An unprotected fish species at the centre of claims a legal loophole is allowing overfishing is now the subject of a rāhui until lawmakers make changes to protect it.

The rāhui (embargo) on fishing for pink maomao, also known as longfin perch, was announced by Ngāti Hei kaumātua Joe Davis Friday.

It applies to the waters of the iwi's rohe (boundaries) along the eastern Coromandel Peninsula between Whangapoua and Whangamatā.

The rāhui is voluntary, but Davis hoped those exploiting pink maomao would respect it until legislation could be changed.

Legally-enforceable rāhui must go through a process which includes public submissions and scientific data showing a species is in danger, he said.

"[What's happening] is of deep concern to Ngāti Hei. The iwi has every right to implement a rāhui - whether people abide by it is the test.

"We're calling on the conscience of New Zealanders to abide by it. It's for their own good, actually it's for their grandchildren's own good that we are vigilant."

The rāhui would stay in place "till the legislators sit up and take notice", Davis said.

"[The legislators are] the [Government's] Māori caucus, and MPI [the Ministry for Primary Industries] are the advisers to our legislators."

Pink maomao is a species of sea bass not included in any recreational catch limits.

Recreational fishing lobby Legasea are already holding urgent talks with Ministry for Primary Industries staff, seeking legislation to protect pink maomao and other reef species of high value to Asian markets.

One of the bins of pink maomao filmed in Tairua on one of several boats at the Tairua Wharf on Thursday. (Photo / Mike Bhana)

This week documentary maker Mike Bhana filmed a group of fishermen returning from nearby coastal fisheries with what he said was 1500 to 2000 pink maomao fish.

He saw another five boats doing the same thing that day, and pleaded for law changes.

"Otherwise we're wholesale slaughtering it."

Tairua residents also said a Tairua-based fishing charter had been booked and taken men out to catch pink maomao at key spots, allowing the area to be GPS recorded before the men returned with their own vessels and gear.

Anger over large takes of the fish sparked unsettling scenes yesterday, with Tairua residents blocking access to their main wharf.

A group of fishers arrived at the wharf below Mt Paku and did not launch their boat after they were told the vehicle and trailer would not be in the same condition when they returned.

Up the coast in Kuaotunu, fisher Neil Chapell witnessed two boats near Cuvier Island on Thursday hauling in large volumes of what he initially thought were small snapper.

Moving closer he saw multiple people and fish bins onboard each boat, with electric reels with small hooks like those used for baitfish.

"One had eight people on board, another had five all going flat out bringing them up endlessly.

"I thought 'that can't be snapper, nobody in their right minds would bring up that many'."

The Ministry for Primary Industries had seen the video footage of pink maomao being caught at Tairua harbour, ministry director of compliance services Gary Orr said.

Fishery officers were patrolling the area, Orr said.

"Over the past week, we've fielded a number of calls from people in the community concerned about the amount of pink maomao being fished in this area.

"If MPI finds evidence that any of this fish is being sold, we would take appropriate compliance action. We encourage anyone who has been approached to buy pink maomao or any recreationally caught fish to contact our 0800 4 POACHER hot line."

The ministry was looking into the concerns raised about overfishing and considering if more controls around the species were needed, he said.