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Title: Kelt Reconditioning: A Research Project to Enhance Iteroparity in Columbia Basin Steelhead (Oncorhynchus mykiss), 2003 Annual Report.

Abstract

Repeat spawning is a life history strategy that is expressed by some species from the family Salmonidae. Rates of repeat spawning for post-development Columbia River steelhead Oncorhynchus mykiss populations range from 1.6 to 17%. It is expected that currently observed iteroparity rates for wild steelhead in the Basin are severely depressed due to development and operation of the hydropower system and various additional anthropogenic factors. Increasing the natural expression of historical repeat spawning rates using fish culturing methods could be a viable technique to assist the recovery of depressed steelhead populations. Reconditioning is the process of culturing post-spawned fish (kelts) in a captive environment until they are able to reinitiate feeding, growth, and redevelop mature gonads. Kelt reconditioning techniques were initially developed for Atlantic salmon Salmo salar and sea-trout S. trutta. The recent Endangered Species Act listing of many Columbia Basin steelhead populations has prompted interest in developing reconditioning methods for wild steelhead populations within the Basin. To test kelt steelhead reconditioning as a potential recovery tool, we captured wild emigrating steelhead kelts from the Yakima River and evaluated reconditioning (short and long-term) success and diet formulations at Prosser Hatchery on the Yakima River. Steelhead kelts from the Yakima Rivermore » were collected at the Chandler Juvenile Monitoring Facility (CJMF, located on the Yakima River at river kilometer 75.6) from 12 March to 28 May 2003. In total, 690 kelts were collected for reconditioning at Prosser Hatchery. Captive specimens represented 30.8% (690 of 2,235) of the entire 2002-2003 Yakima River wild steelhead population, based on fish ladder counts at Prosser Dam. All steelhead kelts were reconditioned in circular tanks, fed freeze-dried krill and received hw-wiegandt multi vit dietary supplement; long-term steelhead kelts also received Moore-Clark pellets. Oxytetracycline was administered to reconditioned fish to boost immune system response following the stress of initial capture. Formalin was also administered to prevent outbreaks of fungus and we also intubated the fish that were collected with Ivermectin{trademark} to control internal parasites (e.g., Salmincola spp.). Captured kelts were separated into two experimental groups: short-term and long-term reconditioning. Success indicators for the short-term experiment include the proportion of fish that survived the reconditioning process and the proportion of fish that initiated a feeding response. Short-term kelts were reconditioned for 3 to 7 weeks. Surviving specimens were released for natural spawning on June 4, 2003. Survival-to-release was very good for the short-term experiment, with a rate of 89.9%. Long-term steelhead kelts were held for 5-9 months then released on December 8, 2003. Long-term success indicators include the proportion of fish that survived the reconditioning process and the proportion of surviving fish that successfully remature. Survival and rematuration for long-term kelts increased as well with 62.4% surviving to release and 91.7% rematuring. A total of 47 reconditioned kelts were radio tagged to assess their spawning migration behavior and success following release from Prosser Hatchery and to evaluate in-season homing fidelity. As in previous years, the kelts reconditioned during this project will substantially bolster the number of repeat spawners in the Yakima River. Valuable knowledge regarding kelt husbandry, condition, and rearing environments were obtained during this research endeavor. The authors were very pleased with the high survival rates. Information collected during this feasibility study has been significantly incorporated into the experimental design for upcoming years of research, and is expected to continue to increase survival of long-term reconditioned fish and successful expression of iteroparity.« less

Authors:
;  [1];  [2]
  1. (Columbia River Inter-Tribal Fish Commission, Portland, OR)
  2. (Yakama Nation, Toppenish, WA)
Publication Date:
Research Org.:
Columbia River Inter-Tribal Fish Commission. Yakama Nation.
Sponsoring Org.:
United States. Bonneville Power Administration.
