Taranaki Regional Council is to investigate the state of kaimoana stocks after multiple hapū banned shellfish gathering.
In early January, the hapū of Ōrimupiko marae placed a rāhui (traditional closure) on taking kaimoana from a 12-kilometre stretch of coast centred on Ōpunake, after a huge influx of gatherers from outside the region.
The rāhui now extends some 40km along the coast from south of Ōpunake to north of Cape Egmont.
The closure is currently in place until 31 July, with hapū further north as far as Ōākura also considering whether to join.
TRC chairman David MacLeod added a late item to Tuesday's Policy and Planning Committee meeting, calling on officers to seek out evidence for a decline in kaimoana over time.
"I personally have anecdotal evidence from when I was younger through to today that kaimoana stocks are worse off."
He said staff needed to work out how bad the problem was, what the implications were, and what measures the regional council could take, perhaps with the Ministry of Primary Industries.
Councillor Neil Walker said three possible causes of decline needed checking: overfishing, pollution and natural causes such as sand drift.
An iwi representative on the committee, Bonita Bigham, said the state of kaimoana was "a huge issue."
"The number of cars coming to the end of Mānihi Road and Arawhata Road, the busloads coming, it is a crisis. Regardless of the science I think the issue is that there is a crisis."
Bigham said the hapū of Taranaki iwi needed to be included in the council investigation.
"Could we please invite Taranaki iwi to come and speak to their rationale for the rāhui, and share their mātauranga (knowledge and understanding)?"
MacLeod's call for an investigation was passed unanimously by the committee.
The hapū of Ōrimupiko are planning to apply for a legal ban under the Fisheries Act, especially for pāua, which could last for two years and be further renewed.
Other hapū that have placed rāhui are also considering a legal ban.
Ōrimupiko kaitiaki o te moana (coastal guardian) Jack Davey said hapū were already moving to survey the coast.
"Our next step is to have a look at which areas have been exhausted, and after two years we might be able to say only particular areas need to be put back under protection."
Separately to the extensive west coast rāhui, Ngāruahine's Ngāti Hāua hapū last July placed a rāhui on their seven-kilometre coastline further south, from Wahamoko Stream near Oeo to Ōtakeho Stream.
Ngāti Hāua kaitiaki Sid Ngātai said they also want a Fisheries Act ban to bolster the rāhui.
"Iwi need to start shutting it down with the assistance of the Crown - shut it down for two years at least."
Despite being 70 years old, Ngātai said he does a stocktake of the hapū's 18 named reefs every six weeks in summer, taking along rangatahi (young people) to pass on knowledge.
"It's really good, since I get to talk with my rangatahi on the hīkoi (stocktake walk) ... I talk to them about how I was taught by my koroua, my pāhake (elders)."
He said the reefs had been "hammered".
"We've got to make a sacrifice now, or there's not going to be anything left for our mokopuna."
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