Coral Reef Analysis

On Roatan, the primary tourist draw is its coral reefs. Described as "spectacular, intact, and very much alive" by Jean-Pierre Panet in 1990, the reefs of Roatan fringe the island and are easily accessible by boat and the beach. While the reefs are vital to sustaining tourism on the island, relatively little site specific research has been conducted.

I assisted Julie Dutcher (the Director of Education at Institute for Marine Sciences) in laying out and monitoring three permanent sampling sites. The purpose of the research is to develop a longitudinal photographic study of the reefs. The sites chosen are differentially impacted by both recreational divers and nearshore development. At depths of 20, 40 and 60 feet at each site, we laid out ten plots using steel ribar set into the coral. A PVC frame was fitted over the ribar and a photograph was taken. The intent of this effort is to monitor the growth and health of individual coral heads over time by comparing photographs taken over the course of time.

Additionally, at Gibson Bight, we conducted a more statistically rigorous sampling design. At depths of 20, 40 and 60 feet, we set a central ribar and laid two tape measures running in opposite directions along that depth profile. Using the ribar and the two tape measures as dividers of our sampling, we ended up with four sampling areas. In each sampling region, we then took photographs of a 50 cm square quadrat at random distances along the tape measure. These photographs will be scanned into a computer and the areas of live and dead corals, various algae and octochorals will be measured using a geographic information system. This procedure will provide statistics on the differences between the density and diversity of marine life at various depths and, with the addition of other sampling sites, will enable us to make comparisons between sites differentially impacted by pressures from development and recreational divers.