%0 Journal Article
%T Massive hard coral loss after a severe bleaching event in 2010 at Los Roques, Venezuela
%A Carolina Bastidas
%A David Bone
%A Aldo Croquer
%A Denise Debrot
%J Revista de Biolog¨Şa Tropical
%D 2012
%I Universidad de Costa Rica
%X Thermal anomalies have become more severe, frequent and well-documented across the Caribbean for the past 30 years. This increase in temperature has caused coral bleaching resulting in reef decline. At Los Roques National Park, Venezuela, temperature has been monitored at four reef sites. In mid-September 2010, seawater temperature reached 30.85ˇăC at 5 m depth in Los Roques, an archipelago only slightly affected by previous bleaching events. For example, bleaching in Los Roques in 2005 was mild compared to the rest of the Caribbean and to the results in this study. In 2010, seawater temperatures remained above 29.0ˇăC from mid-August until the first week of November, resulting in +16 Degree Heating Weeks by that time. Our annual survey of four reef sites indicated that 72% of 563 scleractinian colonies were partial or totally bleached (white) or pale (discolored) in October 2010. In February 2011, there were still 46% of coral colonies affected; but most of them were pale and only 2% were bleached. By February, coral cover had declined 4 to 30% per transect, with a mean of 14.3%. Thus, mean coral cover dropped significantly from 45 to 31% cover (a 34% reduction). In addition to bleaching, corals showed a high prevalence (up to 16%) of black band disease in October 2010 and of white plague (11%) in February 2011. As a consequence, coral mortality is expected to be larger than reported here. Reef surveys since 2002 and personal observations for more than 20 years indicated that this bleaching event and its consequences in Los Roques have no precedent. Our results suggest that reef sites with no previous record of significant deterioration are more likely to become affected by thermal anomalies. However, this archipelago is relatively unaffected by local anthropogenic disturbance and has a high coral recruitment, which may contribute to its recovery Durante las ¨˛ltimas d¨¦cadas las anomal¨Şas t¨¦rmicas han sido m¨˘s frecuentes y severas en el Caribe, quedando pocos arrecifes exentos de eventos masivos de blanqueamiento (EMB). En el Parque Nacional Los Roques, Venezuela, un archipi¨¦lago poco afectado previamente por EMB, la temperatura del agua a 5m de profundidad alcanz¨® 30,85ˇăC en septiembre 2010, y fue >29,0ˇăC entre mediados de agosto y la primera semana de noviembre en cuatro arrecifes. El 72% de 563 colonias de escleractinios estaban blanqueadas o p¨˘lidas para octubre de 2010, mientras que para febrero 2011, el 46% de las colonias a¨˛n estaban afectadas. Para febrero 2011, la cobertura b¨¦ntica coralina promedio disminuy¨® de 45 a 31%. Adem¨˘s, los arrecifes mo
%K blanqueamiento coralino
%K mortalidad
%K p¨¦rdida de cobertura de coral
%K Caribe
%K arrecife coralino
%K coral bleaching
%K mortality
%K loss of coral cover
%K Caribbean
%K coral reefs
%U http://www.scielo.sa.cr/scielo.php?script=sci_arttext&pid=S0034-77442012000500004