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• 111. [Image] Upper Klamath Lake Basin nutrient-loading study: assessment of historic flows in the Williamson and Sprague Rivers

  	"The goal of the project is to quantitatively describe the nature and extent of the ground-water flow systems in the basin."
  	Citation × Citation Citation Abstract Copy Title: Upper Klamath Lake Basin nutrient-loading study: assessment of historic flows in the Williamson and Sprague Rivers Author: Risley, John C. Year: 1999, 2005, 2004 "The goal of the project is to quantitatively describe the nature and extent of the ground-water flow systems in the basin." Title: Upper Klamath Lake Basin nutrient-loading study: assessment of historic flows in the Williamson and Sprague Rivers Author: Risley, John C. Year: 1999, 2005, 2004 "The goal of the project is to quantitatively describe the nature and extent of the ground-water flow systems in the basin." Close

• 112. [Image] Distribution and biology of suckers in Lower Klamath reservoirs : 1999 final report

  	Abstract The objectives of this two-year study (1998-1999) were to document distribution, abundance, age class structure, recruitment success, and habitat use by all life history stages of shortnose and ...
  	Citation × Citation Citation Abstract Copy Title: Distribution and biology of suckers in Lower Klamath reservoirs : 1999 final report Author: Desjardins, Marc; Markle, Douglas F. Year: 2000, 2005 Abstract The objectives of this two-year study (1998-1999) were to document distribution, abundance, age class structure, recruitment success, and habitat use by all life history stages of shortnose and Lost River suckers in three lower Klamath River hydroelectric reservoirs (J. C. Boyle, Copco, and Iron Gate). Lost River sucker catches were sporadic (only 3 adult individuals total) and the focus of our analyses, therefore, shifted to shortnose suckers. Adult and larval suckers were found in all reservoirs both years. All life history stages (larvae, juveniles and adults) were found in J. C. Boyle during both years and in Copco in 1999. Juvenile suckers were not found in Copco in 1998. The number of adult shortnose suckers was highest in Copco reservoir (n=165), followed by J.C. Boyle (n=50) and Iron Gate (n=22). Larger and older individuals dominated Copco and Iron Gate reservoirs and little size structure was detected. J. C. Boyle tended to have smaller adult shortnose suckers and many size classes were present. Unidentifiable larval suckers were most abundant in Copco reservoir where historic spawning of shortnose suckers has been documented. Larval suckers in Copco and Iron Gate reservoirs were most abundant in mid to late June before quickly disappearing from catches. J. C. Boyle larval suckers peaked in mid July, attained larger sizes, and were caught later in the season. It appeared that recruitment of young-of-the-year suckers only occurred in J. C. Boyle with downstream reservoirs recruiting older individuals, perhaps those that had earlier recruited to J. C. Boyle. Tagging studies could clarify adult recruitment dynamics and an additional study of juvenile recruitment would be needed to confirm these patterns. Predation pressure may be somewhat reduced in J. C. Boyle in comparison to the other reservoirs as its fish community was dominated by native fishes while communities in Copco and Iron Gate reservoirs were dominated by exotic predators. J. C. Boyle also possessed proportionally more littoral habitat, which suggests it may provide a more stable environment for young fishes. However, our sampling was inadequate to demonstrate such relationships due to high variance in larval and juvenile catches and potentially confounding habitat variables. One such variable was water level fluctuations, which could interact with habitat and resource availability in complex ways. For example, water level fluctuations, presumed to have a negative impact, were greatest in J. C. Boyle. Extrapolation from the literature suggests it should have had the poorest habitat for larval and juvenile suckers, but our results indicated J. C. Boyle had the most young suckers. Additional study of the relationships between water level fluctuations, habitat availability, the exotic fish community, and juvenile sucker recruitment would be needed to better understand early life history ecology of endangered lake suckers in these systems. Title: Distribution and biology of suckers in Lower Klamath reservoirs : 1999 final report Author: Desjardins, Marc; Markle, Douglas F. Year: 2000, 2005 Abstract The objectives of this two-year study (1998-1999) were to document distribution, abundance, age class structure, recruitment success, and habitat use by all life history stages of shortnose and Lost River suckers in three lower Klamath River hydroelectric reservoirs (J. C. Boyle, Copco, and Iron Gate). Lost River sucker catches