Impact and amelioration of sediment pollution on coral reefs of St. Lucia, West Indies

Abstract

St. Lucia's coral reefs are highly valuable resources. They support a fishing industry worth hundreds of thousands of EC dollars annually, and a tourism industry that nets tens of millions of EC dollars. Efforts to protect and manage reefs have been underway for a decade. Since 1995 the Soufriere Marine Management Area (SMMA) has facilitated a four-fold increase in fish stocks in marine reserves and a three-fold increase in fishing grounds. Fish catches have nearly doubled, and the profitability of the fishery has increased by a similar amount. The SMMA has become a model for successful management of coral reefs worldwide, and expansion of this approach to manage other nearshore resources and fisheries around the island is now warranted. Improvements in fish stocks and the fishery have been made against a background of severe reef degradation. 55% of the coral that was present at the establishment of the SMMA has since died. The causes of coral decline include storms, sediment pollution, coral disease and tourism. To date, storms have been responsible for the greatest losses, followed by sedimentation impacts, then disease. However, sediment pollution is one of the most serious threats to St. Lucia's reefs because it inhibits recovery from other disturbances. Reducing pollution inputs and facilitating reef recovery is also an economic imperative. Tourism depends on a high quality reef environment, and tourists prefer sites with abundant fish, large fish, healthy corals and good underwater visibility. While reserves enhance fish stocks, increasing reef amenity value, sediment pollution increases coral mortality and reduces underwater visibility. This report describes a series of measures that will help reduce rates of sediment input and facilitate reef recovery