layer frame was replaced by a 24k frame in 2007. A Generalized Random Tessellation Stratified design (GRTS) (Stevens 2002) was used to create a spatially balanced, random point distribution. Sites were stratified by Monitoring Area (MA) and stream order (Table 1). A detailed description of the sampling frames and survey designs are found in Jepsen and Rodgers (2004) and Jepsen and Leader (2007). Field crews snorkeled all pools meeting the size criteria (6 m2 in surface area and 40 cm in maximum depth) in one kilometer of stream encompassing the GRTS point. Snorkeling was conducted during the minimum flow period from July to September using a single pass of one to four snorkelers, depending on stream width. In each pool counts were made of juvenile coho, Chinook, steelhead 90 mm, and cutthroat 90 mm. Presence was noted for dace, shiners, and trout < 90 mm. Sites with poor water clarity or quality were electrofished using a single pass without block nets to determine presence for coho, steelhead and cutthroat in each pool. To assess repeatability and quality control supervisory staff resurveyed 10% of tributary sites in each MA. Data were summarized by MA and stream order for analyses. Average pool density and percent pool occupancy for each site was averaged by MA. The percent of sites with at least one fish and with >0.7 coho/m2 are reported for each MA. 0.7 coho/m2 is regarded as full seeding after Nickelson et al. (1992) who reported full seeding based on electrofishing as 1.0 coho/m2 and Rodgers et al. (1992) who found that snorkelers observed 70% of the coho counted by electrofishing. CDFs, variances, and confidence intervals were created using tools developed by the EMAP Design and Analysis Team (EPA 2009). Title: Abundance Monitoring of Juvenile Salmonids In Coastal Oregon and Lower Columbia Streams, 2008 Report Number: OPSW-ODFW-2009-1 Abstract -- As part of the Oregon Plan for Salmon and Watersheds, the Oregon Department of Fish and Wildlife (ODFW) initiated this project in 1998 to monitor the status and trend in abundance and distribution of juvenile coho salmon (Oncorhynchus kisutch) in coastal Oregon streams. This report summarizes the data collected during the summer of 2008 and, for coho salmon, compares it to data previously collected. The project originally surveyed only 1st-3rd order (tributary) streams but was expanded in 2002 to include juvenile steelhead (Oncorhynchus mykiss) and 4th-6th order (mainstem) rearing areas and in 2006 to the Oregon portion of the Lower Columbia River coho evolutionarily significant unit (ESU) (Figure 1). The sampling frame is intended to encompass all non-tidal coho and steelhead rearing habitat. The original 100k stream layer frame was replaced by a 24k frame in 2007. A Generalized Random Tessellation Stratified design (GRTS) (Stevens 2002) was used to create a spatially balanced, random point distribution. Sites were stratified by Monitoring Area (MA) and stream order (Table 1). A detailed description of the sampling frames and survey designs are found in Jepsen and Rodgers (2004) and Jepsen and Leader (2007). Field crews snorkeled all pools meeting the size criteria (6 m2 in surface area and 40 cm in maximum depth) in one kilometer of stream encompassing the GRTS point. Snorkeling was conducted during the minimum flow period from July to September using a single pass of one to four snorkelers, depending on stream width. In each pool counts were made of juvenile coho, Chinook, steelhead 90 mm, and cutthroat 90 mm. Presence was noted for dace, shiners, and trout < 90 mm. Sites with poor water clarity or quality were electrofished using a single pass without block nets to determine presence for coho, steelhead and cutthroat in each pool. To assess repeatability and quality control supervisory staff resurveyed 10% of tributary sites in each MA. Data were summarized by MA and stream order for analyses. Average pool density and percent pool occupancy for each site was averaged by MA. The percent of sites with at least one fish and with >0.7 coho/m2 are reported for each MA. 0.7 coho/m2 is regarded as full seeding after Nickelson et al. (1992) who reported full seeding based on electrofishing as 1.0 coho/m2 and Rodgers et al. (1992) who found that snorkelers observed 70% of the coho counted by electrofishing. CDFs, variances, and confidence intervals were created using tools developed by the EMAP Design and Analysis Team (EPA 2009). Close

• 1883. [Article] 2006 Borax Lake Chub Investigations Progress Reports 2006

  Abstract -- Borax Lake chub (Gila boraxobius) is represented by a single population that inhabits a 4.1 hectare geothermally-heated alkaline lake in Harney County, Oregon. The Borax Lake chub is a small ...

