- 著者
-
Mitsunaga Yasushi
Kawai Syunsuke
Komeyama Kazusoshi
Matsuda Masanari
Yamane Takeshi
- 出版者
- The Japanese Society of Fisheries Engineering
- 雑誌
- Fisheries engineering (ISSN:09167617)
- 巻号頁・発行日
- vol.41, no.3, pp.251-255, 2005-02-15
- 被引用文献数
-
5
To increase catch efficiency, it is necessary to understand the habitat utilization of the target fish around fishing gear. A biotelemetry study using coded ultrasonic transmitters and set receivers was conducted to understand the habitat utilization of largemouth bass around a set net in Lake Biwa, Japan. Three receivers were installed on leader nets of the set net at short intervals by design to understand the fine scale movement of fish. Four fish were implanted with a coded ultrasonic transmitter and released near the set net. Two fish were monitored for over 50 days and showed diurnal habits. Just before the fish left the set net. the main current direction was southwestward and the current velocity was over 5m/sec. In a set net fishery, current profile is an important factor affecting the concentration and dispersion of the target fish.琵琶湖固有の定置網であるエリ周辺で,コード化超音波発信機と設置型受信機を用いてオオクチバスを追跡した。オオクチバス4尾(TL : 34.0~37.0cm)の腹腔内に受信機(Coded V8SCL, VEMCO製)を埋め込み,エリの中心に放流した。エリの垣網に設置型受信機(VR2. VEMCO製)3台を250mと敢えて間隔を狭めて仕置し,詳細な移動を把握した。50日以上追跡した2尾は, 10℃以下の低水温にも関わらず,昼間にエリから遠ざかり,夜間にエリに近づく日周移動を示した。同時にエリ周辺に設置した流向流速計の記録から,5m/sec以上の南西流が卓越した後,個体はエリから遠ざかったことが分かった。受動型漁具である定置網の漁獲には対象魚の移動と周辺の流動環境が密接に関わっていると考えられる。