Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Minato, Tokyo 108-8477, Japan
To reduce sucking forces of squids during the collecting process with chutes in squid jigging fishing, this paper proposes three types of methods of preventing squid-sucker suction, which are based on the concepts of reducing contact between suckers and the chute, and preventing sealing off the suckers. To evaluate the effectiveness of these proposed methods, three types of experimental chutes corresponding to the respective methods and a normal chute, for comparison, were developed. Using the experimental chutes, some experiments were conducted where sucking forces of live squids, frictional forces between a squid body and a chute, and the sum of them were measured and analyzed for the respective chutes. Then, the results showed that the proposed methods were significantly effective and useful.