VOA常速英语:US Agency Says Coral Reef Destruction is Slowing This Year

There's some good news, for a change, in the latest climate forecast from the National Oceanic and Atmospheric Administration.  NOAA scientists say the world's threatened coral reefs, which for decades have been bleaching out and dying off because of climate-induced changes in ocean conditions, might be getting a respite this year.

For nearly three decades, marine scientists and environmentalists have been issuing distress calls about the rapid destruction of coral reefs around the world.  This time, predictions from the National Oceanic and Atmospheric Administration indicate that cooler water temperatures make it unlikely there will be any major bleaching events anywhere in the world this year.  Mark Eakin, who coordinates NOAA's Coral Reef Watch program said the new forcast shows that while "there is a little bit of stress, [it] is not too bad and the forecast for this year doesn’t look bad at all.”

Coral bleaching is caused by a variety of factors, such as excessive chemical nutrients, pesticides and other land-based pollutants washed into the sea by rivers.  Most of these factors affect coral in localized regions.  But the major cause of global bleaching events is warmer ocean temperatures, a direct effect of the climate change triggered by greenhouse gases and higher levels of CO2 in the atmosphere.  Warmer ocean waters can stress or kill coral communities.

Bleaching is easy to identify: the coral literally turn white.  Some of the coral could recover and regain their natural colors, but these are in critical condition and many will probably die. 

Eakin explains that toward the end of last year, massive bleaching occurred around the world and NOAA is now collecting data on the extent of that die-off.  In 2005, 90 percent of the coral in the Caribbean bleached and nearly 60 percent died. 

Last February a coalition of more than two-dozen environmental groups published a study called "Reefs at Risk, Revisited."  At a Washington news briefing, the administrator of the National Oceanic and Atmospheric Administration, Jane Lubchenco, described the report's main findings.

"Approximately 75 per cent of the world’s coral reefs are currently threatened by a combination of local and global pressures," she said.

And the report predicted that if the international community does nothing to ease those pressures, 90 percent of the world’s reefs will be threatened by 2030 and virtually all of them will be at risk in less than 40 years. 

NOAA scientists describe coral reefs as the "rainforests of the sea," noting that these fragile marine ecosystems provide important services such as coastal protection, commercial fish habitats and ecotourism, estimated to be worth as much as $375 billion globally each year.  And if predictions are right, the coral reefs will survive, at least for another year, to share these benefits with the world around them.