A hard cull is the right call

The Ministry of Primary Industries swiftly enough imposed controls on stock movement but the risk of spread through ocean currents meant that concerns mounted with each passing day that those oysters remained in the water.

The ministry now acknowledges that removing all of the flat oyster stocks from all the bay’s the marine farms ‘‘significantly reduces this risk’’. The hell you say? This is what the agitated locals have been insisting for days.

Much as there have been references to legalities needing to be sorted out, MPI says science has ‘‘strongly guided’’ its decision and that a rushed removal process could cause more harm than good. It remains confident that it’s still operating within the ‘‘window of time’’ that the movement controls have bought, although acute nervousness will continue at least until testing of stocks in the strait produce emphatic findings. It does seem the removal process in the farms is a more delicate, precise, matter than might have been generally appreciated outside the industry. It requires ‘‘expert direction’’ not to cause further spread of the parasite.

Any way you look at it, this is high-stakes stuff. And even if all goes well, under the Biosecurity Act compensation issues arise and are likely to be considerable, not only in the south but also in Marlborough marine farms that are also caught in the problem.

The oysters remain safe to eat, as do the more intensively farmed mussels in the area. That may not be the only source of confusion at play. Invercargill Mayor Tim Shadbolt has been particularly downbeat on the implications for the Southland Regional Development Strategy’s focus on marine farming, notably the island. ‘‘That doesn’t look like it’s going to happen because of the disease,’’ he said. That goes beyond being weirdly pessimistic. The parasite doesn’t have any impact whatsoever on finfish, the primary focus of expanded marine farming potentials. Nor mussels, other than the fact that green-lipped mussels, alongside Pacific oysters and geoduck, can be carriers and transmit the parasite to flat oysters, albeit with a risk of spread assessed as low.

These are hard times on the marine farms, scary times out in the strait, But at least a hard call has been made.