DATE 14 October 2005

Picture of Seasquirt Spread Widens

Biosecurity New Zealand says preliminary information from the investigation underway at Auckland’s Viaduct Harbour indicates the invasive seasquirt clubbed tunicate is present in a wide area of the Viaduct, and potentially the greater Waitemata Harbour.

Team Manager Surveillance and Incursion Response Ron Thornton says there is as yet no laboratory confirmation of finds, but the NIWA researchers in the water at the Viaduct have been retrieving specimens of what they believe is the pest.

“There have been samples found in the wider Viaduct Basin, on a boat ramp at Westhaven Marina and on a vessel that had travelled across the Waitemata Harbour to the Viaduct from another marina.

“All of these samples have yet to be scientifically identified, but we are working on the assumption that they are clubbed tunicate,” Ron Thornton says.

The NIWA team will be continuing their examination of the area and will extend their checking and sampling to other areas of the Waitemata.

Divers are also in the water in Waikawa Bay in Picton today, checking the area where a vessel from the Viaduct, found to have a juvenile seasquirt on its hull, was briefly berthed. An examination of Lyttelton Harbour will begin shortly.

“We are in active response mode with this incursion,” Dr Thornton stresses. “As well as having divers in the water in two locations, we are developing response and containment plans and building relationships with international experts who can help us with our knowledge of the organism and how it behaves.”

Dr Thornton says Biosecurity New Zealand is totally focused on its ultimate goal of finding this pest, containing it and eradicating it.

“We are working in partnership with the marine farming industry to develop an identification guide for clubbed tunicate. Biosecurity New Zealand has also invited an industry representative to work with the response team and an industry advisory group is being established.

A meeting is also planned for early next week with marina authorities in Auckland to discuss containment measures for the clubbed tunicate.

As the investigation into the seasquirt’s arrival in New Zealand continues, further reports of its presence here are coming to hand.

“We have indications that the organism has likely been in New Zealand since May 2002 and possibly even earlier,” Ron Thornton says.

“A scientist, in the course of his PhD, surveyed hundreds of vessels around New Zealand during 2002. All the specimens collected as part of that research were identified and stored.”

Dr Thornton says news coverage of this latest clubbed tunicate incursion prompted the scientist to reexamine a specimen from a tugboat from the Lyttelton Harbour. Previously identified as a native species, his re-examination has confirmed it was, in fact, clubbed tunicate.

ENDS

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