GLASSY seas off Sai Kung ruffle white when hit by a gusty breeze. But apart from the slap and fizzle of parting waves as the yacht Delerium Tremens ploughs southwards, the water seems serene.
Beneath the blue-green surface, however, a commotion of creatures feeding, mating, fighting and dying creates an ear-splitting cacophony. A sizzling crackle like chips frying in hot oil fills the headphones transmitting the underwater babble to human ears, normally deaf to the marine world.
The fat of the sea is giving Swire Institute of Marine Science researchers aboard the 37-metre ketch, a headache - literally and scientifically.
'It's shrimp-fantastic,' shouts Lindsay Porter above the din, one ear glued to the headset while she scans the horizon for vessels. Millions of tiny clamorous prawns, as if riotously celebrating their survival in Hong Kong's overfished seas, threaten to hijack the underwater acoustic device designed to track marine mammals.
'That's why we should eat more shrimps, they are good for you and . . .' she breaks off as a tumult of static and buzzing erupts . . . they will not confuse researchers tracking one of Hong Kong's most elusive mammals: the finless porpoise.
Jet black and blunt nosed, the porpoises bear little resemblance to their famous cousins, the Chinese white dolphins. But as Hong Kong's other resident marine mammal - both are locally and internationally protected - they share part of the coastal habitat and suffer similar pressures of development and pollution.
'We are not sure about the abundance of finless porpoises. We know they have been sighted in the east and south parts of Hong Kong but how many there are we don't know,' says Agriculture and Fisheries Department marine parks officer, Dick Choi Kwong-chuen.