  Citation × Citation Citation Abstract Copy Title: 2006 Borax Lake Chub Investigations Progress Reports 2006 Abstract -- Borax Lake chub (Gila boraxobius) is represented by a single population that inhabits a 4.1 hectare geothermally-heated alkaline lake in Harney County, Oregon. The Borax Lake chub is a small minnow endemic to Borax Lake and adjacent wetlands in Oregon’s Alvord Basin (Williams and Bond 1980). Borax Lake is a natural lake, perched 10 meters above the desert floor on sinter deposits, which is fed almost exclusively by thermal groundwater. The Borax Lake chub was listed as endangered under the federal Endangered Species Act in 1982 (U.S. Fish and Wildlife Service 1982). Population abundance estimates obtained in 1991-1996 indicated a fluctuating population ranging from a low of 8,144 fish to a high of 34,634 fish (Salzer 1997). The basis for the Borax Lake chub’s listed status was not population size, but the security of a very limited, unique, isolated, and vulnerable habitat. Because Borax Lake is situated above salt deposits on the desert floor, alteration of the salt crust shoreline could reduce lake levels and the habitat quantity and quality available to Borax Lake chub. At the time of the listing, Borax Lake was threatened by habitat alteration caused by geothermal energy development and alteration of the lake shore crust to provide irrigation to surrounding pasture lands. The Borax Lake chub federal recovery plan, completed in 1987, advocated protection of the lake ecosystem through the acquisition of key private lands, protection of groundwater and surface waters, controls on access, and the removal of livestock grazing (U.S. Fish and Wildlife Service 1987). Numerous recovery measures implemented since listing have improved the conservation status of Borax Lake chub and protection of its habitat (Williams and Macdonald 2003). When the species was listed, critical habitat was designated on 259 hectares of land surrounding the lake, including 129 hectares of public lands and two 65- hectare parcels of private land. In 1983, the U.S. Bureau of Land Management designated the public land as an Area of Critical Environmental Concern. The Nature Conservancy began leasing the private lands in 1983 and purchased them in 1993, bringing the entire critical habitat into public or conservation ownership. The Nature Conservancy ended water diversion from the lake for irrigation and livestock grazing within the critical habitat. Passage of the Steens Mountain Cooperative Management and Protection Act of 2000 removed the public BLM lands from mineral and geothermal development within a majority of the basin. These actions, combined with detailed studies of the chub and their habitat have added substantially to our knowledge of the Borax Lake ecosystem (Scoppettone et al. 1995, Salzer 1992, Perkins et al. 1996). However, three primary threats remain. These include the threat to the fragile lake shoreline, wetlands, and soils from a recent increase in recreational use around the lake (particularly off-road vehicle usage), the threat of introduction of nonnative species, and potential negative impacts to the aquifer from geothermal groundwater withdrawal if groundwater pumping were to occur on private lands outside the protected areas (Williams and Macdonald 2003). Although an increase in abundance is not a goal in the successful recovery of this species, monitoring trends in abundance over time is an important management tool to assess species status. From 1998-2004, data describing the abundance of the Borax Lake chub population are not available. Abundance estimates were obtained from 1986- 1997 by The Nature Conservancy (Salzer 1997) (Figure 1). Abundance estimates for 1986-1990 are not comparable with those obtained in 1991-1997. Prior to 1991, estimates were obtained only from traps set around the perimeter of the lake. In 1991, estimates were obtained from traps set on a regularly spaced grid throughout the lake. A study comparing the methods suggests that prior to 1991 abundance was under estimated, perhaps by as much as 50 percent (Salzer 1992). A recent review of the conservation status of the Borax Lake chub by Williams and Macdonald (2003) cited the lack of recent and ongoing population and ecosystem monitoring as one argument against downlisting or delisting the species at this time. The chub population has experienced substantial fluctuations in abundance over the time period (1986-1997) when abundance data are available (Figure 1). At the time of the review, the most recent abundance estimates that were obtained in 1996 and 1997 were some of the lowest estimates since 1991. Borax Lake chub population abundance estimates from 1986 to 1997 and 2005 to 2006. Horizontal bars represent 95% confidence limits. In 1986-1990 (solid symbols), only the perimeter of the lake was trapped. After 1990 (open symbols) the entire lake was trapped. Estimates are not directly comparable across these time periods. There are limited data on population age structure that offer valuable insight into the productivity of Borax Lake chub. Williams and Bond (1983) examined lengthfrequency data and concluded that the population consisted primarily of age 1 fish, with few age 2 and age 3 fish present. Limited opercle bone aging of chub collected in 1992- 1993 also indicated that most Borax Lake were less than one year of age (67-79%), yet a few individuals were aged at 10+ years (Scoppettone 1995). Because Borax Lake chub are only found in one location and the population is apparently dominated by a single year-class of adults, the species has a high inherent risk of extinction. 