Avoidance reactions of ultrasonic tagged cod during bottom trawling in shallow water
Original version
This report is not to be cited without prior reference to the authorsAbstract
Introduction: Observations made by echo sounder (Ona 1988) have shown that cod (Gadus morhua L.) may
avoid an approaching survey vessel horizontally and vertically. However, there has been a
lack of information on the escapement behaviour of the individual fish. This short note
discribes an experiment carried out in a shallow fjord in Northern Norway, where the
reactions of single cod towards a small survey vessel during bottom trawling were studied,
using ultrasonic tagging technique.