Coral Bay, Cruz Bay Reefs at Highest Risk in Caribbean Coastal Ecosystem Study

Reefs in the Coral Bay Watershed and Cruz Bay Watershed face the highest risk of land-based threats out of St. John’s 11 watersheds, according Lauretta Burke, of the Washington, DC-based World Resources Institute (WRI).

Burke shared the results of an 18-month Reefs at Risk in the Caribbean study conducted by WRI and the National Oceanographic and Atmospheric Administration (NOAA) in Puerto Rico and the U.S. Virgin Islands at the Ninth Annual Nonpoint Source Pollution Conference at the Westin Resort and Villas on Monday, November 28.

The study, which analyzed watersheds throughout the territory and Puerto Rico, focused on a number of factors including an area’s relative vulnerability to erosion, which is based on physical factors in the landscape and relative erosion potential, which took into account an area’s current land cover, explained Burke.

“Coral Bay has the highest percentage of the most erosion vulnerability in the area,” said Burke. “High slope and the converted use of land both contribute to an area’s rate of erosion vulnerability.”

The Cruz Bay Watershed was listed as having a high risk of land-based threats because of the development in the area which contributes to its high relative erosion potential and erosion from the numerous roads.

A number of other reefs throughout the Virgin Islands were also listed as facing a high risk of land-based threats including Eastern St. Croix and Western St. Thomas.

The Reefs at Risk in the Caribbean study aimed to develop indicators of threats to coral like sediment, which screens light and kills algae, toxic substance run-off from roads or agriculture and the amount of nutrients in the reefs from sewage and run-off, Burke explained.

“Looking at erosion prone areas is a good indicator for saving reefs,” said Burke.

The study analyzed an array of threats to reefs in the VI’s roughly 53 watersheds and Puerto Rico, including coastal development, land-based threats and over-fishing – which researchers determined was the biggest threat to reefs in the VI.

“The Reefs at Risk analysis identifies over-fishing as the main predicted threat to these reefs, with over 85 percent under high threat,” according to the first version of NOAA and WRI’s Coastal Data C.D. for the U.S. Caribbean. “Fisheries are close to collapse; even those inside marine protected areas are deteriorating.”

Numerous detailed maps, graphs, research methodology and analysis are available on the C.D. which was handed out at the Nonpoint Source Pollution conference.

The study also aims to support improved management of coastal ecosystems and Burke shared a success story from a similar WRI study in southeast Asia.

“Because of the results of our study in East Malaysia, coastal communities added coral reefs to coastal planning laws and they passed legislation to limit development in areas that highly affect reefs,” said Burke.

For more information on the Reefs at Risk in the Caribbean study, check out WRI’s web site at