3 The objectives of this study were to: 1) obtain a mark-recapture population estimate of Borax Lake chub, and 2) to evaluate ways to reduce handling of Borax Lake chub when monitoring population abundance both by modifying previous mark-recapture protocols and by developing snorkeling survey protocols to use as an alternative to mark-recapture estimates. In addition, we collected data regarding lake temperatures, chub size (age) structure, and the condition of the fragile lake shoreline and outflows. Title: 2006 Borax Lake Chub Investigations Progress Reports 2006 Abstract -- Borax Lake chub (Gila boraxobius) is represented by a single population that inhabits a 4.1 hectare geothermally-heated alkaline lake in Harney County, Oregon. The Borax Lake chub is a small minnow endemic to Borax Lake and adjacent wetlands in Oregon’s Alvord Basin (Williams and Bond 1980). Borax Lake is a natural lake, perched 10 meters above the desert floor on sinter deposits, which is fed almost exclusively by thermal groundwater. The Borax Lake chub was listed as endangered under the federal Endangered Species Act in 1982 (U.S. Fish and Wildlife Service 1982). Population abundance estimates obtained in 1991-1996 indicated a fluctuating population ranging from a low of 8,144 fish to a high of 34,634 fish (Salzer 1997). The basis for the Borax Lake chub’s listed status was not population size, but the security of a very limited, unique, isolated, and vulnerable habitat. Because Borax Lake is situated above salt deposits on the desert floor, alteration of the salt crust shoreline could reduce lake levels and the habitat quantity and quality available to Borax Lake chub. At the time of the listing, Borax Lake was threatened by habitat alteration caused by geothermal energy development and alteration of the lake shore crust to provide irrigation to surrounding pasture lands. The Borax Lake chub federal recovery plan, completed in 1987, advocated protection of the lake ecosystem through the acquisition of key private lands, protection of groundwater and surface waters, controls on access, and the removal of livestock grazing (U.S. Fish and Wildlife Service 1987). Numerous recovery measures implemented since listing have improved the conservation status of Borax Lake chub and protection of its habitat (Williams and Macdonald 2003). When the species was listed, critical habitat was designated on 259 hectares of land surrounding the lake, including 129 hectares of public lands and two 65- hectare parcels of private land. In 1983, the U.S. Bureau of Land Management designated the public land as an Area of Critical Environmental Concern. The Nature Conservancy began leasing the private lands in 1983 and purchased them in 1993, bringing the entire critical habitat into public or conservation ownership. The Nature Conservancy ended water diversion from the lake for irrigation and livestock grazing within the critical habitat. Passage of the Steens Mountain Cooperative Management and Protection Act of 2000 removed the public BLM lands from mineral and geothermal development within a majority of the basin. These actions, combined with detailed studies of the chub and their habitat have added substantially to our knowledge of the Borax Lake ecosystem (Scoppettone et al. 1995, Salzer 1992, Perkins et al. 1996). However, three primary threats remain. These include the threat to the fragile lake shoreline, wetlands, and soils from a recent increase in recreational use around the lake (particularly off-road vehicle usage), the threat of introduction of nonnative species, and potential negative impacts to the aquifer from geothermal groundwater withdrawal if groundwater pumping were to occur on private lands outside the protected areas (Williams and Macdonald 2003). Although an increase in abundance is not a goal in the successful recovery of this species, monitoring trends in abundance over time is an important management tool to assess species status. From 1998-2004, data describing the abundance of the Borax Lake chub population are not available. Abundance estimates were obtained from 1986- 1997 by The Nature Conservancy (Salzer 1997) (Figure 1). Abundance estimates for 1986-1990 are not comparable with those obtained in 1991-1997. Prior to 1991, estimates were obtained only from traps set around the perimeter of the lake. In 1991, estimates were obtained from traps set on a regularly spaced grid throughout the lake. A study comparing the methods suggests that prior to 1991 abundance was under estimated, perhaps by as much as 50 percent (Salzer 1992). A recent review of the conservation status of the Borax Lake chub by Williams and Macdonald (2003) cited the lack of recent and ongoing population and ecosystem monitoring as one argument against downlisting or delisting the species at this time. The chub population has experienced substantial fluctuations in abundance over the time period (1986-1997) when abundance data are available (Figure 1). At the time of the review, the most recent abundance estimates that were obtained in 1996 and 1997 were some of the lowest estimates since 1991. Borax Lake chub population abundance estimates from 1986 to 1997 and 2005 to 2006. Horizontal bars represent 95% confidence limits. In 1986-1990 (solid symbols), only the perimeter of the lake was trapped. After 1990 (open symbols) the entire lake was trapped. Estimates are not directly comparable across these time periods. There are limited data on population age structure that offer valuable insight into the productivity of Borax Lake chub. Williams and Bond (1983) examined lengthfrequency data and concluded that the population consisted primarily of age 1 fish, with few age 2 and age 3 fish present. Limited opercle bone aging of chub collected in 1992- 1993 also indicated that most Borax Lake were less than one year of age (67-79%), yet a few individuals were aged at 10+ years (Scoppettone 1995). Because Borax Lake chub are only found in one location and the population is apparently dominated by a single year-class of adults, the species has a high inherent risk of extinction. 3 The objectives of this study were to: 1) obtain a mark-recapture population estimate of Borax Lake chub, and 2) to evaluate ways to reduce handling of Borax Lake chub when monitoring population abundance both by modifying previous mark-recapture protocols and by developing snorkeling survey protocols to use as an alternative to mark-recapture estimates. In addition, we collected data regarding lake temperatures, chub size (age) structure, and the condition of the fragile lake shoreline and outflows. Close

