Dynamics of the benthic community structure on the shallow coral formations of the San Bernardo Archipelago, Colombian Caribbean

摘要

Coral reefs have experienced an extensive degradation over the last decades as a result of anthropogenic and natural disturbances. This study presents an historical characterization (1989-2015) of changes in composition of the substrate in coral formations in the San Bernardo Archipelago. In addition, in 2015 coral reef health (presence of deterioration signs) was evaluated, and satellite temperature data were analyzed. In general, coral cover showed a stable trend between 1989 and 2010. The observed differences in the coral reef formations in 2013 and 2015 could have been due to the increase in coverage of species of the genus Orbicella, Porites, Agaricia, Siderastrea and the hydrocoral Mil-lepora complanata. The lower coverage in 1989, 1991 and 2005 was possibly related to massive mortality events of reef species due to diseases and bleaching. Abiotic substrate and algal cover exhibited opposing behavior, and algae became the dominant component of the substrate since 2013. Spatially, there were different trends: stations at Ceycen. Tintipan and Mangle presented better coral development conditions over time, while stations at Cabruna and Palma, closer to urban centers, showed signs of deterioration. In addition, temperatures above the bleaching tolerance threshold (29.4 °C) were recorded since June 2015, which is possibly why corals faced thermal stress and bleached in 18 of the 19 evaluated stations. Management actions on local impacts are essential, accompanied by information provided by monitoring programs, so that coral reefs can recover from the natural and anthropogenic impacts that affect them.