Observations of cod reaction to trawling noise
Abstract
Observations made from a stationary echo sounder, passed by a trawling vessel, clearly demonstrate the flight reaction of cod
as a response to the noise from the vessel. Horizontal dispersal and downward swimming has been observed to starts as early as 200 m in front of the vessel propeller, and a descent speed of nearly 17 mjmin has been recorded. The avoidance reaction was seen at depths from 50 - 170 m depth, gradually diminising with increasing depth. Similar, but and weaker responses were also observed during general passages without trawl.
Description
ICES Working Group FAST (WGFAST): Fisheries Acoustics, Science and Technology Working Group (FAST.WG. Oostende, April 20-22, 1988.