• 1884. [Article] 2009 Borax Lake Chub Investigations Progress Reports 2009

  Abstract -- The Borax Lake chub (Gila boraxobius) is a small minnow endemic to Borax Lake and adjacent wetlands in the Alvord Basin in Harney County, Oregon (Williams and Bond 1980). Borax Lake chub are ...

  Citation × Citation Citation Abstract Copy Title: 2009 Borax Lake Chub Investigations Progress Reports 2009 Abstract -- The Borax Lake chub (Gila boraxobius) is a small minnow endemic to Borax Lake and adjacent wetlands in the Alvord Basin in Harney County, Oregon (Williams and Bond 1980). Borax Lake chub are represented by a single population that inhabits a 4.1 hectare geothermally-heated alkaline lake. Borax Lake is a natural lake perched 10 meters above the desert floor on sinter deposits, which is fed almost exclusively by thermal groundwater. The Borax Lake chub was listed as endangered under the federal Endangered Species Act in 1982 (U.S. Fish and Wildlife Service 1982). Population abundance estimates obtained since 1991 indicate a fluctuating population ranging between approximately 4,000 and 34,000 fish (Salzer 1997; Scheerer and Jacobs 2008). The basis for the Borax Lake chub’s listed status was not population size, but the security of a very limited, unique, isolated, and vulnerable habitat. Because Borax Lake is situated above salt deposits on the desert floor, alteration of the salt crust shoreline could reduce lake levels and the habitat quantity and quality available to Borax Lake chub. At the time of the listing, Borax Lake was threatened by habitat alteration caused by geothermal energy development and alteration of the lake shore crust to provide irrigation to surrounding pasture lands. The Borax Lake chub federal recovery plan, completed in 1987, advocated protection of the lake ecosystem through the acquisition of key private lands, protection of groundwater and surface waters, controls on access, and the removal of livestock grazing (U.S. Fish and Wildlife Service 1987). Recovery measures implemented since listing have improved the conservation status of Borax Lake chub and protection of its habitat (Williams and Macdonald 2003). When the species was listed, critical habitat was designated on 259 hectares of land surrounding the lake, including 129 hectares of public lands and two 65-hectare parcels of private land. In 1983, the U.S. Bureau of Land Management designated the public land as an Area of Critical Environmental Concern. The Nature Conservancy began leasing the private lands in 1983 and purchased them in 1993, bringing the entire critical habitat into public or conservation ownership. The Nature Conservancy ended water diversion from the lake for irrigation and livestock grazing within the critical habitat. Passage of the Steens Mountain Cooperative Management and Protection Act of 2000 removed the public BLM lands from mineral and geothermal development within a majority of the basin. These actions, combined with detailed studies of the chub and their habitat, have added substantially to our knowledge of the Borax Lake ecosystem (Scoppettone et al. 1995, Salzer 1992, Perkins et al. 1996). However, three primary threats remain. These include the threat to the fragile lake shoreline, wetlands, and soils from a recent increase in recreational use around the lake (particularly off-road vehicle usage), the threat of introduction of nonnative species, and potential negative impacts to the aquifer from geothermal groundwater withdrawal if groundwater pumping were to occur on private lands outside the protected areas (Williams and Macdonald 2003). A review of the conservation status of the Borax Lake chub by Williams and Macdonald (2003) cited the lack of recent and ongoing population and ecosystem monitoring as one argument against downlisting or delisting the species at that time. Although an increase in abundance is not a goal in the successful recovery of this species, monitoring trends in abundance over time is an important management tool to assess species status. The objectives of this study were to: 1) obtain a mark-recapture population estimate of Borax Lake chub and 2) to evaluate habitat conditions at Borax Lake, including the condition of the fragile lake shoreline and outflows. This report describes results from monitoring conducted by Oregon Department of Fish and Wildlife’s Native Fish Investigations Project in 2009. Title: 2009 Borax Lake Chub Investigations Progress Reports 2009 Abstract -- The Borax Lake chub (Gila boraxobius) is a small minnow endemic to Borax Lake and adjacent wetlands in the Alvord Basin in Harney County, Oregon (Williams and Bond 1980). Borax Lake chub are represented by a single population that inhabits a 4.1 hectare geothermally-heated alkaline lake. Borax Lake is a natural lake perched 10 meters above the desert floor on sinter deposits, which is fed almost exclusively by thermal groundwater. The Borax Lake chub was listed as endangered under the federal Endangered Species Act in 1982 (U.S. Fish and Wildlife Service 1982). Population abundance estimates obtained since 1991 indicate a fluctuating population ranging between approximately 4,000 and 34,000 fish (Salzer 1997; Scheerer and Jacobs 2008). The basis for the Borax Lake chub’s listed status was not population size, but the security of a very limited, unique, isolated, and vulnerable habitat. Because Borax Lake is situated above salt deposits on the desert floor, alteration of the salt crust shoreline could reduce lake levels and the habitat quantity and quality available to Borax Lake chub. At the time of the listing, Borax Lake was threatened by habitat alteration caused by geothermal energy development and alteration of the lake shore crust to provide irrigation to surrounding pasture lands. The Borax Lake chub federal recovery plan, completed in 1987, advocated protection of the lake ecosystem through the acquisition of key private lands, protection of groundwater and surface waters, controls on access, and the removal of livestock grazing (U.S. Fish and Wildlife Service 1987). Recovery measures implemented since listing have improved the conservation status of Borax Lake chub and protection of its habitat (Williams and Macdonald 2003). When the species was listed, critical habitat was designated on 259 hectares of land surrounding the lake, including 129 hectares of public lands and two 65-hectare parcels of private land. In 1983, the U.S. Bureau of Land Management designated the public land as an Area of Critical Environmental Concern. The Nature Conservancy began leasing the private lands in 1983 and purchased them in 1993, bringing the entire critical habitat into public or conservation ownership. The Nature Conservancy ended water diversion from the lake for irrigation and livestock grazing within the critical habitat. Passage of the Steens Mountain Cooperative Management and Protection Act of 2000 removed the public BLM lands from mineral and geothermal development within a majority of the basin. These actions, combined with detailed studies of the chub and their habitat, have added substantially to our knowledge of the Borax Lake ecosystem (Scoppettone et al. 1995, Salzer 1992, Perkins et al. 1996). However, three primary threats remain. These include the threat to the fragile lake shoreline, wetlands, and soils from a recent increase in recreational use around the lake (particularly off-road vehicle usage), the threat of introduction of nonnative species, and potential negative impacts to the aquifer from geothermal groundwater withdrawal if groundwater pumping were to occur on private lands outside the protected areas (Williams and Macdonald 2003). A review of the conservation status of the Borax Lake chub by Williams and Macdonald (2003) cited the lack of recent and ongoing population and ecosystem monitoring as one argument against downlisting or delisting the species at that time. Although an increase in abundance is not a goal in the successful recovery of this species, monitoring trends in abundance over time is an important management tool to assess species status. The objectives of this study were to: 1) obtain a mark-recapture population estimate of Borax Lake chub and 2) to evaluate habitat conditions at Borax Lake, including the condition of the fragile lake shoreline and outflows. This report describes results from monitoring conducted by Oregon Department of Fish and Wildlife’s Native Fish Investigations Project in 2009. Close

