Global Warming
As if overfishing and coastal pollution were not destructive enough, global warming posed a potentially lethal threat to many marine species, two major environmental organisations reported Tuesday. From tropical coral reefs to polar-ice edge communities, and from tiny zooplankton to polar bears, scientists have documented worrying declines in marine life which they believed could be at attributed, at least partly, to the impact of global warming. The new report, "Turning Up the Heat: How Global Warming Threatens Life in the Sea" - compiled by the World Wildlife Fund (WWF) and the Marine Conservation Biology Institute (MCBI) - warned that whole species could be wiped out by warmer waters. The report was based on an extensive review of studies and a meeting earlier this year of some of the world's leading marine researchers. It said that warmer surface air temperatures, which most scientists blamed on the emission of greenhouse gases, also were gradually warming the world's oceans. Surface water temperature had risen by about one degree Celsius over the past century and were expected to increase by up to another three degrees in the next 100 years if emissions - caused mainly by the burning of fossil fuels like oil and gas - continued at current rates. Marine life already was threatened by a number of human activities, the report pointed out. Overfishing had resulted in the collapse of major fisheries, and destructive fishing practices like bottom trawling had devastated the habitat of the sea floor. Coastal development and other activities that resulted in the pollution of coastal waters had converted whole ares of the oceans into so-called "dead zones," while the invasion of alien species, often carried in ships' ballast water to distant habitats, has wiped out many native marine species around the world. "Global climate change is an additional stress on already stressed species and ecosystems, and may be the 'straw that breaks the camel's back' for many types of marine life," according to the 47-page report.