were sporadic (only 3 adult individuals total) and the focus of our analyses, therefore, shifted to shortnose suckers. Adult and larval suckers were found in all reservoirs both years. All life history stages (larvae, juveniles and adults) were found in J. C. Boyle during both years and in Copco in 1999. Juvenile suckers were not found in Copco in 1998. The number of adult shortnose suckers was highest in Copco reservoir (n=165), followed by J.C. Boyle (n=50) and Iron Gate (n=22). Larger and older individuals dominated Copco and Iron Gate reservoirs and little size structure was detected. J. C. Boyle tended to have smaller adult shortnose suckers and many size classes were present. Unidentifiable larval suckers were most abundant in Copco reservoir where historic spawning of shortnose suckers has been documented. Larval suckers in Copco and Iron Gate reservoirs were most abundant in mid to late June before quickly disappearing from catches. J. C. Boyle larval suckers peaked in mid July, attained larger sizes, and were caught later in the season. It appeared that recruitment of young-of-the-year suckers only occurred in J. C. Boyle with downstream reservoirs recruiting older individuals, perhaps those that had earlier recruited to J. C. Boyle. Tagging studies could clarify adult recruitment dynamics and an additional study of juvenile recruitment would be needed to confirm these patterns. Predation pressure may be somewhat reduced in J. C. Boyle in comparison to the other reservoirs as its fish community was dominated by native fishes while communities in Copco and Iron Gate reservoirs were dominated by exotic predators. J. C. Boyle also possessed proportionally more littoral habitat, which suggests it may provide a more stable environment for young fishes. However, our sampling was inadequate to demonstrate such relationships due to high variance in larval and juvenile catches and potentially confounding habitat variables. One such variable was water level fluctuations, which could interact with habitat and resource availability in complex ways. For example, water level fluctuations, presumed to have a negative impact, were greatest in J. C. Boyle. Extrapolation from the literature suggests it should have had the poorest habitat for larval and juvenile suckers, but our results indicated J. C. Boyle had the most young suckers. Additional study of the relationships between water level fluctuations, habitat availability, the exotic fish community, and juvenile sucker recruitment would be needed to better understand early life history ecology of endangered lake suckers in these systems. Close

• 113. [Image] Final progress report for fisheries investigations on Blue Creek, tributary to Klamath River, northern California, FY 1993

  	FINAL PROGRESS REPORT FOR FISHERIES INVESTIGATIONS ON BLUE CREEK, TRIBUTARY TO K1AMATH RIVER, NORTHERN CALIFORNIA FY 1993 (October 1992 - September 1993) ABSTRACT The U.S. Fish and Wildlife Service, ...
  	Citation × Citation Citation Abstract Copy Title: Final progress report for fisheries investigations on Blue Creek, tributary to Klamath River, northern California, FY 1993 Author: Longenbaugh, Matthew H.; Chan, Jeffrey R. Year: 1994, 2008, 2005 FINAL PROGRESS REPORT FOR FISHERIES INVESTIGATIONS ON BLUE CREEK, TRIBUTARY TO K1AMATH RIVER, NORTHERN CALIFORNIA FY 1993 (October 1992 - September 1993) ABSTRACT The U.S. Fish and Wildlife Service, Coastal California Fishery Resource Office (CCFRO) in Arcata, CA, was funded to investigate chinook salmon spawning use, juvenile salmonid emigration and characterize habitats in Blue Creek, Klamath Basin, CA. Investigations that began in October, 1988, have continued to date, with this reporting period covering Fiscal Year 1993 (FY 1993, October, 1992, through September, 1993). In addition, some information already presented in previous progress reports, FY 1989 - FY 1992, is summarized. In 1993, adult chinook spawner escapements were addressed by snorkel surveys of redds and carcasses. Spawner numbers were very low, with only 17 redds observed in fall/winter 1992-93. The peak count of adult chinook was 136 fish in early November. Emigrating juvenile s&lmonids were trapped at river kilometer (rkm) 3.35 with a screw trap and panel weir. The screw trapping period extended from April through July for a total of 91 trapping nights. Screw trap catches totaled 14,526 chinook, 912 steelhead and 69 coho. Chinook emigration was spread over the entire trapping period, with increases during mid-May, and from mid-June throughout July. A juvenile weir was operated 60 nights, and caught a total of 6,334 chinook, 992 steelhead, 49 coho salmon, and 0 juvenile cutthroat. The total index of production for emigrating chinook during the 1993 juvenile trapping period was 101,819. Chinook that were marked with coded-wire tags (n-12,299) were released, with other juvenile fish, into