Bull. Jpn. Soc. Fish. Oceanogr. 84(4), Page 261-270, 2020
  Relationship between damage to set net fisheries caused by Kyucho and vertical structure of current speed at fishery grounds on the coast of the Tango Peninsula

Yuki Funakosh1† and Yoichiro Ueno1

1Fisheries Technology Department, Kyoto Prefectural Agriculture, Forestry and Fisheries Technology Center, 10293 Odasyukuno, Miyazu, Kyoto 6260052, Japan
E-mail: y-funakoshi58@pref.kyoto.lg.jp

To clarify the relationship between multi-layer current conditions and damage to set net fisheries caused by Kyucho events, the current velocities at two layers (10 and 30 m depth) were measured in 2015 and 2016 at four stations off the coast of the Tango Peninsula. Our results showed that the mean current speed at 10 m was faster than that at 30 m at all of the stations. In addition, the Kyucho events occurred on more days at 10 m than at 30 m. However, three out of seven cases of the Kyucho damage were caused by strong flows at 30 m only, while the damage induced by a strong flow at 10 m was only one case. In addition, the maximum current speed at 30 m was faster than that at 10 m in five cases. This indicates the importance of the current monitoring not only at 10 m but also at 30 m to understand and reduce the Kyucho damages. The difference of characteristics of the multi-layer current conditions was recognized among the fishery grounds. The improvement of accuracy of the Kyucho warnings can be expected by monitoring the multi-layer current predictions based on this difference.

Key words: Kyucho, multi-layer currents, set net, disaster prevention, Tango Peninsula