Research to Investigate Effects from Prudhoe Bay Crude Oil on Intertidal Infauna of the Strait of Juan de Fuca. First Annual Report

摘要

An experimental study was designed to measure the influence of oil, site, sediment type, tide level, and season, on in situ intertidal infauna recovery rate in the Strait of Juan de Fuca (Washington State). This progress report on the first year's activities provides details of effects on recovery rate by early colonizers due to oiling, site and sediment type in the late-summer - early-fall season. Data from the study, involving analysis of more than 400 individual core samples, indicate a significant effect on recovery rate for three of seven target species three months after treatment. The target species for which recovery rates were significantly retarded include two opportunistic polychaetes and an herbivorous snail. No effect from oiling on recovery by two bivalve species included as targets was observed. Computation of methodological sensitivity for these species indicates that quite small differences due to oiling would have been detected had they occurred. Significant reductions in sediment oil concentration during the first three months occurred in the two experimental sediment types and at both the experimental sites.