EFFECTS OF DIPOLE MODE AND EL-NINO EVENTS ON CATCHES OF YELLOWFIN TUNA (Thunnus albacares) IN THE EASTERN INDIAN OCEAN OFF WEST JAVA
Abstract: The effects of
Indian Ocean Dipole Mode and El NiƱo–Southern Oscillation events on catches of
YellowfinTuna (Thunnus albacares) in the Eastern Indian Ocean (EIO) off Java
were evaluated through the use of remotely sensed environmental data (sea
surface temperature/SST and chlorophyll-a concentration/SSC) and Yellowfin Tuna
catch data. Analyses were conducted for the period of 2003–2012, which included
the strong positive dipole mode event in association with weak El-Nino
2006.Yellowfin Tuna catch data were taken from Palabuhanratu landing place and
remotely sensed environmental data were taken from MODIS-Aqua sensor.The result
showed that regional climate anomaly Indian Ocean Dipole Mode influenced
Yellowfin Tuna catch and its composition. The catches per unit effort (CPUE) of
Thunnus alabacares in the strong positive dipole mode event in 2006 and weak
El-Nino events in 2011 and 2012 was higher. The increase patern of CPUE
followed the upwelling process, started from May-June achieved the peak between
September-October.Very high increase in CPUE when strong positive dipole mode
event (2006) and a weak El-Nino events (2011 and 2012) had a relation with the
increase in the distribution of chlorophyll-a indicating an increase in the
abundance of phytoplankton (primary productivity) due to upwelling. In
contrast, yellowfin tuna CPUE is very low at the La-Nina event (2005), though
as the dominant catch when compared to others.
Keywords: Indian Ocean Dipole
Mode; YellowfinTuna; Eastern Indian Ocean off west Java
Author: Khairul Amri, Ali
Suman, Hari Eko Irianto, Wudianto
Journal Code: jpperikanangg150050