ABSTRACT
The authors review studies of four taxa—pink salmon, sea otters, harbor seals, and several species of sea-birds—widely believed to have suffered severe impacts from the Exxon Valdez oil spill. These studies were conducted over a 10-year post-spill period and included pre-spill information where possible. They demonstrated earlier suggestions of negative impacts may have been unfounded (harbor seals) or the species either exhibited no obvious detrimental effects from the spill (pink salmon population runs, population density and habitat occupancy of half the 23 seabird species examined) or indicated impacts followed by clear evidence of subsequent recovery (sea otters, the remaining seabird species). These species' apparent resilience to perturbations such as oil spills may be related to these ecosystems' high natural variability. Evaluating spill effects is enhanced by long-term studies that recognize the natural variability of marine environments and use a rigorous study design. The results of such studies also must be interpreted objectively, free of preconceptions about spill effects and divorced from advocacy positions.
Long-term impacts of the Exxon Valdez oil spill on sea otters, assessed through age-dependent mortality patterns
