Author: United States. Bonneville Power Administration
Publisher:
ISBN:
Category : Fish hatcheries
Languages : en
Pages : 74
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Book Description
"This report provides an overview of the first 17 years of the Kootenai River white sturgeon Conservation Aquaculture Program. The report includes a description of the problems that contributed to the decline of Kootenai sturgeon, objectives of the hatchery program, a history of program development, hatchery facilities, aquaculture operations and methods, production numbers, and monitoring and evaluation results."--Program overview.
Author: United States. Bonneville Power Administration
Publisher:
ISBN:
Category : Fish habitat improvement
Languages : en
Pages : 74
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Book Description
Author: Paul J. Anders
Publisher:
ISBN:
Category : Fish hatcheries
Languages : en
Pages : 13
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Book Description
"The Kootenai Tribe of Idaho proposed an experimental hatchery program to address the decline of the white sturgeon population in the Kootenai River. Since its inception in 1990, the Kootenai River White Sturgeon Conservation Aquaculture Program has continued to meet its objective of reducing the threat of extinction by providing annual year classes from native broodstock, representing inherent genetic variability in its broodstock and progeny groups, and minimizing the introduction or transmission of pathogens or disease to the wild (source) population. By the late 1990s it became clear that non-hatchery efforts to restore recruitment were failing to counteract the extinction threat. This trend continues to the present (2008). In 2004 updated demographic analysis suggested that as few as 500 adults remained in the population, and triggered increased hatchery production for demographic and genetic conservation. In 2005, a report was prepared describing endangered Kootenai River white sturgeon population trends and causal factors of decline along with program history, protocols, and accomplishments during its first 15 years of operation (KTOI 2006). Subsequent data analysis revealed newly reduced survival rates based on lower recapture frequencies of earlier life stages and release groups of smaller fish. Embryos and free-embryos (yolks-sac larvae) released during several years in the early 2000s have provided no evidence for post-release survival to date. Review of these analyses warranted an updated report to recommend and delineate 2008 operational changes for the program. This report includes a brief program history for perspective, a summary of postrelease survival analyses of early life stages released from the Kootenai Hatchery (Justice and Pyper 2007), and recommends program operational changes for 2008. This report does not address hatchery operations beyond 2008 because the Program is currently involved in Step 1 of the Northwest Power and Conservation Council's 3- Step Hatchery Master Planning process. Recommendations regarding Program facility and operational changes beyond 2008 will be reported in future Master Planning documents."--Program overview.
Author: United States. Bonneville Power Administration
Publisher:
ISBN:
Category : Fish habitat improvement
Languages : en
Pages : 36
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Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 52
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Book Description
Kootenai River white sturgeon have been declining for at least 50 years and extinction of the wild population is now imminent (Paragamian et al. 2005). Only 630 adults were estimated to remain in 2002 from a population ten times that size just 20 years ago. Significant recruitment of young sturgeon has not been observed since the early 1970s and consistent annual recruitment has not been seen since the 1950s. The remaining wild population consists of a cohort of large, old fish that is declining by about 9% per year as fish die naturally and are not replaced. At this rate, the wild population will disappear around the year 2040. Numbers have already reached critical low levels where genetic and demographic risks are acute. The Kootenai River White Sturgeon Recovery Team was convened in 1994, provided a draft Recovery Plan in 1996 and the first complete Recovery Plan for Kootenai River white sturgeon in 1999 (USFWS 1996, 1999). The Plan outlined a four part strategy for recovery, including: (1) measures to restore natural recruitment, (2) use of conservation aquaculture to prevent extinction, (3) monitoring survival and recovery, and (4) updating and revising recovery plan criteria and objectives as new information becomes available. Sturgeon recovery efforts are occurring against a backdrop of a broader ecosystem protection and restoration program for the Kootenai River ecosystem. With abundance halving time of approximately 8 years, the Kootenai River white sturgeon population is rapidly dwindling, leaving managers little time to act. Decades of study consistently indicate that recruitment failure occurs between embryo and larval stages. This assertion is based on four key observations. First, almost no recruitment has occurred during the last 30 years. Second, thousands of naturally produced white sturgeon embryos, most viable, have been collected over the past decade, resulting from an estimated 9 to 20 spawning events each year. Third, Kootenai River white sturgeon spawning has been documented during most years from 1990 through 2005. Finally, no larvae and very few wild juveniles have been collected during recent decades despite years of intensive sampling. Concurrently, post-release hatchery reared juveniles (as young as 9 months of age at release) consistently exhibit successful growth and survival (Ireland et al. 2002). Recruitment has failed, in part because fish are currently spawning at sites where or when conditions appear unsuitable for successful incubation and early rearing. Research to date suggests that recruitment failure is caused by egg or larval suffocation, predation and/or other mortality factors associated with these early life stages. A variety of interrelated factors have clearly contributed to the decline of Kootenai white sturgeon; various hypotheses for recruitment failure are not mutually exclusive. Anders et al. (2002) suggested that Kootenai River white sturgeon recruitment failure is likely the result of additive mortality from: (1) increased predation efficiencies due to low turbidity, velocity, and an relative increase in predatory fishes, (2) a reduced number of eggs produced by a dwindling spawning population, and (3) spawning in habitat lacking interstitial space (embryo suffocation). Quite simply, the combined egg and embryo mortality from all biotic and abiotic factors kills more eggs and embryos than the dwindling wild population is currently capable of producing. Thus, natural recruitment failure appears to be caused by some combination of habitat and stock limitation, by the mechanisms mentioned above. Although past research has helped narrow the range of possible causes of natural recruitment failure, the relative significance of each potential impact remains uncertain because multiple ecological, biological, and physical habitat changes occurred simultaneously. This makes it difficult to choose among competing hypotheses and difficult to know where exactly to focus recovery efforts for maximum benefit. In an ideal world, specific recovery measures would be identified and implemented based on a series of complementary research investigations to definitively identify the proximate causes and specific mechanisms of recruitment failure. The acute status of Kootenai sturgeon and current inability to compartmentalize the complex ecosystem do not afford the luxury of time for exhaustive research studies on every potential mechanism of recruitment failure. Mechanistic studies cannot replace the need for experimental evaluations of implemented adaptive management experiments.
Author: Kootenai Tribe of Idaho
Publisher:
ISBN:
Category : Burbot
Languages : en
Pages :
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Author:
Publisher:
ISBN:
Category : Aquatic sciences
Languages : en
Pages : 536
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Author: Kootenai Tribe of Idaho
Publisher:
ISBN:
Category : Burbot
Languages : en
Pages :
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Author: Wisconsin. Department of Agriculture, Trade, and Consumer Protection
Publisher:
ISBN:
Category : Aquaculture
Languages : en
Pages : 80
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Book Description
Author: G.T.O LeBreton
Publisher: Springer Science & Business Media
ISBN: 1402028334
Category : Science
Languages : en
Pages : 336
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Book Description
Modern North American sturgeons and paddlefish are the result of 100 million years of evolution. Once an integral part of aboriginal culture, their numbers were decimated by overfishing and habitat destruction during the past two centuries. This book details the extensive science aimed at helping these remarkable species recover from the brink of extinction, and describes the historical, biological, and ecological importance of North American sturgeon and paddlefish. The text is enhanced by photographs and detailed line drawings. This comprehensive volume will be an invaluable resource for researchers, educators, and consultants, in academic and government settings, who work to further scientific understanding of these fishes. No other single compilation has documented current information in such detail.
