CURRENT CONDITION OF ACROPORA PALMATA AND A. CERVICORNIS CORAL FORMATIONS IN THE TAYRONANATIONAL NATURAL PARK (COLOMBIA).

Abstract

To assess the status of coral formations dominated by A c ro p o r a palmata (APF) and A. cervicornis (ACF) in the Tayrona National Natural Park (TNNP), Colombian Caribbean, a study was conducted at the bays of Chengue, Gayraca, Nenguange and Cinto between May- December 2001. The distribution and extension of the formations in the study area were evaluated by swimming along the coast and using draft maps, a GPS and a calibrated flow-meter, and their living cover were estimated in quadrat-belt transects (1x10 m). Atotal of 29 APF (119320 m2) and 12 ACF (21760 m2) were assessed. Almost all the APF exhibited living colonies of A. palmata, but the mean cover by this species reached only about 10%, representing about 14000 m2 of living area and a live: dead tissue proportion of 1: 8. Only four ACF had living colonies of A. cerv i c o r n i s, and the mean live cover by this species was near 5%, corresponding to only 1200 m2 and a live: dead tissue proportion of 1: 15. Algae was the dominant category at both types of formation, covering about 80% of the substrate, followed by stony corals (17% in APF and 12% in ACF) and in less proportion by sand, zoanthids, octocorals and sponges. The hard coral assemblage was composed by 21 species in both formations, but, despite the extensive mortality of acroporids, it continued dominated by A. palmata (60%) in the APF and by A. cer v i c o r n i s (40%) in the A C F. M i l l e p o r a c o m p l a n a t a was the only other stony coral species that reached important cover values (19% in APF and 24% in ACF); this is an opportunist coral that may have been gaining dominance following the decline of acroporid species. The results of our study indicate that acroporid populations of the PNNT have not recovered after 15 years of their mass mortality, and on the contrary, suggest that their status is now more dramatic. This is coincident with the general scenario that was diagnosed recently for the status of these corals in the Wider Caribbean. However, the current condition of acroporids in the PNNT seems better than in other reef areas of the Colombian Caribbean, so that, its remnant surviving populations can represent important reserves for conservation of both species and for future restoration programs.