Friday, August 7, 2009

PS 92-172: Spatial variability in the survivorship of juvenile corals in La Parguera Southwestern Puerto Rico

Irizarry Soto Emmanuel Sr., University of Puerto Rico, Mayaguez campus

Background/Question/Methods

Over the last decades, studies in the reproduction of reef corals have shown the sensitivity of this process to climatic and anthropogenic factors. The effects of these factors (e.g. diseases) have produced significant losses in the population of scleractinian corals. Recruitment is an important process that promotes the replacement of reef coral individuals in depleted populations. However, studies across on the Caribbean on that artificial substrata have shown that is variable in time and space. In this study juvenile coral survivorship was measured over a period of two years (2003-2005) in four reefs at La Parguera southwestern Puerto Rico. Juvenile coral colonies were counted and mapped in six quadrats of 0.25 x 0.25 cm along four transect of 20 meters long, at each of four depth intervals (3m, 5m, 10m, 15m).

Results/Conclusions

A total of 470 colonies were sampled in 2003 in which 255 were alive in 2005. Juvenile coral survivorship was variable between inner and midshelf reefs and ranged from 39%-79%. Juvenile species that showed the highest survivorship among depth and were Diploria spp, Montastraea spp, Porites spp, Agaricia spp and Siderastrea spp. This study show that survivorship of juvenile corals over natural substrata was variable in both space and time for the six reef surveyed. This pattern could be driven by the fact that coral species need different regimes of resources or that interaction between coral species provide means for specialization on habitats.