Fatty acid profiles of juvenile salmon indicate prey selection strategies in coastal marine waters

Winter ichthyoplankton biomass as a predictor of early summer prey fields and survival of juvenile salmon in the northern California Current

“…The essential fatty acid composition of copepods also varies according to ocean conditions, with poor copepod feeding conditions leading to reduction in species that contain the essential fatty acids important to upper trophic levels (El-Sabaawi et al 2009). In describing the lipid and fatty-acid quality of juvenile fish and invertebrate prey available to juvenile salmon, Daly et al (2010) observed an apparent preference for prey with higher levels of essential fatty acids. However, the study was not able to address interannual variability of juvenile salmon prey quality, which can fluctuate substantially between cooler and warmer ocean conditions (Litzow et al 2006.…”

Population dynamics of Chinook salmon Oncorhynchus tshawytscha relative to prey availability in the central California coastal region

“…The reproductive ecology of both E. pacifica and T. spinifera involves multiple spawning attempts throughout the year, the timing of which appears to be synchronized to increased wind events (Brinton 1962, 1976, Tanasichuk 1998a,b, Feinberg & Peterson 2003, Shaw et al 2010. T. spinifera are larger than E. pacifica and more lipid rich (Daly et al 2010). In total, the presence of multiple cohorts of T. spini fera on the shelf offers a potential nutrient-rich and abundant prey resource for juvenile Chinook salmon using that environment.…”

An Exploratory Assessment of Thiamine Status in Western Alaska Chinook Salmon (Oncorhynchus tshawytscha)

“…Juvenile Chinook and coho had lower muscle and liver total thiamine concentrations than chum or pink salmon. Juvenile Chinook salmon are known to be highly piscivorous and are much more selective for fi sh as prey than other salmon species (Brodeur et al 2007;Daly et al 2010;Weitkamp and Sturdevant 2010). Juvenile Chinook had the highest yearly average proportion of thiaminase-positive prey fi sh (63%) in their stomachs followed by coho salmon at 36% (Table 4), yet Chinook and coho muscle and liver total thiamine were similar.…”

“…Over 80% of the Chinook diets from this area were comprised of small forage fi sh, primarily age-0 capelin (Cook and Sturdevant 2013). Typically, the dietary composition of juvenile Chinook in other regions (California Coastal Current, WA, OR, BC, and the Columbia River plume) also tend to be predominantly piscivorous, (Schabetsberger et al 2003;Brodeur et al 2007;Daly et al 2009Daly et al , 2010 but focused on diff erent taxonomic groups (e.g. Sebastes spp., Hexagrammidae, and Engraulis mordax).…”