New Zealand: Biosecurity divers widens search for sea squirts

Biosecurity New Zealand's extended surveillance for the sea squirt the clubbed tunicate begins this week, with divers searching Northland waters.

The sea squirt has to date been confirmed in parts of Auckland's Hauraki Gulf and in Lyttelton Port.

Now Biosecurity New Zealand needs to know if there are other infected locations around New Zealand to help plan any future action.

Senior Marine Advisor Brendan Gould says surveying so far indicates the organism has been in the country for some years and may have spread to areas outside the Hauraki Gulf and Lyttelton.

The National Institute for Water and Atmospheric Research (NIWA) has helped design the national surveillance programme and is undertaking the surveillance work for Biosecurity New Zealand. It is focusing on sites considered to be at high risk of spread due to their proximity to known infestations, or that have a high volume of inward vessel movements. (See footnote for locations).

Along with the surveillance, Biosecurity New Zealand is asking members of the public, especially marine users, to keep an eye out for the clubbed tunicate sea squirt and report any suspected finds to its free 0800 number (0800 80 99 66).

Awareness material about the sea squirt is being spread through media and a variety of media channels used by boaties, aquaculture industry and divers.

And Biosecurity New Zealand is also embarking on further studies looking at possible control and treatment options for the pest.

Research will look into a range of control measures which include wrapping infected structures with plastic, injecting acetic acid into the wrap and dipping in acetic acid for equipment.

While this wider picture of the sea squirt's presence and treatment options is compiled, Biosecurity New Zealand is also asking for help from all marine users to prevent the spread of the creature.

"It's really important that boaties come on board with the effort to curb its spread. Marine users must now take responsibility for keeping their vessel hulls and equipment clean and free of fouling," Mr Gould says.

Biosecurity New Zealand says where people are preparing to move to another region, they should ensure the hull of their vessel is clean. "We're asking people to check their hull before setting sail and where it is heavily fouled, to clean it where it is," Mr Gould says.

It is known that regular cleaning and the use of anti-fouling treatment will greatly help contain the spread of the sea squirt. The organism prefers a dirty boat to hang
onto and if hulls and equipment are clean, the sea squirt is unlikely to be transferred.

Preliminary start dates and locations for initial surveillance are:

Whangarei: Basin Marina, Marsden Point Port over next week (starting today)
Akaroa - Wednesday 2 November
Lyttleton – Thursday 3 November
Greymouth - Wednesday 9 November

There will be surveillance scheduled in the near future for the following areas identified as high-risk due to proximity to known infestations or vessel movements.

These are:
Bay of Islands (Opua)
Mangawhai Harbour
Tutukaka
Nelson Port
Wellington Port
Bluff
Greymouth
Dunedin Port
Napier Port
New Plymouth
Whakatane Port
Whitianga Marina
Tauranga Port

Source: www.scoop.co.nz