Competition and compensatory growth in fish: ecological mechanisms and implications for biological risk assessment

Research Partners: Jörgen Johnsson, Torgny Bohlin & Johan Höjesjö, GU; Robert H. Devlin & Fredrik Sundström, West Vancouver Laboratories, Fisheries and Oceans, Canada

The ecological mechanisms of competition and compensatory growth in fish are addressed in a series of laboratory- and field experiments. The proposed research is of basic ecological interest, but can also generate baseline data to develop guidelines for supplementary release programs and to help predict ecological effects of escaped farm and transgenic fish on natural populations. (1) We investigate the relative importance of exploitative and interference competition on density regulation in salmonids. (2) Furthermore, we estimate the relative strength of competition imposed by normal and transgenic coho salmon on resident conspecifics. (3) Finally we test whether fish are able to use social cues from competitors to monitor their relative energy status and adjust behaviour and growth accordingly.

Granted by Formas, Jan 2006- Dec 2008.