Divers find marine pest at Viaduct

Divers found plenty of evidence in Auckland's Viaduct Harbour yesterday of an invasive marine pest that threatens aquaculture.

Samples of the sea squirt - also known as the clubbed tunicate styela clava - will be sent to Wellington for analysis.

Divers were also searching at Lyttelton, the second site where sea squirt has been found. Tests have already confirmed its presence on a boat in the Marlborough Sounds, the country's main aquaculture site.

Divers are being sent to Waikawa Bay, Picton, to search for the pest, which can grow up to 16cm long and is a prolific breeder, spawning every 24 hours.

Korea is its homeland but it has spread throughout the world, including to parts of Australia, according to Biosecurity NZ.

Nelson-based sea squirt expert Kevin Heaseman, an aquaculture scientist, said sea squirt was the greatest threat to the $300 million aquaculture industry.

In Picton, the sea squirt was found on the fouled hull of a vessel that had been in Lyttelton before spending some months berthed in the Viaduct Harbour.

The sea squirt discovered in Picton was an individual organism so the chances of it having spawned were slim.

- STAFF REPORTER, NZPA