Blue Creek at rkm 3.3. Mean temperatures varied from 6.3 to 18.6 ?C and flows ranged from 0.91 cubic m/s (32 cubic feet/s) to 202.6 cubic m/s (7,160 cubic feet/s) during FY 1993. Extreme flows for FY 1993 were the lowest and highest observed by CCFRO since the project began in 1989, and lower than the previous low of the 13 years of record. Title: Final progress report for fisheries investigations on Blue Creek, tributary to Klamath River, northern California, FY 1993 Author: Longenbaugh, Matthew H.; Chan, Jeffrey R. Year: 1994, 2008, 2005 FINAL PROGRESS REPORT FOR FISHERIES INVESTIGATIONS ON BLUE CREEK, TRIBUTARY TO K1AMATH RIVER, NORTHERN CALIFORNIA FY 1993 (October 1992 - September 1993) ABSTRACT The U.S. Fish and Wildlife Service, Coastal California Fishery Resource Office (CCFRO) in Arcata, CA, was funded to investigate chinook salmon spawning use, juvenile salmonid emigration and characterize habitats in Blue Creek, Klamath Basin, CA. Investigations that began in October, 1988, have continued to date, with this reporting period covering Fiscal Year 1993 (FY 1993, October, 1992, through September, 1993). In addition, some information already presented in previous progress reports, FY 1989 - FY 1992, is summarized. In 1993, adult chinook spawner escapements were addressed by snorkel surveys of redds and carcasses. Spawner numbers were very low, with only 17 redds observed in fall/winter 1992-93. The peak count of adult chinook was 136 fish in early November. Emigrating juvenile s&lmonids were trapped at river kilometer (rkm) 3.35 with a screw trap and panel weir. The screw trapping period extended from April through July for a total of 91 trapping nights. Screw trap catches totaled 14,526 chinook, 912 steelhead and 69 coho. Chinook emigration was spread over the entire trapping period, with increases during mid-May, and from mid-June throughout July. A juvenile weir was operated 60 nights, and caught a total of 6,334 chinook, 992 steelhead, 49 coho salmon, and 0 juvenile cutthroat. The total index of production for emigrating chinook during the 1993 juvenile trapping period was 101,819. Chinook that were marked with coded-wire tags (n-12,299) were released, with other juvenile fish, into Blue Creek at rkm 3.3. Mean temperatures varied from 6.3 to 18.6 ?C and flows ranged from 0.91 cubic m/s (32 cubic feet/s) to 202.6 cubic m/s (7,160 cubic feet/s) during FY 1993. Extreme flows for FY 1993 were the lowest and highest observed by CCFRO since the project began in 1989, and lower than the previous low of the 13 years of record. Close

• 114. [Image] Biological assessment of the Klamath Project's continuing operations on southern Oregon/Northern California esu coho salmon and critical habitat for southern Oregon/northern California esu coho salmon

  	The Bureau of Reclamation (Reclamation) is the responsible Federal agency for operation of the Klamath Project (Project). Operation of the Project has been the subject of numerous previous consultations ...
  	Citation × Citation Citation Abstract Copy Title: Biological assessment of the Klamath Project's continuing operations on southern Oregon/Northern California esu coho salmon and critical habitat for southern Oregon/northern California esu coho salmon Year: 2001, 2004 The Bureau of Reclamation (Reclamation) is the responsible Federal agency for operation of the Klamath Project (Project). Operation of the Project has been the subject of numerous previous consultations with the U.S. Fish and Wildlife Service (Service) and one with the National Marine Fisheries Service (NMFS) under Section 7 of the Endangered Species Act (ESA). Severe drought conditions in 1992 and 1994 and resultant associated shortages in project water supplies coupled with the 1997 listing of the southern Oregon/northern California (SONCC) coho salmon, Oncorhynchus kisutch, as threatened in the Klamath River downstream from the Project led to a review of Reclamation 19s operations. This biological assessment (BA) describes the effects on federally-listed species (i.e., coho salmon) and its designated critical habitat from on-going operation of the project based on historic operations, as described in this BA. The biological opinion (BO) addressing this BA and any subsequent BA amendments will be among the information that will inform the development of alternatives of the long-term operations plan and environmental impact statement (EIS). Reclamation is developing a long-term operations plan and EIS for the Project. The preferred alternative for implementation from the long-term operations plan would be the subject of a separate future ESA consultation. This BA describes the needs of anadromous fish with emphasis on SONCC coho salmon. It was developed using the best available scientific and commercial information on anadromous fish in the Klamath River. Coho salmon were listed as threatened on June 6, 1997 (NMFS 