ABSTRACT
The beach of Ediz Hook, Port Angeles, Washington, was heavily oiled by Alaska North Slope (ANS) crude oil spilled subsequent to the grounding of the Arco Anchorage on December 21, 1985. Intertidal crude oil concentrations measured in beach sediments ranged from less than 50 to 20,000 ppm, with an average of 2,240 ppm. Beach reclamation efforts, concluded in April 1986, reduced average crude oil concentrations to 670 ppm. An intertidal and subtidal sediment chemistry and benthic invertebrate monitoring program was initiated at Ediz Hook in 1986 and was concluded in early 1988. Sediment chemistry data indicated a decline in mean intertidal concentrations from 670 to 110 ppm between April 1986 and July 1987. Shallow subtidal concentrations decreased from a mean of 460 to 110 ppm in the same time period. Benthic invertebrate population indices, developed with core and box sampler data, generally demonstrated a negative correlation with sediment crude oil concentrations. Organism density, taxonomic diversity and biomass increased significantly at numerous stations during the course of the monitoring studies. Successful bivalve population recruitment and growth were evident for several hardshell clam species by the fall of 1987. There was no evidence of petroleum-derived hydrocarbons in the edible tissues of salmonids (rainbow trout and Atlantic salmon) which were gathered for several months after the spill from a net-pen culturing facility in Port Angeles. Despite vigorous bird rehabilitation efforts, approximately 80 percent of the 1,917 oiled birds perished. Pre- and post-spill population census data indicate, however, that population level impacts did not occur. Various reconnaissance, monitoring and damage assessment investigations conducted during and after the spill have documented the environmental value of a rapid and effective spill response and cleanup effort. Significant impacts associated with the spill were short-term in nature and generally limited to the immediate spill area.
Evaluation of optimal dose and mixing regime for alum treatment of Matthiesen Creek inflow to Jameson Lake, Washington