No Bull: Juvenile Bull Sharks May Play Diverse Functional Roles in Coastal Food Webs

Abstract

Wirsing will present a study about bull sharks. These predators may induce numerous direct and indirect effects in food webs. Most studies of these effects have used a “species”-based approach, i.e., individuals within a predator species have the same trophic niche (network of trophic interactions). This approach could mask important variation in the way predator individuals affect community and ecosystem properties. Studies are needed addressing the possibility that top-down effects might vary as function of individual differences in trophic interactions. In our study, we documented among-individual trophic niche variation. We defined food web "endpoints" by determining the extent to which juevenile bull sharks feed in freshwater vs. marine food webs. Study results and implications for conservation will be discussed.