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73-600: The Tāmaki River or Tāmaki Estuary is mostly an estuarial arm and harbour of the Hauraki Gulf , within the city of Auckland in New Zealand. It extends south for 15 kilometres (9 mi) from its mouth between the suburb of Saint Heliers and the long thin peninsula of Bucklands Beach , which reaches its end at Musick Point . The inlet extends past the suburbs of Glendowie , Wai o Taiki Bay , Point England , Glen Innes , Tāmaki , Panmure , and Ōtāhuhu to

146-442: A 1-kilometre shallow crater, as seen today. The ejected magma , together with large amounts of ash, accumulated around the crater to form a tuff ring . At the time of the eruption, the wind was probably blowing from a southwesterly direction, and a more substantial rim built up on the downward side. Interestingly, fossils of the now Australia-based Sydney mud cockle (Anadara trapezia) have been found amongst shell beds deposited from

219-573: A harsh environment for organisms. Sediment often settles in intertidal mudflats which are extremely difficult to colonize. No points of attachment exist for algae , so vegetation based habitat is not established. Sediment can also clog feeding and respiratory structures of species, and special adaptations exist within mudflat species to cope with this problem. Lastly, dissolved oxygen variation can cause problems for life forms. Nutrient-rich sediment from human-made sources can promote primary production life cycles, perhaps leading to eventual decay removing

292-577: A larger house on the north-eastern side of the island which burnt down in 1915. The derelict house was still on the island until the 1960s. In 1906 the island was sold to the Alison family who operated the Devonport Steam Ferry Company, and during their ownership the hulks of 4 coal powered low draught paddle steamers were abandoned on the low western end of the island. Browns Island is also significant in aviation history, with

365-529: A number of coastal water bodies such as coastal lagoons and brackish seas. A more comprehensive definition of an estuary is "a semi-enclosed body of water connected to the sea as far as the tidal limit or the salt intrusion limit and receiving freshwater runoff; however the freshwater inflow may not be perennial, the connection to the sea may be closed for part of the year and tidal influence may be negligible". This broad definition also includes fjords , lagoons , river mouths , and tidal creeks . An estuary

438-513: A port or even ventured upstream of the Panmure Bridge. In the 1890s the mouth of the river was used as a safe anchorage for ships carrying explosives. One such ship, anchored in the mouth of the estuary, caught fire and exploded with loss of life. After this the explosives buoy was moved into a more open area east of Browns Island (Motukōrea) , where it is still located. In 1925 a 1.9-metre (6 ft 2 in) leopard that had escaped from

511-408: A type of ecosystem in some estuaries that have been negatively impacted by eutrophication. Cordgrass vegetation dominates the salt marsh landscape. Excess nutrients allow the plants to grow at greater rates in above ground biomass, however less energy is allocated to the roots since nutrients is abundant. This leads to a lower biomass in the vegetation below ground which destabilizes the banks of

584-407: A variety of factors including soil erosion , deforestation , overgrazing , overfishing and the filling of wetlands. Eutrophication may lead to excessive nutrients from sewage and animal wastes; pollutants including heavy metals , polychlorinated biphenyls , radionuclides and hydrocarbons from sewage inputs; and diking or damming for flood control or water diversion. The word "estuary"

657-563: A well-mixed water column and the disappearance of the vertical salinity gradient . The freshwater-seawater boundary is eliminated due to the intense turbulent mixing and eddy effects . The lower reaches of Delaware Bay and the Raritan River in New Jersey are examples of vertically homogeneous estuaries. Inverse estuaries occur in dry climates where evaporation greatly exceeds the inflow of freshwater. A salinity maximum zone

730-436: A wholly marine embayment to any of the other estuary types. The most important variable characteristics of estuary water are the concentration of dissolved oxygen, salinity and sediment load. There is extreme spatial variability in salinity, with a range of near-zero at the tidal limit of tributary rivers to 3.4% at the estuary mouth. At any one point, the salinity will vary considerably over time and seasons, making it

