A skin disease frequently observed in stranded yearling Northern elephant seals at The Center characterized by alopecia, hyper pigmentation, epidermal ulceration, and squamous metaplasia and atrophy of sebaceous glands, is also associated with low serum thyroid hormone and retinol. Although exposure to PCB could explain the pathology observed in these seals, serum biochemical changes could also be caused by stress and chronic infection. The best documented example of a marine mammal as a sentinel is the beluga whale of the St. Lawrence. This association may be due to poor immuno-surveillance in St. Lawrence animals as a consequence of contaminant exposure. This hypothesis is being investigated by testing function of beluga lymphocytes in vitro following exposure to contaminants.
Animals are thus important sentinels of environmental change.
Detailed observations of the rehabilitation process can advance our knowledge of marine mammal diseases, and thus of the effects of environmental change. This article is excerpted from a presentation to the American Veterinary Medical Association. Include your name, address, fax number and email address. Dr. Frances Gulland is Director of Veterinary Science.