An experimental technique for tracking dolphins in the vicinity of a trawl net

The system described in this paper provides a means of tracking one or more echolocating cetaceans (dolphins, porpoises and whales) in three-dimensional space. The aim of the research is to enable the behaviour of cetaceans to be observed passively in the wild in the vicinity of a large trawl net and to evaluate the effectiveness of deterrents intended to prevent the by-catch of these animals.