A north Auckland iwi has called in Californian scientists to help rid our coastline of caulerpa, an aggressive seaweed that smothers the seafloor.
Ngāti Manuhiri is concentrating efforts on the area around Kawau Island in Tīkapa Moana/Hauraki Gulf.
And the iwi is on a mission because under the ocean surface a monster is multiplying.
"It'll kill our shellfish, our mussels, our kōura (crayfish)," said Ringi Brown, trustee of Ngāti Manuhiri Settlement Trust.
"[It] could be toxic to our fish as well."
Nicola MacDonald, CEO of Ngāti Manuhiri, told Newshub it's crucial to stop the seaweed's spread at all costs.
"Well we're in a crisis, so it is absolutely urgent. So today Ngāti Manuhiri with NIWA, with MPI are doing the work and removing this invasive species."
Caulerpa is spreading fast - it has taken hold in Te Rāwhiti in the Bay of Islands, Aotea/Great Barrier, Ahuahu/Mercury Islands and Waiheke Island.
And, it has been discovered at Kawau by accident by a group of NIWA scientists looking at scallop beds.
That prompted MacDonald to track down the only people in the world who have successfully eradicated the so-called 'killer algae' - scientists in California.
"We've never had caulerpa in New Zealand, not this invasive species. So we needed to know, what does it take to remove it and these guys had the experience, and they were successful," MacDonald told Newshub.
Californian caulerpa expert Eric Munoz said the seaweed is no joke.
"There are a lot of invasions in New Zealand, and you're probably tired of it. But caulerpa is going to make you take notice."
A karakia was carried out before specialist divers head to the site at Iris Shoal in the Kawau channel.
Munoz told Newshub speed was essential.
"It's incredibly urgent. This is one of the fastest-growing things on Earth. Under ideal conditions it can grow up to an inch a day," said Munoz.
In the waters at Kawau, the divers remove the caulerpa by hand, but experts say larger areas will require techniques like mats that cover the sea floor, or suction dredging.
The message to authorities is: act fast.
"You can't study it, you can't think about it anymore. You've got to jump in, where you have small-scale stuff, try and get a victory. [Then move onto] large-scale stuff, try and reduce the biomass," Munoz added.
And to people out on the water - don't try to remove it yourself.
"If you see it, and you can see it on the seafloor, take a GPS coordinate and take a photo, let MPI and biosecurity know," MacDonald implored.
Americans say Aotearoa has the resources to tackle caulerpa, but they're worried we don't yet realise how bad it is.
"Yes New Zealand has the resources, [but] I don't know if New Zealand has the national awareness."
Because what's at stake here is our way of life.
"Fishing, boating, diving, surfing, paddling, OK that's all wonderful. But what's at stake here is a lot deeper, Isobel. What's at stake is the biodiversity and the health of your oceans - your food sources, your scallop beds, your reefs, your fisheries," Munoz told Newshub.
And that should be enough of a wake-up call - to make like Ngāti Manuhiri - and get on with it.
