Mussel farmer wants law change

A Golden Bay mussel farmer is calling for an immediate change of law preventing any foreign boats being defouled in New Zealand waters.

Waitapu Fishing Company director Winston Rountree fears the region's greenshell mussel industry could be "ruined" if the potentially invasive South African brown mussels left behind by an oil-drilling ship in Tasman Bay spread.

He has criticised Biosecurity New Zealand for allowing the ship Ocean Patriot to clean its rig last December while 22km offshore. He's also critical of the organisation for not informing mussel farmers after brown mussels were left behind.

The ship was getting rid of New Zealand greenshell mussels at the order of the Victoria state government before being towed to Australia.

"The first I heard about it was when I read it in the newspaper and I've had no correspondence from the ministry since then," said Mr Rountree, a member of the Golden Bay Marine Farms Consortium.

He said Biosecurity NZ should supply mussel farmers with information on brown mussels so they knew what to look for.

An independent aquaculture contracting business, Waitapu Fishing Company, owns and manages seven marine farms in Golden Bay.

It employs four fulltime staff and is about to employ another two people.

"If these brown mussels spread they could ruin the whole industry," Mr Rountree said.

"The law should be changed immediately to stop foreign boats being defouled in New Zealand waters within 200 miles of the coastline."

Mussel farmers in the area already had to contend with other pests including sea squirt, undaria weed and blue mussels.

Greenshell mussels from Tasman and Golden bays are exported all over the world, including Japan and the United States.

The potentially invasive brown mussel is a fast-growing edible species that is quick to spread.

When introduced on the Texas coast in ballast water discharged from Venezuelan ships, it colonized 1300km of coastline within four years from 1999.

New Zealand biosecurity incursion response manager David Yard admitted there was a "gap in the law" regarding defouling ships in New Zealand waters.

"Australia and New Zealand have raised the profile of this issue with the International Maritime Organisation and we're working to close that gap but the law can't be changed overnight," he said.

Defouling was a global problem and any standards needed to be ratified by all countries.

"We are looking to change the law but New Zealand can't do it alone."

Mr Yard said the ministry surveyed 10 percent of international vessels coming into New Zealand to assess the problem of unwanted marine species getting into the country.

The ministry had distributed information on brown mussels to the mussel industry and councils but unfortunately Mr Rountree had "slipped through the net".