New monitoring and eradication programme for undaria
on Seafresh 1

29 March 2001

A comprehensive new monitoring and eradication programme has been announced that will eliminate the invasive seaweed Undaria pinnatifida (undaria) from the trawler Seafresh 1, which sank off Hanson Bay, Chatham Island in March last year.

"My aim is to prevent undaria spreading from Seafresh 1 to Chatham Island, so I have put in place measures that will contain the remaining undaria and eradicate it within four years," said Ministry of Fisheries Chief Technical Officer for Marine Biosecurity, Dr Chris O'Brien.

The new programme will include:

• Monitoring and eradication of any undaria found on Seafresh 1 for at least four years;
• Additional surveillance of inshore areas near to Seafresh 1;
• Hot water treatment of the vessel to kill any remaining microsopic stages of undaria;
• Development of an undaria incursion response protocol for the Chatham Islands;
• Annual review of the management programme by a Technical Advisory Group organised by the Ministry.

Dr O'Brien said two major factors led to his decision to implement the new approach. One was the development of heat treatment techniques that kill the microscopic stages of undaria.

The other factor was the success of the existing monitoring and eradication approach, put in place when the salvage operation was postponed in June last year.

Under this approach 479 undaria plants have been found and removed, 423 of these from one area - a decorative strip on the hull that was not treated with antifouling paint. Only one of the plants was fertile, but it showed no signs of having released spores.

"These new management tools mean the risk of undaria spreading to Chatham Island can now be managed effectively without removing the vessel," Dr O'Brien said. "This is a significant change from the situation last year, when removing the vessel was the only viable option to manage undaria.

"No management approach in this situation has zero risk. Even the original plan to move the vessel posed a risk. For example, it is possible the vessel could have broken up into several pieces, or it could have been dropped during salvage in a position closer inshore, or the salvage operation itself might have mobilised undaria spores, gametophytes or plants.

"Under the new management approach there is a low risk of spreading undaria to the coast, and ultimately undaria will be completely eradicated from the vessel."

ends

For further information please contact:
Dr Chris O'Brien
Chief Technical Officer - Marine Biosecurity
Ministry of Fisheries
Tel. 04 470 2609