Abstract
Grazing by the black sea urchin Diadema antillarum reduces algal cover and enhances coral recruitment. The overall goal of this project was to examine if there is a relationship between densities of D. antillarum with algal cover and abundance of juvenile corals. Population densities of the black sea urchin, juvenile coral abundances and algal cover were assessed along four 20m2 transects at two depth intervals (0-3 and 3-8m) within each of two inner shelf coral reefs off La Parguera Natural Reserve (San Cristóbal and Enrique) in southwest, Puerto Rico using a 1m2 quadrat (divided into 100 areas of 100cm2, each area encompassing 1% of the quadrat). Juvenile coral densities were counted and identified to genus or species. Algal cover and composition was measured using each 1% square of the 1m2 quadrat. Urchin population densities were significantly higher at 0-3m at the two sites studied. Population densities were higher at Enrique at 0-3m than at San Cristobal but at 3-8m Diadema was not seen at Enrique. A total of 30 juvenile corals belonging to eight different genera were found. Juvenile coral densities were higher at 3-8m at the two reef sites studied. Algal cover and composition was mainly composed by crustose coralline algae at 0-3m at both reef sites. Macroalgal cover was low at both reefs. The results of this study suggest that densities of coral recruits at inner shelf reefs in La Parguera, Puerto Rico are driven mainly by differences in habitats (depth).KEY WORDScoral recruitment, abundance, Diadema antillarum, densities, composition, correlation
Highlights
RESUMEN El pastoreo del erizo negro, Diadema antillarum reduce la cobertura de algas y provee sustrato disponible para el reclutamiento coralino
The aim of this study is to determine if there is any relationship between D. antillarum population densities, algal cover and composition and juvenile coral abundances at two depth intervals (0-3; 3-8m) at two fringing, inner shelf coral reefs in La Parguera, Puerto Rico
Diadema antillarum population densities were significantly higher at 0-3m than at 3-8m at the two sites studied (PERMANOVA; p=0,0002)
Summary
RESUMEN El pastoreo del erizo negro, Diadema antillarum reduce la cobertura de algas y provee sustrato disponible para el reclutamiento coralino. The aim of this study is to determine if there is any relationship between D. antillarum population densities, algal cover and composition and juvenile coral abundances at two depth intervals (0-3; 3-8m) at two fringing, inner shelf coral reefs in La Parguera, Puerto Rico. This will show at which depth (0-3m or 3-8m) Diadema can help in the regulation of these processes within each reef
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.