1997). The NMFS published a final rule designating critical habitat for SONCC coho salmon in May, 1999 (NMFS 1999a). Designated critical habitat for SONCC coho salmon encompasses accessible reaches of all rivers (including estuarine areas and tributaries) between the Mattole River in California and the Elk River in Oregon. Critical habitat includes all waterways, substrate, and adjacent riparian zones below longstanding, naturally impassable barriers. The areas upstream from Iron Gate Dam (IGD) (river mile 190) were not proposed critical habitat because areas downstream were considered sufficient for the conservation of the species. Reclamation has not evaluated whether the action that is the subject of this BA is consistent with its trust responsibility to Klamath Basin Indian Tribes. There are several important scientific reports and analyses (e.g., Phase II flow study) currently not available to Reclamation concerning threatened coho salmon, their habitat, and water quality as it relates to appropriate river flows that may be necessary to operate the Project consistent with the trust responsibility to Klamath Basin Indian Tribes. When this additional information becomes available, Reclamation intends to consider it during the development of the Project operations plans and include it in subsequent consultations with NMFS, as appropriate. Title: Biological assessment of the Klamath Project's continuing operations on southern Oregon/Northern California esu coho salmon and critical habitat for southern Oregon/northern California esu coho salmon Year: 2001, 2004 The Bureau of Reclamation (Reclamation) is the responsible Federal agency for operation of the Klamath Project (Project). Operation of the Project has been the subject of numerous previous consultations with the U.S. Fish and Wildlife Service (Service) and one with the National Marine Fisheries Service (NMFS) under Section 7 of the Endangered Species Act (ESA). Severe drought conditions in 1992 and 1994 and resultant associated shortages in project water supplies coupled with the 1997 listing of the southern Oregon/northern California (SONCC) coho salmon, Oncorhynchus kisutch, as threatened in the Klamath River downstream from the Project led to a review of Reclamation 19s operations. This biological assessment (BA) describes the effects on federally-listed species (i.e., coho salmon) and its designated critical habitat from on-going operation of the project based on historic operations, as described in this BA. The biological opinion (BO) addressing this BA and any subsequent BA amendments will be among the information that will inform the development of alternatives of the long-term operations plan and environmental impact statement (EIS). Reclamation is developing a long-term operations plan and EIS for the Project. The preferred alternative for implementation from the long-term operations plan would be the subject of a separate future ESA consultation. This BA describes the needs of anadromous fish with emphasis on SONCC coho salmon. It was developed using the best available scientific and commercial information on anadromous fish in the Klamath River. Coho salmon were listed as threatened on June 6, 1997 (NMFS 1997). The NMFS published a final rule designating critical habitat for SONCC coho salmon in May, 1999 (NMFS 1999a). Designated critical habitat for SONCC coho salmon encompasses accessible reaches of all rivers (including estuarine areas and tributaries) between the Mattole River in California and the Elk River in Oregon. Critical habitat includes all waterways, substrate, and adjacent riparian zones below longstanding, naturally impassable barriers. The areas upstream from Iron Gate Dam (IGD) (river mile 190) were not proposed critical habitat because areas downstream were considered sufficient for the conservation of the species. Reclamation has not evaluated whether the action that is the subject of this BA is consistent with its trust responsibility to Klamath Basin Indian Tribes. There are several important scientific reports and analyses (e.g., Phase II flow study) currently not available to Reclamation concerning threatened coho salmon, their habitat, and water quality as it relates to appropriate river flows that may be necessary to operate the Project consistent with the trust responsibility to Klamath Basin Indian Tribes. When this additional information becomes available, Reclamation intends to consider it during the development of the Project operations plans and include it in subsequent consultations with NMFS, as appropriate. Close

• 115. [Image] Lower Klamath River instream flow study : scoping evaluation for the Yurok Indian Reservation

  	ABSTRACT The U.S. Fish and Wildlife Service, Lower Columbia River Fishery Resource Office was funded by Bureau of Indian Affairs to conduct an instream flow assessment for the lower Klamath River within ...
