Final approval for one of the largest mussel farms in New Zealand, to be built at Clifford Bay south of Blenheim, will depend on a study of Hector’s dolphins there.

The Minister of Conservation has approved the application from Clifford Bay Marine Farms, but the go ahead is conditional on the outcome of a three-year survey of the dolphins that live in the bay.

The survey will be funded by the developers and will look at whether the area is a breeding ground, nursery or zone of real importance for the dolphins.

Associate conservation minister Mahara Okeroa says he accepts the view of the Environment Court that there is a low risk of the farm causing harm.

In another case involving Hector