THE INFLUENCE OF PETROCHEMICALS AND STRESS ON THE IMMUNE-SYSTEM OF SEABIRDS

There is increasing attention directed to the role of environmental po llutants in altering immune function. Only with the identification of the responsible environmental toxicants, and an understanding of their mechanisms of action, can we hope to treat immunotoxic injuries. This situation is exemplified by the exposure of wild birds to oil spills, the subsequent potential for direct toxicity from the oil, and the se condary toxicity of stress-induced immune modulation. Immunosuppressiv e mechanisms related to oil ingestion and handling stress are implicat ed in the morbidity and mortality of seabirds during care and followin g reentry into the wild. This does suggest that improvements in the tr eatment of these affected animals will enhance their survival and well -being. However, a survey of the literature shows that the implementat ion of better techniques are hampered by inadequate information on the immunological consequences of oil contact with seabirds. Marine oil p ollution is a constant occurrence and will continue as long as oil and oil products are important commodities transported by sea routes. Amo ng the numerous negative consequences of oil pollution are its effects on marine wildlife. There is much evidence that oil spills are respon sible for massive seabird deaths. However, the constant, low level rel eases of petrochemicals probably contribute to the harmful effects of oil pollution on seabird populations. In an attempt to rectify the dam age inflicted on seabirds by accidental oil discharge, rehabilitation centers are established for the cleaning and care of affected wildlife . Unfortunately, there is evidence that the ingestion of oil by preeni ng and the handling stress undergone by birds in these centers lowers their ability to survive and reproduce following release to their nati ve habitats, Although the reasons for this are unclear, there is the s uggestion that both oil and handling will induce immunosuppressive mec hanisms that ultimately predispose birds to infections and immune-medi ated diseases, as well as reproductive, behavioral, and other problems . Thus, there are questions concerning the effectiveness of interventi on measures currently being used in the rehabilitation of seabirds. (C ) 1996 Academic Press, Inc.