  	Citation × Citation Citation Abstract Copy Title: Lower Klamath River instream flow study : scoping evaluation for the Yurok Indian Reservation Author: Anglin, Donald R Year: 1994, 2007, 2006 ABSTRACT The U.S. Fish and Wildlife Service, Lower Columbia River Fishery Resource Office was funded by Bureau of Indian Affairs to conduct an instream flow assessment for the lower Klamath River within the Yurok Indian Reservation in northern California using the Instream Flow Incremental Methodology (IFIM). Specific study tasks consisted of developing an explicit statement of purpose, definition of the study area and target species, assembly and evaluation of hydrologic, water quality, and physical data as well as biological and fish habitat information. A reconnaissance survey of the proposed study area was also conducted. The purpose for conducting the proposed flow study was the Yurok Tribe's desire to protect the Klamath basin water supply for the production of anadromous fish. The ultimate goal was to protect, restore, and enhance the anadromous fishery resources on the Reservation and in the basin as a whole. The study area was defined as the lower Klamath River and tributaries from the confluence with the Trinity River downstream to the area of tidal influence. Although the mainstem Klamath only was proposed for flow studies, the tributaries were included in the study area as a result of their hydrologic and biological relevance. Target species were identified as chinook salmon {Oncorhynchus tshawytscha), coho salmon (0. kisutch), steelhead trout (0. mykiss) , green sturgeon {Acipenser medirostris) , eulachon (Thaleichthys pacificus) , and Pacific lamprey (Lampetra tridentata) . Assembly and evaluation of relevant information was accomplished from results of a public scoping meeting and the review of a large volume of both published and file reports as well as numerous personal communications. Hydrology of the lower Klamath River is affected by U.S. Bureau of Reclamation projects in both the upper Klamath and upper Trinity subbasins. Several hydroelectric projects in the upper Klamath subbasin affect flow patterns, and agricultural activities in the upper Klamath subbasin and tributaries and the Central Valley Project in the upper Trinity subbasin have reduced water yield from the basin. Water quality concerns were identified as elevated water temperatures and nutrient levels resulting from land use activities throughout the basin. Hydrologic and water quality impacts are partially mitigated in the lower Klamath by tributary inflow throughout the basin. The physical environment in the basin has been altered by land use practices and several major flood events. Alterations include loss of riparian vegetation and stream channel stability, loss of soil moisture storage capacity and infiltration potential, debris slides and logjams resulting in migration barriers, reduced supply of large woody debris for recruitment into the stream channel, and sedimentation of spawning and rearing habitat. Fish habitat in most lower Klamath tributaries has been surveyed and deficiencies as well as good quality habitat have been described. Significant production potential exists in most tributaries, however much restoration work needs to be completed to realize the potential. Habitat characteristics for the mainstem Klamath have not been described. Life history and production data are presented for target species and a brief review of sources for suitability criteria is presented. Harvest management and escapement for naturally spawning fall chinook salmon were reviewed from 1978 through 1993. Escapement has varied over the years but a general downward trend in naturally spawning fall chinook can be observed, particularly in recent years. Escapement goals for the Klamath basin varied from 115,000 in 1978 to an "emergency" floor of 27,000 in 1992. Actual escapement of naturally spawning adult fall chinook varied from a high of 113,000 in 1986 to a low of 11,600 in 1991. Escapement in 1978 totalled 58,500 and preliminary estimates of escapement in 1993 were 21,000 naturally spawning adults. Factors affecting production and subsequent stock size and escapement included variable ocean survival, degraded freshwater habitat conditions, the recent six-year drought, releases of large numbers of hatchery juveniles, and harvest management methodologies that have failed to adequately match harvest to predicted stock size. Differential harvest rates for Klamath and Trinity subbasin fall chinook have also complicated attempts to structure the harvest. Field reconnaisance surveys were conducted in spring and summer 1993 for the proposed mainstem Klamath study area. Two distinct river segments were identified based on macrohabitat characteristics. Microhabitat was classified within each river segment and mapped on USGS quadrangle maps. Cross section identification was postponed pending the decision to move forward with the flow study. Following the scoping tasks described above, conclusions and recommendations were developed. No information was reviewed that indicated the need for an instream flow study in the lower Klamath River. The two basic problems affecting anadromous fish production are degraded freshwater habitat and chronic underescapement. Coordination and planning for instream flow studies on a basin-wide scale was recommended. Biological data gaps were identified which need to be addressed before an instream flow study can be completed for the lower Klamath. Suitability criteria for habitat analysis also need to be identified. Habitat restoration and protection and proper management of anadromous fishery resources were identified as the highest priorities to begin restoration of anadromous stocks. Specific recommendations for habitat restoration included watershed and riparian zone restoration, barrier removal, instream habitat inventory, restoration, and monitoring, estuary studies, and description of streamflow characteristics for lower Klamath tributaries. Recommended fishery resource studies included collection of basic life history data, monitoring for adult escapement and juvenile production, description of estuary usage, effects of hatchery programs on both adult and juvenile wild fish, evaluation of the accelerated stocking program, and refinement of harvest management methodologies to achieve appropriate escapement of naturally spawning stocks into all subbasins. Title: Lower Klamath River instream flow study : scoping evaluation for the Yurok Indian Reservation Author: Anglin, Donald R Year: 1994, 2007, 2006 