SGER: Linking Physiological Performance to Population Demography in a Temperate Reef Fish

San Diego State University Foundation, San Diego CA

Investigators

Abstract

Links between physiological processes and their ecological implications to individuals and populations are poorly understood despite suggestions that such links may have important consequences. Both physiologists and ecologists underscore the need to couple physiology and population ecology in explaining variation in recruitment success and the ecological relevancy of physiological condition, respectively. Experiments designed for this purpose have never been published or possibly even attempted. The goal of this project is to couple physiological performance with the survival of recent settlers of a temperate reef fish, the kelp bass Paralabrax clathratus. A novel approach will be employed in which specially constructed submersible swim tunnels will be positioned on the sea bottom for in situ measurements of swimming performance and metabolic rate, followed by placing fish on experimental kelp beds and subsequently recording predator?induced mortality rate. This approach is meant to reduce as much as possible any effects of stress in recording physiological measurements. Kelp bass settle readily to plastic mesh devices suspended in the water column. Working completely underwater on SCUBA, fish will be collected from these devices, placed in swim tunnels stationed nearby, swimming performance and metabolic rate measured, fish marked individually with elastomer (colored silicone), and then released to small experimental kelp beds constructed on sand bottom. Monitoring of marked fish will be done over a 2?3 week period to determine if mortality from older conspecifics is correlated with previously measured individual swimming performance or metabolic rate.