803-477: A wide effect on the surrounding water bodies.  In turn, this can decrease fishing industry sales in one area and across the country. Production in 2016 from recreational and commercial fishing contributes billions of dollars to the United States' gross domestic product (GDP). A decrease in production within this industry can affect any of the 1.7 million people the fishing industry employs yearly across

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876-455: Is a dynamic ecosystem having a connection to the open sea through which the sea water enters with the rhythm of the tides . The effects of tides on estuaries can show nonlinear effects on the movement of water which can have important impacts on the ecosystem and waterflow. The seawater entering the estuary is diluted by the fresh water flowing from rivers and streams. The pattern of dilution varies between different estuaries and depends on

949-513: Is derived from the Latin word aestuarium meaning tidal inlet of the sea, which in itself is derived from the term aestus , meaning tide. There have been many definitions proposed to describe an estuary. The most widely accepted definition is: "a semi-enclosed coastal body of water, which has a free connection with the open sea, and within which seawater is measurably diluted with freshwater derived from land drainage". However, this definition excludes

1022-463: Is designed to resolve this bottle-neck as one of its goals. The Tāmaki River also has a marina / ferry wharf at Half Moon Bay , from where commuter ferries depart for the Auckland CBD and car/passenger ferries for Waiheke Island . Many yachts are also moored in its relatively well protected interiors. The river channel is marked with large green buoys. Deep draught vessels should stay close to

1095-411: Is formed, and both riverine and oceanic water flow close to the surface towards this zone. This water is pushed downward and spreads along the bottom in both the seaward and landward direction. Examples of an inverse estuary are Spencer Gulf , South Australia, Saloum River and Casamance River , Senegal. Estuary type varies dramatically depending on freshwater input, and is capable of changing from

1168-566: Is less restricted, and there is a slow but steady exchange of water between the estuary and the ocean. Fjord-type estuaries can be found along the coasts of Alaska , the Puget Sound region of western Washington state , British Columbia , eastern Canada, Greenland , Iceland , New Zealand, and Norway. These estuaries are formed by subsidence or land cut off from the ocean by land movement associated with faulting , volcanoes , and landslides . Inundation from eustatic sea-level rise during

1241-653: Is the Colorado River Delta in Mexico, historically covered with marshlands and forests, but now essentially a salt flat. Browns Island (Auckland) Motukorea or Browns Island is a small New Zealand island, in the Hauraki Gulf north of Musick Point , one of the best preserved volcanoes in the Auckland volcanic field . The age of eruption is about 25,000 years ago, when the Tāmaki Estuary and

1314-646: Is the whitefish species from the European Alps . Eutrophication reduced the oxygen levels in their habitats so greatly that whitefish eggs could not survive, causing local extinctions. However, some animals, such as carnivorous fish, tend to do well in nutrient-enriched environments and can benefit from eutrophication. This can be seen in populations of bass or pikes. Eutrophication can affect many marine habitats which can lead to economic consequences. The commercial fishing industry relies upon estuaries for approximately 68 percent of their catch by value because of

1387-748: The Holocene Epoch has also contributed to the formation of these estuaries. There are only a small number of tectonically produced estuaries; one example is the San Francisco Bay , which was formed by the crustal movements of the San Andreas Fault system causing the inundation of the lower reaches of the Sacramento and San Joaquin rivers . In this type of estuary, river output greatly exceeds marine input and tidal effects have minor importance. Freshwater floats on top of

1460-610: The Mandovi estuary in Goa during the monsoon period. As tidal forcing increases, river output becomes less than the marine input. Here, current induced turbulence causes mixing of the whole water column such that salinity varies more longitudinally rather than vertically, leading to a moderately stratified condition. Examples include the Chesapeake Bay and Narragansett Bay . Tidal mixing forces exceed river output, resulting in

1533-640: The Mid-Atlantic coast, and Galveston Bay and Tampa Bay along the Gulf Coast . Bar-built estuaries are found in a place where the deposition of sediment has kept pace with rising sea levels so that the estuaries are shallow and separated from the sea by sand spits or barrier islands. They are relatively common in tropical and subtropical locations. These estuaries are semi-isolated from ocean waters by barrier beaches ( barrier islands and barrier spits ). Formation of barrier beaches partially encloses

