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.