カテゴリ

論文発表

発表または掲載年月日

2026.06.13

発表学会／学会誌名

日本水産学会

発表題目

琵琶湖に侵入したチャネルキャットフィッシュの個体数抑制

発表者

石崎大介，1a＊ 田口貴史，1 山本充孝，1 大植伸之，1 藤井明美，2 倉本真央，2 松田　涼，2 近藤昭宏，2 中村昌文，2 亀甲武志，3 山中裕樹

発表者所属

1滋賀県水産試験場，2株式会社日吉，3近畿大学大学院農学研究科， 4龍谷大学生物多様性科学研究センター，5龍谷大学先端理工学部

概要

The channel catfish Ictalurus punctatus has become established below the Setagawa weir, built to pre-
vent the Lake Biwa water system flooding into the Seta River, the only river outflowing from Lake Biwa.
The channel catfish is believed to naturally migrate upstream toward Lake Biwa, leading to targeted re-
moval through eradications and surveys (using longlines) conducted above the weir since 2019. To evaluate
the effectiveness of such a control practice, changes in capture efficiency, individual fish body length, and
annual numbers of newly produced juvenile were analyzed. The results indicated that continued longline
fishing suppressed the population, as evidenced by declining capture efficiency, increasing periods of zero
captures of juveniles or adults, yearly decreases in the number of newly produced juveniles, and lower cap-
ture rates of individuals thought to have resulted from the latter. The findings confirmed the effectiveness
of longline fishing in controlling channel catfish, and the necessity of continuing such capture and removal
practices to prevent further invasions of the species into Lake Biwa.