CONTAMINANT EFFECTS ON OVARIAN DEVELOPMENT AND SPAWNING SUCCESS IN ROCK SOLE FROM PUGET-SOUND, WASHINGTON

The objective of this study was to determine if exposure to aromatic h ydrocarbons (AHs) or polychlorinated biphenyls (PCBs) was associated w ith altered ovarian development or reduced spawning success in rock so le Pleuronectes bilineatus. This objective was addressed in two separa te phases. In the first study, concentrations of AHs and PCB s were me asured in individual fish from four sites in Puget Sound, Washington ( Eagle Harbor, Sinclair Inlet, Yukon Harbor, and Pilot Point) with diff erent levels of AH and PCB contamination in sediments and their ovaria n development was monitored during the 1989-1991 spawning seasons. In these fish, egg weight was negatively correlated with levels of PCBs i n the liver. However, contaminant exposure levels were not significant ly associated with the probability of entering vitellogenesis or with gonadosomatic index, plasma estradiol concentrations, or fecundity. In the second study, gravid female soles were taken from Eagle Harbor. S inclair Inlet, Yukon Harbor, and University Point (known spawning area s for rock soles), and hormonally induced to spawn in the laboratory. Eggs were fertilized with pooled sperm from reference males. Consisten t with the first study's findings, fish from Sinclair Inlet, where sed iments contain elevated concentrations of PCBs, produced eggs with sig nificantly reduced weight. Furthermore, the overall spawning success o f fish from the site with the highest level of AH contamination (Eagle Harbor) was significantly impaired. These findings suggest that envir onmental exposure to AHs and PCBs may reduce reproductive success in f emale rock soles, but this species appears to be more resistant to suc h effects than other Puget Sound flatfish species, such as the English sole Pleuronectes vetulus.