Caribbean Corals in Crisis: Record Thermal Stress, Bleaching, and Mortality in 2005

Abstract

BackgroundThe rising temperature of the world's oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin.Methodology/Principal FindingsSatellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers' field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles.Conclusions/SignificanceThermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch's Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate.

Monitoreo en aguas cercanas al área marina protegida en la costa de Granada, Caribe Oriental: cobertura bentónica y poblaciones de peces

“…Local impacts such as overfishing, nutrient and soil runoff from farms, municipal pollution and damage from tourist activities combine with the impacts of global climate change to cause degradation of coral communities (Gardner, Côte´, Gill, Grant & Watkinson, 2003;Burke & Maidens, 2004;Knowlton & Jackson, 2008;Burke et al, 2011;Jackson et al, 2012). Changes in global climate have resulted in ocean temperatures high enough to cause bleaching and stress to corals (Baker, Glynn & Riegl, 2008;Bruckner & Hill, 2009;Cantin et al, 2010;Eakin et al, 2010;Buddemeier, lane & Martinich, 2011;Riegl, Berumen & Bruckner, 2013). Local impacts such as increased nutrient levels have now been shown to increase sensitivity of corals to bleaching (Wiedemann et al, 2013).…”

Temperature regulation of virulence factors in the pathogen Vibrio coralliilyticus

“…In coral reefs, an estimated one third of coral species are at a risk of extinction largely because of global warming and disease (Carpenter et al, 2008). Mass mortality of Caribbean coral ecosystems occurred in 1998 (Aronson et al, 2000) and 2005 (Eakin et al, 2010), two of the hottest years recorded, with record breaking sea surface temperatures (SST) (NOAA, 2011). Localized temperaturerelated bleaching episodes have also increased in frequency (Whiteman, 2010) and are predicted to occur biannually within 20 years (Donner et al, 2007).…”

Lipid biomarkers in Symbiodinium dinoflagellates: new indicators of thermal stress

“…In recent years, anomalously high temperatures have been observed to correlate with coral bleaching (e.g., Goreau and Hayes 1994;Eakin et al 2010) and may also be implicated in exacerbating coral diseases (Harvell et al 1999;Cervino et al 2004;Sutherland et al 2004). High temperature bleaching episodes in recent years are among the most severe symptoms of a longer-term decline in reef health worldwide (Pandolfi et al 2003).…”