제주근해 태평양참다랑어(Thunnus orientalis)의 어업생태학적 특성과 환경의 관계

Abstract

Pacific bluefin tuna (Thunnus orientalis) is one of the important species in the North Pacific as well as in Korea. Investigation on the important environmental factors for controlling the biology and fisheries of T. orientalis was carried out using Korean fishery statistics and climate and oceanographic information. Korean fishermen caught small pelagic fishes such as chub mackerel by offshore large purse seines, and T. orientalis accidently were caught mostly by this fishery. The monthly catch of T. orientalis around Jeju Island from 2004 to 2013 showed a negative correlation (r=-0.870, p<0.01) with the seawater temperature at 50 m and had a significant positive correlation (r=0.856, p<0.01) with the Pacific Decadal Oscillation (PDO) Index. The highest catch of T. orientalis around Jeju Island occurred in the seawater temperature range of 16 - 17°C or near the frontal area where offshore and coastal water masses collide. The length of T. orientalis ranged from 19 cm to 193 cm in fork length. The mean length of T. orientalis in each year had a negative correlation (r=-0.592, p<0.01) with the seawater temperature at 50 m and had a significant positive correlation (r=0.688, p<0.05) with the PDO Index.