• 1885. [Article] Warner Valley Fish Investigations- Warner Suckers Progress Reports 2008

  Abstract -- The Warner sucker (Catostomus warnerensis) is endemic to the Warner Valley, an endorheic subbasin of the Great Basin in southeastern Oregon and northwestern Nevada. This species was historically ...

  Citation × Citation Citation Abstract Copy Title: Warner Valley Fish Investigations- Warner Suckers Progress Reports 2008 Abstract -- The Warner sucker (Catostomus warnerensis) is endemic to the Warner Valley, an endorheic subbasin of the Great Basin in southeastern Oregon and northwestern Nevada. This species was historically abundant and its historical range includes three permanent lakes (Hart, Crump, and Pelican), several ephemeral lakes, a network of sloughs and diversion canals, and three major tributary drainages (Honey, Deep, and Twentymile Creeks). Warner sucker abundance and distribution has declined over the past century and it was federally listed as threatened in 1985 due to habitat fragmentation and threats posed by the proliferation of piscivorous non-native game fishes (U.S. Fish and Wildlife Service 1985). The Warner Valley is a northeast-southwest trending endorheic basin which extends approximately 90 km (Figure 1). The elevation of the valley floor is approximately 1,370 m and the basin is bound by fault block escarpments, the Warner Rim on the west and Hart Mountain and Poker Jim Ridge on the east. The Warner basin was formed during the middle Tertiary and late Quaternary geologic periods as a result of volcanic and tectonic activity (Baldwin 1976). Abundant precipitation during the Pleistocene Epoch resulted in the formation of Pluvial Lake Warner (Hubbs and Miller 1948). At its maximum extent approximately 11,000 years ago, the lake reached approximately 100 m in depth and 1,300 km2 in area (Snyder et al. 1964, Weide 1975). In 2008, precipitation and snow pack were near average and Hart and Crump Lakes never filled completely. In 2007, Crump Lake water levels were very low with less than a quarter of the surface area wetted during the winter. Both lakes have been watered continuously since 1993. The Warner sucker inhabits the lakes and low gradient stream reaches of the Warner Valley. Two life history forms are present that comprise the metapopulation of Warner suckers: lake and stream morphs. The lake suckers are lacustrine adfluvial or potamodromous fish which normally spawn in the streams. However, upstream migration may be blocked by low stream flows during dry water years or by irrigation diversion dams and spawning may occur in nearshore areas of the lakes (White et al. 1990). The stream suckers inhabit and spawn in the three major tributary drainages (Honey, Deep, and Twentymile Creeks). Large lake-dwelling populations of introduced fishes in the lakes likely reduce sucker recruitment by predation on young suckers (U.S. Fish and Wildlife Service 1998). The Recovery Plan for the Threatened and Rare Native Fishes of the Warner Basin and Alkali Subbasin (U.S. Fish and Wildlife Service 1998) sets recovery criteria for delisting the species. These criteria require that (1) a self-sustaining metapopulation is distributed throughout the Twentymile, Honey, and Deep Creek (below the falls) drainages, and in Pelican, Crump, and Hart Lakes, (2) passage is restored within and among the Twentymile, Honey, and Deep Creek (below the falls) drainages so that the individual populations of Warner suckers can function as a metapopulation, and (3) no threats exist that would likely threaten the survival of the species over a significant portion of its range. In 2008, we conducted investigations in Hart and Crump Lakes to quantify the abundance and distribution of Warner suckers, to search for evidence of recent recruitment, and to estimate sucker abundance relative to nonnative fish abundance. In addition we investigated growth and movement patterns. We used Passive Integrated Transponder (PIT) tagged suckers to determine growth rates and movements, tracked radio-tagged suckers to document seasonal spawning migrations, fished a screw trap in Twelvemile Creek to monitor downstream movements, and operated a trap at the Dyke diversion dam on Twentymile Creek to monitor upstream movements. Title: Warner Valley Fish Investigations- Warner Suckers Progress Reports 2008 Abstract -- The Warner sucker (Catostomus warnerensis) is endemic to the Warner Valley, an endorheic subbasin of the Great Basin in southeastern Oregon and northwestern Nevada. This species was historically abundant and its historical range includes three permanent lakes (Hart, Crump, and Pelican), several ephemeral lakes, a network of sloughs and diversion canals, and three major tributary drainages (Honey, Deep, and Twentymile Creeks). Warner sucker abundance and distribution has declined over the past century and it was federally listed as threatened in 1985 due to habitat fragmentation and threats posed by the proliferation of piscivorous non-native game fishes (U.S. Fish and Wildlife Service 1985). The Warner Valley is a northeast-southwest trending endorheic basin which extends approximately 90 km (Figure 1). The elevation of the valley floor is approximately 1,370 m and the basin is bound by fault block escarpments, the Warner Rim on the west and Hart Mountain and Poker Jim Ridge on the east. The Warner basin was formed during the middle Tertiary and late Quaternary geologic periods as a result of volcanic and tectonic activity (Baldwin 1976). Abundant precipitation during the Pleistocene Epoch resulted in the formation of Pluvial Lake Warner (Hubbs and Miller 1948). At its maximum extent approximately 11,000 years ago, the lake reached approximately 100 m in depth and 1,300 km2 in area (Snyder et al. 1964, Weide 1975). In 2008, precipitation and snow pack were near average and Hart and Crump Lakes never filled completely. In 2007, Crump Lake water levels were very low with less than a quarter of the surface area wetted during the winter. Both lakes have been watered continuously since 1993. The Warner sucker inhabits the lakes and low gradient stream reaches of the Warner Valley. Two life history forms are present that comprise the metapopulation of Warner suckers: lake and stream morphs. The lake suckers are lacustrine adfluvial or potamodromous fish which normally spawn in the streams. However, upstream migration may be blocked by low stream flows during dry water years or by irrigation diversion dams and spawning may occur in nearshore areas of the lakes (White et al. 1990). The stream suckers inhabit and spawn in the three major tributary drainages (Honey, Deep, and Twentymile Creeks). Large lake-dwelling populations of introduced fishes in the lakes likely reduce sucker recruitment by predation on young suckers (U.S. Fish and Wildlife Service 1998). The Recovery Plan for the Threatened and Rare Native Fishes of the Warner Basin and Alkali Subbasin (U.S. Fish and Wildlife Service 1998) sets recovery criteria for delisting the species. These criteria require that (1) a self-sustaining metapopulation is distributed throughout the Twentymile, Honey, and Deep Creek (below the falls) drainages, and in Pelican, Crump, and Hart Lakes, (2) passage is restored within and among the Twentymile, Honey, and Deep Creek (below the falls) drainages so that the individual populations of Warner suckers can function as a metapopulation, and (3) no threats exist that would likely threaten the survival of the species over a significant portion of its range. In 2008, we conducted investigations in Hart and Crump Lakes to quantify the abundance and distribution of Warner suckers, to search for evidence of recent recruitment, and to estimate sucker abundance relative to nonnative fish abundance. In addition we investigated growth and movement patterns. We used Passive Integrated Transponder (PIT) tagged suckers to determine growth rates and movements, tracked radio-tagged suckers to document seasonal spawning migrations, fished a screw trap in Twelvemile Creek to monitor downstream movements, and operated a trap at the Dyke diversion dam on Twentymile Creek to monitor upstream movements. Close

• 1886. [Article] Passage behavior of radio-tagged yearling chinook salmon and steelhead at Bonneville Dam associated with the Surface Bypass Program, 2000

  Abstract -- In 1994, the U.S. Army Corps of Engineers (COE) initiated a program to develop and evaluate surface-oriented juvenile salmonid bypass systems at hydroelectric dams on the Columbia and Snake ...

