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Observaciones biológicas preliminares sobre el arrecife coralino en el Parque Nacional de Cahuita, Costa Rica
(1980) Risk, Michael J.; Murillo, Manuel M.; Cortés Núñez, Jorge
Un levantamiento biológico preliminar del componente coralino del Parque Nacional de Cahuita, Costa Rica, sugiere que el arrecife está en un estado de deterioro. El número de especies de corales no alcanza el 50% de aquellas que son comunes en otras formaciones del Caribe. No obstante, las tasas de crecimiento propias de estructuras individuales de coral son tan altas como las que caracterizan a otras áreas del Caribe. Las esponjas perforadoras son abundantes, aunque su diversidad es baja, sólo se encontró 4 especies. Se describe y se incluye diagramas de los diferentes habitats que caracterizan el arrecife. La información correspondiente a hábitos de crecimiento y composición de especies, desplazamiento y circulación del agua a lo largo de la costa y los estudios acerca de la tasa de sedimentación, son indicativos de que la carga de sedimentos puede haber afectado al arrecife, determinando el presente estado de desarrollo.
Mortandad de Gorgonia flabellum Linneaus (Octocorallia: Gorogoniidae) en la Costa del Caribe de Costa Rica
(1984-11-01) Guzmán, Héctor M.; Cortés Núñez, Jorge
During 1982, the population of the coral Gorgonia flabellum started to die on the Caribbean coast of Costa Rica. Seven possible causes were analyzed: temperature-salinity variation, sedimentation, predation, wave action, bioerosion, pollution and diseases. The pathology of "Black band" disease coincides with our observations. Death of other octocorallia was not observed. This is the first time that mass mortality of G. flabellum is reported.
Impact of upwelling events on the sea water carbonate chemistry and dissolved oxygen concentration in the Gulf of Papagayo (Culebra Bay), Costa Rica: implications for coral reefs
(2012-04-01) Rixen, Tim; Jiménez, Carlos E.; Cortés Núñez, Jorge
Abstract. The Gulf of Papagayo, Pacific coast of Costa Rica, is one of the three seasonal upwelling areas of Mesoamerica. In April 2009, a 29-hour experiment was carried out at the pier of the Marina Papagayo, Culebra Bay. We determined sea surface temperature (SST), dissolved oxygen concentration, salinity, pH, and the partial pressure of CO2 (pCO2). The aragonite saturation state (Ωa) as well as the other parameters of the marine carbonate system such as the total dissolved inorganic carbon (DIC) and the total alkalinity (TA) were calculated based on the measured pH and the pCO2. The entrainment of subsurface waters raised the pCO2 up to 645 μatm. SSTs, dissolved oxygen concentrations decreased form 26.4 to 23.7°C and from 228 to 144 μmol l-1. Ωa dropped down to values of 2.1. Although these changes are assumed to reduce the coral growth, the main reef building coral species within the region (Pocillopora spp. and Pavona clavus) reveal growth rates exceeding those measured at other sites in the eastern tropical Pacific. This implies that the negative impact of upwelling on coral growth might be overcompensated by an enhanced energy supply caused by the high density of food and nutrients and more favorable condition for coral growth during the non-upwelling season.
Status and conservation of coral reefs in Costa Rica
(2009-05-03) Cortés Núñez, Jorge; Jiménez, Carlos E.; Fonseca Escalante, Ana C.; Alvarado Barrientos, Juan José
Costa Rica has coral communities and reefs on the Caribbean coast and on the Pacific along the coast and off-shore islands. The Southern section of the Caribbean coast has fringing and patch reefs, carbonate banks, and an incipient algal ridge. The Pacific coast has coral communities, reefs and isolated coral colonies. Coral reefs have been seriously impacted in the last 30 years, mainly by sediments (Caribbean coast and some Pacific reefs) and by El Niño warming events (both coasts). Monitoring is being carried out at three sites on each coast. Both coasts suffered significant reductions in live coral cover in the 1980’s, but coral cover is now increasing in most sites. The government of Costa Rica is aware of the importance of coral reefs and marine environments in general, and in recent years decrees have been implemented (or are in the process of approval) to protect them, but limited resources endanger their proper management and conservation, including proper outreach to reef users and the general public.
Marine biodiversity of Bahía Culebra, Guanacaste, Costa Rica: published records
(2012-04-01) Cortés Núñez, Jorge; Vargas Castillo, Rita; Nivia Ruiz, Jaime
A survey of the published records of marine organisms ofBahía Culebra, an enclosed embayment on the north Pacific coast of Costa Rica, is analyzed resulting in a list of 577 species representing 22 phyla. The most diverse groups documented were crustaceans, cnidarians and mollusks in order of species number. The first published record of any marine organism from the area, a polychaete, occurred in 1922, with a peak of published records of species between 1940 and 1949 and, more recently, from 2000 to the present. Several additional taxa are known from the region but there are no published records of their occurrence. This is especially evident for such groups as the free living flatworms and black corals. Additionally, several habitats, including soft bottom sediments, have not been sampled. Because of the paucity of knowledge on the biodiversity of Bahia Culebra, much more research is needed in order to evaluate and understand the effect of climate change and increasing anthropogenic activities.