Oceanographic aspects of Lakshadweep waters in relation to skipjack tuna fisheries

Abstract

The variations noticed on important oceanographic parameters such as surface currents, seawater temperature. salinity and dissolved oxygen content of waters around Lakshadweep group of islands are discussed in brief. An attempt is made to correlate selected parameters with the occurrence/abundance of Skipjack tuna catches in and around the islands. It is observed that apart trom factors such as sea water, temperature and salinity, the resultant effect of the phenomenon of 'upwelling ' mainly caused by diverging current systems contribute towards concentration of Skipjack tuna in certain localities. It may be possible that fishing areas for Skipjack tuna could be predicted sufticiently in advance by monitoring the formation and shifting of divergence zones around these islands during the period, November - March, the season for the Skipjack tuna fishery. The possibilities of utilising Satellite Remote Sensing data to locate thermal boundaries, resulting out of divergence, is also suggested.