ABSTRACT The U.S. Fish and Wildlife Service, Lower Columbia River Fishery Resource Office was funded by Bureau of Indian Affairs to conduct an instream flow assessment for the lower Klamath River within the Yurok Indian Reservation in northern California using the Instream Flow Incremental Methodology (IFIM). Specific study tasks consisted of developing an explicit statement of purpose, definition of the study area and target species, assembly and evaluation of hydrologic, water quality, and physical data as well as biological and fish habitat information. A reconnaissance survey of the proposed study area was also conducted. The purpose for conducting the proposed flow study was the Yurok Tribe's desire to protect the Klamath basin water supply for the production of anadromous fish. The ultimate goal was to protect, restore, and enhance the anadromous fishery resources on the Reservation and in the basin as a whole. The study area was defined as the lower Klamath River and tributaries from the confluence with the Trinity River downstream to the area of tidal influence. Although the mainstem Klamath only was proposed for flow studies, the tributaries were included in the study area as a result of their hydrologic and biological relevance. Target species were identified as chinook salmon {Oncorhynchus tshawytscha), coho salmon (0. kisutch), steelhead trout (0. mykiss) , green sturgeon {Acipenser medirostris) , eulachon (Thaleichthys pacificus) , and Pacific lamprey (Lampetra tridentata) . Assembly and evaluation of relevant information was accomplished from results of a public scoping meeting and the review of a large volume of both published and file reports as well as numerous personal communications. Hydrology of the lower Klamath River is affected by U.S. Bureau of Reclamation projects in both the upper Klamath and upper Trinity subbasins. Several hydroelectric projects in the upper Klamath subbasin affect flow patterns, and agricultural activities in the upper Klamath subbasin and tributaries and the Central Valley Project in the upper Trinity subbasin have reduced water yield from the basin. Water quality concerns were identified as elevated water temperatures and nutrient levels resulting from land use activities throughout the basin. Hydrologic and water quality impacts are partially mitigated in the lower Klamath by tributary inflow throughout the basin. The physical environment in the basin has been altered by land use practices and several major flood events. Alterations include loss of riparian vegetation and stream channel stability, loss of soil moisture storage capacity and infiltration potential, debris slides and logjams resulting in migration barriers, reduced supply of large woody debris for recruitment into the stream channel, and sedimentation of spawning and rearing habitat. Fish habitat in most lower Klamath tributaries has been surveyed and deficiencies as well as good quality habitat have been described. Significant production potential exists in most tributaries, however much restoration work needs to be completed to realize the potential. Habitat characteristics for the mainstem Klamath have not been described. Life history and production data are presented for target species and a brief review of sources for suitability criteria is presented. Harvest management and escapement for naturally spawning fall chinook salmon were reviewed from 1978 through 1993. Escapement has varied over the years but a general downward trend in naturally spawning fall chinook can be observed, particularly in recent years. Escapement goals for the Klamath basin varied from 115,000 in 1978 to an "emergency" floor of 27,000 in 1992. Actual escapement of naturally spawning adult fall chinook varied from a high of 113,000 in 1986 to a low of 11,600 in 1991. Escapement in 1978 totalled 58,500 and preliminary estimates of escapement in 1993 were 21,000 naturally spawning adults. Factors affecting production and subsequent stock size and escapement included variable ocean survival, degraded freshwater habitat conditions, the recent six-year drought, releases of large numbers of hatchery juveniles, and harvest management methodologies that have failed to adequately match harvest to predicted stock size. Differential harvest rates for Klamath and Trinity subbasin fall chinook have also complicated attempts to structure the harvest. Field reconnaisance surveys were conducted in spring and summer 1993 for the proposed mainstem Klamath study area. Two distinct river segments were identified based on macrohabitat characteristics. Microhabitat was classified within each river segment and mapped on USGS quadrangle maps. Cross section identification was postponed pending the decision to move forward with the flow study. Following the scoping tasks described above, conclusions and recommendations were developed. No information was reviewed that indicated the need for an instream flow study in the lower Klamath River. The two basic problems affecting anadromous fish production are degraded freshwater habitat and chronic underescapement. Coordination and planning for instream flow studies on a basin-wide scale was recommended. Biological data gaps were identified which need to be addressed before an instream flow study can be completed for the lower Klamath. Suitability criteria for habitat analysis also need to be identified. Habitat restoration and protection and proper management of anadromous fishery resources were identified as the highest priorities to begin restoration of anadromous stocks. Specific recommendations for habitat restoration included watershed and riparian zone restoration, barrier removal, instream habitat inventory, restoration, and monitoring, estuary studies, and description of streamflow characteristics for lower Klamath tributaries. Recommended fishery resource studies included collection of basic life history data, monitoring for adult escapement and juvenile production, description of estuary usage, effects of hatchery programs on both adult and juvenile wild fish, evaluation of the accelerated stocking program, and refinement of harvest management methodologies to achieve appropriate escapement of naturally spawning stocks into all subbasins. Close

• 116. [Image] Reproductive biology and demographics of endangered Lost River and shortnose suckers in Upper Klamath Lake, Oregon

  	We analyzed the reproductive biology and demographics of the Lost River sucker Deltistes luxatus and shortnose sucker Chasmistes brevirostris, two endangered species endemic to the upper Klamath Basin ...
