More than 20 million trees and other natives will be planted around New Zealand's biggest harbour in the groundbreaking $200 million Kaipara Moana Remediation project.
Alan Wilcox, a senior manager for the Kaipara Moana Remediation interim management unit, said planting the 20 million trees was the foundation of a new intergenerational approach.
The first plantings are planned this month. They will be the start of New Zealand's biggest large-scale harbour restoration programme - across 6000sq km of land with more than 8000km of waterways.
Tame Te Rangi, chair of the governing body Kaipara Moana Remediation joint committee, said it was positive to see the community working towards improving the health of the harbour.
He said two groups had already applied to be involved in harbour improvement through riparian planting and other efforts – the Wairua River group catchment group in Northland and the Hoteo River catchment group in Auckland.
Te Rangi said he was looking forward to all landowners in the catchment - including farming and importantly, forestry - working towards improving harbour health.
The initial Kaipara riparian planting catchment work will be further boosted by millions more native trees and plants in coming years on more than 800sq km of highly erodible land.
The Kaipara Moana Remediation (KMR) project is New Zealand's second large-scale harbour catchment repair project – after Raglan's much smaller Whaingaroa Harbour Catchment Care project.
For the Raglan project, 2.1 million trees were planted out across 150 property owners' land in the 450ha catchment from 1995. Sediment in this harbour has decreased by 90 per cent and other water quality indicators have also improved. Research on fish catch rates shows a shift from one fish caught every 18 hours to three fish every hour.
KMR aims to boost the harbour's health by slashing sediment running into its waters, reducing nitrogen levels and boosting swimmability and the health of shellfish for kai moana.
"Ninety-six per cent of the west coast's snapper comes from breeding grounds in the Kaipara," Te Rangi said.
There are about 1500 farms across the catchment – many of which already have fenced-off waterways with riparian strip planting.
Eco-sourced native trees and plants will be produced over the next decade by nurseries in or close to the catchment. These will be purchased by farmers and other landowners to plant along riparian margins and in wetlands.
Remediation aims to cut the 700,000 or so tonnes of sediment running off catchment land into the harbour each year. This is seven times higher than before human settlement, according to research estimates.
Te Rangi said forestry companies, particularly those now harvesting, were also being approached about sediment production mitigation.
He said waterways' headwaters were important places to start the improvement work.
Matauranga Māori and western science are combining in the KMR project. Native plants will include taonga species used for purposes such as medical or health.
The Government in October put $100 million into the KMR project, with the local community expected to match that.
"The programme is the first of its kind [in New Zealand] – a long-term, catchment-wide remediation initiative involving iwi, central and local government, landowners and wider community working together to restore the 602,000ha catchment," said Environment Minister David Parker at Waihāua Marae, Arapaoa, about 60km south of Dargaville, at the formal signing of a memorandum of understanding for the $200m project.
Minister of Conservation Eugenie Sage was also at the formal signing aimed at restoring the harbour's mauri.
There are about 30 marae in the harbour catchment. They are potentially contributing to remediation in various ways, starting with some producing plants. Other work includes seed collecting and putting together fencing gangs.
The KMR nursery strategy's first stage was formally adopted at the Kaipara Moana Remediation joint committee April meeting held at Ahikiwi Marae, Kaihu Valley, north of Dargaville.
John Panaho, Ahikiwi Marae chairman said tangata whenua around his marae and others were definitely looking to participate in the KMR project, benefits including local employment to bring young people home to their marae.
The next meeting will be at Northland's Oruawharo Marae near Topuni this month.
The KMR joint committee's members include representatives from Kaipara uri Ngāti Whātua, Te Uri o Hau, Te Roroa and Ngā Maunga Whakahī o Kaipara, the Northland Regional Council (NRC) and the Auckland Council.
Previous monthly meetings have been held at Taita Marae at Mamaranui north of Dargaville, along with Auckland's Haranui Marae near Parakai and Puatahi Marae north of Helensville.
Plant production and distribution for this year's late-autumn planting season will be boosted at Te Uri o Hau's nursery at Te Arai, near Mangawhai, after the KMR joint committee granted $600,000 at the Ahikiwi Marae towards this for the about-to-start annual planting season. It will also be among mana whenua working with Māori landowners.
The KMR project will see plants produced across about 20 existing nurseries in and around Kaipara Harbour's catchment, with others showing interest. A seed bank nursery will be set up at the south of the catchment as a resource to provide species protection into the future.
KMR research shows existing nursery production capacity roughly matches plant demand.