Spatial Distribution, Behaviour, and Biological Aspect of Albacore (Thunnus alalunga) Caught in Eastern Indian Ocean
Abstract: This study
highlighted the occurrence of the Indonesian tuna longline fishery targeting
albacore (Thunnus alalunga) caught in the Eastern Indian ocean. The data used
in this study based on the Research Institute for Tuna Fisheries (RITF)
observer program in Benoa. This paper presents the current information on
biological aspect (size distribution and length-weight relationship) and fish
behavior (swimming layer and feeding periodicity) of albacore. Total albacore
samples of 3,152 were taken from
scientific observer data from 2010-2013. The study area of albacore was between
0-33°S and 75-131°E. Albacore length
distributed from 70-196 cmFL (median=93 cmFL, mode=100 cmFL, mean=92.12
cmFL) and dominated at size of 95 cmFL. The highest percentage length of
albacore was >90 cm (L50) occured in
the area between (30-35°S and 80-95°E) and (10-15°S and 120-125°E). The length
weight relationship was determined to be W=0.0045 FL1.8211 (W in kg, FL in cm). The expected season to
catch the ALB was from April to July with the peak season in June and July. The
swimming layer of albacore based on minilogger data were distributed from at
118 to 341 m depth and mostly catch at depth of 156 m with temperature degree
18°C. The feeding periodicity of
albacore’s are start from 7:45am to 17:59 pm, mostly active at 10 am to 11 am.
The majority of ALB caught by Indonesian longliner was mature condition and
negative allometric growth. The ALB peak season was in June-July and the best
time to catch was 10 am to 11 am at depth of 156 m.
Keywords: albacore, feeding
periodicity, swimming layer, CPUE
Author: Fathur Rochman, Irwan
Jatmiko, Bram Setyadji
Journal Code: jpperikanangg170038