Effects of interspecific competition and coastal oceanography on population dynamics of the Olympia oyster, Ostrea lurida, along estuarine gradients

In estuaries, we often see predictable patterns of spatial and temporal variation in physical and biological factors that are influenced by oceanic and riverine inputs. This provides an excellent system to study variation in population and community dynamics. I documented demographic factors of and competitive effects on the oyster Ostrea lurida along estuarine gradients. Position along gradients influenced recruitment and growth but not survival. Increasing water residence time toward the head of Tomales Bay best predicted recruitment patterns, while growth was coupled with a longitudinal food gradient in the intertidal but not subtidal. Competition directly affected earlier life history stages but not later stages, but these effects varied between Tomales and San Francisco Bays. There was variation in percent cover and composition of the sessile communities in each bay. These results better our understanding of how variation in habitat characteristics and life history stage together alter demography and species interactions.