  Citation × Citation Citation Abstract Copy Title: Passage behavior of radio-tagged yearling chinook salmon and steelhead at Bonneville Dam associated with the Surface Bypass Program, 2000 Abstract -- In 1994, the U.S. Army Corps of Engineers (COE) initiated a program to develop and evaluate surface-oriented juvenile salmonid bypass systems at hydroelectric dams on the Columbia and Snake rivers. The goal of the program was to develop juvenile bypass systems that would significantly improve the passage efficiency and survival of juvenile salmonids during their downstream migration. In 1998 a prototype surface collector (PSC) was installed at Bonneville Dam's first powerhouse. The PSC was designed not to bypass fish around the turbines but rather to examine fish behavior and hydraulics at the entrances and to determine the efficacy of surface bypass at BI before building a full production surface bypass system. In 1998 and 1999, our radio telemetry evaluation indicated that only 27-49% of the fish that came within 6 m of the entrances entered the PSC. We also determined that a 6 m entrance width was more efficient than a 1.5 m entrance width. In 2000, the PSC was extended to include turbines 1-6 and each of the six entrances was 6 m wide. To continue our evaluation of the PSC in 2000, we used radio telemetry to examine the movements and behavior of subyearling chinook salmon Oncorhynchus tshawytscha in the forebay of Bonneville Dam. The objectives of this research were to: 1) determine the behavior, distribution, and approach patterns of subyearling chinook salmon in the forebay areas of Bonneville Dam; 2) determine the time and route of dam passage of sub yearling chinook salmon; 3) determine movement patterns and behavior of subyearling chinook salmon in the vicinity of the PSC; and 4) assess the efficiency and effectiveness of the PSC. From 25 April to 1 June 2000, we radio-tagged and released 1,193 juvenile hatchery steelhead and 2,075 yearling chinook salmon. These fish were released from four locations upstream of Bonneville Dam: Rock Creek, John Day Dam, The Dalles Dam, and Hood River, Oregon. Median travel times from release to Bonneville Dam ranged from 14 h to 76 h, depending on species and the location of release. Of all the fish released, we detected 80% of steelhead and 82% of chinook salmon at Bonneville Dam. Of the fish released at Hood River, we detected 95% of steelhead and 94% of chinook salmon. Median residence time in the forebay areas of Bonneville Dam ranged from 8 min to 9 .7 h, depending on species and forebay area. Discharge rates and die! periods effected residence times of both species. Passage routes were determined for 91 % of steelhead and 92% of chinook salmon detected at Bonneville Dam. Nearly half ( 49%) of steelhead passed at powerhouse one (BI), and the largest proportion ( 44%) of chinook salmon passed through the spillway. Thirty-four percent of steelhead detected at Bonneville Dam passed through the spillway. Of the steelhead that passed at Bl, 44% passed into the sluiceway, 33% were guided into the downstream migration channel (DSM) via the standard-length submersible traveling screens (STS) or extended-length submersible bar screens (ESBS), and 23% were unguided and passed directly through the turbines. Of the chinook salmon that passed at Bl, 29% passed into the sluiceway, 36% were guided into the DSM, and 35% were unguided and passed directly through the turbines. Of the fish that passed at B2, 55% of steelhead and 39% of chinook salmon were guided into the DSM by the STS and 45% of steelhead and 60% of chinook salmon passed through the turbines unguided. No steelhead and 1 % of chinook salmon were detected passing through the sluice chute at B2, which was minimally operated during spring 2000. Passage rates were highest for both species during the day at the spillway and B 1. However, passage rates were highest for both species during the night at B2. Of the fish that entered the Bl forebay, 74% of steelhead and 63% of chinook sahnon were detected within 6 m of the PSC and were therefore considered to have discovered the PSC. Of the fish that discovered the PSC, 60% of steelhead and 72% of chinook salmon entered the PSC. However, of the fish that entered the PSC, only 29% (61 of 214) of steelhead and 41 % (100 of 246) of chinook salmon entered the PSC via the entrance they were first detected at without meandering to one or more entrances. Therefore, of the fish that entered the PSC, 71 % (153 of214) of steelhead and 59% (146 of 246) of chinook salmon meandered to one or more entrances before entering the PSC. In relation to units 1-6 at B 1, the PSC was quite efficient at collecting fish. Of the fish that passed at units 1-6 (guided and unguided) 83% of steelhead and 78% of chinook salmon entered the PSC. The PSC was also relatively effective compared to water passing into the turbines and the spillway. An effectiveness of 2.5 for steelhead and 2.4 for chinook salmon indicated that the proportion of fish that entered the PSC out of total passage at units 1-6 was over twice as high as the proportion of discharge that entered the PSC out of total discharge into and under the PSC at units 1-6. When compared to spillway effectiveness (1.0 for steelhead and 1.3 for chinook salmon), PSC effectiveness was about twice as high. Since fish that entered the PSC could pass through other routes, the PSC was not considered an actual passage route for purposes of calculating passage metrics such as FPE. However, if the PSC were an actual passage route, FPE would have increased from 78% to 85% for steelhead and from 73% to 78% for chinook salmon. Title: Passage behavior of radio-tagged yearling chinook salmon and steelhead at Bonneville Dam associated with the Surface Bypass Program, 2000 Abstract -- In 1994, the U.S. Army Corps of Engineers (COE) initiated a program to develop and evaluate surface-oriented juvenile salmonid bypass systems at hydroelectric dams on the Columbia and Snake rivers. The goal of the program was to develop juvenile bypass systems that would significantly improve the passage efficiency and survival of juvenile salmonids during their downstream migration. In 1998 a prototype surface collector (PSC) was installed at Bonneville Dam's first powerhouse. The PSC was designed not to bypass fish around the turbines but rather to examine fish behavior and hydraulics at the entrances and to determine the efficacy of surface bypass at BI before building a full production surface bypass system. In 1998 and 1999, our radio telemetry evaluation indicated that only 27-49% of the fish that came within 6 m of the entrances entered the PSC. We also determined that a 6 m entrance width was more efficient than a 1.5 m entrance width. In 2000, the PSC was extended to include turbines 1-6 and each of the six entrances was 6 m wide. To continue our evaluation of the PSC in 2000, we used radio telemetry to examine the movements and behavior of subyearling chinook salmon Oncorhynchus tshawytscha in the forebay of Bonneville Dam. The objectives of this research were to: 1) determine the behavior, distribution, and approach patterns of subyearling chinook salmon in the forebay areas of Bonneville Dam; 2) determine the time and route of dam passage of sub yearling chinook salmon; 3) determine movement patterns and behavior of subyearling chinook salmon in the vicinity of the PSC; and 4) assess the efficiency and effectiveness of the PSC. From 25 April to 1 June 2000, we radio-tagged and released 1,193 juvenile hatchery steelhead and 2,075 yearling chinook salmon. These fish were released from four locations upstream of Bonneville Dam: Rock Creek, John Day Dam, The Dalles Dam, and Hood River, Oregon. Median travel times from release to Bonneville Dam ranged from 14 h to 76 h, depending on species and the location of release. Of all the fish released, we detected 80% of steelhead and 82% of chinook salmon at Bonneville Dam. Of the fish released at Hood River, we detected 95% of steelhead and 94% of chinook salmon. Median residence time in the forebay areas of Bonneville Dam ranged from 8 min to 9 .7 h, depending on species and forebay area. Discharge rates and die! periods effected residence times of both species. Passage routes were determined for 91 % of steelhead and 92% of chinook salmon detected at Bonneville Dam. Nearly half ( 49%) of steelhead passed at powerhouse one (BI), and the largest proportion ( 44%) of chinook salmon passed through the spillway. Thirty-four percent of steelhead detected at Bonneville Dam passed through the spillway. Of the steelhead that passed at Bl, 44% passed into the sluiceway, 33% were guided into the downstream migration channel (DSM) via the standard-length submersible traveling screens (STS) or extended-length submersible bar screens (ESBS), and 23% were unguided and passed directly through the turbines. Of the chinook salmon that passed at Bl, 29% passed into the sluiceway, 36% were guided into the DSM, and 35% were unguided and passed directly through the turbines. Of the fish that passed at B2, 55% of steelhead and 39% of chinook salmon were guided into the DSM by the STS and 45% of steelhead and 60% of chinook salmon passed through the turbines unguided. No steelhead and 1 % of chinook salmon were detected passing through the sluice chute at B2, which was minimally operated during spring 2000. Passage rates were highest for both species during the day at the spillway and B 1. However, passage rates were highest for both species during the night at B2. Of the fish that entered the Bl forebay, 74% of steelhead and 63% of chinook sahnon were detected within 6 m of the PSC and were therefore considered to have discovered the PSC. Of the fish that discovered the PSC, 60% of steelhead and 72% of chinook salmon entered the PSC. However, of the fish that entered the PSC, only 29% (61 of 214) of steelhead and 41 % (100 of 246) of chinook salmon entered the PSC via the entrance they were first detected at without meandering to one or more entrances. Therefore, of the fish that entered the PSC, 71 % (153 of214) of steelhead and 59% (146 of 246) of chinook salmon meandered to one or more entrances before entering the PSC. In relation to units 1-6 at B 1, the PSC was quite efficient at collecting fish. Of the fish that passed at units 1-6 (guided and unguided) 83% of steelhead and 78% of chinook salmon entered the PSC. The PSC was also relatively effective compared to water passing into the turbines and the spillway. An effectiveness of 2.5 for steelhead and 2.4 for chinook salmon indicated that the proportion of fish that entered the PSC out of total passage at units 1-6 was over twice as high as the proportion of discharge that entered the PSC out of total discharge into and under the PSC at units 1-6. When compared to spillway effectiveness (1.0 for steelhead and 1.3 for chinook salmon), PSC effectiveness was about twice as high. Since fish that entered the PSC could pass through other routes, the PSC was not considered an actual passage route for purposes of calculating passage metrics such as FPE. However, if the PSC were an actual passage route, FPE would have increased from 78% to 85% for steelhead and from 73% to 78% for chinook salmon. Close

