A conservation group is calling for a total fishing ban for crayfish in the Hauraki Gulf and Bay of Plenty as the population "collapses towards extinction".
Forest & Bird is calling for the wider Hauraki Gulf to Bay of Plenty crayfishing area (known as CRA2) to be closed for three years to allow the species to start recovering.
"The wider Hauraki Gulf to Bay of Plenty crayfish population has undergone a significant decline," Forest & Bird marine conservation advocate Katrina Goddard said.
"Without an urgent end to fishing pressure, crayfish could become functionally extinct throughout the entire area within a few years."
The Fisheries New Zealand branch of the Ministry for Primary Industries had already more than halved the total allowable catch from 416.5 tonnes to 173 tonnes, under new measures introduced in April.
This included allocations of 80 tonnes for commercial fishers, 16.5 tonnes for customary Māori and 34 tonnes for recreational.
Fisheries New Zealand was now consulting on reducing the recreational daily bag limit from six to three spiny rock lobsters, to help ensure recreational catch does not exceed the new 34-tonne recreational allowance.
But Forest & Bird is challenging the value of these proposals, as the population in the wider Hauraki Gulf area was at "critically low levels".
"The crayfish in the area have been overfished down to almost nothing," Goddard said.
"We have reached a point where crayfish are so rare in some areas they are considered functionally extinct. Asking recreational fishers to take only three a day, when they often can't find any, is pointless.
"Similarly, when the commercial crayfish quota was reduced early in 2018, the quota wasn't able to be caught. The crayfish just aren't there."
Goddard said recreational fishers, iwi, and scientists have been warning of the crayfish collapse for many years, to little effect.
"For Forest & Bird it isn't about recreational versus commercial rights, nor is it about the economics — it's about the health of our oceans and taking sustainability seriously.
"Crayfish are a hugely important part of the ecosystem. Without crays in sufficient numbers, the ocean floor and reefs are swarmed by kina which destroy kelp forest and other habitat for fish and marine life. The flow-on effects are very serious."
The call for a ban has the support of the New Zealand Sport Fishing Council.
"I just don't think there is any other option," spokesman Scott Macindoe said.
Macindoe said he had been fishing in the CRA2 area for over 50 years, but four years ago stopped catching crayfish.
"They just aren't there any more. Growing up, they were abundant, we used to catch them using craypots around Whangaparaoa, and fishing over on Kawau Island. Now they are all gone.
"I personally won't be fishing for them for a long time. Another year of unconstrained commercial and recreational harvest will probably break this fishery, and won't make closure very difficult as there will be nothing there."
The council supported the MPI's proposal to reduce bag takes from six to three, but Macindoe said it likely wouldn't make a difference.
"The vast majority of trips these days will result in one or two crayfish. Reducing it to three is not going to make any difference."
A spokeswoman for Minister of Fisheries Stuart Nash told the Herald a ban had been considered during consultation on the cuts announced earlier this year.
That decision was based on stock assessments done in 2017.
The minister had asked Fisheries New Zealand to keep working with other scientists and the industry to improve monitoring and management of the CRA2 rock lobster fishery and he expects an update in 2019.