Contamination of coral reefs by heavy metals along the Caribbean coast of Central America (Costa Rica and Panama)

Abstract

A survey of 12 heavy metals in the skeleton of the coral Siderastrea siderea and reef sediments in 23 reefs along the Caribbean coast of Costa Rica and Panama (1497 km) indicates high levels of pollution in the region. The entire coast is influenced by hundreds of rivers increasingly loaded with suspended sediments (associated with deforestation) which carry most of the metals several kilometres from the sources to the sea, where they are probably transported and distributed by currents through the entire region, even to pristine offshore reefs. Central America coastal areas are currently exposed to a larger range of metal pollution (natural and anthropogenic) than ever before, as a result of the increasing environmental contamination from sewage discharges, oil spills (from refineries and tankers), the misuse of agricultural chemicals and fertilizers, and topsoil erosion.