PARENT SESSION
Poster Session 4: Marine Ecology
Monday, August 8, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

A description of reef fish communities based on size and trophic function.

Ballantyne, Ford ^*,1, ¹ Scripps Instiution of Oceanography, La Jolla, CA, USA

ABSTRACT- I asses the utility of different descriptions of reef fish communites in the Gulf of California. First, I show that describing communities based on abundance fails to capture significant trophic dynamics and then evaluate the effects of taxonomic aggregation on temporal patterns of variability in biomass. I examine the similarity of temporal trajectories of replicate communities in community phase space along a gradient of functional/taxonomic aggregation. A community description based on trophic function and body size generalizes dynamics with a minimal loss of ecological detail. Spatial variability in recruitment is highest during El Nino and La Nina years which results in high spatial variability in ontogenetic shifts in habitat use in subsequent years. The body size spectrum for the entire fish community is the most constant feature of communities we studied altough this also manifests a high degree of spatial variability. These results indicate that reef fish community dynamics are highly influenced by large scale climatic variability and that trophic dynamics are largely dictated by body size.

Key words: Reef Fish, Community, Trophic Dynamics, Body Size