THE FUNDAMENTAL STUDY ON THE OPTIMUM DESIGN OF SHRIMP POT FOR THE COON-STRIPE SHRIMP (PANDALUS HYPSINOTUS BRANDT) IN HOKKAIDO

摘要

This study was conducted to develop an optimally designed pot that is capable of controlling catch selectively. To achieve the optimum design for the shrimp pot, tank experiments were conducted to investigate the catch mechanism and catch selectivity of differently shaped pots. In this study, the catch selectivity of pots was estimated with different slope lengths. The experiments were conducted using model shrimp pots with five different slope lengths (24, 34, 44, 54, and 64cm) in an experimental tank (2 m × 2 m × 1 m). The catch mechanism was analyzed through a video recording system and catch selectivity was estimated using the SELECT model and master curve method. Two models using the likelihood ratio test and Akaike's information criterion (AIC) evaluated the goodness of fit of the selectivity curve. That results, the slope length with 50% retention of individuals with carapace length of 25 mm (about 1 year old) was 60.1cm, which is about 16 cm longer than the commercial pot design.