Kaipara Harbour is a large enclosed harbour

estuary An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...

complex on the north western side of the

North Island The North Island, also officially named Te Ika-a-Māui, is one of the two main islands of New Zealand, separated from the larger but much less populous South Island by the Cook Strait. The island's area is , making it the world's 14th-larges ...

of New Zealand. The northern part of the harbour is administered by the

Kaipara District The Kaipara District is located in the Northland Region in northern New Zealand. History Kaipara District was formed through the 1989 New Zealand local government reforms and was constituted on 1 November 1989. It was made up of five former bo ...

and the southern part is administered by the

Auckland Council Auckland Council ( mi, Te Kaunihera o Tāmaki Makaurau) is the local government council for the Auckland Region in New Zealand. It is a territorial authority that has the responsibilities, duties and powers of a regional council and so is a ...

. The local

Māori Māori or Maori can refer to: Relating to the Māori people * Māori people of New Zealand, or members of that group * Māori language, the language of the Māori people of New Zealand * Māori culture * Cook Islanders, the Māori people of the Co ...

tribe The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English is in the discipline of anthropology. This definition is contested, in part due to confl ...

Ngāti Whātua Ngāti Whātua is a Māori iwi (tribe) of the lower Northland Peninsula of New Zealand's North Island. It comprises a confederation of four hapū (subtribes) interconnected both by ancestry and by association over time: Te Uri-o-Hau, Te Roroa, ...

. By area, the Kaipara Harbour is one of the largest harbours in the world. It covers at high tide, with exposed as

mudflat Mudflats or mud flats, also known as tidal flats or, in Ireland, slob or slobs, are coastal wetlands that form in intertidal areas where sediments have been deposited by tides or rivers. A global analysis published in 2019 suggested that tidal f ...

s and sandflats at low tide.Heath, RA (1975) ''Stability of some New Zealand coastal inlets.'' New Zealand Journal of Marine and Freshwater Research, 9 (4):449-57. According to

tradition, the name Kaipara had its origins back in the 15th century when the Arawa chief, Kahumatamomoe, travelled to the Kaipara to visit his nephew at Pouto. At a feast, he was so impressed with the cooked root of the para fern, that he gave the name Kai-para to the district. ''Kaipara'' comes from the

meaning "food", and meaning "king fern".

Geography

Kaipara North Head Lighthouse (6946080607)

The harbour extends for some from north to south. Several large arms extend into the interior of the peninsula at the northeast of the harbour, one of them ending near the town of Maungaturoto, only ten kilometres (6 mi) from the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the conti ...

coast. The harbour has extensive catchments feeding five rivers and over a hundred streams, and includes large estuaries formed by the

Wairoa Wairoa is a town and territorial authority district in New Zealand's North Island. The town is the northernmost in the Hawke's Bay region, and is located on the northern shore of Hawke Bay at the mouth of the Wairoa River and to the west o ...

, Otamatea, Oruawharo, Tauhoa (Channel) and Kaipara. A number of small islands off the shoreline are connected to the mainland by mudflats at low tide. The Kaipara Harbour is broad and mostly shallow, as it is formed from a system of drowned river valleys. The harbour shoreline is convoluted by the entry of many rivers and streams, and is about long, being the drainage catchment for about 640,000 ha of land. The harbour entrance is a channel to the

Tasman Sea The Tasman Sea (Māori: ''Te Tai-o-Rēhua'', ) is a marginal sea of the South Pacific Ocean, situated between Australia and New Zealand. It measures about across and about from north to south. The sea was named after the Dutch explorer ...

. It narrows to a width of , and is over deep in parts. On average, Kaipara tides rise and fall . Spring tidal flows reach 9 km/h (5 knots) in the entrance channel and move 1,990 million cubic metres per tidal movement or 7,960 million cubic metres daily.Bellve, AR; Austin, G and Woods, B (2007
Pathway to energy generation from marine tidal currents in New Zealand's Kaipara Harbour
University of Auckland. The harbour head is a hostile place. Big waves from the Tasman Sea break over large sandbanks about five metres below the surface, two to five kilometres from the shore. The sand in these sandbanks comes mainly from the

Waikato River The Waikato River is the longest river in New Zealand, running for through the North Island. It rises on the eastern slopes of Mount Ruapehu, joining the Tongariro River system and flowing through Lake Taupō, New Zealand's largest lake. It th ...

