The West Falmouth oil spill

Abstract

A spill of 650,000 to 700,000 1iters of #2 fuel oil in Buzzards Bay, Mass., USA, on September 16, 1969, has severely polluted the coastal waters, the marshes, the offshore sediments and the shell fish resources of Falmouth and of Bourne, Mass. In preliminary publications and reports we have discussed the chemical and biological data available during the first few months after the accident. The present report documents the continuation of our analytical effort; we include analyses of stations that had not previously been covered and present the data that were available by October, 1971. Three distinct, though partly overlapping, series of events followed the spill. First, within the first few hours or days after the accident, there was a very heavy kill of those organisms which came into contact with the oil. It extended over all phyla and over benthic and intertidal organisms. Next, within weeks or months after the spill, the oil pollution spread to areas that had not been immediately affected; and the kill extended, though in some cases more slowly than the spread of the oil, to outlying areas. Oil entered the marine food web and made the shellfish resources of our area unacceptable to human nutrition. The oil showed an unexpected persistence in the sediments and in marine life, especially in view of its relatively low boiling range and of earlier assertions that fuel oil pollution was transitory in nature and without long term consequences. For considerable time after the spill, the oil pollution of the sediments prevented the resettlement by the original fauna. Now, degradation of the oil has become evident. Biochemical and physical processes lead to a gradual reduction of the oil content of the polluted sediments. Concurrent with the degradation, there has been a gradual reduction in the immediate toxicity of the oil in the sediments. This has permitted resettlement of the polluted region first by the most resistant opportunists and later by a more varied and more normal fauna. However, oil-derived hydrocarbons have remained at all stations during the entire two year span for which data are now available, and it appears that the life span of pollution, even by a low boiling fuel oil must be measured in terms of many years. The eventual aim of this study is the documentation of the effects, the persistence and the eventual disappearance of pollutant hydrocarbons from a relatively small spill in a limited and previously clean coastal area. Of necessity, most of our analytical effort in the past was aimed at a survey of the extent of the oiling of the sediments and of some of the commercially important animals. As the degradation proceeds, we expect to devote a greater effort to a more detailed chemical analysis of the hydrocarbons remaining in the environment in order to define and understand the modes of degradation and to correlate chemical analyses with biological data. Parallel investigations on the weathering of different oils under other ecological and climatic circumstances are under way here and should, in combination with the West Falmouth study, give a more realistic assessment of the environmental hazard and persistence of crude oil than has been available until now.