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1606-734: The Severn Estuary in the United Kingdom and the Ems Dollard along the Dutch-German border. The width-to-depth ratio of these estuaries is typically large, appearing wedge-shaped (in cross-section) in the inner part and broadening and deepening seaward. Water depths rarely exceed 30 m (100 ft). Examples of this type of estuary in the U.S. are the Hudson River , Chesapeake Bay , and Delaware Bay along

1679-466: The Waitemata Harbour were forested river valleys. Due to centuries of cultivation, little native bush remains except on the north-eastern cliffs, leaving the volcanic landforms easily visible. It exhibits the landforms from three styles of eruption. The island consists of one main scoria cone with a deep crater, a small remnant arc of the tuff ring forming the cliffs in the northeast, and

1752-478: The black-tailed godwit , rely on estuaries. Two of the main challenges of estuarine life are the variability in salinity and sedimentation . Many species of fish and invertebrates have various methods to control or conform to the shifts in salt concentrations and are termed osmoconformers and osmoregulators . Many animals also burrow to avoid predation and to live in a more stable sedimental environment. However, large numbers of bacteria are found within

1825-581: The Auckland Zoo three weeks earlier was found dead in the Tāmaki river by a fishing party in Karaka Bay. Due to its extent north–south and its position between the Auckland isthmus and East Auckland , the river is a natural barrier to traffic, especially as only three bridges cross it, all heavily trafficked and increasingly incapable of taking the peak hour flows. The Eastern Busway is a project that

1898-537: The Barnard brothers of Auckland carrying out what may have been New Zealand's first glider flights from the upper slopes of the cone in June 1909. In the 1920s the Devonport Steam Ferry Company regularly brought picnickers to the island landing them on a substantial wooden wharf about 120 ft long on the north side of the island. A 1922 survey plan shows a cottage in on the north western flat presumably built to replace

1971-583: The Department of Conservation. In November 2016 a woman became stranded on the island. She was rescued after a fire she lit to attract attention started burning out of control. Browns Island is part of the Hauraki Gulf Maritime Park . There are three pa sites on the island, with the largest occupying the slopes of the main scoria cone. The island's highest point is 68 metres (223 ft) above sea level. The mineral motukoreaite

2044-400: The United States. Estuaries are incredibly dynamic systems, where temperature, salinity, turbidity, depth and flow all change daily in response to the tides. This dynamism makes estuaries highly productive habitats, but also make it difficult for many species to survive year-round. As a result, estuaries large and small experience strong seasonal variation in their fish communities. In winter,

2117-541: The area of immense strategic importance in both pre-European times and during the early years of European occupation. Portage Road, Ōtāhuhu is the approximate historical location of Te Tō Waka. Karetu and went between the extreme north-east corner of the Manukau Harbour to a bay close to the site of the newest bridge across the Tāmaki, about 1 kilometre (0.6 mi) south of the Panmure Basin . The river

2190-452: The bottom where they are harmless. Historically the oysters filtered the estuary's entire water volume of excess nutrients every three or four days. Today that process takes almost a year, and sediment, nutrients, and algae can cause problems in local waters. Some major rivers that run through deserts historically had vast, expansive estuaries that have been reduced to a fraction of their former size, because of dams and diversions. One example

2263-437: The buoys as the channel, although averaging 20 metres (66 ft) deep is very narrow in many places. Near the large Point England sand spit there are numerous mudflats which are barely covered at high tide. The speed limit in the river is 10 km/h (5.4 kn). Rocks at the western mouth of the river at St Heliers are marked by a distinctive barber's pole . Vessels of more than 4-metre (13 ft) draught should not attempt

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2336-409: The dissolved oxygen from the water; thus hypoxic or anoxic zones can develop. Nitrogen is often the lead cause of eutrophication in estuaries in temperate zones. During a eutrophication event, biogeochemical feedback decreases the amount of available silica . These feedbacks also increase the supply of nitrogen and phosphorus, creating conditions where harmful algal blooms can persist. Given

