Seismic survey will harm dolphins and whales, say greens

A seismic survey about to begin in the waters of Southeast Asia will harm and possibly kill dolphins and whales, green groups say.

Hong Kong celebrated its first known sighting of a humpback whale last week. But the groups warned that the arrival of the Marcus G. Langseth survey vessel could endanger already threatened marine mammal populations in the region.

Organisers of the Taiwan Integrated Geodynamics Research survey have defended the programme, which aims to better understand the fault lines around the island that cause earthquakes and occasionally deadly tsunamis.

Samuel Hung Ka-yiu, director of the Hong Kong Cetacean Research Project and chairman of the Hong Kong Dolphin Conservation Society, questioned the need for the survey, which would see the Langseth towing high-powered air guns firing pulsed sounds at high volume at the seabed. 'In our region a lot of cetaceans are endangered so we need to be very careful we don't harm them any more than necessary,' he said.

Because of the suspected link between surveys and injury to marine mammals, permission from the American government was required.

Documents supporting the application for a permit suggest that in shallow water the sound of the air guns detonating will be at a level of 190 decibels - equivalent to standing next to the space shuttle launch pad during takeoff - out to 2.2km.