OSTI Identifier:
902991
Report Number(s):
DOE/BP-00004185-4
R&D Project: 200001700; TRN: US200720%%337
DOE Contract Number:
00004185
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
13 HYDRO ENERGY; 54 ENVIRONMENTAL SCIENCES; COLUMBIA RIVER; ENDANGERED SPECIES; FEEDING; FISH PASSAGE FACILITIES; FORMALDEHYDE; GONADS; JUVENILES; MONITORING; OXYTETRACYCLINE; PARASITES; PELLETS; REARING; RIVERS; SALMON; TANKS; Steelhead (Fish) - Spawning - Washington (State) - Yakima River Watershed

Citation Formats

Hatch, Douglas R., Branstetter, Ryan, and Blodgett, Joe. Kelt Reconditioning: A Research Project to Enhance Iteroparity in Columbia Basin Steelhead (Oncorhynchus mykiss), 2003 Annual Report.. United States: N. p., 2004. Web. doi:10.2172/902991.
Hatch, Douglas R., Branstetter, Ryan, & Blodgett, Joe. Kelt Reconditioning: A Research Project to Enhance Iteroparity in Columbia Basin Steelhead (Oncorhynchus mykiss), 2003 Annual Report.. United States. doi:10.2172/902991.
Hatch, Douglas R., Branstetter, Ryan, and Blodgett, Joe. Mon . "Kelt Reconditioning: A Research Project to Enhance Iteroparity in Columbia Basin Steelhead (Oncorhynchus mykiss), 2003 Annual Report.". United States. doi:10.2172/902991. https://www.osti.gov/servlets/purl/902991.
@article{osti_902991,
title = {Kelt Reconditioning: A Research Project to Enhance Iteroparity in Columbia Basin Steelhead (Oncorhynchus mykiss), 2003 Annual Report.},
author = {Hatch, Douglas R. and Branstetter, Ryan and Blodgett, Joe},
abstractNote = {Repeat spawning is a life history strategy that is expressed by some species from the family Salmonidae. Rates of repeat spawning for post-development Columbia River steelhead Oncorhynchus mykiss populations range from 1.6 to 17%. It is expected that currently observed iteroparity rates for wild steelhead in the Basin are severely depressed due to development and operation of the hydropower system and various additional anthropogenic factors. Increasing the natural expression of historical repeat spawning rates using fish culturing methods could be a viable technique to assist the recovery of depressed steelhead populations. Reconditioning is the process of culturing post-spawned fish (kelts) in a captive environment until they are able to reinitiate feeding, growth, and redevelop mature gonads. Kelt reconditioning techniques were initially developed for Atlantic salmon Salmo salar and sea-trout S. trutta. The recent Endangered Species Act listing of many Columbia Basin steelhead populations has prompted interest in developing reconditioning methods for wild steelhead populations within the Basin. To test kelt steelhead reconditioning as a potential recovery tool, we captured wild emigrating steelhead kelts from the Yakima River and evaluated reconditioning (short and long-term) success and diet formulations at Prosser Hatchery on the Yakima River. Steelhead kelts from the Yakima River were collected at the Chandler Juvenile Monitoring Facility (CJMF, located on the Yakima River at river kilometer 75.6) from 12 March to 28 May 2003. In total, 690 kelts were collected for reconditioning at Prosser Hatchery. Captive specimens represented 30.8% (690 of 2,235) of the entire 2002-2003 Yakima River wild steelhead population, based on fish ladder counts at Prosser Dam. All steelhead kelts were reconditioned in circular tanks, fed freeze-dried krill and received hw-wiegandt multi vit dietary supplement; long-term steelhead kelts also received Moore-Clark pellets. Oxytetracycline was administered to reconditioned fish to boost immune system response following the stress of initial capture. Formalin was also administered to prevent outbreaks of fungus and we also intubated the fish that were collected with Ivermectin{trademark} to control internal parasites (e.g., Salmincola spp.). Captured kelts were separated into two experimental groups: short-term and long-term reconditioning. Success indicators for the short-term experiment include the proportion of fish that survived the reconditioning process and the proportion of fish that initiated a feeding response. Short-term kelts were reconditioned for 3 to 7 weeks. Surviving specimens were released for natural spawning on June 4, 2003. Survival-to-release was very good for the short-term experiment, with a rate of 89.9%. Long-term steelhead kelts were held for 5-9 months then released on December 8, 2003. Long-term success indicators include the proportion of fish that survived the reconditioning process and the proportion of surviving fish that successfully remature. Survival and rematuration for long-term kelts increased as well with 62.4% surviving to release and 91.7% rematuring. A total of 47 reconditioned kelts were radio tagged to assess their spawning migration behavior and success following release from Prosser Hatchery and to evaluate in-season homing fidelity. As in previous years, the kelts reconditioned during this project will substantially bolster the number of repeat spawners in the Yakima River. Valuable knowledge regarding kelt husbandry, condition, and rearing environments were obtained during this research endeavor. The authors were very pleased with the high survival rates. Information collected during this feasibility study has been significantly incorporated into the experimental design for upcoming years of research, and is expected to continue to increase survival of long-term reconditioned fish and successful expression of iteroparity.},
