Interest in the health of marine mammals has grown with the increase in unexplained mortalities and strandings of coastal species. Investing time and resources into exploring the causes behind these incidents is justifiable in that we have such an enormous influence on the environment in which these animals live; perhaps our impact is responsible for these occurrences, in which case, we must direct our energy into both preventing contaminating circumstances and regenerating the habitability of coastal regions.

Thus far, direct correlations between exposure to pollutants and its effect on the immune systems of marine mammals have not been made. The consequences of exposure could be either immunosuppressive or immuno-enhancing. Regarding the former, cases in which pathogenic agents have been isolated from mortalities or from stranded animals may simply represent opportunistic infections; however, increased sensitivity to pathogens could be the result of immunosuppression stemming from contaminant exposure. In addition, no one has addressed the latter possibility of immuno enhancement; autoimmune or hypersensitivity reactions can, indeed, result from toxin exposure, as has been shown in terrestrial animals. Before we can demonstrate any association between pollutant exposure and immune abnormalities in marine mammals, we absolutely must acquire a basic understanding of the immune systems of the various coastal species.

We have been engaged in establishing an extensive panel of reagents and techniques for the comprehensive assessment of immunologic health of harbor seals (phoca vitulina) and for the establishment of baseline values for the species. Such tools and data will be used to define potential associations between acute and/or chronic exposure to petroleum products, as well as other chemical pollutants, and immune system dysfunction. This type of study is most appropriate as harbor seals occupy coastal waters and thus are at considerable risk of exposure to chemical pollutants.