. Sand discharged from this river is transported northward by the prevailing coastal currents. Some of this sand is carried into the Kaipara harbour entrance, but mostly cycles out again and then continues moving northwards along the west coast. The southern sandbanks at the entrance are constantly accumulating and releasing this sand. These treacherous sandbanks shift and change position, and are known locally as ''the graveyard''. The graveyard is responsible for more shipwrecks than any other place in New Zealand, and has claimed at least 43 vessels—some say as many as 110. For this reason, a lighthouse was built in 1884 on the northern arm of the entrance ( Pouto Peninsula). It was automated in 1947 and closed in the mid 1950s. The structure still exists and was renovated in 1982–84. In

Māori mythology Māori mythology and Māori traditions are two major categories into which the remote oral history of New Zealand's Māori may be divided. Māori myths concern fantastic tales relating to the origins of what was the observable world for the pr ...

, the ocean-going canoe ''Māhuhu'' voyaged from

Hawaiki In Polynesian mythology, (also rendered as in Cook Islands Māori, in Samoan, in Tahitian, in Hawaiian) is the original home of the Polynesians, before dispersal across Polynesia. It also features as the underworld in many Māori stories. ...

to New Zealand and overturned on the northern side of the entrance. It was commanded by the chief

Rongomai In Māori mythology, Rongomai refers to several entities: * a deity by whose assistance Haungaroa traveled from Hawaiki to New Zealand as she went to tell Ngātoro-i-rangi that he had been cursed by Manaia. * a being in whale form which attacked ...

, who drowned. His body was eaten by araara (white trevally), and his descendants to this day will not eat that type of fish. The first European shipwreck was the ''Aurora'', a 550-ton barque, in 1840, and the most recent was the yacht ''Aosky'' in 1994. Today, the remains of wrecks still become visible under certain tidal and sand conditions. The Kaipara is rarely used today for shipping, and no large settlements lie close to its shores, although many small communities lie along its coastline.

Geology

The Kaipara Harbour is a drowned river valley system, which first formed 2-3 million years ago as an open bay, becoming a sheltered harbour as elongated sand dune barriers formed at the harbour's mouth. Over the last two million years, the harbour has cycled between periods of being a forested river valley and a flooded harbour, depending on changes in the global

sea level Mean sea level (MSL, often shortened to sea level) is an average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardis ...

. The present harbour formed approximately 8,000 years ago, after the

Last Glacial Maximum The Last Glacial Maximum (LGM), also referred to as the Late Glacial Maximum, was the most recent time during the Last Glacial Period that ice sheets were at their greatest extent. Ice sheets covered much of Northern North America, Northern Eu ...

Ecology

The Kaipara Harbour is a productive

marine ecosystem Marine ecosystems are the largest of Earth's aquatic ecosystems and exist in waters that have a high salt content. These systems contrast with freshwater ecosystems, which have a lower salt content. Marine waters cover more than 70% of the sur ...

, with diverse

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

s and

ecotone An ecotone is a transition area between two biological communities, where two communities meet and integrate. It may be narrow or wide, and it may be local (the zone between a field and forest) or regional (the transition between forest and gras ...

s. There are tidal reaches,

intertidal The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species ...

s and sandflats, freshwater

swamps A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...

, maritime rushes,

reed bed A reedbed or reed bed is a natural habitat found in floodplains, waterlogged depressions and estuaries. Reedbeds are part of a succession from young reeds colonising open water or wet ground through a gradation of increasingly dry ground. As ...

s and coastal

scrubland Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominated by shrubs, often also including grasses, herbs, and geophytes. Shrubland may either occur naturally or be the result of human activity. It ...

s.Kaipara Harbour
/ref> The area includes 125 square kilometres of

mangrove forest Mangrove forests, also called mangrove swamps, mangrove thickets or mangals, are productive wetlands that occur in coastal intertidal zones. Mangrove forests grow mainly at tropical and subtropical latitudes because mangroves cannot withstand fre ...

. with subtidal fringes of

seagrass Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families ( Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the ...