2409-467: The east and west coasts of New Zealand: Te Tō Waka at Ōtāhuhu , the shortest portage between the two coasts, Karetu to the north at Southdown / Sylvia Park , and the Waokauri / Pūkaki portage , to the south between Middlemore and Papatoetoe . Here, Māori would beach their waka (canoes) and drag them overland to the other coast, thus avoiding having to paddle around North Cape . The portages made

2482-401: The effects of modifying the estuarine circulation. Fjord -type estuaries are formed in deeply eroded valleys formed by glaciers . These U-shaped estuaries typically have steep sides, rock bottoms, and underwater sills contoured by glacial movement. The estuary is shallowest at its mouth, where terminal glacial moraines or rock bars form sills that restrict water flow. In the upper reaches of

2555-601: The estuary impacted by human activities, and over time may shift the basic composition of the ecosystem, and the reversible or irreversible changes in the abiotic and biotic parts of the systems from the bottom up. For example, Chinese and Russian industrial pollution, such as phenols and heavy metals, has devastated fish stocks in the Amur River and damaged its estuary soil. Estuaries tend to be naturally eutrophic because land runoff discharges nutrients into estuaries. With human activities, land run-off also now includes

2628-506: The estuary was first crossed by the Panmure Bridge , a steel swing bridge, to improve connection between Auckland and Howick . The location is 20 metres (66 ft) to the left of the left hand (Panmure) bridge shown in the photo. The circular base swivel was only removed in the 1980s from the southern shore. Stones and steel had been imported from Australia, possibly reflecting the still very basic nature of industrial construction in

2701-424: The estuary, the depth can exceed 300 m (1,000 ft). The width-to-depth ratio is generally small. In estuaries with very shallow sills, tidal oscillations only affect the water down to the depth of the sill, and the waters deeper than that may remain stagnant for a very long time, so there is only an occasional exchange of the deep water of the estuary with the ocean. If the sill depth is deep, water circulation

2774-776: The estuary, with only narrow inlets allowing contact with the ocean waters. Bar-built estuaries typically develop on gently sloping plains located along tectonically stable edges of continents and marginal sea coasts. They are extensive along the Atlantic and Gulf coasts of the U.S. in areas with active coastal deposition of sediments and where tidal ranges are less than 4 m (13 ft). The barrier beaches that enclose bar-built estuaries have been developed in several ways: Fjords were formed where Pleistocene glaciers deepened and widened existing river valleys so that they become U-shaped in cross-sections. At their mouths there are typically rocks, bars or sills of glacial deposits , which have

2847-609: The fish community is dominated by hardy marine residents, and in summer a variety of marine and anadromous fishes move into and out of estuaries, capitalizing on their high productivity. Estuaries provide a critical habitat to a variety of species that rely on estuaries for life-cycle completion. Pacific Herring ( Clupea pallasii ) are known to lay their eggs in estuaries and bays, surfperch give birth in estuaries, juvenile flatfish and rockfish migrate to estuaries to rear, and anadromous salmonids and lampreys use estuaries as migration corridors. Also, migratory bird populations, such as

2920-400: The great biodiversity of this ecosystem. During an algal bloom , fishermen have noticed a significant increase in the quantity of fish. A sudden increase in primary productivity causes spikes in fish populations which leads to more oxygen being utilized. It is the continued deoxygenation of the water that then causes a decline in fish populations. These effects can begin in estuaries and have

2993-420: The impacts do not end there. Plant death alters the entire food web structure which can result in the death of animals within the afflicted biome . Estuaries are hotspots for biodiversity , containing a majority of commercial fish catch, making the impacts of eutrophication that much greater within estuaries. Some specific estuarine animals feel the effects of eutrophication more strongly than others. One example

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3066-494: The island in 1827 and reported it abandoned, probably on account of the musket wars . Being already abandoned by Ngāti Tamaterā and located a considerable distance from where they were based in Coromandel, Te Kanini of Ngāti Tamaterā and the sub-chiefs Katikati and Ngatai were willing to sell Motukorea when William Brown and Logan Campbell indicated a desire to buy the island on 22 May 1840. Brown and Campbell settled on

