THE INFLUENCE OF SWIMMING LAYER AND SUB-SURFACE OCEANOGRAPHIC VARIABLES ON CATCH OF ALBACORE (Thunnus alalunga) IN EASTERN INDIAN OCEAN
Abstract: The current study
highlighted the relationship between the number of ALB catch, swimming layer
and sub-surface oceanographic variables (temperature, dissolved oxygen,
salinity, nitrate, phosphate and silicate) in Eastern Indian Ocean. This data
used in this study were based on the Research Institute for Tuna Fisheries
(RITF) observer program in Benoa from 2010-2013. This paper presents the
information about vertical distribution of Albacore and its relations to sub
surface oceanographic variables (SSOV). Results show that the optimum catch of
albacore occurred at depth of 118 to 291 m with the average temperature
between 12.41-20.47 °C, dissolved
oxygen 3.24-4.68 ml/l , salinity 34.78-35.01 psu, nitrate 6.78-17.50 µ mol/l,
phosphate 0.62-1.27 µ mol/l and silicate
10.06-24.77 µ mol/l. The highest catches of albacore are mostly at depth of 156
m (hook number 2 and 11) with the average temperature 18.71°C, dissolved oxygen
4.68 ml/l, salinity 34.78 psu, nitrate 10.71 µ mol/l, phosphate 0.86 µ mol/l
and silicate 15.95 µ mol/l. The highest influence of swimming layer and
sub-surface oceanographic variable to the number of ALB catch contained at
depth of 291 m of albacore swimming layer with coefficient correlation ( r )
0.934 and determination coefficient ( R2) 0.872. The lowest influence of swimming layer and sub-surface oceanographic
variable to the number of ALB catch
contained at depth of 156 m of albacore swimming layer with coefficient
correlation ( r ) 0.528 and determination coefficient ( R2) 0,279. The relationship between
swimming layer and sub-surface oceanographic variable on catch of ALB tuna was low (<0.500).
Keywords: swimming layer, sub
surface oceanographic variable, albacore and Easter Indian Ocean
Author: fathur rochman, Widodo
Setiyo Pranowo, Irwan Jatmiko
Journal code: jpperikanangg160056
