Whistling Kites in my experience seldom make much of a splash in their infrequent efforts to take fish. Unlike Ospreys they lack specialised flexi-talons and grip-pads for the job, and deep plunges without plumage waterproofing could be life-threatening.
But, along with the odd Black Kite, a few Whistlers will snatch dying fish from the surface as they float up from deoxygenated water during the late dry season. Again, in my experience, few watching kites follow their more opportunistic snatch and grabbers.
So Whistling Kite's swoop down near edge of pool and take of unidentified fish in front of Payets Tower in the Town Common Conservation Park, Townsville, two mornings back, was probably because fish was freshly dead and floating in paragrass at pool's edge. The kite flew to cover in nearby trees and made short work of the small fish. A lucky scavenger rather than a skilled fisher, in my judgement. Others may disagree.