Indonesian Fisheries Research Journal
Vol 27, No 1 (2021): (June) 2021

ESTIMATES OF LENGTH-BASED POPULATION PARAMETERS OF SKIPJACK TUNA (KATSUWONUS PELAMIS, LINNAEUS 1798) FROM A POLE & LINE FISHERY IN MAUMERE-SIKKA, INDONESIA

Agus Setiyawan (Center for Fisheries Research, Ministry for Marine Affairs and Fisheries, Gd. Balitbang II, Pasir Putih 2, Ancol Timur, 14430 Indonesia)
Michael A Rice (Dept of Fisheries, Animal & Veterinary Science, University of Rhode Island)
Fayakun Satria (Research Institute for Marine Fisheries, Ministry for Marine Affairs and Fisheries, Nanggewer Mekar, Cibinong Bogor, Jawa Barat-16912, Indonesia)
Agustinus Anung Widodo (Research Institute for Marine Fisheries, Ministry for Marine Affairs and Fisheries, Nanggewer Mekar, Cibinong Bogor, Jawa Barat-16912, Indonesia)



Article Info

Publish Date
10 Jun 2021

Abstract

Several population parameters of skipjack tuna (Katsuwonus pelamis) taken by pole and line gear from Maumere Waters from March 2017 to February 2018 were analyzed. A total of 2,194 skipjack tuna was sampled randomly. Fishing activities were carried out around FADs (Fish Aggregating Devices) and free fish shoal. Observers and enumerators collected data from several landing sites and by direct on-board observations. This study aims to provide length-frequency distribution by season, estimate growth mortality parameters, and estimate stock exploitation rate using FISAT software. The results showed that the total catch was dominated by skipjack tuna; up to 80% with the CPUE of 30.8 kg/person/trip, and the skipjack tuna’s length distribution ranged from 26 to 69 cm FL. Length at first capture (Lc) was 34.71 cm FL, and immature fish dominated the total catch with 53%, indicating growth overfishing. The calculated von Bertalanffy growth (VBG) parameters were L= 70.35 cm, K = 0.55 yr-1, and t0 = -0.39 yr. Natural mortality (M) was estimated to be 0.92 and fishing mortality (F) was 0.91. The mean longevity of skipjack tuna is estimated to be 3.2 years, with an exploitation rate (E) of 0.50. Sustainable exploitation of skipjack tuna determined from this analysis could be developed with an Emax of 0.73. There is a focus on reducing the catch of immature fish through various methods that include changing the fishing target area from FADs to fishing on natural fish schools and using gear modifications such as larger-sized (lower number) hooks.

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Journal Info

Abbrev

ifrj

Publisher

Subject

Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology

Description

Indonesian Fisheries Research Journal published in Indonesia by Center for Fisheries Research. Indonesian Fisheries Research Journal publishes research results on resources, fisheries biology, management, environment related to marine, coastal and inland ...