Organochlorine pesticides, polychlorinated biphenyls (PCBs) including non-ortho PCBs, polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) were measured in sea otter liver tissue from California, southeast Alaska, and the western Aleutian archipelago collected between 1988 and 1992. Average total dichlorodiphenyltrichloroethane concentrations for California otters (850 µg/kg wet weight) were over 20 times higher than in Aleutian otters (40 µg/kg) and over 800 times higher than otters from southeast Alaska (1 µg/kg). Levels for total PCBs in Aleutian otters (310 µg/kg) were 1.7 times higher than levels in California otters (190 µg/kg) and 38 times higher than otters from southeast Alaska (8 µg/kg). Levels for PCDD and PCDF were extremely low in all otter populations. Levels of PCBs in Aleutian and Californian otters are abnormally high when compared with southeast Alaskan otters. The source of PCBs to the Aleutian Islands remains unclear and vital to understanding the potential impacts to sea otters.
Levels of blood haptoglobin (Hp) and interleukin-6 immunoreactive protein (IL-6 ir) were significantly elevated in river otters (Lutra canadensis) inhabiting oiled areas of Prince William Sound, Alaska (USA) following the Exxon Valdez oil spill in 1989. By May and June 1992, however, such differences were not apparent. Mean body mass of otters, adjusted for sex, age-class, and total length with analysis of covariance, differed between oiled and non-oiled areas from 1990 to 1992, but were nearly identical by May and June 1992. We propose that river otters may be recovering from chronic effects that we observed in 1990 and 1991 following the 1989 Exxon Valdez oil spill, but further research is necessary to test this hypothesis.
In winter 1990, an adult male sea otter (Enhydra lutris) was found dead along the eastern shore of Prince William Sound, Alaska. Necropsy findings included an enlarged retained left testicle with a twisted spermatic cord, enlarged left sublumbar lymph node, emaciation, dental attrition, oral papules and ulcers, and luminal intestinal hemorrhage associated with numerous acanthocephalids. A malignant seminoma was present in the left testicle and left sublumbar lymph node. Additionally, herpesvirus like intranuclear inclusion bodies were found in oral, esophageal, and corneal epithelial cells. Virions consistent with a herpesvirus were found in esophageal epithelium. Dental attrition, severe intestinal acanthocephaliasis, the malignant seminoma, and emaciation were considered contributing factors in causing death. The herpesviral disease was probably secondary to the debilitation and stress. This is the first report of malignant seminoma with metastasis in a sea otter.