FRESHWATER OIL SPILL CONSIDERATIONS: PROTECTION AND CLEANUP

Abstract

ABSTRACT Oil spills occurring in freshwater (and upper estuarine) environments produce different effects than similar spills in marine environments, and thus require different considerations in protection and cleanup. Freshwater spills are primarily land- or river-based, and retention time of the oil in the environment takes one of two extremes, either very brief or very long. As in the marine environment, spills in marshes (predominantly grasses and sedges) are generally most destructive, especially when marshes have little or no flushing. The return of the marsh to a natural state is dependent upon the amount and type of oil, the amount of flushing, the type of vegetation, the type of cleanup, and the potential for natural revegetation (recovery). Spills in swamps (predominantly shrubs and trees) are influenced by similar factors and by the amount and type of understory vegetation. Spills occurring in marsh and swamp habitats in rivers are much less destructive and frequently result in oiling of the outer fringing vegetation rather than pooling or oiling of interior vegetation. Case studies of spills on the Cape Fear (North Carolina), Columbia (Washington), and St. Lawrence (New York) Rivers and in southern swamps (Louisiana and Texas) are given as examples of some points concerning freshwater spills. International examples are given by considering Nigeria and other countries. Suggestions for protection and cleanup are developed from these case studies.