CONTINUING LONG-TERM STUDIES OF THE TROPICS PANAMA OIL AND DISPERSED OIL SPILL SITES

摘要

The TROPICS(Tropical Oil Pollution Investigations in Coastal Systems)oil spill experiment was conducted on the Caribbean coast of Panama,near Bocas del Toro.In November 1984,crude and dispersed crude oil were released in two separate boom-enclosed areas representative of intertidal mangrove and subtidal seagrass/coral ecosystems.The present information is based on site visits over the past two years,including 2002.Following the degradation of oil over the past 18 years,sheen identified from the spilled oil in 1994 is still visible in non-dispersed Oil Site sediments.In mangroves,previously denuded areas exposed to crude oil are currently occupied by new seedlings and saplings,which are growing rapidly but with morphological prop-root deformations.Tree mortality occurred in both the Dispersed Oil and Reference Sites,but was nonlocalized and appeared as natural mortality in aged trees.Recent data have revealed an invasion of seagrass beds by finger coral at the Oil Site.Since treatment,percent coverage of corals at this site has grown from a pretreatment value of 33.5% in March 1984 to 67.5% in June 2001.