SS1.05 How Will Aquatic Ecosystems Respond to Climate Change?
Date: Tuesday, June 11, 2002
Time: 11:30:00 AM
Location: Oak Bay
 
TanasichukRW, Fisheries and Oceans Canada, Pacific Biological Station, Nanaimo, Canada, tanasichukr@pac.dfo-mpo.gc.ca
Luedke, W, , Fisheries and Oceans Canada, Fisheries Branch, Nanaimo, Canada, luedkew@pac.dfo-mpo.gc.ca
 
EUPHAUSIID BIOMASS VARIATION EXPLAINS MARINE SURVIVAL VARIATION FOR BARKLEY SOUND COHO AND SOCKEYE SALMON
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We have been monitoring the population biology of euphausiids (Thysanoessa spinifera, Euphausia pacifica) from the southwest coast of Vancouver Island (SWCVI) since 1991, a period when there were significant ocean warming and cooling events. Coho (Oncorhynchus kisutch) and sockeye (O. nerka) smolts originating in Barkley Sound feed on T. spinifera when they move out of the Sound and into continental shelf waters along the SWCVI. Coho and sockeye ate 9 12 and 3 5 mm long T. spinifera respectively. Results of multiple regression analyses show that median T. spinifera biomass over June August of the first marine year and smolt abundance account for 97% of the variation in number of returning coho adults. Multiple regression analyses results show that median T. spinifera biomass over March June of the first marine year explained between 60 and 90% of marine survival variation depending on the lake and age-group for which the analysis was done.