. File:BartailedGodwit24.jpg, Bar-tailed godwit File:Fernbird.jpg, Fern bird File:Clianthus puniceus.jpg, Kaka beak leaves and flowers The Kaipara is a

migratory bird Bird migration is the regular seasonal movement, often north and south along a flyway, between breeding and wintering grounds. Many species of bird migrate. Migration carries high costs in predation and mortality, including from hunting b ...

habitat of international significance. Forty–two coastal species are known, and up to 50,000 birds are common. Rare species use the harbour for feeding during summer before returning to the Northern Hemisphere to breed, such as the bar-tailed godwit, lesser

knot A knot is an intentional complication in cordage which may be practical or decorative, or both. Practical knots are classified by function, including hitches, bends, loop knots, and splices: a ''hitch'' fastens a rope to another object; a ...

, and

turnstone Turnstones are two bird species that comprise the genus ''Arenaria'' in the family Scolopacidae. They are closely related to calidrid sandpipers and might be considered members of the tribe Calidriini. The genus ''Arenaria'' was introduced by ...

. Threatened or endangered native species, such as the North Island fernbird, fairy tern,

crake The rails, or Rallidae, are a large cosmopolitan family of small- to medium-sized, ground-living birds. The family exhibits considerable diversity and includes the crakes, coots, and gallinules. Many species are associated with wetlands, althou ...

, Australasian

bittern Bitterns are birds belonging to the subfamily Botaurinae of the heron family Ardeidae. Bitterns tend to be shorter-necked and more secretive than other members of the family. They were called ''hæferblæte'' in Old English; the word "bittern ...

, banded

rail Rail or rails may refer to: Rail transport *Rail transport and related matters *Rail (rail transport) or railway lines, the running surface of a railway Arts and media Film * ''Rails'' (film), a 1929 Italian film by Mario Camerini * ''Rail'' ( ...

, grey‑faced

petrels Petrels are tube-nosed seabirds in the bird order Procellariiformes. Description The common name does not indicate relationship beyond that point, as "petrels" occur in three of the four families within that group (all except the albatross f ...

, banded and NZ dotterels, South Island pied

oystercatcher The oystercatchers are a group of waders forming the family Haematopodidae, which has a single genus, ''Haematopus''. They are found on coasts worldwide apart from the polar regions and some tropical regions of Africa and South East Asia. The ...

, pied stilt, and wrybill are also present . Significant local populations of

black swan The black swan (''Cygnus atratus'') is a large waterbird, a species of swan which breeds mainly in the southeast and southwest regions of Australia. Within Australia, the black swan is nomadic, with erratic migration patterns dependent upon ...

, pukeko, and grey

duck Duck is the common name for numerous species of waterfowl in the family Anatidae. Ducks are generally smaller and shorter-necked than swans and geese, which are members of the same family. Divided among several subfamilies, they are a form ...

also breed in the area. Land habitats adjacent to the harbour support some rare botanical species, including native orchids, the king fern, and the endangered kaka beak. In particular, Papakanui Spit on the south head of the harbour entrance, a mobile sandspit, is important as a breeding and roosting area for the New Zealand dotterel and the fairy tern. It also has areas of

pingao ''Ficinia spiralis'' (pīngao, pīkao, or golden sand sedge) is a coastal sedge endemic to New Zealand (including the Chatham Islands). Originally widespread, it has suffered severely from competition with introduced marram grass and animal gra ...

. The spit was an important habitat for the

Caspian tern The Caspian tern (''Hydroprogne caspia'') is a species of tern, with a subcosmopolitan but scattered distribution. Despite its extensive range, it is monotypic of its genus, and has no accepted subspecies. The genus name is from Ancient Greek ' ...

. The birds have moved to other parts of Kaipara Harbour, possibly due to human disturbance. An air weapons range used by the New Zealand Defence Force is a short distance south of the spit.

Human use

Māori history

Māori settlements and

marae A ' (in New Zealand Māori, Cook Islands Māori, Tahitian), ' (in Tongan), ' (in Marquesan) or ' (in Samoan) is a communal or sacred place that serves religious and social purposes in Polynesian societies. In all these languages, the term a ...

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. Today most marae are associated with the

sub-tribes, Te Taoū and

Te Uri-o-Hau Te Uri-o-Hau (sometimes spelt Te Uri O Hau or Te Uriohau) is a Māori iwi (tribe) based around New Zealand's Kaipara Harbour. It is both an independent iwi and a hapū (sub-tribe) of the larger Ngāti Whātua iwi, alongside Ngāti Whātua-o-Ō ...

