People are stealing paua brought to the surface during Monday's 7.8 magnitude quake, forcing an increase in surveillance around Kaikoura's coastline.

The Ministry for Primary Industries made the move following reports that people were continuing to take paua exposed as a result of the quake.

MPI's manager of compliance operations, Gary Orr, said it was critical surviving shellfish and rock lobster stocks in the new intertidal zone are protected.

"That's where the paua brood stocks live and we need to do everything we can to look after them as they are the key to the future of this fishery," Orr said.

"The paua fishery is traditionally 'at-risk' and Monday's earthquake has now put it in a perilous position.

"We cannot afford any further pressure on this fishery. That means we'll be increasing patrols in the area for the foreseeable future.

MPI would be ramping up their presence in the area and fishery officers and honorary fishery officers will be present to ensure people are complying with catch limits and legal size requirements.

"There will be no excuses for non-compliance. People need to know and respect the rules and understand they will be rigidly enforced," said Orr.

Fines for breaking the rules range from $250-$20,000 and rule-breakers can face prosecution and the forfeiture of property used in any offending.

MPI urged locals who witness any offending to urgently contact MPI's 0800 line to report it on 0800 47 62 24.

People also need to be aware that taking dead or dying seafood will pose a serious risk to health.

Orr said consideration was still being given to a temporary closure of the fishery until the full impact of the earthquake is understood.