Cuando la conservación no puede seguir el ritmo del desarrollo: Estado de salud de los ecosistemas coralinos del Pacífico Norte de Costa Rica

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. Rev. Biol. Trop. 66(Suppl. 1): S280-S308. Epub 2018 April 01.

Conservation status of fish and marine invertebrate of rocky reefs and sandy substrates in two unprotected bays of the Papagayo Gulf, Costa Rica

“…Biomass, trophic groups, and juvenile fishes: reef fish biomass at Cocos Island National Park (Costa Rica), a biodiversity hotspot highly protected from fishing, was estimated as 12.5 t ha -1 (Fourriére et al 2019), much higher than what we found (1.57 t ha -1 ). However, North Pacific Costa Rica has been subjected to habitat loss and intense fishing and fish biomass here is much lower (1.5 t ha -1 Alvarado et al, 2018) and similar to our findings. This suggest that Cabuyal and Zapotillal Bays, similarly to other areas in the region, (Villalobos-Rojas et al, 2014), have suffered impacts from fishing and habitat loss.…”

“…This leads to high densities of other herbivores such as the sea urchin D. mexicanum, which affects coral recruitment (Alvarado, Cortés, & Reyes-Bonilla, 2012). Thus, the low coral cover and high density of D. mexicanum that we found could be explained by a low biomass of herbivorous fish, similar to that reported by Alvarado et al (2018).…”

“…At rocky reefs, we identified more invertebrates (70 species) than previously reported for coral reefs (38 species) in North Pacific Costa Rica. Our results suggest that rocky reefs in North Pacific Costa Rica hold a high number of species, however reefs have been strongly affected by human impacts in the region in recent years (Alvarado et al, 2018). MPAs are not always located in the areas with the highest biodiversity or are not large enough to fully protect highly diverse areas, leaving unprotected areas of high biodiversity subject to human exploitation (Sibaja-Cordero et al, 2014), as could be the case of the study sites.…”

“…While predatory fishes are most heavily exploited, herbivores are also targeted by artisanal fisheries, which may lead to reduced grazing of macroalgae, negatively affecting live coral cover (Jennings & Polunin, 1997;Edwards et al, 2014). In Costa Rican North Pacific, coral cover has declined from 43 to 5 % in the last 15 years, and reefs have become macroalgae dominated (Alvarado et al, 2018). This leads to high densities of other herbivores such as the sea urchin D. mexicanum, which affects coral recruitment (Alvarado, Cortés, & Reyes-Bonilla, 2012).…”

Impact of El Niño 2015-2016 on the coral reefs of the Pacific of Costa Rica: the potential role of marine protection

“…Between 2013 and 2017, a series of coral reefs health assessments in the Pacific of Costa Rica were conducted (Alvarado, Beita, Mena, Fernández-García, & Guzmán, 2015;Alvarado et al, 2016Alvarado et al, , 2018. These assessments focused solely on establishing the health status of these ecosystems, and here provides the baseline of their condition prior to the 2015-2016 global warming event.…”