Fishermen in Bay of Plenty say their nets are being damaged by container debris from the Rena.
Bay of Plenty Fishermen's Association president Brian Kiddie says the sunken debris is snagging their nets and can pose a danger to their boats when it snaps their towing lines.
He says the debris is too deep to be removed and there's no way to tell it's there until a net is snagged.
Mr Kiddie says the nets cannot be insured and a full set costs about $50,000 to replace.
He says the association is slowly building up a map of the containers, but fishermen are worried that, as the Rena disintegrates, it could create even more snags.