The government is ordering a cull of Stewart Island oysters to try to stop a lethal parasite from spreading further.
Two Stewart Island oyster farmers have told RNZ that Ministry for Primary Industries officials called them this morning with the news.
They said the two infected farms, plus all other oysters in Big Glory Bay, will have be to removed, and the government was setting up a compensation programme.
The lethal oyster parasite Bonamia ostreae was found on the two farms a fortnight ago.
The Bluff oyster industry has been pushing hard for a complete cull, saying it is the only possible way of stopping the infection from reaching Foveaux Strait.
Mussel farmers on Stewart Island said they feared they would lose millions of dollars if the government ordered a mass cull of infected oysters.
But industry sources said there were at least a dozen fish farms around the two affected ones and Stewart Island growers feared being caught up in any mass eradication plan.
Big Glory Bay is growing millions of oysters in total, but many are sown in among hundreds of millions of mussels, and a cull of the lot would cost millions of dollars.