Canterbury fishing crews are frantically relocating exposed paua underwater after Monday's 7.5 earthquake pushed parts of the coastal seabed up to two metres above the waterline.
Paua Industry Council chairman Storm Stanley said the patches of raised seabed stretched from the Kaikoura coast through to Cape Campbell in Marlborough.
Affecting many of the region's most important paua grounds and reefs, he estimated tens, if not hundreds, of tonnes of the edible sea snails had been left high and dry.
With paua able to survive for a only few days out of water, he said Kaikoura and Marlborough crews were racing to save the animals.
"This is probably the last day that it is possible (to relocate them) because there is a very warm north-west wind going and paua like cool, damp conditions," Mr Stanley said.
"Anything that is exposed is either dead or dying now."
With the Kaikoura region accounting for around 10 per cent of New Zealand's total paua catch, he said it was too early to put a cost on the damage done to the industry or if jobs will be lost.
"We know it is very serious," he said.
He said recreational fishers and Maori will also be affected because the Kaikoura coastline was one of the country's most accessible.
"For a local Maori, it is going to be heartbreaking," he said.
"They have lived on the Kaikoura coast ... for 400-or-500 years and they have always been able to get paua from the rocks. It looks like that is going to take a big hit."