Wounding of Pacific salmon in relation to the spatio-temporal variation in distribution patterns of important predatory fishes in the Russian economic zone

Variation in distribution patterns of major predatory fishes in the Russian economic zone was analyzed using Pacific Scientific Research Fisheries Center (TINRO-Centre) archival trawl survey data for 1980-2004. Species analyzed include Alepisaurus ferox, Anotopterus nikparini, Lamna ditropis, Lampetra tridentata, L. camtschatica, Prionace glauca, Somniosus pacificus and Squalus acanthias. Our data show that there is strong geographic variation in the relative abundance of predatory fishes. Differences in predator abundance were noted among large-scale geographical units (Bering, Okhotsk and Japan seas and adjacent waters of the North Pacific Ocean) and small-scale geographical units (shelf, continental slope, and deep-water basins; the upper epipelagic layer, lower epipelagic layer, upper mesopelagic layer, lower mesopelagic layer). We conclude that the rate of occurrence of Pacific salmon injuries was species-, age- and region-specific. This implies that it is necessary to consider species, age and region when estimating predator-related mortality of Pacific salmon.