1Kumaishi Research Branch, Hokkaido Fish Hatchery, Hokkaido 043-0402, 2Hokkaido Fish Hatchery, Hokkaido 061-1433, 3Hokkaido Forestry Research Institute, Hokkaido 079-0198, 4Department of Aquatic Biosciences, Tokyo University of Fisheries, Tokyo 108-8477, Japan
To estimate the catch of juvenile masu salmon Oncorhynchus masou by anglers in a river which flows in an urban area in central Hokkaido, we randomly surveyed anglers from June to October 1999 using questionnaires and interviews. Total numbers of anglers were estimated using a two-stage sampling design; fishing days were sampled at the first stage, vehicles at the second stage, and numbers of anglers in each vehicle were recorded. Of 21,874 (95% confidence interval: 20,785-22,963) juvenile masu salmon inhabiting the study area in June, we estimated that 14,219 (4,613-23,825) fish were caught by anglers. Our study indicates that the mortality of juvenile masu salmon caused by recreational fishing in an urban area is substantial although the precision of the estimate was not high.