Spatial and Temporal Trends in Juvenile Sockeye Salmon Diets Across Oceanographic Regimes on the Coast of British Columbia
Samantha James Evgeny Pakhomov & Brian Hunt
Research Aims
Measure juvenile sockeye diets across fine spatial and temporal scales to determine:
1)How much are they eating? Drivers? 2)What are they eating? Juvenile Salmon Program
4 Where?
Queen Charlotte Strait Mainland BC
Vancouver Vancouver Strait of Island Georgia
Pacific Ocean
5 Queen Charlotte Strait Mainland Where? BC
Vancouver Vancouver Strait of Island Georgia
Pacific Queen Ocean Charlotte Strait Johnstone Strait Discovery Islands
Dosser in prep Queen Charlotte Strait Mainland Where? BC
Vancouver Vancouver Strait of Island Georgia
Pacific Ocean
Dosser in prep How?
Calculate Gut Fullness Index (GFI): 푀 푠푐 × 100 푀푓 Results: How much do they eat? Spatial
Queen Charlotte Strait Johnstone Strait Discovery Islands N. Strait of Georgia
North South IQR of gut fullness values for the entire coast (Brodeur et al. 2007) Results: How much do they eat? Temporal Johnstone Strait Discovery Islands
IQR gut fullness for northeast Pacific (Brodeur et al. 2007)
IQR sockeye outmigration (Johnson et al. 2018) Results: What are they eating? Spatial
Queen Charlotte N. Strait of Strait Johnstone Strait Discovery Islands Georgia
North South Results: What are they eating? Temporal Johnstone Strait Discovery Islands Results: What are they eating? Spatial Why?
Discovery Islands
Johnstone Strait
1 Cooler 2 Warmer Higher salinity Lower salinity Results: What are they eating? Teporal Why?
DI
JS Conclusions
Measure juvenile sockeye diets across fine spatial and temporal scales. 1)How much are they eating? Biological hotspots vs. low foraging success Inter- vs Intra- annual trends 2)What are they eating? Different prey in different areas over time Timing matters @sockeyejames References
Johnson, B.T., J.C.L. Gan, C.V. Janusson, and B.P.V. Hunt. 2018. Juvenile salmon migration dynamics in the Discovery Islands and Johnstone Strait; 2015–2017. NPAFC Doc. 1790. 10 pp. Hakai Institute, Institute for the Oceans and Fisheries and Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia (Available at http://www.npafc.org)
Brodeur, R.D., E.A. Daly, M.V. Sturdevant, T.W. Miller, J.H Moss, M. Thiess, M. Trudel, L.A. Weitkamp, J. Armstrong, and E.C. Norton. 2007. Regional Comparisons of Juvenile Salmon Feeding in Coastal Marine Waters off the West Coast of North America. American Fisheries Society Symposium, 57