PS 4-39 - Effects of herbivory and habitat type on the recruitment and succession of epibenthos in the eastern Gulf of Mexico

Monday, August 8, 2016
ESA Exhibit Hall, Ft Lauderdale Convention Center
Kara R. Wall, College of Marine Science, University of South Florida, St.Petersburg, FL
Background/Question/Methods

Marine epibenthic communities are shaped by a wide variety of pre- and post-recruitment processes. For instance, the environmental cues that signal marine larvae (pre-recruitment) and the predation of juveniles (post-recruitment) may differ across season and habitat type. Determining the relative influence of these processes and whether they vary between natural and artificial reefs is important to our understanding of how different habitats function within an ecosystem. Using in situ photographic surveys and settlement plates, this study aims to identify patterns in the recruitment and succession of the epibenthos in the eastern Gulf of Mexico (eGOM). While many studies have been conducted to examine these processes in temperate and tropical ecosystems, little is known about the factors that influence epibenthic development in subtropical communities, such as the eGOM. Considering that the structure of the epibenthos influences the associated faunal communities, it is important to understand the potential that these processes have in affecting community development.

Results/Conclusions

Preliminary analyses of existing epibenthic communities show differences between natural and artificial reefs. Natural reef communities are commonly dominated by red algae, and during spring months host thick blooms of cyanobacteria. Artificial reefs host more diverse communities of octocorals and higher abundances of green algal taxa. Additionally, sea urchin densities are highest on artificial reefs. Settlement plates are currently deployed on natural and artificial sites to quantify how grazing from herbivorous sea urchins affects the composition of epibenthic communities. Initial results suggest that communities developing independent of urchin grazing have increased algal cover and lower overall diversity. By investigating how season, habitat type and herbivore communities influence epibenthic community composition, the results of this study will fill a critical gap in the knowledge of ecosystem dynamics in a region of economic and ecological importance.