• 1887. [Article] Fish Management Plan Detroit Reservoir 1982

  Abstract -- Detroit Reservoir is a 3,580 acre Corps of Engineers multipurpose reservoir located at river mile 48.5 on the North Santiam River. The dam is located just below the confluence of the North ...

  Citation × Citation Citation Abstract Copy Title: Fish Management Plan Detroit Reservoir 1982 Abstract -- Detroit Reservoir is a 3,580 acre Corps of Engineers multipurpose reservoir located at river mile 48.5 on the North Santiam River. The dam is located just below the confluence of the North Santiam and Breitenbush rivers. The reservoir was impounded in 1953 and is 9 miles long and over 1 mile at its widest point. Surface elevation is 1,569 ft at full pool. The reservoir is located about 50 miles east of Salem and road access is via State Highway 22. A large overnight campground and a day use area, both with boat launching facilities, are maintained by the Parks and Recreation Division of the Oregon Department of Transportation. The U.S. Forest Service (USFS) maintains two campgrounds on the south side of the reservoir, and there are two commercial boat concessions near the town of Detroit. Most of the area surrounding the lake is USFS land, although there are some private homesites on the North Santiam arm near Detroit. The reservoir receives heavy recreational use during the spring and summer months, including fishing, swimming, boating, camping, and water skiing. Fish passage structures were not incorporated in either Detroit or Big Cliff (reregulating dam) dams and consequently some 82 miles of stream are no longer available to former runs of spring chinook salmon and winter steelhead. In July 1982, the Oregon Fish and Wildlife Commission accepted the Department's recommendation to manage Detroit Reservoir for hatchery fish. Title: Fish Management Plan Detroit Reservoir 1982 Abstract -- Detroit Reservoir is a 3,580 acre Corps of Engineers multipurpose reservoir located at river mile 48.5 on the North Santiam River. The dam is located just below the confluence of the North Santiam and Breitenbush rivers. The reservoir was impounded in 1953 and is 9 miles long and over 1 mile at its widest point. Surface elevation is 1,569 ft at full pool. The reservoir is located about 50 miles east of Salem and road access is via State Highway 22. A large overnight campground and a day use area, both with boat launching facilities, are maintained by the Parks and Recreation Division of the Oregon Department of Transportation. The U.S. Forest Service (USFS) maintains two campgrounds on the south side of the reservoir, and there are two commercial boat concessions near the town of Detroit. Most of the area surrounding the lake is USFS land, although there are some private homesites on the North Santiam arm near Detroit. The reservoir receives heavy recreational use during the spring and summer months, including fishing, swimming, boating, camping, and water skiing. Fish passage structures were not incorporated in either Detroit or Big Cliff (reregulating dam) dams and consequently some 82 miles of stream are no longer available to former runs of spring chinook salmon and winter steelhead. In July 1982, the Oregon Fish and Wildlife Commission accepted the Department's recommendation to manage Detroit Reservoir for hatchery fish. Close

• 1888. [Article] Fish Management Plan Hosmer Lake 1990

  Abstract -- Hosmer Lake and it's water supply are entirely in US Forest Service ownership. The lake and adjacent lands, are managed by the Forest under recreation and visual classifications. The water ...