  	Citation × Citation Citation Abstract Copy Title: Reproductive biology and demographics of endangered Lost River and shortnose suckers in Upper Klamath Lake, Oregon Author: Perkins, David L.; Scoppettone, Gary; Buettner, Mark Year: 2000, 2005 We analyzed the reproductive biology and demographics of the Lost River sucker Deltistes luxatus and shortnose sucker Chasmistes brevirostris, two endangered species endemic to the upper Klamath Basin of Oregon and California, from 1984-1997. Lost River suckers had distinct river and lake shoreline spawning stocks, and individuals of both species commonly spawned in consecutive years. In the Williamson River and lower Sprague River, spawning migration by both species occurred mainly during a 5-week period that started within the first three weeks of April and peaked between mid April and early May, although a separate, earlier (mid March) run of Lost River suckers may also spawn in the upper Sprague River. Migration of both species was several times higher at dawn (0500-0730 h) and evening (1800-2200 h) than other times of the day. Peak migrations almost always corresponded to peaks in water temperature, usually at 10-15°C. Lost River suckers were captured at springs along the east shore of the lake from late February through mid May, with peak spawning usually in mid March to mid April. Shortnose suckers were generally captured at the springs from late March through late May, but the time of peak spawning was not determined. Size and age at maturity was determined by recruitment from a strong year class (1991). Male Lost River suckers began recruitment into the adult population at age 4+ (375-475 mm). Substantial recruitment of females did not begin until age 7+ (510-560 mm). Male and female shortnose suckers began recruitment at age 4+, with the majority offish recruited by age 5+. Males recruited at 270-370 mm; females recruited at 325-425 mm. Fecundity estimates were quite variable ranging from 44,000-236,000 eggs per female Lost River sucker and 18,000-72,000 eggs per female shortnose sucker. In 1984 and 1985, the spawning populations of both species were dominated by large, old individuals, with little indication of recent adult recruitment. In the next 13 years, only one strong year class (1991) recruited into the spawning populations of both species. This year class temporarily boosted population numbers, but annual fish kills from 1995 to 1997 eliminated most adults of both species. Associated with poor water quality caused by the proliferation and decay of blue-green algae Aphanizomenonflos-aquae, these fish kills raise concern that alterations to the lake ecosystem over the past several decades have Perkins et al. Lost River and shortnose suckers 5 increased the magnitude and frequency of poor water quality. As a result, mortality rates of all life stages may have increased, thereby disrupting the species' life history pattern and potentially decreasing long-term population viability. Introduction The Lost River sucker Deltistes luxatus and shortnose sucker Chasmistes brevirostris are large, long-lived suckers endemic to the upper Klamath Basin of Oregon and California. Both species are typically lake dwelling but migrate to tributaries or shoreline springs to spawn (Moyle 1976, Scoppettone and Vinyard 1991). Once extremely abundant (Cope 1884, Gilbert 1898), both species have experienced severe population declines and were federally listed as endangered in 1988 (USFWS 1988). Much of the original habitat of these suckers has been destroyed or altered by conversion of lake areas to agriculture, dams, instream flow diversions, and water quality problems associated with timber harvest, loss of riparian vegetation, livestock grazing, and agricultural practices (USFWS 1988). Knowledge of the life history of Lost River and shortnose suckers is fundamental to recovery of these species. The objective of this report was to present the results of studies conducted from 1987-1998 on the reproductive biology and demographics of Lost River and shortnose suckers, and to compare these results with earlier unpublished data. Study Sites Studies were conducted on Upper Klamath Lake and the lower Williamson-Sprague river system (Figure 1). These waters form the upper portion of the Klamath River Basin in south-central Oregon and represent most remaining native habitat of Lost River and shortnose suckers. Upper Klamath Lake is a remnant of pluvial Lake Modoc that included eight major basins and encompassed 2,839 km2 (Dicken 1980). Today, Upper Klamath Lake serves as a storage reservoir that provides water for agricultural irrigation, waterfowl refuges, instream flow requirements of anadromous fish, and hydroelectric power generation. At full capacity, the lake covers approximately 360 km2 and has an average depth of 2.4 m. Most deeper water (3-12 m) is restricted to narrow trenches along the western shore. Lake elevation is controlled at the