The U.S. National Oceanic and Atmospheric Administration released a study Thursday that found high levels of pollutants in Guanica Bay, off southwestern Puerto Rico, saying they pose a "serious threat" to corals and other marine life.

"The pollutants measured in the sediments of Guanica Bay, Puerto Rico ... were among the highest concentrations of PCBs, chlordane, chromium and nickel" detected since the NOAA began its nationwide contaminant monitoring program in 1986, the agency said.

David Whitall, an NOAA ecologist and the study's main investigator, was quoted as saying in a press release that "these concentrations of pollutants represent serious toxic threats to corals, fish and benthic fauna - bottom dwelling animal life and plants."

Lower indicators of biological health, including a lesser amount of coral covering the sea floor offshore from Guanica Bay relative to an adjacent study area, La Parguera, also were detected, Whitall said.

"Further research is needed to determine if this is the result of the toxins or some other cause. At this point, we cannot definitively link it to pollution," he added.

The bay is located near the southern tip of the U.S. commonwealth and is an area of the Caribbean that attracts divers from around the world due to its rich marine life. EFE