Sublethal effects of the Exxon Valdez oil spill on herring embryos and larvae: Morphological, cytogenetic, and histopathological assessments, 1989-1991

Following the Exxon Valdez oil spill in Prince William Sound, Alaska, in March 1989, Pacific herring (Clupea pallasi) larvae were evaluated for sublethal damage. From 1989 to 1991, egg masses were collected from oiled and unoiled beaches and incubated to hatch. Newly hatched herring larvae were assessed for morphological (skeletal, craniofacial, and finfold) deformities, cytogenetic abnormalities (anaphase-telophase aberrations), and histopathological lesions. In 1989, herring larvae from both oiled areas (Rocky Bay on Montague Island and Naked Island) had significantly more morphological deformities and cytogenetic abnormalities than did larvae from the unoiled location (Fairmont Bay). The extent of morphological and cytogenetic damage was correlated with oil exposure in adjacent native bay mussels. Larvae had no oil-related histopathological lesions. In 1990 and 1991, oil-related developmental and genetic effects were undetectable.