. 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 Tainui is a tribal waka confederation of New Zealand Māori iwi. The Tainui confederation comprises four principal related Māori iwi of the central North Island of New Zealand: Hauraki, Ngāti Maniapoto, Ngāti Raukawa and Waikato. There are ...

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.Rāwiri Taonui
''Ngāti Whātua: The tribes of Ngāti Whātua
Te Ara: The Encyclopedia of New Zealand, updated 28-Oct-2008.

European history

In 1839, European settlers began arriving in the Kaipara to fell and mill kauri trees and build boats for local requirements. 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. The first sailing ship wrecked at the entrance to the harbour was the ''Aurora'' in April 1840. The brigantine ''Sophia Pate'' was wrecked at South Head in August 1841 with the loss of all 21 on board. The

is the main river feeding the Kaipara from the north. Thirty kilometres upstream, the town of

Dargaville Dargaville ( mi, Takiwira) is a town located in the North Island of New Zealand. It is situated on the bank of the Northern Wairoa River in the Kaipara District of the Northland region. The town is located 55 kilometres southwest of Whangāre ...

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 , image_flag = Flag of Croatia.svg , image_coat = Coat of arms of Croatia.svg , anthem = " Lijepa naša domovino"("Our Beautiful Homeland") , image_map = , map_caption = , capi ...

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 Tasman most often refers to Abel Tasman (1603–1659), Dutch explorer. Tasman may also refer to: Animals and plants * Tasman booby * Tasman flax-lily * Tasman parakeet (disambiguation) * Tasman starling * Tasman whale People * Tasman (n ...

to Australia.Claudia Orange
''Northland places: Dargaville and the Northern Wairoa''
Te Ara: The Encyclopedia of New Zealand, updated 8-May-2008 The Kaipara River is the principal river feeding Kaipara Harbour from the south. From 1863

Helensville Helensville is a town in the North Island of New Zealand. It is sited northwest of Auckland, close to the southern extremity of the Kaipara Harbour. State Highway 16 passes through the town, connecting it to Waimauku to the south, and Kauka ...

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. 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. As the kauri ran out, the Kaipara became a backwater. 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. Coastal sawmill settlements at Tinopai, Arapaoa,

Batley Batley is a market town in the Metropolitan Borough of Kirklees, in West Yorkshire, England. Batley lies south-west of Leeds, north-west of Wakefield and Dewsbury, south-east of Bradford and north-east of Huddersfield. Batley is part of the ...

Matakohe Matakohe is a settlement in Northland, New Zealand. The Matakohe River is a short river which runs from the north into the Arapaoa River, which is part of the Kaipara Harbour. State Highway 12 passes through Matakohe. Ruawai is 16 km t ...

, Oneriri, Ōruawharo, Pahi,

Paparoa Paparoa is a settlement in Northland, New Zealand. The Paparoa Stream flows from the east, through the settlement, and into the Paparoa Creek to the south, which joins the Arapaoa River which is part of the Kaipara Harbour. State Highway 12 p ...

, Tanoa and Whakapirau (history photos on th
Whakapirau Community
Website) have become quiet backwaters. Pahi has become a launch point for

houseboat A houseboat is a boat that has been designed or modified to be used primarily as a home. Most houseboats are not motorized as they are usually moored or kept stationary at a fixed point, and often tethered to land to provide utilities. Ho ...

s and fishing. Matakohe has a museum which commemorates the kauri industry and the early

Pākehā Pākehā (or Pakeha; ; ) is a Māori term for New Zealanders primarily of European descent. Pākehā is not a legal concept and has no definition under New Zealand law. The term can apply to fair-skinned persons, or to any non-Māori New Z ...

settlers. 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.

Fisheries

Much of the coastal

fishing industry in New Zealand As with other countries, New Zealand’s 200 nautical miles exclusive economic zone gives its fishing industry special fishing rights. It covers 4.1 million square kilometres. This is the sixth largest zone in the world, and is fourteen times th ...

depends on

s. About 80% of fish caught commercially are linked to

food chain A food chain is a linear network of links in a food web starting from producer organisms (such as grass or algae which produce their own food via photosynthesis) and ending at an apex predator species (like grizzly bears or killer whales), de ...

s 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 Flounders are a group of flatfish species. They are demersal fish, found at the bottom of oceans around the world; some species will also enter estuaries. Taxonomy The name "flounder" is used for several only distantly related species, thou ...

