A Comparison of Escapement Estimate Methods Plus Escapement-recruitment Relationships for Chinook Salmon and Coho Salmon in a Coastal Stream PDF Download
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Author: Stephen A. Gough
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 136
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Book Description
Author: Stephen A. Gough
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 136
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Book Description
Author: Katrina A. Wright
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 226
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Book Description
![An Investigation Into the Factors Influencing Escapement Estimation for Chinook Salmon (Oncorhynchus Tshawytscha) on the Lower Shuswap River, British Columbia [microform] PDF](https://books.google.com/books/content/images/frontcover/5NQBywEACAAJ?fife=w80-h100)
Author: Nicole Dorothy Trouton
Publisher: Library and Archives Canada = Bibliothèque et Archives Canada
ISBN: 9780494036549
Category : Chinook salmon
Languages : en
Pages : 214
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Book Description
The area-under-the-curve (AUC), method based on helicopter visual enumeration, is a commonly used technique to estimate escapement of chinook salmon (Oncorhynchus tshawytscha) for the Fraser River and its tributaries. Two key factors associated with this method are survey life and observer efficiency. The survey life currently assumed by Fisheries and Oceans Canada (DFO) for Thompson Basin streams is seven days and for most counting flights the assumed observer efficiency is 100%. Telemetry and tower observations were used to estimate annual (2000-2002) survey lives for male (telemetry) and female (telemetry and tower observation) chinook salmon in the Lower Shuswap River. Mark-recapture based survey lives were directly estimated by dividing the mark-recapture escapement estimate by the AUC estimate of total spawner days. Observer efficiency was estimated by comparing observer counts from helicopters to counts from photographs. Various combinations of total fish counts, observer efficiencies, and survey lives were used in AUC escapement estimates, and compared to mark-recapture and peak count estimates. Survey lives varied annually. Many of the estimated mean survey lives were significantly less than seven days; mark-recapture based survey lives were generally less than those estimated from telemetry and observations from towers; and mean survey lives for males were higher than for females. The mean observer efficiency of helicopter enumeration was 97% (95% CI is * 6%), this is not significantly different than the 100% assumed by DFO.
Author: C. J. Perrin
Publisher:
ISBN:
Category :
Languages : en
Pages : 49
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Book Description
Escapement estimates provide a basis for setting exploitation rates and for assessing the effect of exploitation or habitat manipulation on stocks, as well as for comparing and contrasting management policies using stock-recruitment relationships. Several methods are available to estimate escapement, but for any one spawning run they can field widely different results. This report reviews estimates of `survey life' (SL) (the number of days that mature salmon are alive in a survey area) for Pacific salmon. SL is an important parameter in the area-under-the-curve (AUC) method often used to estimate the spawning escapement of Pacific salmon. The report assembles data from many sources to determine if variation in SL measurements collected for the 5 species of Pacific salmon found in B.C. can be explained by biological and environmental variables. The study determined if extrapolation of SL estimates among streams and years is valid when the AUC method is used to estimate escapement.
Author: Canada. Department of Fisheries and Oceans
Publisher: Nanaimo, B.C. : Fisheries and Oceans, Canada
ISBN:
Category :
Languages : en
Pages : 49
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Book Description
Author: Irvine, James R
Publisher: Nanaimo, B.C. : Science Branch, Department of Fisheries and Oceans, Pacific Biological Station
ISBN:
Category : Escapement (Fisheries)
Languages : en
Pages : 97
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Book Description
This report documents results from a workshop on the estimation of salmon escapement, defined to be the number of adult salmon that escape marine fisheries and return to freshwater to spawn. The introductory session discussed effective methods for estimating escapement and the variability associated with different estimation techniques. Separate sessions provided area overviews and case studies of escapement estimation in British Columbia and Washington state; a review of salmon escapement databases; presentations on the training of fisheries staff in escapement data collection; and papers on new and developing technologies for salmon escapement estimation, including video technology and hydroacoustics. The bibliography includes references to literature on capture-recapture, visual counts, electronic and video techniques, hydroacoustic and other methods, and geographically-specific studies on escapement.
Author: D. T. Lightly
Publisher: Nanaimo, B.C. : Fisheries and Oceans, Canada
ISBN:
Category : Chinook salmon
Languages : en
Pages : 52
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Book Description
Author: T. F. Shardlow
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 52
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Book Description
The chinook escapement to the Campbell and Quinsam Rivers in 1984 was estimated by using a simple carcass tagging method. Marked carcasses from the Quinsam hatchery were released on 2 occasions in each river and the proportion of these carcasses recovered in the dead pitch was used as an index of the effectiveness of the dead pitch. In this report, the theory behind the use of carcass tagging is examined and the expected levels of precision and the potentials for bias are assessed. Two different estimation methods are examined, one based on a Petersen approach and the other on the Schaefer method, and the need for corrections for differences in the sex ratio between live sampling and dead sampling is discussed.
Author: Kale T. Bentley
Publisher:
ISBN:
Category : Chinook salmon
Languages : en
Pages : 73
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Book Description
Author: B. Alan Johnson
Publisher:
ISBN:
Category : Escapement (Fisheries)
Languages : en
Pages : 16
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Book Description
Presents a methodology for estimating a spawner abundance curve from survey counts.
