Coral diseases and bleaching on Colombian Caribbean coral reefs

Raúl Navas-Camacho,Jaime Garzón-Ferreira,Alberto Rodríguez-Ramírez,María Catalina Reyes-Nivia,Diego Luis Gil-Agudelo

doi:10.15517/rbt.v58i1.20026

Abstract

Since 1998 the National Monitoring System for the Coral Reefs of Colombia (SIMAC) has monitored the occurrence of coral bleaching and diseases in some Colombian coral reefs (permanent stations at San Andres Island, Rosario Islands, Tayrona, San Bernardo Islands and Urabá). The main purpose is to evaluate their health status and to understand the factors that have been contributing to their decline. To estimate these occurrences, annual surveys in 126 permanent belt transects (10 x 2m) with different depth intervals (3-6 meters, 9-12 meters and 15-18 meters) are performed at all reef sites. Data from the 1998-2004 period, revealed that San Andrés Island had many colonies with diseases (38.9 colonies/m2), and Urabá had high numbers with bleaching (54.4 colonies/m2). Of the seven reported coral diseases studied, Dark Spots Disease (DSD), and White Plague Disease (WPD) were noteworthy because they occurred in all Caribbean monitored sites, and because of their high interannual infection incidence. Thirty five species of scleractinian corals were affected by at least one disease and a high incidence of coral diseases on the main reef builders is documented. Bleaching was present in 34 species. During the whole monitoring period, Agaricia agaricites and Siderastrea siderea were the species most severely affected by DSD and bleaching, respectively. Diseases on species such as Agaricia fragilis, A. grahamae, A. humilis, Diploria clivosa, Eusmilia fastigiata, Millepora complanata, and Mycetophyllia aliciae are recorded for first time in Colombia. We present bleaching and disease incidences, kinds of diseases, coral species affected, reef localities studied, depth intervals of surveys, and temporal (years) variation for each geographic area. This variation makes difficult to clearly determine defined patterns or general trends for monitored reefs. This is the first long-term study of coral diseases and bleaching in the Southwestern Caribbean, and one of the few long-term monitoring studies on coral diseases worldwide.

Highlights

Agaricia agaricites was the species with the highest number of diseased colonies, TABLE 1 Distribution of diseases and bleaching on SIMAC reef sites surveyed
No temporal patterns were evident for diseases occurrence or bleaching throughout the seven years of monitoring, but all coral diseases reported for the Caribbean were found during this study affecting a large number of coral species
In 1998, 16 coral species were found to be affected by at least one disease, while in 2004 this number increased to 35. This agrees with the observed increase of coral diseases and bleaching, and their direct link to the reduction of coral cover in the Caribbean (Bruckner & Bruckner 1997, Santavy & Peters 1997, Hayes & Goreau 1998, Garzón-Ferreira et al 2001, Weil et al 2002, Sutherland et al 2004)

Summary

Introduction

During the last three decades coral reefs have suffered extensive loss of living tissue mainly due to coral bleaching (Glynn 1993, Wilkinson 2000, Richard & Precht 2001, Aronson et al 2002, Rosenberg & Ben-Haim 2002) and coral diseases (Peters 1997, Santavy & Peters 1997, Goreau et al 1998, Green & Bruckner 2000, Sutherland et al 2004). The importance of coral diseases and bleaching for Colombian Caribbean reefs are well recognized, studies have been restricted to only document their occurrence. This is the first study that analyzes spatial (monitoring areas and depth levels) and temporal (years) variation on the occurrence of coral diseases and bleaching in Colombia.

Results

Conclusion