doi = {10.2172/902991},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Mar 01 00:00:00 EST 2004},
month = {Mon Mar 01 00:00:00 EST 2004}
}

Technical Report:

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  • Repeat spawning is a life history strategy that is expressed by some species from the family salmonidae. Natural rates of repeat spawning for Columbia River steelhead Oncorhynchus mykiss populations range from 1.6 to 17%. Increasing this repeat spawning rate using fish culture techniques could assist the recovery of depressed steelhead populations. Reconditioning is the process of culturing post-spawned fish (kelts) in a captive environment until they are able to grow and develop mature gonads. Kelt reconditioning techniques were initially developed for Atlantic salmon Salmo salar and sea-trout S. trutta. The recent Endangered Species Act listing of many Columbia Basin steelheadmore » populations has prompted interest in developing reconditioning methods for local populations. The primary purpose of this project in 2000 was to test the general feasibility of collecting, feeding, and treating steelhead kelts in a captive environment. Steelhead kelts were collected from the Yakima River at the Chandler Juvenile Evaluation Facility (Rkm 48) from 12 March to 13 June 2000. Kelts were reconditioned at adjacent Prosser Hatchery in both rectangular and circular tanks and fed a mixed diet of starter paste, adult sized trout pellets, and freeze-dried krill. Formalin was used to control outbreaks of fungus, and we tested the use of ivermectin to control internal parasites (e.g., Salmincola spp.). Some the kelts that died during the reconditioning process were analyzed via pathology and gonad histology to ascertain the possible cause of death and to describe their reproductive development at the time of death. All surviving specimens were released for natural spawning on 12 December 2000. Overall success of the reconditioning process was based on the proportion of fish that survived captivity, gained weight, and on the number of fish that successfully underwent gonadal recrudescence. Many of the reconditioned kelts were radio tagged to assess their spawning migration behavior and success following release from Prosser Hatchery. In total, 512 kelts were collected for reconditioning at Prosser Hatchery. Captive specimens represented 37% (512/1,380) of the entire 1999-2000 Yakima River wild steelhead population, based on fish ladder counts at Prosser Dam. At the conclusion of the experiments ({approx}240 days from capture), 91 fish (18%) had survived and were released to spawn in the wild. Ultrasound examination--to determine sex and reproductive development--determined that 87 (96%) of 91 specimens were female, and we estimated 62 fish (12% of the total collected) had successfully reconditioned. Unfortunately, the majority (82%) of the kelts collected died during the experiment, with the bulk of the moralities occurring during the first 100 days of captivity. Much was learned from the mortalities and modifications were made to the facility to reduce loss for future projects. Overall, the kelts reconditioned during this project will substantially bolster the number of repeat spawners in the Yakima River. Knowledge regarding kelt husbandry, food type preferences, condition, and rearing environments were obtained during this research endeavor. Although the reconditioning success rate achieved (estimated at 12%) was substantially lower than we initially hoped yet still six times higher than the natural rate of respawning and the authors are encouraged by the results of this innovative project. Information collected during this feasibility study will be incorporated into the experimental design for the upcoming year of research and is expected to increase survival.« less
  • Repeat spawning is a life history strategy that is expressed by some species from the family Salmonidae. Rates of repeat spawning for post-development Columbia River steelhead (Oncorhynchus mykiss) populations range from 1.6 to 17%. It is expected that currently observed iteroparity rates for wild steelhead in the Basin are artificially and in some cases severely depressed due to development and operation of the hydropower system and various additional anthropogenic factors. Increasing the natural expression of historical repeat spawning rates using fish culturing means could be a viable technique to assist the recovery of depressed steelhead populations. Reconditioning is the processmore » of culturing post-spawned fish (kelts) in a captive environment until they are able