Survival in air of Mytilus trossulus following long-term exposure to spilled Exxon Valdez crude oil in Prince William sound

Mussels, Mytilus trossulus, were sampled in 1996 from beaches in Prince Wil liam Sound (PWS) which contained residual oil resulting from the Exxon Vald ez oil spill of March 1989, and from one beach which had been lightly oiled in 1989, but contained no residual oil in 1996. The latter mussels served as un-oiled references. Mussels were also collected from Tee Harbor, Southe ast Alaska, to be used as an additional reference group. Where the size of the individuals in the resident population would permit, two size groups we re sampled, 32-35 and 18-20 mm in length. Polynuclear aromatic hydrocarbon (PAH) concentrations in mussel tissue, and air survival time were determine d for each group of mussels. Total PAH concentrations were significantly gr eater in tissue of mussels from oiled beds (0.6-2.0 mu g g(-1)) than from r eferences (0.01-0.12 mu g g(-1)) (P < 0.01). Oil-exposed mussels had signif icantly lower LT50 values (P < 0.05) for air survival than reference groups . Tolerance of small mussels to air exposure was significantly greater (P < 0.01) than large mussels in both the unoiled reference and oil exposed gro ups. (C) 1999 Elsevier Science Inc. All rights reserved.