SS1.07 Ecological Links to Population Dynamics and Productivity of Salmon
Date: Friday, June 14, 2002
Time: 9:30:00 AM
Location: Lecture Theatre
TrudelM, Fisheries and Oceans Canada, Nanaimo, Canada,
Tucker, S, , Dalhousie University, Halifax, Canada,
Zamon, J, E, Fisheries and Oceans Canada, Nanaimo, Canada,
Welch, D, W, Fisheries and Oceans Canada, Nanaimo, Canada,
We conducted a study to assess the effects of ocean conditions and climate change on salmon growth. Juvenile coho salmon were collected off British Columbia (BC) and South East Alaska (SEA) in 1998-2000. Sea surface temperature (SST) was higher in 1998 by about 2-3°C due to a warm El Niņo that was followed by a cool La Niņa. Coho salmon were two-fold smaller in southern BC than in SEA in 1998. Lipid and energy contents were also lower in coho from southern BC in 1998. These differences disappeared in 1999-2000. Food consumption rates of coho salmon averaged about 10% of their body weight per day and did not vary significantly between regions or years. Simulations performed using a bioenergetic model showed that summer growth was reduced by only 10 grams when temperature increased by 3°C, but could easily vary by a factor of two with small differences in prey caloric contents. Our analyses suggest that the effects of SST on salmon growth is mediated by changes in prey community structure rather than by changes in food consumption and metabolic rates.