Publications by authors named "Juan Jose Alvarado"

Article Synopsis
  • Atlantic reef-building corals are declining due to climate change, disease, pollution, and human activities, prompting a reassessment of their extinction risk under the IUCN Red List.
  • The latest evaluation shows an increase in the percentage of species at high extinction risk, with nearly 46% to 54% of shallow water corals now classified as threatened, compared to 15% to 40% in 2008.
  • Although there's been a slight improvement in coral coverage over historical data, projections indicate that severe bleaching events could significantly threaten the future survival of 26 species, which are now labeled as Critically Endangered.
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Coral reefs in Culebra Bay (North Pacific of Costa Rica) are threatened by multiple anthropogenic disturbances including global warming, overfishing, eutrophication, and invasive species outbreaks. It is possible to assist their recovery by implementing ecological restoration techniques. This study used artificial hexagonal steel structures, called "spiders" to compare growth of spp.

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With 51 100km2 of terrestrial area and 589 000km2 of national waters, Costa Rica is considered one of the countries with the greatest biodiversity. It has approximately 3.5% of the world marine species.

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Costa Rica is recognized as one of the most diverse countries in species and ecosystems, in their terrestrial realm as well as in the marine. Besides this relevance, the country presents a delay on conservation and management of marine and coastal biodiversity, with respect to terrestrial. For 2006, the marine protected surface was 5,208.

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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.

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Article Synopsis
  • This paper analyzes marine biodiversity distribution in the Caribbean and summarizes the Census of Marine Life program's activities in the region.
  • The Caribbean features diverse ecosystems such as coral reefs and mangroves, home to 12,046 marine species across various taxonomic groups, though sampling is primarily focused on shallow waters.
  • The study highlights issues such as uneven sampling efforts, variable collection methods, limited taxonomic knowledge, and insufficient deep-sea data, affecting the accuracy of biodiversity distribution patterns.
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A total of 15 species of echinoderms (one asteroid, seven ophiuroids, five echinoids and two holothurians) were recorded at the Cahuita National Park reef lagoon, between September and October 2003, using a 1 m2 quadrant. The sites with coral substrate and algae were the most diverse, while those with seagrass and sand were the least. Ophiuroids were the most abundant group with 170 individuals, asteroids were the least abundant.

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A total of 25 species of echinoderms (four asteroids, six ophiuroids, five echinoids and ten holothurians) were recorded at Marino Ballena National Park, using 25 m2 quadrants, parallel to the coast, at seven sites. The ophiuroids were the most abundant group with 581 individuals and the asteroids the less abundant (48 individuals). Echinoderms densities were low, with the exception of the ophiuroids.

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This paper describes the Punta Cocles reef (Limón, Costa Rica). Data were obtained by sampling nine transects along the coast and observations done by skin diving between September and November of 2002. This reef consist of 10.

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Centrostephanus coronatus reaches a density of 0.06 individuals/m2 in shallow reef waters in Parque Nacional Marino Ballena, Pacific of Costa Rica, in the same habitat occupied by the urchin Diadema mexicanum. It is the fourth species of diadematoid urchins reported for Costa Rican and a first new report for Central America.

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