to reinitiate feeding, growth, and again develop mature gonads. Kelt reconditioning techniques were initially developed for Atlantic salmon (Salmo salar) and sea-trout (S. trutta). The recent Endangered Species Act listing of many Columbia Basin steelhead populations has prompted interest in developing reconditioning methods for wild steelhead populations within the Basin. To address recovery, we captured wild emigrating steelhead kelts from the Yakima River and tested reconditioning and the effects of several diet formulations on its success at Prosser Hatchery on the Yakama Reservation. Steelhead kelts from the Yakima River were collected at the Chandler Juvenile Evaluation Facility (CJEF, located at Yakima River kilometer 48) from 12 March to 5 July 2001. Kelts were reconditioned in circular tanks and fed a mixed diet of starter paste, adult sized trout pellets, and freeze-dried krill. Formalin was used to control outbreaks of fungus and we tested the use of Ivermectin{trademark}to control internal parasites (e.g., Salmincola spp.). Surviving specimens were released for natural spawning in two groups on 15 November 2001 and 18 January 2002. Overall success of the reconditioning process was based on the proportion of fish that survived in captivity, gained weight, and the number of fish that successfully underwent gonadal recrudescence. Many of the reconditioned kelts were radio tagged to assess their spawning migration behavior and success following release from Prosser Hatchery. In total, 551 kelts were collected for reconditioning at Prosser Hatchery. Captive specimens represented 18.7% (551 of 2,942) of the entire 2000-2001Yakima River wild steelhead population, based on fish ladder counts at Prosser Dam. At the conclusion of the experiments (208-323 days from capture), 108 fish (19.6%) had survived and were released to spawn in the wild. Ultrasound examination--to determine sex and reproductive development--determined that 100 (94.3%) of 106 sex-identified specimens were female and we estimated that 96% of the reconditioned releases gained weight and developed mature gonads. Nearly one quarter (24.3%) of all reconditioned kelts survived for the duration of the experiment. As in previous years, the kelts reconditioned during this project will substantially bolster the number of repeat spawners in the Yakima River. Valuable knowledge regarding Kelt husbandry, food type preferences, condition, and rearing environments were obtained during this research endeavor. Although higher survival rates would have been desirable, the authors were encouraged by the positive results of this innovative project. Nearly 20% of the kelts collected were successfully reconditioned, and radio telemetry allowed us to track some of these fish to the spawning grounds and to obtain documentation of successful redd construction. Information collected during this feasibility study has been significantly incorporated into the experimental design for upcoming years of research, and is expected to continue to increase survival and successful expression of iteroparity.« less
  • Repeat spawning is a life history strategy that is expressed by some species from the family Salmonidae. Rates of repeat spawning for post-development Columbia River steelhead Oncorhynchus mykiss populations range from 1.6 to 17%. It is expected that currently observed iteroparity rates for wild steelhead in the Basin are severely depressed due to development and operation of the hydropower system and various additional anthropogenic factors. Increasing the natural expression of historical repeat spawning rates using fish culturing means could be a viable technique to assist the recovery of depressed steelhead populations. Reconditioning is the process of culturing post-spawned fish (kelts)more » in a captive environment until they are able to reinitiate feeding, growth, and again develop mature gonads. Kelt reconditioning techniques were initially developed for Atlantic salmon Salmo salar and sea-trout S. trutta. The recent Endangered Species Act listing of many Columbia Basin steelhead populations has prompted interest in developing reconditioning methods for wild steelhead populations within the Basin. To test kelt steelhead reconditioning as a potential recovery tool, we captured wild emigrating steelhead kelts from the Yakima River and evaluated reconditioning (short and long-term) success and diet formulations at Prosser Hatchery on the Yakima River. Steelhead kelts from the Yakima River were collected at the Chandler Juvenile Evaluation Facility (CJEF, located at Yakima River kilometer 48) from March 12 to June 13, 2002. In total, 899 kelts were collected for reconditioning at Prosser Hatchery. Captive specimens represented 19.8% (899 of 4,525) of the entire 2001-2002 Yakima River wild steelhead population, based on fish ladder counts at Prosser Dam. Kelts were reconditioned in circular tanks and were fed freeze-dried krill, Moore-Clark pellets, altered Moore-Clark pellets (soaked in krill extract and