%0 Journal Article
%T Sea Surface Temperature Variability in the Florida Keys and Its Relationship to Coral Cover
%A I. M. Soto
%A F. E. Muller Karger
%A P. Hallock
%A C. Hu
%J Journal of Marine Biology
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/981723
%X The hypothesis that moderate variability in Sea Surface Temperature (SST) is associated with higher coral cover and slower rates of decline of coral cover within the Florida Keys National Marine Sanctuary (FKNMS) was examined. Synoptic SST time series covering the period 1994¨C2008 were constructed for the FKNMS with the National Oceanic and Atmospheric Administration Advanced Very High Resolution Radiometer satellite sensors. The SST data were compared with coral-cover time-series data from 36 sites monitored by the Coral Reef and Evaluation Monitoring Program. Sites that experienced moderately high SST variability relative to other sites showed a trend toward higher percentage coral cover in 2008 and relatively slower rates of decline over the 14-year study period. The results suggest that corals at sites that are continuously exposed to moderate variability in temperature are more resilient than corals typically exposed either to low variability or to extremes. 1. Introduction The disruption to the symbiotic relationship between corals and their zooxanthellae known as coral bleaching is a common stress response to one or multiple disturbance events [1¨C6]. Coral mass-bleaching events have primarily been associated with elevated photo-oxidative stress caused by high levels of solar irradiance, prolonged sea temperatures warmer than normal conditions, or both [1, 2, 7¨C11]. Anomalously low temperatures can also trigger bleaching [1, 12, 13]. Moreover, natural or anthropogenic exposure to somewhat elevated nutrient flux can lower warming thresholds for bleaching [14, 15]. The upper temperature threshold for bleaching also can be influenced by the thermal history of the reef site, season and environmental background [16, 17]. Sammarco et al. [18], for example, found that not all reef sites studied exhibited mass bleaching during anomalously high mean temperatures in Puerto Rico. However, bleaching occurred when both high biweekly mean temperatures and high sea surface temperature (SST) coefficients of variation were present. A record of SST variability can provide insights about the thermal history of a coral reef. McClanahan and Maina [19] found that coral cover was inversely proportional to the temperature variation experienced in four reef sites in Kenya¡¯s southern fringing reef. Yet an opposite relationship was found regarding taxonomic richness [19, 20]. McClanahan et al. [17] and Ateweberhan and McClanahan [21] also found that coral bleaching responses to warm-water anomalies were negatively correlated with temperature variability in coral reefs in
%U http://www.hindawi.com/journals/jmb/2011/981723/