* Warmer seas, higher carbon emissions threaten reefs
* Three-fourths of all reefs now at risk, study says
* Most vulnerable in Pacific, Caribbean, Indian Ocean
By Deborah Zabarenko, Environment Correspondent
WASHINGTON, Feb 23 (Reuters) - Globally warmer seas, rising carbon dioxide emissions and local factors like over-fishing have pushed the threat level on the world’s coral reefs into the danger zone, environmental advocates said on Wednesday.
More than 75 percent of all reefs — which harbor fish, attract tourists and shelter marine biodiversity — are currently threatened, the advocates from U.S. government and non-governmental organizations said in releasing a report, “Reefs at Risk Revisited.”
“Mounting pressures on land, along the coast and in the water converge in a perfect storm of threats to reefs,” Jane Lubchenco, administrator at the U.S. National Oceanic and Atmospheric Administration, said at a briefing. “Since the last ‘Reefs at Risk’ report ... threats have gone from worrisome to dire.”
The last report, released in 1998, found nearly 60 percent of coral reefs were threatened by human activity.
More than 500 million people around the world depend on coral reefs for food and income; the report estimated coral reefs provide $30 billion a year in benefits.
The carbon dioxide emissions that fuel climate change also contribute to making oceans more acidic, which impedes coral formation. In addition, warmer sea surface temperatures cause damaging coral bleaching, the report said.
Local pressures include over-fishing, destructive fishing methods such as explosives or poison, pollution from farm chemical run-off, unchecked coastal development, ships that drag anchors and chains across the reefs and unsustainable tourism.
If these threats don’t change, more than 90 percent of reefs will be at risk by 2030 and nearly all reefs will be at risk by 2050, according to the report, visible online at www.wri.org/reefs.
More than 275 million people live within 18 miles (30 km) of coral reefs. In more than 100 countries, coral reefs protect over 93,000 miles (150,000 km) of shorelines.
The report identified 27 nations — most in the Caribbean, the Pacific and the Indian oceans — that are socially and economically vulnerable if coral reefs are degraded or lost. Among those 27, the nine most vulnerable are Comoros, Fiji, Grenada, Haiti, Indonesia, Kiribati, Philippines, Tanzania and Vanuatu.
The three drivers of this national vulnerability are a high dependence on reefs, a high threat of exposure and a limited ability to adapt. The nine most vulnerable nations have all three.
Local efforts to curb over-fishing and protect reefs are a known part of the solution, while limiting climate-warming emissions is more challenging, the advocates said.
“It’s pretty clear that reducing greenhouse gas emissions, especially carbon dioxide, is absolutely necessary if we want any hope of preventing a lot of the dire situations that are presented in the report,” Lubchenco said. (Editing by Eric Walsh)