DISTRIBUTION OF NEOPLASMS AND OTHER DISEASES IN MARINE FISHES RELATIVE TO THE DISCHARGE OF WASTE WATER*

Abstract

This study was based on an examination of approximately 290,000 fishes that comprised 151 species collected from southern California coastal waters, 1969 to 1976. Approximately 5 percent of the fishes were affected with external signs of disease, such as fin erosion, tumors, color anomalies, and attached macroparasites. Fin erosion diseases were reported in the greatest number of species and occurred at the highest frequencies. Fin erosion in Dover sole is the only disease that appears to be directly associated with discharge of municipal waste waters in southern California. It occurs primarily at one site, the Palos Verdes shelf, and appears to result from exposure to contaminated sediments at that site. The occurrence of skin tumors on young Dover sole covers an even wider geographic area, and the disease is quite similar to that which affects pleuronectids as far north as Bristol Bay, Alaska. The lack of association with specific waste discharge conditions coupled with an apparent relation to the life cycle of the Dover sole suggest that changes in waste discharge practices will have little impact on the prevalence of these tumors unless the changes affect survival rates and distributional patterns of young fish. The lack of infestation of Pacificmore » sanddabs by the parasite P. cincinnatus at Palos Verdes is curious and deserves further study. It is possible that the high levels of chlorinated hydrocarbons in the tissues of bottom fish at Palos Verdes are inimical to this and, possibly other, attached macroparasites.« less