Using community-wide recruitment and succession patterns to assess sediment stress on Jamaican coral reefs

Sedimentation resulting from the direct and indirect effects of coastal development is an increasing threat to Caribbean coral reefs. This study investigated taxonomic diversity, percent cover and successional patterns of recruited organisms over a period of 30 months to understand the community-wide consequences of increased coastal development and sediment supply along the northern coast of Jamaica. Terra cotta tiles were secured to the reef and the communities inhabiting both the cryptic and exposed sides of the tiles were monitored. The location with the highest sediment supply had the lowest Shannon diversity (H'; 1.37-1.41) and percent cover of organisms inhabiting the cryptic tile sides after 30 months (bare space was between 37 and 40%). The cryptic communities at each of the locations were similar in composition of organisms after 30 months; however, the cryptic community trajectories (analyzed using the second-stage nMDS ordination) varied and two distinct clusters were found, with the most impacted location differing from the other locations in the deep depth strata. The exposed communities at all locations were primarily composed of macroalgae, turf and encrusting algae; the location with the highest sediment supply had higher diversity of algae and lower amounts of turf than the other locations. This study provides evidence that differences in sediment supply between these locations may play a subtle role in structuring communities.