Rooker, Jay Professor

My research centers on the community and population ecology of aquatic organisms, with a special emphasis on marine fishes. I am particularly interested in linkages between habitat selection, individual responses, and survival. My work is both laboratory and field-based, and I typically use both quantitative and experimental approaches to elucidate the importance of biotic and abiotic factors that influence growth, condition, and survival. In addition, we are currently using a variety of natural markers to solve ecological problems. Otolith chemistry is being used to retrospectively determine the environmental histories of marine fishes. The premise of otolith chemistry is that certain elements or isotopes are incorporated into otoliths in proportion to their concentrations in the environment, and thus we use these elemental fingerprints to distinguish individuals from different environments or regions. We also use dietary tracers (stable isotopes, fatty acids) to investigate marine food web structure since consumer tissues reflect the isotopic and fatty acid composition of prey in a predictable manor. These natural biomarkers provide time-integrated or long-term measures of diet, and both approaches afford information on source(s) of organic matter supporting local food webs as well as trophic relationships of associated consumers. Recent work also involves the use of sophisticated electronic tags to investigate movement and population connectivity of coastal and pelagic fishes.