REGIONAL PATTERNS OF SEA SURFACE TEMPERATURE RISE: IMPLICATIONS FOR GLOBAL OCEAN CIRCULATION CHANGE AND THE FUTURE OF CORAL REEFS AND FISHERIES

Since the 1980s, corals have undergone unprecedented high temperature mass bleaching and mortality. Locations, intensity, and severity of bleaching are predictable by the sea surface temperature (SST) "HotSpot" method (Goreau & Hayes, 1994). HotSpot patterns over the last 2 decades show strong regional trends: SST increases are many times average rates in some regions, but lower in others. The regional spatial HotSpot patterns suggest that ocean circulation is being systematically altered by world-wide changes in winds, ocean currents, and upwelling. The data suggest that: 1) intensities of all warm currents are increasing; 2) intensities of all cold currents are decreasing; 3) coastal upwelling is being reduced at all major sites; 4) open-ocean upwelling is increasing in the interiors of all ocean basins; 5) wind driven upwelling is increasing all around Antarctica; and 6) flow from the Pacific to the Indian Ocean through Indonesia is increasing. Because of their magnitude, these changes will have much greater effects on regional climatic extremes and ecosystem alterations than mean global warming rates. The most rapidly warming areas are potential sites of regional coral reef ecosystem collapse. Corals may survive in areas where warming is slowest due to increased upwelling. However they will persist in marginal coral communities, not constructional coral reefs, due to increased competition from algae and filter feeders. These changes have strong implications for future patterns of global warming, ocean-atmosphere CO2 fluxes, marine biodiversity, fisheries catches, and primary productivity. Pelagic fisheries should be displaced from intense coastal upwelling zones to less productive open-ocean upwelling areas, with