For a second year, unusually high temperatures in the Caribbean Sea are threatening the reefs around the Virgin Islands and Puerto Rico. Sea temperaures reached nearly 84 degrees, the Associated Press reported. This is warmer than their annual average high. The U.S. National Oceanic and Atmospheric Administration’s Coral Reef Watch warned scuba dive operators and underwater researchers to look for damage around reefs. Last year, abnormally nigh temperatures killed 40% of coral around the islands, the AP reported. This is the second coral warning this year. In 2005, ocean temperatures reached 86 degrees, the highest they had been in five years.