, sole, kahawai,

white trevally The white trevally (''Pseudocaranx dentex''), also known as striped jack,) is a jack of the family Carangidae widespread in tropical and warm temperate areas between 40°N and 47°S, in the Atlantic, Mediterranean, Indian, and Pacific Oceans. It h ...

, gurnard, yellow‑eyed mullet and

skate Skate or Skates may refer to: Fish * Skate (fish), several genera of fish belonging to the family Rajidae * Pygmy skates, several genera of fish belonging to the family Gurgesiellidae * Smooth skates or leg skates, several genera of fish belongi ...

ray Ray may refer to: Fish * Ray (fish), any cartilaginous fish of the superorder Batoidea * Ray (fish fin anatomy), a bony or horny spine on a fin Science and mathematics * Ray (geometry), half of a line proceeding from an initial point * Ray (gr ...

s and

shark Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachi ...

s.Department of Conservation (1990) ''Coastal resource inventory: First order survey - Northland conservancy.'' Department of Conservation, Wellington. The Kaipara is the largest estuarine harbour on the west coast of New Zealand and provides significant areas of suitable breeding grounds and

s for juvenile fish. It has fewer problems with water quality than the

Manukau Manukau (), or Manukau Central, is a suburb of South Auckland, New Zealand, centred on the Manukau City Centre business district. It is located 23 kilometres south of the Auckland Central Business District, west of the Southern Motorway, so ...

, and is the single most significant wetland for west coast fisheries. In 2009,

NIWA The National Institute of Water and Atmospheric Research or NIWA ( mi, Taihoro Nukurangi), is a Crown Research Institute of New Zealand. Established in 1992, NIWA conducts research across a broad range of disciplines in the environmental scienc ...

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 Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often p ...

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

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

scallop Scallop () is a common name that encompasses various species of marine bivalve mollusks in the taxonomic family Pectinidae, the scallops. However, the common name "scallop" is also sometimes applied to species in other closely related families ...

s in the tidal channels. 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

s have resulted in temporary closures of the scallop fisheries. Early versions of

oyster farming Oyster farming is an aquaculture (or mariculture) practice in which oysters are bred and raised mainly for their pearls, shells and inner organ tissue, which is eaten. Oyster farming was practiced by the ancient Romans as early as the 1st century ...

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. 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. 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. In recent years, there has been a perception amongst locals that commercial fishers have damaged

fisheries Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, ...

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''.Claudia Orange
''Northland places:Upper Kaipara Harbour''
Te Ara: The Encyclopedia of New Zealand, updated 8-May-2008

Sand mining

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 Auckland (pronounced ) ( mi, Tāmaki Makaurau) is a large metropolitan city in the North Island of New Zealand. The most populous urban area in the country and the fifth largest city in Oceania, Auckland has an urban population of about I ...

. The sand is used in the production of concrete and asphalt, and also in

drainage Drainage is the natural or artificial removal of a surface's water and sub-surface water from an area with excess of water. The internal drainage of most agricultural soils is good enough to prevent severe waterlogging (anaerobic condition ...

systems and

beach nourishment Beach nourishment (also referred to as beach renourishment, beach replenishment, or sand replenishment) describes a process by which sediment, usually sand, lost through longshore drift or erosion is replaced from other sources. A wider beach ...

. 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.Sand mining on the East Coast and in the Kaipara Harbour
Auckland Regional Council Concerns about possible negative consequences of this sand mining have also been raised.

Tidal power

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.Crest Energy
/ref> 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. 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. The project is costed at about $600 million and to be economic would have to be scaled up rapidly to near full capacity. 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

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syst ...

s and charter fishing (see the section above on

). Appeals before the Environment Court are still likely.''Harnessing tidal power not all smooth sailing'' - ''The Business Herald'' (insert of ''

The New Zealand Herald ''The New Zealand Herald'' is a daily newspaper published in Auckland, New Zealand, owned by New Zealand Media and Entertainment, and considered a newspaper of record for New Zealand. It has the largest newspaper circulation of all newspape ...

