Behavior analysis of the tuna longline gear for improved performance and efficiency in Fiji

Abstract

In this study, a numerical method and the catenary curve system of analyzing longline fishing gear was used to assess the performance and improve the efficiency of the tuna longline fishing gears in Fiji. The results showed that the analyzing methods used in Fiji was inefficient and did not provide accurate and realistic longline mainline and hook depth data. The SimuLine computer software and the Korean displacement analysis method provided more dependable mainline and hook depth data because they considered the principles of the mass spring model within their calculations. An improved understanding of the relationship between the effects of ocean currents and the configuration of longline gear (the shortening ratio, number of hooks) was the outcome. These factors affect the mainline and hook depth of longline gears which finally influence the selectivity of offshore fish species and the degree of damage to the offshore marine environment. Application of these results will lead to an improved and efficient offshore fisheries industry in Fiji.