Island-specific Responses of Bahamian Benthic Flora to Environmental Features

We completed presence-absence and point-intercept surveys of benthic flora around four major islands of The Bahamas to determine the effects of various environmental features on benthic flora assemblages. Assemblages were analyzed at species and functional group levels of resolution. Multivariate analyses indicated that each island hosted a very distinct assemblage. Island-specific differences were ob- served along north-south and east-west gradients, suggesting that climate, geomorphology, and oceanogra- phy may play a fundamental role in shaping coastal benthic flora assemblages. Wave energy and substrate significantly affected the occurrences and/or abundances of benthic flora at Eleuthera and North Andros sites, with responses most often detected at the species level. The abundances of functional groups varied among different islands and, within North Andros, among different substrate and wave energy levels. Coastal terrestrial features related to nutrient and sediment regulation had low to moderate influence on floral assemblages, with benthic flora occurrence patterns responding more strongly than patterns in benthic flora abundances. Responses to terrestrial vegetation and land-use patterns were similar at the species and functional group levels of analysis. Overall, our study provides limited support of a broader-scale functional group approach. When properly defined and appropriately used, functional groups may help explain ob- served distribution patterns, but until this approach is better refined, a species-level approach to describe benthic flora assemblage dynamics is recommended.