ABSTRACT

During 1979 the Gulf of Mexico experienced the initiation of the world's largest oil spill (Ixtoc I in the Bay of Campeche) and a major oil tanker spill near a metropolitan area and an estuarine system (Burmah Agate spill off Galveston). Pre-spill sampling (after the oil came ashore in each area, the south Texas and Galveston beaches) illustrated immediate responses to oil in the water column (death of meroplanktonic and holoplanktonic forms, but an apparent congregation of copepods that were feeding on the oil); and perhaps, rapid (increase in nematode standing stock) and longer term (increase in nematodes and benthonic foraminiferans) responses to the oil as it reached the bottom. Four pelagic avenues of oil to the bottom were recognized -- tar balls and oil on the bodies of dead plankton near the Burmah Agate, flocculation of adhering of clay-sized particles to sheen or mousse, fecal pellet transport, and aerosol transport to the turbid nearshore zone with the adhering of silt-sized particles. Impact was noticeable near the Burmah Agate, in nearshore regions, and under open-ocean areas covered by extensive mousse and tar balls; however most of the open-ocean continental shelf appeared to he unaffected.