Oyster parasite concerning

MPI biosecurity manager Dr Cath Duthie in Invercargill on Friday.

AN oyster-killing parasite has been found in the wild population in Foveaux Strait, and some are worried about the future of the oyster industry.

Last week, three wild oysters were found to be infected with bonamia ostreae in a small area near Stewart Island.

Bluff oyster fisherman John Edminstin said if it was true, it could be more than serious.

“If it’s that, the future doesn’t look very bright at all.”

It was scary.

“It could mean the end of it.”

The outlook had been relatively optimistic of late, with larger-sized oysters being seen.

“We were all quite buoyant about the future of the industry, but now this happens.”

He believed it was the first time it had been found in the wild and was concerned it would be hard to contain.

Sharing his concerns was Fowlers Oysters manager Terina Stockwell.

She said she had been spiralling since hearing the news.

“Hopefully it hasn’t spread further because that would be horrible for us.”

However, the knowledge no-one had fished in the area the infected oysters were found in was good.

“That’s something to cling on to while we can.”

A plan between Southlanders and the Government on how to tackle the incursion was in the works.

Representatives from the Ministry for Primary Industries visited Southland on Friday to speak with locals following the discovery.

Biosecurity manager Dr Cath Duthie said the meeting, which ran for more than three hours, went well.

About 25 people attended, including members of the biosecurity team and representatives from local councils, iwi, and the local oyster industry.

Dr Duthie acknowledged they had little information but made the journey to Invercargill to start conversations early.

“The mood was, they were very concerned. It is a significant thing for them.”

The meeting, however, was constructive and everyone was in agreement about the next steps, she said.

A rahui, or access restriction, would be put in place around the small area in which the infected oysters were found to allow more intensive testing to be conducted.

This would help increase knowledge of the infection and how widespread it was, as well as enable future decision making, she said.

Testing would include genomic testing.

Late last year, oysters in Big Glory Bay, Stewart Island, were found to be infected.

In 2017, the parasite was found in the bay on oyster farms which were consequently removed and a surveillance programme began.

It was not yet known if the confirmation of infection in wild oysters was linked, but it was possible.

Dr Duthie said there was little known about the species.

She said the unknown was always of concern, but hoped the find was caught early.

It would not impact the oyster fishery take, or availability, as the now restricted site had not been fished for five years.

“There will still be heaps of oysters to buy.”

Further testing would also be conducted during the next few weeks at the other five monitoring sites, as well as with fishers’ catch.

Bonamia ostreae is not a food safety issue and fresh Bluff oysters remain safe to eat, she said.

The parasite was first found in New Zealand in 2015 in oysters from the Marlborough Sounds.