Yellowfin Tuna Fishing Dynamic During Low IOD Positive and Negative at Eastern Indian Ocean; Study Case at Western Waters of Sumatera

Abstract

Effect of Indian Ocean Dipole (IOD) was highly significant on term of environments parameter variabilities at the Indian Ocean. Variation in the abundance and distribution of yellowfin tuna have been well known associated with environment parameters that drive by large-scale climatic indices such us Indian Ocean Dipole. To better understanding on yellowfin tuna fishing activities at the Western waters of Sumatera, we investigated hand line fishing catch during 2016 and 2017 as the IOD negative and positive events representation. Our result showed significant different fishing variabilities between year with negative and positive indices. Mean annual yellowfin tuna catch significantly higher during positive IOD both of abundance and weight, following by mean annual catch per unit effort (CPUE). During positive IOD hand line fishing trips were significantly lower compare than negative IOD. We also evaluated the geographic distribution of hand line fishing activities, we found that fishing activities cover significant wider area during positive IOD. In the opposite, during negative IOD yellowfin tuna fishing activities became centralized. This study gave us new perception on large-scale climatic events effect on yellowfin tuna fishing activities at a narrow study area.