A comprehensive assessment of the impacts of contaminants on fish from an urban waterway

Abstract

The Hylebos Waterway, in central Puget Sound in the state of Washington, is severely contaminated by a variety of organic and inorganic contaminants. Studies in the 1970s had shown that flatfish residing in the Hylebos Waterway had increased prevalences of several types of toxicopathic liver disease, including neoplasms. In 1994, studies were initiated to: (i) determine if contaminant source control had resulted in improvements in habitat quality, as determined by prevalences of liver disease in flatfish; (ii) encompass the assessment of reproductive function in flatfish; and (iii) determine whether and to what degree there might be contaminant exposure of juvenile salmonids which migrate through this waterway. The findings show that there have been no appreciable changes in disease prevalences or apparent contaminant exposure of flatfish from this site since the 1970s. Moreover, female flatfish from the Hylebos Waterway are showing evidence of precocious sexual maturation in young animals, and inhibited gonadal development in older fish. The results also showed that two species of juvenile salmon sampled from this site are being exposed to a wide range of chemical contaminants, and the levels of exposure are comparable to levels which have previously been shown to cause impaired growth, immunosuppression, and increased mortality following pathogen exposure. These studies, which were done to provide a scientific and legal basis for cleaning up and restoring this degraded habitat, provide an example of how studies of pollutant responses in marine organisms (PRIMO) are being applied to societal and resource manager needs.