ABUNDANCE OF OIL SARDINE (SARDINELLA-LONGICEPS) AND UPWELLING ON THE SOUTHWEST COAST OF INDIA

During this century there have been several periods of relatively high abundance, and several major population crashes. O-group recruitment to the fishery begins towards the end of the summer monsoon, and its success is statistically related to sea level at Cochin just prior to onset of the monsoon. At this time, sea level indicates remote forcing of upwelling, rather than the wind-driven upwelling that occurs during the monsoon. Unusually early remote-forcing appears to inhibit subsequent recruitment, perhaps through exclusion of spawning fish from the neritic zone by oxygen-deficient upwelled water. -from Authors