3139-474: The island include worked moa bone, and one-piece fishhooks. Exotic stone resources including chert , basalt , argillite and obsidian from both local gulf island sources and as far afield as Coromandel Peninsula and Great Barrier Island . The name Motukorea means "Oystercatcher Island". Starting from 1820, early European visitors included Richard Cruise, Samuel Marsden and John Butler, who both traded with Maori for produce. Dumont D’Urville visited

3212-455: The island remained under the control of Ngāti Tamaterā. Opinion is divided as to why this may be, Phillips postulates that mana may have been vested in return for assistance in battle, whereas Monin regards the occupation and sale of Motukorea as evidence of more widespread penetration of the inner Gulf by numerous Hauraki iwi and hapu. Motukorea's location at the mouth of the Tāmaki River

3285-624: The island until 1968 when it became part of the Hauraki Gulf Maritime Park . Management control was vested in the Department of Lands and Survey and in 1987 this was transferred to the Department of Conservation. After the demise of the Hauraki Gulf Maritime Park Board in July 1990, the Auckland City Council was again the designated administering body, and passed back the responsibility for management to

3358-496: The island until February the following year to manage the pig farm, and likely to watch over their vested interest in the island. In 1856 both men left the colony for Great Britain, appointing a resident manager in charge of their affairs. Campbell eventually bought out Brown's share in their business, including Motukorea, in May 1873 for £40,000 when Brown refused to return from Britain to resume control of their affairs. This transaction

3431-405: The island where there is a 100 m (328 ft) long beach, backed by a steep cliff. Navigation is difficult as there is a 70 m (230 ft) long rock reef parallel to the beach. The reef is marked by a beacon. Inside the reef there are small isolated rocks but there is sufficient water between them for a small (up to 6 m or 19.7 ft) craft to move. A crew member should be placed in

3504-525: The many chemicals used as fertilizers in agriculture as well as waste from livestock and humans. Excess oxygen-depleting chemicals in the water can lead to hypoxia and the creation of dead zones . This can result in reductions in water quality, fish, and other animal populations. Overfishing also occurs. Chesapeake Bay once had a flourishing oyster population that has been almost wiped out by overfishing. Oysters filter these pollutants, and either eat them or shape them into small packets that are deposited on

3577-422: The marine environment, such as plastics , pesticides , furans , dioxins , phenols and heavy metals . Such toxins can accumulate in the tissues of many species of aquatic life in a process called bioaccumulation . They also accumulate in benthic environments, such as estuaries and bay muds : a geological record of human activities of the last century. The elemental composition of biofilm reflect areas of

3650-575: The marsh causing increased rates of erosion . A similar phenomenon occurs in mangrove swamps , which are another potential ecosystem in estuaries. An increase in nitrogen causes an increase in shoot growth and a decrease in root growth. Weaker root systems cause a mangrove tree to be less resilient in seasons of drought, which can lead to the death of the mangrove. This shift in above ground and below ground biomass caused by eutrophication could hindered plant success in these ecosystems. Across all biomes, eutrophication often results in plant death but

3723-504: The new capital for the colony. A flagpole was to be erected on the summit and the island claimed for the Crown, but upon hearing what was transpiring, Brown and Campbell returned to their island and protested their right to occupy the island. The idea was abandoned, but Governor Hobson refused the application for a Crown grant made by Brown in August 1840. The official reason for the refusal

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3796-440: The now off-balance nitrogen cycle , estuaries can be driven to phosphorus limitation instead of nitrogen limitation. Estuaries can be severely impacted by an unbalanced phosphorus cycle, as phosphorus interacts with nitrogen and silica availability. With an abundance of nutrients in the ecosystem, plants and algae overgrow and eventually decompose, which produce a significant amount of carbon dioxide. While releasing CO 2 into

3869-544: The one that was lost in 1915. The Auckland Metropolitan Drainage Board purchased the island in 1946 proposing to build a sewage treatment plant. Controversy surrounding the proposal forced the plan to be abandoned and the island was eventually purchased by Sir Ernest Davis, who presented it as a gift to the people of Auckland in July 1955. Ernest Davis had been the chairperson of the Devonport Steam Ferry Company for 20 years which may further explain some of his affinity with Browns Island. The Auckland City Council administered

