Laboratory and field observations of sublethal damage in marine fish larvae: lessons from the Exxon Vmldez oil spill

摘要

The Exxon Valdez oil spill (EVOS) of 1989 presented scientists with an unprecedented opportunity to study the effects of a massive oil spill on a complex and productive ecosystem for which decades of fisheries data existed on several economically important fishes such as Pacific herring {Clupea pallasi). Definitive data have been slow to emerge because of a lack of consensus between Natural Resource Damage Assessment (NRDA) and Exxon-funded scientists over even the most basic information such as the exact trajectory of the Exxon Valdez oil (EVO) and methods to reliably measure Prudhoe Bay crude oil in sediments and marine organisms. The extent of exposure to marine fishes, particularly herring, is still being debated since Exxon scientists found EVO in only 1 of J75 samples taken in 1989-1990 (herring eggs from a heavily contaminated beach 1 month after the spill) (Bence and Burns 1995), whereas NRDA scientists did not collect sufficient tissue for determination of EVO at parts-per-billion (ppb) concentrations. Levels of dissolved EVO in water were believed to be at low- to sub-ppb levels throughout the spring following the spill, although a significant quantity of EVO was dispersed throughout the water column to a depth of at least 25 m and was detected throughout summer 1989 (Short and Harris 1996a), Such dispersed oil probably would also be bioavailable to water column organisms such as herring larvae or prey items.