Toxins may be harming coral reef ecosystems
By Summit Voice
FRISCO — Standing along the shore of Guánica Bay, Puerto Rico, the dazzling aquamarine Caribbean waters look normal. But deep below the surface, there may be trouble brewing, according to researchers with the National Oceanic and Atmospheric Administration.
Pollutants measured in the sediments of the bay are among the highest ever measured by NOAA’s National Status & Trends, a nationwide contaminant monitoring program that began in 1986. The pollutants include PCBs, chlordane, chromium and nickel, according to the new NOAA study.
“These concentrations of pollutants represent serious toxic threats to corals, fish and benthic fauna — bottom dwelling animal life and plants,” said NOAA ecologist Dr. David Whitall, the report’s principal investigator.
“We also observed lower indicators of biological health, such as how much of the coral covers the sea floor offshore from Guánica Bay when compared to an adjacent study area, La Parguera. 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,” Whitall said.
Researchers from the National Ocean Service’s National Centers for Coastal Ocean Science studied the reef’s ecology to help establish baseline conditions that coastal managers can use to measure changes resulting from new efforts to manage pollution. Among the items studied were habitat types, coral cover, fish and pollution stressors such as nutrients, sedimentation, toxic contaminants in Guánica Bay.
The new measurements demonstrate the importance of long-term contaminant monitoring programs like National Status & Trends, which allow new data to be placed in national and historical perspective.
Funding was provided by NCCOS and NOAA’s Coral Reef Conservation Program. NOAA is the co-chair of the U.S. Coral Reef Task Force, which had designated Guánica Bay as a priority watershed. Project partners included: NOAA’s Restoration Center, and the University of Puerto Rico at Mayagüez.