眺めていたらこのような記述がありました。 Japanese Whaling and Other Cetacean Fisheries Kasuya, Env Sci Pollut Res 14: 39 – 48 (2007)
Tobayama et al. (1992) observed that an average number of minke or other baleen whales (dead or alive) found in the Japanese trap nets was only seven animals per year, which was too small as compared with the results of some trap nets monitored by them. Considering the extremely high value of minke whales taken in trap nets and sold secretly, 6,400 to 40,200 US dollars per whale (when the US dollar was equal to 140 yen), they speculated that most of the minke whales taken in such nets were processed unreportedly and that the real number of minke whales taken in the trap nets would be close to 100 or more in the entire Japan. If this is the case, the mortality of minke whales in Japanese trap nets can have a significant effect on management.
This new rule of 2001 resulted in a sudden increase of minke whales reported as being taken in trap nets to 120–130 individuals a year. In addition to minke whales and other small cetaceans, trap nets occasionally take other large baleen whales. Species of particular concern are gray whales (Eschrichtius robustus), humpback whales (Megaptera novaeangliae), and right whales (Eubalaena japonica) (e.g. Kasuya et al. 2002, IWC 2006a).