[The coral reefs and coral communities of Bahía Culebra , Pacific coast of Costa Rica: biological aspects, economic-recreational and diving activities].

The coral reefs (AC) and coral communities on basalts (CCB) or sand (CCA) of Bahía Culebra (Golfo de Papagayo, northern Pacific coast of Costa Rica), were compared with descriptors such as cover percentage, diversity, substrate topographical heterogeneity (I(H)), associated organisms and frequency of recreational-commercial diving activities on them. Sea urchin abundance and I(H) were similar among the three reefal environments. The AC had higher coral cover (ca. 40%) and total live cover (>50%). The CCB had higher macro and calcareous algae (>5%) and sponges (>2%). Associated organisms (>2%) and general diversity (0.6) were higher in the CCA. Branching coral species (Pocillopora spp.) accounted for >40% of total coral cover in the reefs, followed by massive species (ca. 30%). In the CCB, branching species contributed ca. 80% and massive ca. 19%, whilst in the CCA ca. 68% and ca. 29% respectively. This differences could be related with the substrate consolidation and ample depth range of coral communities. Most of the recreational dives were conducted at the CCB; only occasionally the CCA and AC are visited. Interviewed divers had a principal interest on fish and it is precisely at the CCB where highest fish diversity and biomass are observed. Commercial divers tend to prefer the CCB because of their abundance and distribution in the bay. At the outer littoral of Bahía Culebra, diversity of all taxa and live coral cover zonal distribution are generally higher. In addition to these descriptors, indexes that indicate the regional value of a particular reef or coral community is recommended. Coastal infrastructure is mainly concentrated at three areas of the bay; one of them harbors a rare Leptoseris papyracea reef (the only reported so far in the eastern Pacific) and the solely Costa Rican living population of the free living coral Fungia (Cycloseris) curvata. A resort marina will be built over this reef. A protection plan for this and other reefal environments of Bahía Culebra is urgent and must include the monitoring of environmental variables and coral health.