Salmon diet & growth across the shifting habitat mosaic
PI/co-PI on three projects:
1) Reconstructing juvenile salmon growth, condition and Delta habitat use in the 2014-15 drought & beyond
2) Juvenile salmon distribution, abundance, and growth in restored and relict Delta marsh habitats
3) Synthesis of juvenile salmon growth, condition and Delta habitat use among extreme hydrologic conditions
Diverse freshwater and estuarine habitats support a variety of fish life history types and gives rise to differing growth and feeding opportunities. We hypothesize that this variation increases the resilience of native fish species (e.g. by broadening the window over which juvenile salmon enter the ocean), but this is rarely empirically tested. Using otolith and soft tissue isotope clocks we are estimating the frequency, residence time, and relative success (condition, diet, and growth rate) of juvenile salmon using non-natal habitats, and linking this to variation in adult production.
We are analyzing juvenile salmon feeding ecology, growth rates and habitat use to understand how variable hydroclimatic conditions influence salmon behavior, survival and resilience. We are focusing on the highly altered freshwater Sacramento-San Joaquin River Delta and San Francisco Bay (see image - right), where significant restoration is planned, but little information is available about the extent to which these habitats successfully support salmon rearing.
Dana Myers (UC Davis undergraduate student assistant) dissecting juvenile salmon and identifying gut contents