The Community Mission To Protect Northland’s Iconic Surf Beach Dunes

Friday, 24 January 2025, 9:30 pm
Article: Susan Botting - Local Democracy Reporter

Around 250,000 nursery-raised sand dune plants are helping the health of Te Tai Tokerau beaches thanks to Northland coastal communities’ efforts over the last 20 years.

The native spinifex and pingao sand dune plants have been grown from seeds gathered by hundreds of people over that time – and planted on dunes at various surf beaches from Cape Reinga south to Mangawhai along the east coast, and to Ripirō Beach along the west coast.

Northland Regional Council senior biodiversity advisor coastal Laura Shaft said the communities’ efforts are critical.

“No plants, no dunes. No dunes, no beach,” Shaft said.

“Sand dune plants are a critical part of keeping our dunes healthy.”

Shaft chairs New Zealand’s Coastal Restoration Trust and is also Northland CoastCare Co-ordinator.

Native sand dune grasses play a life-and-death role in protecting the unique coastal landform around Northland’s 3200km coastline.

Northlanders from 30 CoastCare groups, hapū and schools are among those who have played a role in a cycle of seed gathering to produce the pingao and spinifex dune plants.

Pingao seeds are harvested before Christmas. Seeds from tumbleweed-like female sand dune spinifex seedheads are gathered roughly through January and February.

This year’s annual summer seed gathering is taking place around Northland now.

The sand binding native grasses’ seedheads are gathered in brown paper rubbish bags, then head to Northland Regional Council for a specialised nursery in Whakatāne, or direct to several nurseries including at Ngātaki, Ngunguru and Mangawhai.

The resulting young plants are planted in their source dunes about 18 months later.

“They’re quite tricky to grow, not like normal nursery plants.”

The iconic golden rolling female spinifex seedheads on Northland surf beaches signal spinifex seedhead gathering time.

Gatherers head for areas of dunes thick with male and female seedheads, harvesting the latter.

Each seedhead contains about 100 spikelets. These contain fertilised seeds and are anchored into the seedhead’s centre by their heads.

“We collect seed from a specific beach. It’s tracked from that stage through its nursery growing then planted out back at that beach or very close by,” Shaft said.

The dune grasses grow to about knee height, their leaves slowing passing winds at about the height where most of the sand they carry is found. This results in the sand falling to the ground around the plant.

More sand gradually builds, like money in the bank. Native dune plants thrive in constant movement.

Some of that sand at the dune’s seaward edge can be washed out to sea when huge stormy waves smash into the dunes - only to return through a different sort of wave action when waters calm. The never-ending cycle is akin to the constantly changing balance of a bank account.

Dunes are like sand reservoirs replenishing the beach.

Shaft said Northland’s sand dune strips face intensifying coastal squeeze. They’re in a zone that's constantly under pressure from both sides with urbanisation and development from the land behind, and the pressures of climate change’s sea level rise in front.

Sand dune plants are easily damaged by people, horses and vehicles.

Weeds are an ongoing issue with problems from garden plants like iceplant and grasses such as Kikuyu and buffalo grass.

Shaft said the width of a beach’s dune strip was important.

Too narrow and it would constantly be at risk of disappearing in a storm.

Sand dune systems ideally graduated from foredune at their front beach edge to mid-dune then back dune at their rear. Many Northland dune systems no longer have complete graduation.

Dunes play an important role in protecting the land behind them and can be home to native lizards and other creatures.

Shaft said Northland sand dune faced growing pressures and were only just holding their own in some areas.

Dunes in areas such as Langs Beach and Long Beach were now thriving as a result of communities’ seed gathering and planting and general dune care.

But others such as at Taipa, which had ongoing weed issues, were not faring so well.

Shaft said all Northlanders could play their part in looking after dunes.

This could be something as simple as making sure to use beach access boardwalks rather than crossing the dunes, or not riding motorbikes or four-wheel drives over dunes.

Killing off dune plants could accentuate sand dunes blowing in onto the land.

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