Large-scale ecological impacts of development on tropical islands systems: Comparison of developed and undeveloped islands in the central Bahamas

The relationship between density of development and the health of nearshore marine habitats is explored through spatial and temporal comparisons of patch reef environments in the central Bahamas. Nearshore patch reefs are important fish habitats, and tend to have high, but variable, coral cover and benthic diversity in the Bahamian archipelago. Twelve patch reef stations were established off developed and undeveloped islands in the central Bahamas. Environmental parameters were measured over an 18-mo period to examine seasonal, tidal, and diurnal variability. Water quality measurements were not significantly different between developed and undeveloped sites for temperature, salinity, dissolved oxygen, chlorophyll-a, total nitrogen and total phosphorus. Only turbidity measurements were significantly different among sites, attributed to storm events. Ecological surveys recorded macroalgae species, stony coral species, coral cover, and coral vitality. Significant differences in species composition between developed and undeveloped stations were seen, with a higher coral diversity, lower coral cover, and higher incidence of coral lesions on developed patch reefs. A 53-yr comparison of nearshore environments from aerial imagery showed significant loss of patch reefs and seagrass areas with increasing development density. Results stress the importance of comparison reefs in marine protected areas for evaluating impacts of coastal development on nearshore marine habitats.