NATURALLY OCCURRING HYDROCARBONS IN THE GULF OF MEXICO AND THE CARIBBEAN

Abstract

ABSTRACT Results are presented of 8 years of research on naturally occurring hydrocarbons in the Gulf of Mexico and the Caribbean. They are found beneath the bottom, on the bottom, in the water column, and floating on the surface. The geographic emphasis has been in the Gulf and the Caribbean, but data on hydrocarbons floating at or near the surface have also been collected along a profile from Dakar, Africa, to Trinidad. Tar samples were also collected seasonally along the entire Texas coast, as well as off the eastern Mexican coast and the western Florida coast. Various types of geologic, geophysical, and oceanographic data were obtained from research vessels and a submersible. They corroborate historical evidence of tar on beaches from naturally occurring seeps, including its use in pottery by the Karankawa Indians in pre-Columbian times and for caulking ships by early Spanish explorers. Charts published in 1902 through 1909 indicate heavy oil slicks off the Louisiana and Texas coasts, and in 1903, oil ponds off the Sabine River. The present research has also documented scores of active gas seeps on seismic subbottom profiler records and by visual and photographic observation from a submersible. The major conclusion of this study is that a low-intensity, persistent introduction of hydrocarbons over thousands of years has not been deleterious to the marine environment. An ecosystem influenced in this manner can continue to be biologically active and should not be considered to have been irreparably harmed.