Effects of releasing date and phase differences of amago salmon (Oncorhynchus masou ishikawae) angling efficiency

For the purpose of effective management and control for angling of released large size-amago salmon, we examined suitable releasing dates and phase difference between anadromous form smolt and resident form parr in a stream. Tagged smolt and parr were released on three different dates from late February to 1st March in 2006 and 2007. From 1st March when the fishing season of amago salmon was started, we conducted a creel census of anglers. The number of days from releasing to starting had a close relation to angling rate, and fish released on the starting day made the highest angling rate. Our results also indicated as follows, an effective fishing period was very short for releasing large size-amago salmon; angling rate of parr was not less than that of smolt.