The fate of fresh and artificially weathered South Louisiana crude oil was investigated in large-scale experimental oil spills. The oil, originally introduced to the surface of a creek bounded by walls of transite (but open at subtidal level to allow communication with surrounding waters), was distributed by tidal action over a marsh of Spartina alterniflora. Samples of surface film, water, organic detritus, sediment, fish (Fundulus heteroclitus), oyster (Crassostrea Virginica), and clam (Mercenaria mercenaria) were collected over long periods and subjected to detailed chemical analysis by gas chromatography and computerized low resolution GC-MS techniques. Results are presented for water and Fundulus.
Maximum concentrations of individual aromatic compounds found in fish were similar for both oils. This maximum occurred six hours after the spill for weathered crude, and 76 hours after the spill for fresh crude for all aromatic compounds except naphthalene and the methylnaphthalenes. Uptake appeared to be non-specific. In all cases investigated, hydrocarbon concentrations in animal tissue reached a maximum and then decreased to levels below measurability (<10 ppb). In the interpretation of the data, a distinction is made between environmental residence times observed in natural systems and the biological residence times measured in laboratory experiments.