Rebuilding Atlantic Cod: Lessons from a Spawning Ground in Coastal Newfoundland
Atlantic cod (Gadus morhua) was studied at the Bar Haven, Placentia Bay, Newfoundland (NAFO 3Ps stock unit) spawning ground from 1996 to 2003. Lessons applicable to management of rebuilding stocks derived from these studies are reviewed: (1) cod spawn in the same area each year, but numbers and timi...
| Main Authors: | , , , , , , , |
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.529.2344 http://www.physics.mun.ca/~bdeyoung/rose_etal_Wakefield_Gadids_book.pdf |
| Summary: | Atlantic cod (Gadus morhua) was studied at the Bar Haven, Placentia Bay, Newfoundland (NAFO 3Ps stock unit) spawning ground from 1996 to 2003. Lessons applicable to management of rebuilding stocks derived from these studies are reviewed: (1) cod spawn in the same area each year, but numbers and timing vary (spawning biomass varied from 2,000 to 25,000 t, with timing protracted over at least 100 days); (2) courtship and spawning behavior is complex, and includes lekking, sound production, and vertical rituals; (3) large fish in good condition are necessary to large egg potential because fecundity increases expo-nentially with fish size—total egg potential varied considerably from year to year with spawning abundance, age changes, and mean liver condition in spawning females; (4) retention of early life stages did not explain local recruitment and rankings of annual densities of eggs, larvae and juveniles did not match with local recruitment during three years of study; (5) dispersal of early life stages, juveniles, and adults was density-dependent; (6) individual adults homed to the same spawn- |
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