Reports by Hindu News suggest the onset of the South Western Monsoon (SWM) in Kerala region around the 1st (plus minus 4 days) of June 2012, while a meteorology enthusiast at Cyclonewarningcenter.com predicts that the Monsoon may advance to Maldives as soon as 22nd of May.
In Maldives the monsoons govern the migrations of manta rays from the West to the East (and vice versa) of the Maldives archipelago. Strong monsoonal winds generate upwelling of nutrient rich, oxygenated deep ocean water, which supports a bloom of plankton. As you may already know a plankton bloom is exactly what the mantas are looking for, as plankton is the staple diet for these gentle giants.
Last year the SWM monsoonal winds were particularly weak, due to Indian Ocean Dipole and El Nino Southern Oscillation events. Weak winds have resulted in low densities of plankton and, thus very low number of mantas at Hanifaru Marine Protected Area (which is normally packed with mantas during SWM) reports MantaTrust.
So far we have spotted a few individual mantas over the last month. The normal onset of Manta season here in the east Maldives is May, and by mid-June Manta rays should come in greater numbers. Seems that everything is still by the schedule, just let the wind blow !