Ministry slammed for inaction over oysters

A delicacy under threat. Photo: Stephen Jaquiery.

The Ministry for Primary Industries has been labelled "incompetent" after ignoring international scientific advice designed to prevent the spread of a lethal parasite threatening the Bluff oyster industry.

The accusation came from Graeme Wright, a key Bluff oyster industry figure, a day after he met MPI officials in Wellington to discuss the Bonamia ostreae parasite found at Stewart Island oyster farms.

MPI officials were expected to announce, possibly as soon as today, whether the Stewart Island farms' oyster beds would have to be pulled up.

Mr Wright said that needed to happen with "urgency" to prevent the parasite's spread across Foveaux Strait to Bluff's wild oyster beds, or the entire industry could be threatened.

But the Barnes Wild Bluff Oysters manager  also criticised MPI's handling of the  threat since it was first detected in Marlborough's oyster farms in January 2015.

He said  following the discovery, MPI had received scientific advice from an international panel on how best to minimise the risk of the parasite's spread.

"That advice was clearly that the only way to minimise the risk to the wild [oyster] fishery . . . was to remove any infected oysters from the water in Marlborough.

"To date they haven't acted on it."

Mr Wright, who used to sit on the MPI panel, said he was "frustrated" by MPI's "incompetent" and "dysfunctional" response.

"They've had two years to contemplate it ... but for whatever reason, MPI haven't taken that action of removing those farms, and 'bingo' - it's down here.

"They're a group of specialists and they just seem to be dithering ... They've dropped the ball."

MPI readiness and response director Geoff Gwyn, in an emailed statement, did not respond directly to the suggestion scientific advice on the removal of all contaminated oysters had been ignored.

Instead, he would say only that MPI had "at all times acted on the best available science" while working to control the parasite's spread.

That included introducing movement restrictions and a permit system following the parasite's detection in Marlborough, and additional surveillance and testing in Marlborough, the Chathams, Otago and Southland since then, he said.

Further restrictions were introduced following the discovery of the parasite in Stewart Island oysters, and more testing and surveillance would follow, he said.

Mr Wright said there was continuing uncertainty about how the parasite had made it to New Zealand, and subsequently spread to Stewart Island.

MPI had introduced restrictions in 2015, but it was possible the parasite was already present when oysters and equipment moved from Marlborough to Bluff prior to its discovery.

"You don't find it unless you're looking for it.

"But ideally, in a perfect world, if the measures had been effective in Marlborough, we may not have it in [Stewart Island] now."

The parasite was a new strain of Bonamia and "far more destructive" to oysters than Bonamia exitiosa, which was already "endemic" in the species.

Bluff oysters remained "100% safe to eat", even if contaminated, but the risk of further spread came when the parasite killed its host oyster, which then released contaminated particles.