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

Coral Reef Watch, National Oceanic and Atmospheric Administration, Silver Spring, Maryland, USA.
PLoS ONE (Impact Factor: 3.23). 11/2010; 5(11):e13969. DOI: 10.1371/journal.pone.0013969
Source: PubMed


The 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.
Satellite-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.
Thermal 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.

Download full-text


Available from: Michael James C Crabbe
  • Source
    • "c o m / l o c a t e / j m a r s y s produced the most severe and extensive mass coral-bleaching event ever recorded in the region. The repeated coral bleaching events in the Caribbean Sea since the 1980's have been broadly attributed to anthropogenic climate change (Eakin et al., 2010; van Hooidonk et al., 2013; van Hooidonk et al., submitted for publication). "
    [Show abstract] [Hide abstract]
    ABSTRACT: This study examines the potential impact of anthropogenic greenhouse warming on the Intra-Americas Sea (IAS, Caribbean Sea and Gulf of Mexico) by downscaling the Coupled Model Intercomparison Project phase-5 (CMIP5) model simulations under historical and two future emission scenarios using an eddy-resolving resolution regional ocean model. The simulated volume transport by the western boundary current system in the IAS, including the Caribbean Current, Yucatan Current and Loop Current (LC), is reduced by 20-25% during the 21st century, consistent with a similar rate of reduction in the Atlantic Meridional Overturning Circulation (AMOC). The effect of the LC in the present climate is to warm the Gulf of Mexico (GoM). Therefore, the reduced LC and the associated weakening of the warm transient LC eddies have a cooling impact in the GoM, particularly during boreal spring in the northern deep basin, in agreement with an earlier dynamic downscaling study. In contrast to the reduced warming in the northern deep GoM, the downscaled model predicts an intense warming in the shallow (≤ 200 m) northeastern shelf of the GoM especially during boreal summer since there is no effective mechanism to dissipate the increased surface heating. Potential implications of the regionally distinctive warming trend pattern in the GoM on the marine ecosystems and hurricane intensifications during landfall are discussed. This study also explores the effects of 20th century warming and climate variability in the IAS using the regional ocean model forced with observed surface flux fields. The main modes of sea surface temperature variability in the IAS are linked to the Atlantic Multidecadal Oscillation and a meridional dipole pattern between the GoM and Caribbean Sea. It is also shown that variability of the IAS western boundary current system in the 20th century is largely driven by wind stress curl in the Sverdrup interior and the AMOC.
    Full-text · Article · Aug 2015 · Journal of Marine Systems
  • Source
    • "The most severe bleaching event ever recorded in the Caribbean occurred in 2005 due to high ocean temperatures in the tropical Atlantic and Caribbean Sea. During this event, 80% of corals by area were affected by bleaching and 40% died at many locations across 22 countries (Eakin et al., 2010). Coral reefs provide numerous goods and services such as coastal protection and can be critically important to livelihoods. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Projections of climate change impacts on coral reefs produced at the coarse resolution (~1°) of Global Climate Models (GCMs) have informed debate but have not helped target local management actions. Here, projections of the onset of annual coral bleaching conditions in the Caribbean under Representative Concentration Pathway (RCP) 8.5 are produced using an ensemble of 33 Coupled Model Intercomparison Project phase-5 models and via dynamical and statistical downscaling. A high-resolution (~11 km) regional ocean model (MOM4.1) is used for the dynamical downscaling. For statistical downscaling, sea surface temperature (SST) means and annual cycles in all the GCMs are replaced with observed data from the ~4-km NOAA Pathfinder SST dataset. Spatial patterns in all three projections are broadly similar; the average year for the onset of annual severe bleaching is 2040-2043 for all projections. However, downscaled projections show many locations where the onset of annual severe bleaching (ASB) varies 10 or more years within a single GCM grid cell. Managers in locations where this applies (e.g., Florida, Turks and Caicos, Puerto Rico, and the Dominican Republic, among others) can identify locations that represent relative albeit temporary refugia. Both downscaled projections are different for the Bahamas compared to the GCM projections. The dynamically downscaled projections suggest an earlier onset of ASB linked to projected changes in regional currents, a feature not resolved in GCMs. This result demonstrates the value of dynamical downscaling for this application and means statistically downscaled projections have to be interpreted with caution. However, aside from west of Andros Island, the projections for the two types of downscaling are mostly aligned; projected onset of ASB is within ±10 years for 72% of the reef locations. © 2015 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.
    Full-text · Article · Apr 2015 · Global Change Biology
  • Source
    • "Anomalously warm water temperatures have been observed to be one of the major causes of mass coral bleaching worldwide (Munday et al., 2009; Eakin et al., 2010). Critical water temperatures (30–31 • C), duration extent (hours, days, or weeks) and event intensity (Berkelmans and Willis, 1999; Craig et al., 2001; Vargas-Angel et al., 2001; Berkelmans, 2002; Sammarco et al., 2006) are all known to affect coral bleaching (Berkelmans and Willis, 1999; Reaser et al., 2000; Eakin et al., 2010; Bastidas et al., 2012). Coral often dies after having been partially or totally bleached for long periods (Crabbe, 2008). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Global climate change and local anthropogenic pressures are among the primary factors leading to the decline of functional biodiversity and critical habitats in coral reefs. Coral bleaching, the potential decreases in dissolved oxygen concentration (deoxygenation) and pH (acidification) in the oceans can induce severe changes in coral reef ecosystem biodiversity and functionality. The main objective of this study was to apply four Ecopath with Ecosim models of a Caribbean coral reef system to individually and collectively model the effects of coral bleaching on the trophic web, deoxygenation on fish, and acidification on calcifying organisms. These three sources of stress were used as forcing functions on several trophic groups depending on the model. The forcing functions were scaled according to the species’ responses achieved in previously tested climate change marine models. For the bleaching model, a mediation function was also considered that represents the degree of coral reef protection on small and intermediate fish groups. The dynamic models were constructed from an extensive database of 171 reef fish species (abundance and biomass) and benthic communities from 13 coral reefs that were evenly distributed parallel to approximately 400 km of the Mexican Caribbean coast as well as fishery landings in this area. Simulations driven with these different forcing and mediation functions predicted different changes in the biomasses of fish and non-fish functional groups as well as the biomass of the functional groups of fished species. Coral bleaching and pH reduction caused a phase shift to a decrease in coral biomass and an increase in primary producer biomass. This shift produced a cascading decrease in the biomass of small and intermediate fish groups. Additionally, the fished functional group biomass increased with coral bleaching but decreased with the effects of decreased oxygen on fish and pH on calcifying organisms. The biomasses of certain macroinvertebrate functional groups were predicted to respond favourably to the combined effect of the sources of stress. However, when all the sources of stress were combined, we found a general decrease of biomass in fish, non-fish, and some commercially valuable fish and macroinvertebrate functional groups, suggesting that the combined effects of stress induced synergistic effects as a result of global climate change and overfishing, which can result in a potential loss of biodiversity and ecosystem services in coral reefs.
    Full-text · Article · Oct 2014 · Ecological Modelling
Show more