Severe gross and microscopic lesions and other changes were found in adult aquatic birds and in embryos from Kesterson Reservoir (a portion of Kesterson National Wildlife Refuge), Merced County, Calif., during 1984. Adult birds from that area were emaciated, had subacute to extensive chronic hepatic lesions, and had excess fluid and fibrin in the peritoneal cavity. Biochemical changes in their livers included elevated glycogen and non-protein-bound sulfhydryl concentrations and glutathione peroxidase activity but lowered protein, total sulfhydryl, and protein-bound sulfhydryl concentrations. Congenital malformations observed grossly in embryos were often multiple and included anophthalmia, microphthalmia, abnormal beaks, amelia, micromelia, ectrodactyly, and hydrocephaly. Mean concentrations of selenium in livers (94.4 ppm, dry weight) and kidneys (96.6 ppm) of birds collected at the Kesterson ponds were about 10 times those found at a nearby control area (8.3 and 12.2 ppm). We conclude that selenium present in the agricultural drainage water supplied to the Kesterson ponds accumulated in the food chain of aquatic birds to toxic concentrations and caused the lesion and other changes observed.

Ten stranded cetaceans, representing five species, from the Oregon Coast were examined between 1973-1977. Fourteen genera of parasites, together with the pathogenesis and pathology associated with the presence of some of these parasites are reported.

Sixty-eight marine mammals stranded on the Oregon beaches were examined at necropsy. Gunshot was the primary cause of death in 30% of the pinnipeds examined. Bacterial infections (27%) and parasitism (27%) were also of major importance in the death and debilitation of Oregon marine mammals. Traumatic death or debilitation other than gunshot was observed in 11 animals (16%). Predation, starvation due to neonatal abandonment, viral encephalitis (presumptive diagnosis), dystocia and neoplasia were diagnosed as primary or contributory causes of stranding.

Abstract:Forty-two seals and sea lions found dead along the Oregon Coast were examined for parasites and associated pathology.