A temporary ban on fishing is likely across the Kaikoura region, according to Primary Industries Minister Nathan Guy.
He says more than 40 kilometres of coastline has been affected.
"I saw it today when I flew in on the helicopter, where we've had effectively the seabed rise out of the water by one… to three or four metres," he says.
"It's clear to me there will be a huge amoung of loss and wastage and mortality of paua and also of crayfish."
The temporary ban will probably be in place for months, rather than years, while scientists ascertain the extent of the damage and work out a long-term management plan.
"We want to protect the long-term breeding stock for future generations to enjoy," says Mr Guy.
The Government will have discussions about customary fishing rights with local iwi before a temporary ban is imposed.
"I think that everyone recognises the fact that the fishery has been dealt a severe blow by Mother Nature. The biomass has severely reduced and I think everyone will be on board saying we need to rebuild that."