Abstract:
When conservation can keep up with development´s pace: Health status of coral ecosystems in
the North Pacific of Costa Rica. Coral reefs are diverse and productive ecosystems, despite this, they are being
threatened by human activities that enhance the detrimental impact of the natural phenomenon’s like Harmful
Algal Blooms (HAB). The north Pacific of Costa Rica has been characterized as one of the best regions for the
coral reefs development in the country. However, many of these ecosystems are being lost as a result of eutrophication,
overfishing, invasive species and others impacts that affect the region. In the present study, live coral
cover in the north Pacific was 5.0 ± 10.4(s.d.) %, with a domination in the ecosystems by turf algae. Twenty-six
invertebrate taxa were registered in the region with the predominance of the sea urchin Diadema mexicanum.
Ninety-four species of reef fish were identified. Snappers and some planktivores species were the groups with
the highest frequency and abundance. The localities previously studied in the 1990 decade, presented a mean live
coral cover between 40-50 %, whereby the actual state of the reef reflect a significant deterioration. This decline
in coral cover is due to natural events like the El Niño, as well as the decrease in water quality in the region. In
recent years, proliferations of the invasive seaweed Caulerpa sertularioides and high densities of bioerosive sea
urchins have been reported, mainly associated with HAB events. Likewise, fish communities have low biomass,
especially in the vicinity of fishing villages. The state of the reefs in the North Pacific is worrying and requires
actions for its recovery and conservation, for which there must be better planning of the development of projects
and activities on the coast.