3942-505: The opening between Musick Point and Browns Island. The channel in this area is marked by port and starboard markers about 20 metres (66 ft) apart. It is 0.5 kilometres (0.3 mi) northwest of Musick Point. Large mussel beds extend out 200 metres (660 ft) from Browns Island into the river. Estuary Most existing estuaries formed during the Holocene epoch with the flooding of river-eroded or glacially scoured valleys when

4015-599: The origins of Ngāti Tamaterā mana whenua and their right to sell the island in 1840, few dispute it. Phillips makes mention of the Tainui canoe stopping at the island after leaving Wakatiwai on the Firth of Thames , before proceeding to Rangitoto where she met up with the Arawa canoe . In the intervening years, the general area came to be controlled by Ngāti Paoa and the lands to the west were controlled by Ngāti Whātua , but

4088-435: The sea level began to rise about 10,000–12,000 years ago. Estuaries are typically classified according to their geomorphological features or to water-circulation patterns. They can have many different names, such as bays , harbors , lagoons , inlets , or sounds , although some of these water bodies do not strictly meet the above definition of an estuary and could be fully saline. Many estuaries suffer degeneration from

4161-427: The seawater in a layer that gradually thins as it moves seaward. The denser seawater moves landward along the bottom of the estuary, forming a wedge-shaped layer that is thinner as it approaches land. As a velocity difference develops between the two layers, shear forces generate internal waves at the interface, mixing the seawater upward with the freshwater. An examples of a salt wedge estuary is Mississippi River and

4234-411: The sediment which has a very high oxygen demand. This reduces the levels of oxygen within the sediment often resulting in partially anoxic conditions, which can be further exacerbated by limited water flow. Phytoplankton are key primary producers in estuaries. They move with the water bodies and can be flushed in and out with the tides . Their productivity is largely dependent upon the turbidity of

4307-403: The upper portions of lava flows . The area was dry land when the eruptions occurred, but much of the lava is now submerged beneath the sea. 36°49′50″S 174°53′41″E  /  36.8306°S 174.8948°E  / -36.8306; 174.8948 Motukorea erupted approximately 24,500 years ago. It began life with a series of wet explosive eruptions that cleared it of any debris and created

4380-512: The volcano. After dry, fire-fountaining eruptions built the several scoria cones around the main crater, the sea rapidly eroded the tuff on the northern side of the island, and together with shell deposited the extensive flats on the south and west of the cone. A shallow reef extends 200m offshore. During the Last Glacial Maximum , sea levels around Motukorea dropped to 100 metres lower than present day levels, meaning Motukorea

4453-456: The volume of freshwater, the tidal range, and the extent of evaporation of the water in the estuary. Drowned river valleys are also known as coastal plain estuaries. In places where the sea level is rising relative to the land, sea water progressively penetrates into river valleys and the topography of the estuary remains similar to that of a river valley. This is the most common type of estuary in temperate climates. Well-studied estuaries include

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4526-453: The water and atmosphere, these organisms are also intaking all or nearly all of the available oxygen creating a hypoxic environment and unbalanced oxygen cycle . The excess carbon in the form of CO 2 can lead to low pH levels and ocean acidification , which is more harmful for vulnerable coastal regions like estuaries. Eutrophication has been seen to negatively impact many plant communities in estuarine ecosystems . Salt marshes are

4599-835: The water. The main phytoplankton present are diatoms and dinoflagellates which are abundant in the sediment. A primary source of food for many organisms on estuaries, including bacteria , is detritus from the settlement of the sedimentation. Of the thirty-two largest cities in the world in the early 1990s, twenty-two were located on estuaries. As ecosystems, estuaries are under threat from human activities such as pollution and overfishing . They are also threatened by sewage, coastal settlement, land clearance and much more. Estuaries are affected by events far upstream, and concentrate materials such as pollutants and sediments. Land run-off and industrial, agricultural, and domestic waste enter rivers and are discharged into estuaries. Contaminants can be introduced which do not disintegrate rapidly in