  Citation × Citation Citation Abstract Copy Title: Fish Management Plan Hosmer Lake 1990 Abstract -- Hosmer Lake and it's water supply are entirely in US Forest Service ownership. The lake and adjacent lands, are managed by the Forest under recreation and visual classifications. The water of the lake is state-owned and the fish resources are managed by the Oregon Department of Fish and Wildlife (ODFW). Hosmer Lake is a natural lake located about 40 miles west of Bend via County Road 46 (Century Drive) and Forest Road 470. One main campground, one overflow campground and a concrete boat ramp are managed by the Deschutes National Forest. Hosmer Lake covers 160 surface acres and lies at an elevation of 4,950 feet. Maximum water depth is 11 feet and most of the lake is very shallow. The only inlet to the lake is Quinn Creek, a spring-fed stream with a flow of 25 cfs and a near-constant temperature of 42°F. Hosmer Lake contains Atlantic salmon ("Salmo salar") and brook trout ("Salvelinus fontinalis"). The lake was chemically treated in 1957 to remove a population of carp ("Cyprinus carpio"), Tui chub ("Siphateles bicolor") and brook trout. The treatment successfully removed all carp and Tui chub, but not all brook trout. Non-game fish have not reappeared since 1957. Originally, it was hoped the Atlantic salmon would spawn successfully in Quinn Creek. However, they cannot ascend the six-foot falls in lower Quinn Creek. The pumice bottom and annual anchor-ice scouring also nullifies egg development. The population of salmon at Hosmer has been maintained soley by hatchery fish since 1958. Title: Fish Management Plan Hosmer Lake 1990 Abstract -- Hosmer Lake and it's water supply are entirely in US Forest Service ownership. The lake and adjacent lands, are managed by the Forest under recreation and visual classifications. The water of the lake is state-owned and the fish resources are managed by the Oregon Department of Fish and Wildlife (ODFW). Hosmer Lake is a natural lake located about 40 miles west of Bend via County Road 46 (Century Drive) and Forest Road 470. One main campground, one overflow campground and a concrete boat ramp are managed by the Deschutes National Forest. Hosmer Lake covers 160 surface acres and lies at an elevation of 4,950 feet. Maximum water depth is 11 feet and most of the lake is very shallow. The only inlet to the lake is Quinn Creek, a spring-fed stream with a flow of 25 cfs and a near-constant temperature of 42°F. Hosmer Lake contains Atlantic salmon ("Salmo salar") and brook trout ("Salvelinus fontinalis"). The lake was chemically treated in 1957 to remove a population of carp ("Cyprinus carpio"), Tui chub ("Siphateles bicolor") and brook trout. The treatment successfully removed all carp and Tui chub, but not all brook trout. Non-game fish have not reappeared since 1957. Originally, it was hoped the Atlantic salmon would spawn successfully in Quinn Creek. However, they cannot ascend the six-foot falls in lower Quinn Creek. The pumice bottom and annual anchor-ice scouring also nullifies egg development. The population of salmon at Hosmer has been maintained soley by hatchery fish since 1958. Close

• 1889. [Article] Trout Management Plan Lost Lake 1982

  Abstract -- Lost Lake is located adjacent to State Highway 20 about 43 mi west of Bend and 4 mi west of the Santiam Pass. The lake has about 50 surface acres and is located at an elevation of 3,980 ft. ...

  Citation × Citation Citation Abstract Copy Title: Trout Management Plan Lost Lake 1982 Abstract -- Lost Lake is located adjacent to State Highway 20 about 43 mi west of Bend and 4 mi west of the Santiam Pass. The lake has about 50 surface acres and is located at an elevation of 3,980 ft. Three tributaries enter the lake, the largest being Lost Lake Creek. The lake has a maximum depth of 12 ft, but most of the lake basin is from 3 to 4 ft deep. The U.S. Forest Service (USFS) maintains a campground on the west side of the lake, but it is not accessible until snow melts. Recreational use is primarily camping and angling. The lake receives varying amounts of angling pressure. In 1979, the USFS estimated all recreational use to be 4,000 visitor days. In 1957, the lake receded to only the stream channels, as considerable flow was visible escaping through the lava fissures. With help from the local resort operator, truckloads of cinders and lava rock were used to fill the two known outlets. Water still escapes through the cinder fills, but the lake has never dropped to the low level experienced in 1957. In July 1982, the Oregon Fish and Wildlife Commission accepted the Department's recommendation to manage Lost Lake for wild and hatchery fish. Title: Trout Management Plan Lost Lake 1982 Abstract -- Lost Lake is located adjacent to State Highway 20 about 43 mi west of Bend and 4 mi west of the Santiam Pass. The lake has about 50 surface acres and is located at an elevation of 3,980 ft. Three tributaries enter the lake, the largest being Lost Lake Creek. The lake has a maximum depth of 12 ft, but most of the lake basin is from 3 to 4 ft deep. The U.S. Forest Service (USFS) maintains a campground on the west side of the lake, but it is not accessible until snow melts. Recreational use is primarily camping and angling. The lake receives varying amounts of angling pressure. In 1979, the USFS estimated all recreational use to be 4,000 visitor days. In 1957, the lake receded to only the stream channels, as considerable flow was visible escaping through the lava fissures. With help from the local resort operator, truckloads of cinders and lava rock were used to fill the two known outlets. Water still escapes through the cinder fills, but the lake has never dropped to the low level experienced in 1957. In July 1982, the Oregon Fish and Wildlife Commission accepted the Department's recommendation to manage Lost Lake for wild and hatchery fish. Close

• 1890. [Article] Fish Management Plan Tenmile Lakes System 1981

  Abstract -- The Tenmile Lakes are large, shallow, highly productive freshwater lakes located in Coos County on Oregon's Pacific Coast. North and South Tenmile lakes have respective surface areas of 970 ...

  Citation × Citation Citation Abstract Copy Title: Fish Management Plan Tenmile Lakes System 1981 Abstract -- The Tenmile Lakes are large, shallow, highly productive freshwater lakes located in Coos County on Oregon's Pacific Coast. North and South Tenmile lakes have respective surface areas of 970 and 1,170 acres and are connected by a narrow, shallow canal. Several smaller lakes also drain into Tenmile Creek below the large lakes. The lakes originally contained excellent populations of coho salmon and cutthroat trout. However, these species declined with the development of large populations of warm water fish including largemouth bass, bluegill, yellow perch, and brown bullhead. Management problems in the lakes today concern continued reduction of salmonid populations and high abundance of bluegill. Largemouth bass appear incapable of fully utilizing bluegill as forage. As a result, the Department has considered introducing additional predator species to provide fishing diversity and to better utilize bluegill. Title: Fish Management Plan Tenmile Lakes System 1981 Abstract -- The Tenmile Lakes are large, shallow, highly productive freshwater lakes located in Coos County on Oregon's Pacific Coast. North and South Tenmile lakes have respective surface areas of 970 and 1,170 acres and are connected by a narrow, shallow canal. Several smaller lakes also drain into Tenmile Creek below the large lakes. The lakes originally contained excellent populations of coho salmon and cutthroat trout. However, these species declined with the development of large populations of warm water fish including largemouth bass, bluegill, yellow perch, and brown bullhead. Management problems in the lakes today concern continued reduction of salmonid populations and high abundance of bluegill. Largemouth bass appear incapable of fully utilizing bluegill as forage. As a result, the Department has considered introducing additional predator species to provide fishing diversity and to better utilize bluegill. Close