SAN FRANCISCO — The delicate interplay between the oceans and atmosphere is changing with catastrophic consequences. Entire marine ecosystems have been wiped out, devastating populations of sea birds and larger marine mammals. These ‘dead zones’ occur where there are disturbances to the nutrient-rich ocean currents, which are driven by coastal winds. Extreme marine suffocations have occurred off the west coast of the US every year for the last five years. The most intense event, which left the ocean floor littered with the carcasses of crabs, happened in 2006. It was unlike anything that we’ve measured along the Oregon coast in the past five decades,’ said Dr Francis Chan, of Oregon State University (OSU). Other coastal countries including Chile, Namibia and South Africa have also been affected. Plant bloom The common factor between all of the areas is that marine currents off the coast rise from the deep ocean. These upwelling zones bring nutrient-rich water up from the deep, triggering plankton blooms that underpin the coastal food chain. Nearly 50% of the world’s fisheries are in these areas. The currents are driven by winds that move surface water away from the […]