''), Friday 29 August 2008, page 22.

Management issues

Management of the Kaipara Harbour does not have a central administration. Management is distributed among the

Council,

, Northland Regional Council, the Department of Conservation's Northland and Auckland section, and the Ministry of Fisheries. The Ministry of Fishing allocates quota for the north west region of New Zealand as a whole, but does not tailor quota specifically for the Kaipara. Local iwi feel they are not sufficiently involved in management issues, and to further compound matters, the local iwi is split between Te Uri-o-Hau in the northern part and Te Taoū in the southern part.

Environmental issues

As of 2011, the environmental state of the harbour has been called as "nearing crisis" and "in significant decline", with shrinking fish and shellfish stocks, more sedimentation, declining water quality and competition for resource use and development being noted as the main issues, with "ninety-nine per cent of the rivers in the catchment repolluted". As part of the worldwide trend, there is a decline in

biodiversity Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic ('' genetic variability''), species ('' species diversity''), and ecosystem ('' ecosystem diversity'') ...

within the Kaipara.''Management issues''
Integrated Kaipara Harbour Management Group. The timber industry removed most of the native forest. Much of the kauri and kahikatea forest, and scrub and riparian vegetation, has been replaced with farm and urban areas. Mangrove forests and wetlands have been "reclaimed". Soil erosion has increased on the land and sedimentation in the harbour. Shellfish abundance has declined, especially toheroa, scallops, tuatua, cockles and pipi. Finfish like mullet, snapper, kanae and school shark have diminished.

Habitat fragmentation Habitat fragmentation describes the emergence of discontinuities (fragmentation) in an organism's preferred environment (habitat), causing population fragmentation and ecosystem decay. Causes of habitat fragmentation include geological process ...

has also occurred. Natural vegetation in the Kaipara catchments have been reduced to islands of wetlands and forest in man-made landscapes—separated by urban areas, roads, exotic forests and pastures. More information is needed on biodiversity in the Kaipara Harbour and habitats in associated coastal areas. A recent pilot survey found that habitats in the estuaries are still extensive, but ninety percent of land cover is no longer indigenous wetland or vegetation. Even if the key existing areas were to be protected, further buffers and corridors that give better connection between the natural areas would be needed to encourage the recovery of biodiversity.

Timeline

* c. 1300: The Maori chief

arrives in his

canoe A canoe is a lightweight narrow water vessel, typically pointed at both ends and open on top, propelled by one or more seated or kneeling paddlers facing the direction of travel and using a single-bladed paddle. In British English, the ter ...

''Māhuhu'' from

, and is drowned at the harbour entrance. * 1807 or 1808: Ngapuhi fight Ngāti Whātua, Te-Uri-o-Hau and Te Roroa iwi at the

battle of Moremonui The battle of Moremonui was fought between Ngāti Whātua and Ngāpuhi, two Māori '' iwi'' (tribes), in northern New Zealand in either 1807 or 1808. The Ngāpuhi force had a few muskets, making this the first occasion Māori used muskets in wa ...

on the west coast of Northland, the first battle in which Maori used muskets. * 1839: European settlers begin arriving to fell and mill kauri trees. * 1840: The ''Aurora'', a 550-ton

barque A barque, barc, or bark is a type of sailing vessel with three or more masts having the fore- and mainmasts rigged square and only the mizzen (the aftmost mast) rigged fore and aft. Sometimes, the mizzen is only partly fore-and-aft rigged, b ...

, is the first European ship to be wrecked at the entrance. * 1860s: The timber industry is established. * 1899: The timber industry peaks. * c. 1939: Timber trade ends, and the area becomes a backwater. * 2002: Crown settles historical claims of Te Uri o Hau * 2005: Filmmaker Barry Barclay makes his documentary, ''The Kaipara Affair''. * 2008: Biomarine receives resource consent to establish an oyster farm * 2008: Crest Energy receives resource consent to install tidal turbines

References

External links

Integrated Kaipara Harbour Management GroupKaipara Moana Remediation Programme

Te Tiaki Mahinga Kai
– coalition of Māori environmental guardians supporting the management of customary fishing areas.
Kaipara lighthouse 1884, NZ
* Geography of the Auckland Region Geography of the Northland Region Kaipara District Ports and harbours of New Zealand Rodney District