Kaipara Harbour

Māori settlements and marae have been scattered around the harbour margins for hundreds of years. The waterways of the Kaipara provided, and still provide, Māori with resources and a ready means of moving between marae.[24]

Today most marae are associated with the Ngāti Whātua sub-tribes, Te Taoū and Te Uri-o-Hau.[24] These sub-tribes both descend from the chief Haumoewhārangi who settled on the north end of the Kaipara entrance at Poutō. He was killed in an argument about kūmara (sweet potatoes). His widow Waihekeao developed a partnership with a Tainui warrior chief, Kāwharu. Kāwharu led several destructive campaigns around Kaipara. Eventually the descendants of Waihekeao and Haumoewhārangi came to control the Kaipara Harbour. Te Uri-o-Hau was founded by Hakiputatōmuri, and controlled the northern part of Kaipara Harbour. Te Taoū was founded by Mawake, and controlled the south.[25]

Dargaville statue commemorating the gumdiggers of early European settlement times.

In 1839, European settlers began arriving in the Kaipara to fell and mill kauri trees and build boats for local requirements.[24] Despite the perilous bar at the harbour entrance, the Kaipara became a busy timber port from the 1860s, shipping thousands of tonnes of kauri timber and gum.[26] The first sailing ship wrecked at the entrance to the harbour was the Aurora in April 1840.[27] The brigantine Sophia Pate was wrecked at South Head in August 1841 with the loss of all 21 on board.[28]

The Wairoa is the main river feeding the Kaipara from the north. Thirty kilometres upstream, the town of Dargaville was established. The stretch of water to Dargaville is broad and straight and provides an easy to navigate route into what were then kauri forests in the interior. Dargaville flourished and immigrants from Britain and Croatia were attracted to the area. Ships up to 3,000 tons carried timber and logs out along the Wairoa to defy the bar at the harbour entrance before continuing on, usually to another New Zealand port or across the Tasman to Australia.[29]

The Kaipara River is the principal river feeding Kaipara Harbour from the south. From 1863 Helensville established itself as a timber port on this river, and provided shipping services about the Kaipara. When the timber ran out, Helensville developed sheep and dairy farms, and more recently nut plantations, vineyards and deer farms.[26]

Further south, Riverhead was an important trading link with the Kaipara and Helensville, and a centre for gum digging. Also set by a river, it milled timber and flour, and made paper. Later it turned to tobacco. From 1929 to 1933, the Riverhead State Forest was developed from 5,000 ha of exhausted gum land.[26]

As the kauri ran out, the Kaipara became a backwater.[26] After 1920 the gum and timber industries dwindled, and farming, mainly dairying, took over. In particular, there is dairying on the rich Ruāwai flats. These flats are below sea level, and are protected by a stopbank and a drainage system.[29] Coastal sawmill settlements at Tinopai, Arapaoa, Batley, Matakohe, Oneriri, Ōruawharo, Pahi, Paparoa, Tanoa and Whakapirau (history photos on the Whakapirau Community Website) have become quiet backwaters. Pahi has become a launch point for houseboats and fishing. Matakohe has a museum which commemorates the kauri industry and the early Pākehā settlers.[24]

Today, Dargaville is the principal centre in the Kaipara area. Its population levelled in the 1960s. It is the country's main kūmara (sweet potato) producer.[29]

Juvenile white trevally (araara)

New Zealand cockle

Much of the coastal fishing industry in New Zealand depends on mangrove forests. About 80% of fish caught commercially are linked to food chains dependent on the mangroves, and at least 30 species of fish use mangrove wetlands at some stage of their life cycle.

The marine and estuarine areas in the Kaipara Harbour breed snapper, mullet, flounder, sole, kahawai, white trevally, gurnard, yellow‑eyed mullet and skates, rays and sharks.[30] The Kaipara is the largest estuarine harbour on the west coast of New Zealand and provides significant areas of suitable breeding grounds and habitats for juvenile fish. It has fewer problems with water quality than the Manukau, and is the single most significant wetland for west coast fisheries.[30]

In 2009, NIWA scientists discovered that 98 percent of snapper on the west coast of the North Island were originally juveniles from nurseries in the Kaipara. Snapper is New Zealand's largest recreational fishery, and is also a commercial fishery with an annual export value of $32 million. The findings show how fragile some fish stocks can be, and highlights the importance of protecting natural habitats, like the Kaipara.

Native rock oysters are plentiful on the rocky shores, and the introduced Pacific oysters flourish lower in the intertidal zone. There are cockles and tuatua on the lower tidal flats, mussels from low tide on the rocks to subtidal beds closer to the mouth of the harbour, and scallops in the tidal channels.[18]

The scallop population has periodic incidences of high mortality, the causes of which have not been identified. Concerns in recent years about the size and availability of scallops have resulted in temporary closures of the scallop fisheries.[31][32]

Early versions of oyster farming occurred between the early 1900s and 1950s. Thousands of tons of rocks were placed along the shorelines to act as an additional substrate on which the natural rock oyster could grow.[18][33] In 2002, the Crown settled the historical claims of Te Uri o Hau, a hapu of the northern Kaipara Harbour. As part of the settlement, access to and the rights of the hapu to gather oysters within the existing "Maori Oyster Areas" were recognised.[34][35] In 2008, resource consent was given to Biomarine to establish New Zealand's largest oyster farm in the Kaipara. The farm is projected to produce about NZ$30 million in annual exports and 100 new jobs.[36]

In recent years, there has been a perception amongst locals that commercial fishers have damaged fisheries in the Kaipara. Locals have been frustrated in their attempts to gain government support. The veteran filmmaker Barry Barclay has examined this in his 2005 documentary, The Kaipara affair.[24][37][38]

Currently (2007) about 219,000 cubic metres of sand is mined each year from the entrance and tidal deltas of the Kaipara. This sand contributes over half the sand requirements for Auckland. The sand is used in the production of concrete and asphalt, and also in drainage systems and beach nourishment. A suction pump is usually used to extract the sand from the seabed. It is pumped into a barge as a sand and water slurry. As the barge loads, shells and other objects are screened out and the sea water drained back to the sea. The availability of sea sand within the Auckland region means the road costs of transporting sand from further parts of the country are avoided.[39] Concerns about possible negative consequences of this sand mining have also been raised.[40][41]

External images
Kaipara Harbour main channel[42]
Proposed cable and turbines[42]

In 2008, Crest Energy, a power company, received resource consent to install about 200 underwater tidal turbines in the Kaipara Harbour, which would use the substantial tidal flows moving in and out every day near the harbour mouth to produce electricity for approximately 250,000 homes.[43]

Crest plans to place the turbines at least 30 metres deep along a ten kilometre stretch of the main channel. Historical charts show this stretch of the channel has changed little over 150 years. The output of the turbines will cycle twice daily with the predictable rise and fall of the tide. Each turbine will have a maximum output of 1.2 MW, and is expected to generate 0.75 MW averaged over time.[9][44]

The peak level of generation for the combined turbines is about 200 MW. This exceeds the projected peak electricity needs of Northland. It would have environmental benefits in offsetting annual carbon emissions from a thermal-based, gas turbine generator of 575,000 tonnes of carbon.[9] The project is costed at about $600 million and to be economic would have to be scaled up rapidly to near full capacity.[45]

However, while the Department of Conservation has approved the project, and has made substantial environmental monitoring conditions part of the consent, the project also has objectors on the grounds of claimed influences on the local ecosystems and charter fishing (see the section above on fisheries). Appeals before the Environment Court are still likely.[46]