Development of a migration path and environmantal factor recording system

发展过程分为两个部分；一是研制一种超声波ping信号装置，以了解鱼在自由自在的自然游动条件下的心率；二是利用大于5节拖曳速度的船舶上的ping信号，开发一种新的声波信号接收和定位系统。最终目标是将这两个系统有效地结合起来，并在海上长期可用。接收定位系统由4个水听器及其计算机分析系统组成。目标鱼的方向能够检测到水听器之间的声压差异以及心跳速率。心率是通过将电极插入测试鱼心脏附近的肌肉来测量的。它通过前置放大器转换成电压，形成声波信号。我们可以通过船上的音响系统来计数这些声音信号。新的记录系统于1997年首次在若狭湾进行了为期2个月的测试，测试对象是一条成年红鲷鱼，记录了它的游泳路线和迁徙行为。1997年在长岛人工养鱼池中记录了心率跳动。连续30小时测量心率。我们发现这个系统可以在海上使用。

The developing process is separated into two parts ; one is the development of an apparatus of ultrasonic pinger to know fish heart beat rate in free-ranging natural swimming condition and the other is to develop new sonic signal receiving and positioning system through sonic signals of a pinger on the ship with higher than 5 knot towing speed. The final goal is to combine both systems effectively and available in the sea for long periods. The receiving and positioning system is consisted of 4 phydrophones and its analyzing system through personal computer. The target fish direction is able to detect the difference of sound pressure among phydrophones as well as heart beat rate. The heart beat rate is measured by an electrode inserted into the muscle near the heart of the test fish. It was transformed into electro volt through a pre-amplifier to make a sonic signal. We can count these sonic signals through the phydorphone system on the ship. The new recording system was tested at first in 1997 at the Wakasa Bay using an adult red sea bream for 2 months and obtained its swimming path and migration behavior. The heart rate beat was recorded in the artificial fish farming pond in Hakatashima in 1997. Heart beat rate was continuously measured for 30 hours. We found the system is able to use in the sea.