dyed), or a combination of the altered Moore-Clark/unaltered Moore-Clark pellets. Formalin was used to prevent outbreaks of fungus and we also intubated the fish that were collected with Ivermectin{trademark} to control internal parasites (e.g., Salmincola spp.). Captured kelts were separated into two experimental groups: short-term and long-term reconditioning. Success indicators for the short-term experiment include the proportion of fish that survived the reconditioning process and the proportion of fish that initiated a feeding response. Short-term kelts were then subsequently split into two groups for either 1 or 2-month reconditioning. Surviving specimens were released for natural spawning in two groups, corresponding with reconditioning duration, with releases on May 20/28, 2002. Survival rates for both short-term experiments were high. Long-term reconditioned kelts were subsequently split into three groups that were given three different diet formulations and then released on December 10, 2002. Long-term success indicators include the proportion of fish that survived the reconditioning process and the proportion of surviving fish that successfully remature. A total of 60 reconditioned kelts were radio tagged to assess their spawning migration behavior and success following release from Prosser Hatchery and to evaluate in-season homing fidelity. As in previous years, the kelts reconditioned during this project will substantially bolster the number of repeat spawners in the Yakima River. Valuable knowledge regarding kelt husbandry, food preferences, condition, and rearing environments were obtained during this research endeavor. Although survival rates were higher in 2002, even higher survival rates would be desirable; overall the authors were encouraged by the positive results of this innovative project. Information collected during this feasibility study has been significantly incorporated into the experimental design for upcoming years of research, and is expected to continue to increase survival and successful expression of iteroparity.« less
  • Iteroparity, the ability to repeat spawn, is a life history strategy that is expressed by some species from the family Salmonidae. Rates of repeat spawning for post-development Columbia River steelhead Oncorhynchus mykiss populations range from 1.6 to 17%. It is expected that currently observed iteroparity rates for wild steelhead in the Basin are severely depressed due to development and operation of the hydropower system and various additional anthropogenic factors. Increasing the expression of historical repeat spawning rates using fish culturing methods could be a viable technique to assist the recovery of depressed steelhead populations, and could help reestablish this naturallymore » occurring life history trait. Reconditioning is the process of culturing post-spawned fish (kelts) in a captive environment until they are able to reinitiate feeding, growth, and redevelop mature gonads. Kelt reconditioning techniques were initially developed for Atlantic salmon Salmo salar and sea-trout S. trutta. The recent Endangered Species Act listing of many Columbia River Basin steelhead populations has prompted interest in developing reconditioning methods for wild steelhead populations within the Basin. To test kelt steelhead reconditioning as a potential recovery tool, wild emigrating steelhead kelts were placed into one of three study groups (direct capture and transport, short-term reconditioning, or long-term reconditioning). Steelhead kelts from the Yakima River were collected at the Chandler Juvenile Monitoring Facility (CJMF, located on the Yakima River at river kilometer 75.6) from 15 March to 21 June 2004. In total, 842 kelts were collected for reconditioning at Prosser Hatchery. Captive specimens represented 30.5% (842 of 2,755) of the entire 2003-2004 Yakima River wild steelhead population, based on fish ladder counts at Prosser Dam. All steelhead kelts were reconditioned in 20-foot circular tanks, and fed freeze-dried krill initially or for the duration of the experiment. All steelhead kelts received hw-wiegandt multi vit dietary supplement as a means to improve initial nutrition. Long-term steelhead kelts received Moore-Clark pellets to provide essential minerals and nutrients necessary for gonadal redevelopment. Oxytetracycline was administered to all reconditioned fish to boost immune system response following the stress of initial capture. To control parasitic infestations two methods were used, first, after initial capture an intubation of Ivermectin{trademark} was administered to control internal parasites (e.g., Salmincola spp.). Next, a Formalin drip was used for the duration of reconditioning to prevent fungal outbreaks. Captured kelts were separated into three experimental groups: short-term reconditioning, long-term reconditioning, and direct transport and release. Success indicators for the short-term experiment include the proportion of fish that survived the reconditioning process and the