Divers have successfully plugged air vents in the fuel tanks of the fishing vessel Torea, which remains semi-submerged close to the shore of Ruapuke Island in Foveaux Strait.

Environment Southland's Regional On-Scene Commander, Dallas Bradley, said that this would prevent further seepage of small amounts of diesel from the vessel.

Reports from aircraft flying over the scene this morning suggested that only a small amount of diesel had escaped through the air vents. This had caused a thin slick about 10m wide which was being carried offshore by the wind and was dispersing naturally in choppy seas.

Environment Southland has been liaising with the Department of Conservation and Iwi about the potential impact on the environment and wildlife. Mr Bradley said that there were no concerns that the small amount of diesel which had seeped from the Torea had caused problems.

Revised estimates are that 2500 litres of diesel is on the Torea, which went aground with 23 people on board yesterday.

Now that the air vents have been plugged, the focus will shift to salvaging the vessel and Mr Bradley said that responsibility lay with the Torea's owner and insurer. He expected to receive regular reports on salvage plans and Environment Southland will continue to monitor the situation. "Our ongoing interest is to ensure that there is no spillage of diesel from the vessel during the salvage," Mr Bradley said.