Marine Mortality Schedules of Pink Salmon of the Bella Coola River, Central British Columbia
The hypothesis that natural mortality rates of pink salmon during early life are generally much larger than during the later period has been tested for 3 brood-years of the Bella Coola River stock using a two-stage marking technique. Average daily losses to the population during the first 40 days ar...
Published in: | Journal of the Fisheries Research Board of Canada |
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Language: | English |
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Canadian Science Publishing
1968
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Online Access: | http://dx.doi.org/10.1139/f68-068 http://www.nrcresearchpress.com/doi/pdf/10.1139/f68-068 |
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crcansciencepubl:10.1139/f68-068 2024-09-15T18:30:34+00:00 Marine Mortality Schedules of Pink Salmon of the Bella Coola River, Central British Columbia Parker, Robert R. 1968 http://dx.doi.org/10.1139/f68-068 http://www.nrcresearchpress.com/doi/pdf/10.1139/f68-068 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Journal of the Fisheries Research Board of Canada volume 25, issue 4, page 757-794 ISSN 0015-296X journal-article 1968 crcansciencepubl https://doi.org/10.1139/f68-068 2024-08-29T04:08:48Z The hypothesis that natural mortality rates of pink salmon during early life are generally much larger than during the later period has been tested for 3 brood-years of the Bella Coola River stock using a two-stage marking technique. Average daily losses to the population during the first 40 days are estimated to vary between 2 and 4%, and for the later 410-day period between 0.4 and 0.8%. These rates produce losses amounting to between 59 and 77% of the initial population during the first 40 days. Of the population surviving at 40 days, further losses of between 78 and 95% occurred. The latter losses are considered to be maximum estimates because of bias introduced by catches of unknown magnitude. Thus, although the early mortality is exceeded by the later, the time period is approximately 10 times as long, and the intensity of the mortality rate is much higher during early sea life. Article in Journal/Newspaper Pink salmon Canadian Science Publishing Journal of the Fisheries Research Board of Canada 25 4 757 794 |
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Open Polar |
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Canadian Science Publishing |
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crcansciencepubl |
language |
English |
description |
The hypothesis that natural mortality rates of pink salmon during early life are generally much larger than during the later period has been tested for 3 brood-years of the Bella Coola River stock using a two-stage marking technique. Average daily losses to the population during the first 40 days are estimated to vary between 2 and 4%, and for the later 410-day period between 0.4 and 0.8%. These rates produce losses amounting to between 59 and 77% of the initial population during the first 40 days. Of the population surviving at 40 days, further losses of between 78 and 95% occurred. The latter losses are considered to be maximum estimates because of bias introduced by catches of unknown magnitude. Thus, although the early mortality is exceeded by the later, the time period is approximately 10 times as long, and the intensity of the mortality rate is much higher during early sea life. |
format |
Article in Journal/Newspaper |
author |
Parker, Robert R. |
spellingShingle |
Parker, Robert R. Marine Mortality Schedules of Pink Salmon of the Bella Coola River, Central British Columbia |
author_facet |
Parker, Robert R. |
author_sort |
Parker, Robert R. |
title |
Marine Mortality Schedules of Pink Salmon of the Bella Coola River, Central British Columbia |
title_short |
Marine Mortality Schedules of Pink Salmon of the Bella Coola River, Central British Columbia |
title_full |
Marine Mortality Schedules of Pink Salmon of the Bella Coola River, Central British Columbia |
title_fullStr |
Marine Mortality Schedules of Pink Salmon of the Bella Coola River, Central British Columbia |
title_full_unstemmed |
Marine Mortality Schedules of Pink Salmon of the Bella Coola River, Central British Columbia |
title_sort |
marine mortality schedules of pink salmon of the bella coola river, central british columbia |
publisher |
Canadian Science Publishing |
publishDate |
1968 |
url |
http://dx.doi.org/10.1139/f68-068 http://www.nrcresearchpress.com/doi/pdf/10.1139/f68-068 |
genre |
Pink salmon |
genre_facet |
Pink salmon |
op_source |
Journal of the Fisheries Research Board of Canada volume 25, issue 4, page 757-794 ISSN 0015-296X |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f68-068 |
container_title |
Journal of the Fisheries Research Board of Canada |
container_volume |
25 |
container_issue |
4 |
container_start_page |
757 |
op_container_end_page |
794 |
_version_ |
1810472034491170816 |