Recent Changes in Stock Composition of Atlantic Salmon ( Salmo salar ) in the Miramichi River, New Brunswick
Data collected from 1954 to 1971 show that the recent decline in Miramichi River Atlantic salmon (Salmo salar) abundance has been accompanied by changes in the ratio of grilse to large salmon (2-sea-years and older) entering the river. From 1954 to 1962 trap samples were composed of about equal numb...
| Published in: | Journal of the Fisheries Research Board of Canada |
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| Main Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Canadian Science Publishing
1973
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1139/f73-133 http://www.nrcresearchpress.com/doi/pdf/10.1139/f73-133 |
| Summary: | Data collected from 1954 to 1971 show that the recent decline in Miramichi River Atlantic salmon (Salmo salar) abundance has been accompanied by changes in the ratio of grilse to large salmon (2-sea-years and older) entering the river. From 1954 to 1962 trap samples were composed of about equal numbers of grilse and large salmon. Since 1963 the grilse catch has averaged 87%. Large declines in abundance of the fall-run grilse portion of the spawning stock occurred in 1968 and similar declines occurred in the fall-run large salmon component in 1969. An increase in commercial fishing mortality of large salmon is believed responsible for shifting the river escapement in favor of grilse. The result has been a reduction in reproductive potential and declines in the fall-run stocks of both large salmon and grilse. |
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