proportion of fish that initiated a feeding response. Short-term kelts were reconditioned for 3 to 5 weeks. Surviving specimens were released for natural spawning on May 11, 2004. Survival-to-release was good for the short-term experiment, with a rate of 79.0%. Long-term steelhead kelts are currently being held for a 6-9 month period with a scheduled release in December 2004. Long-term success indicators include the proportion of fish that survived the reconditioning process and the proportion of surviving fish that successfully remature. Survival and rematuration for long-term kelts has not been determined and will be presented in the 2005 annual report. Direct transport and release kelts and short-term reconditioned kelts were radio or acoustic tagged to assess their travel time and migratory behaviors below Bonneville Dam. A total of 29 direct-transport and release kelts and 29 short-term reconditioned kelts received surgically implanted radio tags, and a total of 28 direct-transport/release and 26 short-term reconditioned fish received surgically implanted hydro acoustic tags. These tags will allow us to determine outmigration timing for adults as well as determine if reconditioning has any deleterious effects on migration behavior. Long-term reconditioned fish will have radio tags inserted gastrically to monitor migration to spawning grounds. As in previous years, the kelts reconditioned during this project should substantially bolster the number of repeat spawners in the Yakima River. Valuable knowledge regarding kelt husbandry, condition, and rearing environments were obtained during this research endeavor. The authors were very pleased with the high survival rates. Information collected during this feasibility study will be incorporated into the experimental design for next year's research, and is expected to continue to increase survival of long-term reconditioned fish and the successful expression of iteroparity.« less
  • Iteroparity, the ability to repeat spawn, is a natural life history strategy that is expressed by some species from the family Salmonidae. Estimated rates of repeat spawning for post-development Columbia River steelhead Oncorhynchus mykiss populations range from 1.6 to 17%. It is expected that currently observed iteroparity rates for wild steelhead in the Basin are severely depressed due to development and operation of the hydropower system and various additional anthropogenic factors. Increasing the current expression of repeat spawning rates using fish culturing methods could be a viable technique to assist the recovery of depressed steelhead populations, and could help reestablishmore » this naturally occurring life history trait. Reconditioning is the process of culturing post-spawned fish (kelts) in a captive environment until they are able to reinitiate feeding, growth, and redevelop mature gonads. Reconditioning techniques were initially developed for Atlantic salmon Salmo salar and sea-trout S. trutta. The recent Endangered Species Act listing of many Columbia River Basin steelhead populations has prompted interest in developing reconditioning methods for wild steelhead populations within the Basin. To test kelt steelhead reconditioning as a potential recovery tool, wild emigrating steelhead kelts were placed into one of four study groups (in river release, direct capture and transport, short-term reconditioning, or long-term reconditioning). Steelhead kelts from the Yakima River were collected at the Chandler Juvenile Monitoring Facility (CJMF, located on the Yakima River at river kilometer 75.6) from 11 March to 23 June 2005. In total, 519 kelts were collected for reconditioning at Prosser Hatchery. Captive specimens represented 15.0% (519 of 3,451) of the entire 2004-2005 Yakima River wild steelhead population, based on fish ladder counts at Prosser Dam. Steelhead kelts were reconditioned in 20-foot circular tanks, and fed freeze-dried krill initially (first 2 months of long-term reconditioning) or for the duration of the experiment. Long-term steelhead kelts also received Moore-Clark pellets to provide essential minerals and nutrients necessary for gonadal redevelopment. Oxytetracycline was administered to all reconditioned fish to boost immune system response following the stress of initial capture. To control parasitic infestations two methods were used: an intubation of Ivermectin{trademark} was administered to control internal parasites (e.g., Salmincola spp). and, a Formalin drip system was administered via drip system for the duration of reconditioning to prevent fungal outbreaks. From the steelhead kelts collected at the CJMF, four experimental groups were established; in-river release, direct transport and release, short-term reconditioning and long-term reconditioning. Short-term kelts were reconditioned for 3 to 5 weeks. Surviving specimens were released on May 13, 2005 and June 30, 2005. Long-term steelhead kelts are currently being held for a 6-9 month period with a scheduled release in late November 2005.« less