Atlantic Salmon and Climate Variation in the North Atlantic
The largest component of natural mortality affecting Atlantic salmon populations in the marine environment occurs during the first year at sea. The juveniles are referred to as post-smolts during this period, which begins after their migration to the ocean and continues up until the first winter. Th...
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| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.523.4031 http://www.npafc.org/new/publications/Technical Report/TR4/page 12-14(Friedland).pdf |
| Summary: | The largest component of natural mortality affecting Atlantic salmon populations in the marine environment occurs during the first year at sea. The juveniles are referred to as post-smolts during this period, which begins after their migration to the ocean and continues up until the first winter. The stock complexes for Europe and North America appear to have different climate-controlling mechanisms reflecting theorized differences in post-smolt distribution and ecology. The nursery zone for European post-smolts is located in the open ocean whereas North American post-smolts appear to utilize inshore habitats. Holm et al. (2000) described the distribution of European post-smolts from surface trawling operations in the Northeast Atlantic. The nursery is confined to a region within the Norwegian Sea, the northern extent of which would appear to be defined by current transport. In North America, post-smolts can be found in high numbers in the Labrador Sea during the fall of the year (Reddin and Short 1991). However, during the earlier part of the post-smolt period, i.e. through the spring and summer months, fish are also found in the Gulf of St. Lawrence, the coast of Nova Scotia, and elsewhere (Dutil and Coutu 1988; Ritter 1989; Friedland et al. 1999). Furthermore, North American stocks may not physically mix for many months after entering the ocean whereas it appears European stocks are concentrated in a single, albeit large, ocean area (Friedland and Reddin 2000). If in some years the North American post-smolt nursery is distributed along the coast, it would function in |
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