Farmed Non-native Coho Salmon in Sanriku Region Affected by Recent Intense Natural Disasters

Abstract Excerpt:
Coho salmon farming is an economically important activity in the Sanriku region, which has recently experienced unprecedented natural disasters, including the Great East Japan Earthquake (GEJE), and the direct impacts of large typhoons. Each of these events was associated with a large number of farmed coho salmon escaping from hatcheries or net pens. As a result, there is considerable concern about the impact of these escapes on the ecosystem, especially on native masu salmon which occupy a similar ecological niche to coho salmon. Furthermore, coho salmon can hybridize with masu salmon (Ito et al. 2006), and hybridization is widely considered to have deleterious effects on native salmonid populations (Allendorf et al. 2001; Muhlfeld et al. 2009).