outlet by Link River Title: Reproductive biology and demographics of endangered Lost River and shortnose suckers in Upper Klamath Lake, Oregon Author: Perkins, David L.; Scoppettone, Gary; Buettner, Mark Year: 2000, 2005 We analyzed the reproductive biology and demographics of the Lost River sucker Deltistes luxatus and shortnose sucker Chasmistes brevirostris, two endangered species endemic to the upper Klamath Basin of Oregon and California, from 1984-1997. Lost River suckers had distinct river and lake shoreline spawning stocks, and individuals of both species commonly spawned in consecutive years. In the Williamson River and lower Sprague River, spawning migration by both species occurred mainly during a 5-week period that started within the first three weeks of April and peaked between mid April and early May, although a separate, earlier (mid March) run of Lost River suckers may also spawn in the upper Sprague River. Migration of both species was several times higher at dawn (0500-0730 h) and evening (1800-2200 h) than other times of the day. Peak migrations almost always corresponded to peaks in water temperature, usually at 10-15°C. Lost River suckers were captured at springs along the east shore of the lake from late February through mid May, with peak spawning usually in mid March to mid April. Shortnose suckers were generally captured at the springs from late March through late May, but the time of peak spawning was not determined. Size and age at maturity was determined by recruitment from a strong year class (1991). Male Lost River suckers began recruitment into the adult population at age 4+ (375-475 mm). Substantial recruitment of females did not begin until age 7+ (510-560 mm). Male and female shortnose suckers began recruitment at age 4+, with the majority offish recruited by age 5+. Males recruited at 270-370 mm; females recruited at 325-425 mm. Fecundity estimates were quite variable ranging from 44,000-236,000 eggs per female Lost River sucker and 18,000-72,000 eggs per female shortnose sucker. In 1984 and 1985, the spawning populations of both species were dominated by large, old individuals, with little indication of recent adult recruitment. In the next 13 years, only one strong year class (1991) recruited into the spawning populations of both species. This year class temporarily boosted population numbers, but annual fish kills from 1995 to 1997 eliminated most adults of both species. Associated with poor water quality caused by the proliferation and decay of blue-green algae Aphanizomenonflos-aquae, these fish kills raise concern that alterations to the lake ecosystem over the past several decades have Perkins et al. Lost River and shortnose suckers 5 increased the magnitude and frequency of poor water quality. As a result, mortality rates of all life stages may have increased, thereby disrupting the species' life history pattern and potentially decreasing long-term population viability. Introduction The Lost River sucker Deltistes luxatus and shortnose sucker Chasmistes brevirostris are large, long-lived suckers endemic to the upper Klamath Basin of Oregon and California. Both species are typically lake dwelling but migrate to tributaries or shoreline springs to spawn (Moyle 1976, Scoppettone and Vinyard 1991). Once extremely abundant (Cope 1884, Gilbert 1898), both species have experienced severe population declines and were federally listed as endangered in 1988 (USFWS 1988). Much of the original habitat of these suckers has been destroyed or altered by conversion of lake areas to agriculture, dams, instream flow diversions, and water quality problems associated with timber harvest, loss of riparian vegetation, livestock grazing, and agricultural practices (USFWS 1988). Knowledge of the life history of Lost River and shortnose suckers is fundamental to recovery of these species. The objective of this report was to present the results of studies conducted from 1987-1998 on the reproductive biology and demographics of Lost River and shortnose suckers, and to compare these results with earlier unpublished data. Study Sites Studies were conducted on Upper Klamath Lake and the lower Williamson-Sprague river system (Figure 1). These waters form the upper portion of the Klamath River Basin in south-central Oregon and represent most remaining native habitat of Lost River and shortnose suckers. Upper Klamath Lake is a remnant of pluvial Lake Modoc that included eight major basins and encompassed 2,839 km2 (Dicken 1980). Today, Upper Klamath Lake serves as a storage reservoir that provides water for agricultural irrigation, waterfowl refuges, instream flow requirements of anadromous fish, and hydroelectric power generation. At full capacity, the lake covers approximately 360 km2 and has an average depth of 2.4 m. Most deeper water (3-12 m) is restricted to narrow trenches along the western shore. Lake elevation is controlled at the outlet by Link River Close