Oyster cull on track to start next week

Ministry for Primary Industries staff are hoping to harvest oysters from Stewart Island farms next week in an effort to prevent the spread of the parasite Bonamia ostreae.

The ministry has ordered a cull of farmed oysters in Stewart Island’s Big Glory Bay and the Marlborough Sounds to try to stop the spread of Bonamia ostreae, which is threatening the Bluff oyster industry.

Ministry staff were in Bluff yesterday speaking to the affected farmers in an effort to gauge the scale of the cull that lay ahead.

Ministry readiness and response manager Geoff Gwyn said the plan was for staff to work with the six affected farmers this week to create a plan for to dispose of the oysters, which they hoped would be carried out next week.

Gwyn said he did not have an exact number of how many oysters were affected but said it was in the thousands of tonnes. ‘‘We won’t have an exact figure till we start pulling them out of the water.’’

Planning staff would arrive in Invercargill today and be based out of the Department of Conservation office while they looked for a location in Bluff to work from, Gwyn said.

Staff would work to identify how farmers could lift the oysters out of the water, transport them and then dispose of them in a way that met requirements, he said.

The were several options for destroying the oysters and the ministry would work with farmers to find the best method of disposal, Gwyn said.

Ministry staff had been in talks with the Southland District Council, Environment Southland and local iwi to try to identify sites where the oysters could be disposed of.

Sites on Stewart Island and the mainland had been identified where the oysters could be buried deep in the ground, he said.

Ministry staff would meet with farmers next week to discuss compensation, he said. They would have to apply for compensation under the Biosecurity Act based on how much stock was lost, he said

It would be a commercial decision by farmers whether or not they would want to sell any of the affected oysters if they had any to sell, he said.

The decision to remove the oysters would have the most impact on farmers who solely farmed flat oysters, and those who farmed other shellfish might be able to get by on their other stock, Gwyn said.

Staff who worked for the farmers would probably feel the impact too, he said.

The regular oyster season would not be affected, he said.

Sampling to date has found no evidence of Bonamia ostreae in Bluff oysters in Foveaux Strait, but the ministry was continuing its sampling and surveillance.

The ministry was still investigating how the parasite spread to farms on Stewart Island.