Research Technical Report
A PDF version of this report is available at:
Occurrence of external lesions on flatfishes in Monterey Bay, CA
Johnson, K.A., G.M. Cailliet, M. Stephenson, and G. Gardner (1997)
In: S.L. Eittreim (editor), Southern Monterey Bay Continental Shelf Investigations: Former Fort Ord Restricted Zone. U.S. Department of the Interior, U.S. Geological Survey, Open File Report 97-450. p. 104-113.
Tumor-like lesions were observed on Dover and English sole in Monterey Bay, CA during a 1994 field survey conducted to develop information on population dynamics. The lesions, focal areas of raised epithelium, in these important groundfish raised concern about a possible relationship with anthropogenic contaminants emanating from the FORZ, the Pajaro River, and/or the Salinas River. As a result, monitoring activities were conducted to develop information on the distribution of these tumor-like lesions. Dover sole lesions were histologically diagnosed as X-cell pseudotumors, and English sole lesions as trematode cercaria infestations. At these Monterey Bay locations, we determined the mean percent o'f Dover sole affected with X-cell tumors to be 7.4, 7.7 and 6.9, and the mean percent of English sole with trematodiasis to be 10.7, 12.3 and 17.6, respectively. The occurrence of external lesions on flatfishes in Monterey Bay is not significantly elevated above normal baseline levels for southern California. This study has not demonstrated a relationship between past military activities associated with FORZ and the occurrence of external lesions on fishes in Monterey Bay.