CHARLOTTE AMALIE, U.S. Virgin Islands —
Scientists issued a warning Tuesday that temperatures in the Caribbean Sea were
abnormally high and approaching levels that could be disastrous for coral reefs
-- many of which suffered unprecedented die-offs last year due to hot waters.
Sea temperatures around Puerto Rico and the U.S. Virgin Islands reached about 83.66 degrees Fahrenheit (28.7 degrees Celsius) -- 3.36 degrees Fahrenheit (0.2 degrees Celsius) warmer than their annual average high, which normally occurs in September or October, said Al Strong, a scientist with the U.S. National Oceanic and Atmospheric Administration's Coral Reef Watch.
NOAA alerted scuba-dive operators and underwater researchers in the U.S. Caribbean territories to look for coral damage and to be careful around the reefs, which are easily damaged by physical contact, Strong told The Associated Press in a telephone interview from Maryland. The agency issued a warning that is in effect until the waters cool off.
Researchers fear hot summer temperatures could be disastrous for reefs recovering from widespread damage last year, when up to 40 percent of coral died in abnormally warm seas around the U.S. Virgin Islands. Scientists have not pinpointed what is behind the warm sea temperatures but some speculate global warming might be the cause.
High sea temperatures stress coral, making the fragile undersea life more susceptible to disease and premature death. A building block for undersea life, the coral reefs are a sheltered habitat for fish, lobsters and other animals to feed and breed.
Prolonged bleaching -- when the water temperature gets so high that it kills the algae that populate and build the reefs -- kills coral.
Tropical Storm Chris, which passed through the region in early August, helped to briefly cool the seas, Strong said.
Despite being the second coral warning this year -- the first was released in July -- Strong said it wasn't as bad as last year, when sea temperatures topped 86.36 Fahrenheit (30.2 degrees Celsius) in Puerto Rico -- the highest levels in the territories in the last five years, Strong said.
Millions of people visit the Caribbean each year to dive and snorkel over the region's coral reefs, part of a multibillion-dollar tourism industry.