Pertumbuhan dan Laju Eksploitasi Ikan Tongkol Komo (Euthynnus affinis Cantor 1849) yang di Daratkan di KUD Gabion Pelabuhan Perikanan Samudera Belawan Sumatera Utara

Abstract

Eastern Little Tuna is one of fisheries commodity that has high economic value in Medan. This type of fish is the most demand in the local market, thus it becomes the main target catch for fisherman. However, that activity has negative impact for the population of Eastern Little Tuna. This study was done at KUD Gabion on November 2014 until April 2015, and the aims were to study about the growth pattern, growth parameter, factor condition, and also the rate of exploitation in order to provide appropriate management model for the fish resource. The primary data is the total length and wet weight of 371 samples of Eastern Little Tuna, while the secondary data is the temperature of sea surface. The cohort length of fish is separated by Bhattacarya method in FISAT II software. The Von Bertalanffy growth parameters estimated were asymtotic length (L∞) = 628,95 mm, growth coefficient (K) = 0,24 year-1 and the age at zero length (t0) = -0,30 from Pauly’s empirical equation. Then, the growth equation for Eastern Little Tuna is Lt = 628.95 (1‐e[-0.24(t+0,30)]), whereas value of b obtained from relations of lenght – weight Eastern Little Tuna is 2,963. A growth pattern of Eastern Little Tuna is negative allometric with an equation growth W=0,00002L2,963. The highest and the lowest value of factor condition are 0,40 and 2,11. The rate of total mortality (Z) Eastern Little Tuna is 2,097 year-1 with natural mortality rate (M) 0,30 year-1 and fishing mortality rate (F) 1,79 year-1 thus the rate of exploitation is obtained with the amount 0,85 and the value of this exploitation rate has exceeded the value of the optimum exploitation, which is 0,5.