Article ID: 19-00028
Populations of masu salmon Oncorhynchus masou masou occur as anadromous and fluvial forms, which are known in Japanese as sakuramasu and yamame, respectively; the former is an important resource for coastal fisheries, and the latter for inland-water leisure fishing. Current management emphasizes stocking with hatchery fish but has not considered the biological differences between the two forms. Therefore, interpopulation stocking is actively undertaken. However, recent studies suggested that interpopulation stocking may cause not only a loss of inherent genetic traits in some populations but also alter their life history. Moreover, hatchery fish may competitively displace wild fish, and ultimately may not contribute to resource enhancement. In addition, the value of wild fish has gradually increased as a result of their more marketable appearance as well as greater management efficiency relative to hatchery production. This paper reviews previous studies on the ecological and genetic traits of sakuramasu and yamame, and proposes suggestions for more comprehensive management based on management practices for wild fish.
