|Document Type:||Journal Article|
|Title:||Prevalence of marine-mammal tooth and claw abrasions on adult anadromous salmonids returning to the Snake River|
|Author:||Jerrel R. Harmon, Kenneth L. Thomas, Kenneth W. McIntyre, Neil N. Paasch|
|Journal:||North American Journal of Fisheries Management|
During 1990, a relatively high prevalence of marine mammal tooth and claw abrasions was observed on adult anadromous salmonids returning to the Snake River. From 1990 through 1992, annual prevalence of these injuries ranged between 14.0 and 19.2% for spring/summer chinook salmon Oncorhynchus tshawytscha and between 5.6 and·l4.2% for steelhead O. mykiss. Open wounds were observed on about one-third of the fish with abrasions. Although these results suggest that predation by pinnipeds may be an important mortality factor for Snake River spring/summer chinook salmon, further research is needed to accurately define the magnitude of the predation.