Despite a successful clean up on the East Coast of oil and debris from the Rena, Ngati Porou chairman Apirana Mahuika says there is a chance of a rahui (ban) being imposed on the harvesting of kaimoana (seafood).
Dr Mahuika says the reason for the concern is the unusual behaviour of crayfish near Te Araroa.
People saw several crayfish come ashore and wander up the beach.
Dr Mahuika says there is a possibility their strange behaviour could be linked to oil from the Rena which spread almost to East Cape and they were sent away for scientific analysis.
He says once scientists have worked out what caused the odd crayfish behaviour, the iwi will discuss whether there should be a temporary ban on the taking of kaimoana from some areas.
Dr Mahuika says locals are also concerned about dead birds found with oil on them.