A Far North marae is urging people to keep their motorbikes and four-wheel-drives off the dunes at two popular beaches before the dunes are damaged irreparably.
Earlier this week signs instructing motorised vehicles to stay off the sand dunes were put up at entry points to Tokerau Beach and Puwheke Beach, both on the Karikari Peninsula, by local hapū Te Whānau Moana and Te Rorohuri.
Thomson Lawrence, spokesman for Haiti-tai-marangai Marae, said the move came after years of concern about increasing erosion of the dunes and damage to wāhi tapu (sacred places).
People had been taking vehicles into the dunes for about 30 years but the problem had worsened as four-wheel-drives had become more common and more powerful.
''At one time these dunes were covered in all sorts of greenery and grasses. Now it's getting to the stage where they will end up as a desert.''
The hapū decided to put up the signs last week Wednesday. During the Easter holiday vehicles could be heard ''roaring around in the dunes'' but it was still too early to say how the public would respond.
Lawrence expected most locals would support the ''common sense'' measure.
There was no plan to impose a rāhui or ban at this stage.
''We'll try signs and Facebook first ... If people don't respect it you can't say we didn't try. Then we'll take it to another level,'' he said.
Further steps could include signs on the dunes themselves, replanting to help the dunes recover, and even blocking vehicles trying to access the dunes.
The vehicles came from as far away as Kerikeri and Kawakawa, Lawrence said.
''I've kicked a lot of people out of there over the years, I'm over it. You can't be up there all the time. It's a total lack of respect for a place where there's wāhi tapu and koiwi (bones).''
Te Rūnanga-ā-Iwi o Ngāti Kahu chief executive Anahera Herbert-Graves said the iwi ''absolutely'' supported any measures hapū took to fulfil their obligations as mana whenua such as kaitiakitanga (guardianship).
Last year west coast iwi Te Rarawa went a step further by fencing off about 4km of dunes it owns on Tauroa Pt, east of Ahipara, and along Ninety Mile Beach near Lake Waimimiha.
The fence blocks entry points to some of the most vulnerable dunes as well as middens and other cultural sites.
Construction of the fence prompted a Whangārei off-road enthusiast to organise a ''truck and bike day to take back Ahipara dunes'' but local residents closed the road leading to Shipwreck Bay and Tauroa Pt. In the end only a few bikes turned up.
Lawrence said the cost of putting up fences along Tokerau Beach would be prohibitive. He believed some of the drivers who used to frequent Ahipara's dunes were now targeting Karikari Peninsula instead.