4672-467: The west, and Bucklands Beach , Half Moon Bay , Farm Cove, Sunnyhills and Pakuranga to the east. It was originally called Te Wai o Taiki, meaning "The Waters of Taiki". The name Taiki is a shortened form of Taikehu, the name of an ancestor of Ngāi Tai . The estuarine Tāmaki River is a harbour in the Auckland Region , with four arms: the Ōtāhuhu Creek, Middlemore Creek, Pakuranga Creek and

4745-557: The western side of the island from 13 August 1840, making it one of the earliest European settlements in the Auckland area. They built a raupo whare and ran pigs on the island, using it as a base from which they aspired to establish and supply the town of Auckland as soon as land was available on the isthmus. Not long after Brown and Campbell had taken up residence on the island, Ngāti Whātua chief Āpihai Te Kawau gifted it to Captain Hobson in order to entice him to select Auckland as

4818-560: The young colony. In the 1860s and 70s, the Tāmaki River was one of the busiest waterways in New Zealand, due to the transportation of agricultural goods such as wheat between Ōtāhuhu and the city of Auckland. The popularity of alternative transportation such as roads and rail (including the extension of the Southern Line to Ōtāhuhu in 1875) led to a decline of the use of the Tāmaki River, and by 1910 very few vessels used Ōtāhuhu as

4891-475: The Ōtara Creek. In addition to these, the Panmure Basin is a tidal basin found in a volcanic crater on the western shores of the river. The Ōtāhuhu Creek forms the eastern shore of the narrowest point on the Auckland isthmus : here it is about 1.25 kilometres (0.75 mi) to the waters of the Manukau Harbour , an arm of the Tasman Sea . The Tāmaki River is the location of three portages which connected

4964-481: Was carried out via William Baker who appears to have acted as an intermediary, receiving Brown's share for two days while the transaction was being carried out. In 1877 Campbell proposed to transplant olive trees to Motukorea and 5000 seedlings were grown in a nursery on One Tree Hill for this purpose, but were never transplanted. Campbell eventually sold the island to the Featherstone family in 1879, who built

5037-524: Was certainly important as it effectively controlled access up the river, and as a result Te Tō Waka (the Ōtāhuhu portage) and nearby Karetu portage through to the Manukau Harbour . The archaeological remains suggest Motukorea was intensively occupied in pre-European times, with people engaged in stone working industry, marine exploitation, gardening of the fertile volcanic soils, and establishing open and defended settlements. Three pā sites have been identified by Simmons. ‘Archaic’ type artifacts found on

5110-420: Was discovered in 1977 on the island and named for it. Other features include a collapsed Lava cave depression which can be seen on the northwestern flats of the island. The island is not served by ferries , so private boats and seaplanes are the only means of access. There is no wharf or easy access to the island for larger vessels. For small craft the best landing is on the more sheltered northern side of

5183-547: Was part of the first steam ferry route in Auckland, the PS Governor Wynyard connecting Auckland to Ōtāhuhu , which began service in 1851. By the next year, the ferry was sold to Melbourne as it was unprofitable. By the late 1850s, the Tāmaki River was one of the busiest waterways in New Zealand. The east bank at Pakuranga was the main point where cattle were transported towards the city of Auckland. In 1865,

5256-546: Was surrounded by a vast coastal plain where the Hauraki Gulf / Tīkapa Moana exists today, a part of the forested river valley of the Waitematā (now the Waitematā Harbour . Sea levels began to rise 7,000 years ago, after which Motukorea became an island separated from the rest of New Zealand. The history of Motukorea prior to European arrival is not well documented, and while many of the sources available speculate as to

5329-562: Was that Brown and Campbell's purchase was made after Sir George Gipps' 1840 proclamation forbidding direct land purchases from the Maori. It was not until Robert FitzRoy assumed the role of governor in 1843 that Brown and Campbell's fortunes changed. The grant was officially made on 22 October 1844. Campbell left the island in December 1840 to set up a trading business in the newly established settlement of Auckland, while Brown remained on

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