Whangamarino Wetland
Encyclopedia
The Whangamarino Wetland in the Waikato Region is the second largest wetland complex of the North Island of New Zealand
. Encompassing a total area of more than 7200 hectares, the Department of Conservation Te Papa Atawhai manages 5,923 hectares of peat bog
, swamp
, mesotrophic lags, open water and river systems listed as a wetland of international importance under the Ramsar Convention
. Fish and Game New Zealand
are the second largest landowner, managing 748 hectares of the wetland primarily as gamebird hunting habitat.
The site is also one of three of New Zealand’s foremost wetlands included in the Arawai Kākāriki wetland restoration programme, which aims to “enhance the ecological restoration of three of New Zealand’s foremost wetland/freshwater sites, making use of strong community involvement and promoting research into wetland restoration techniques”.
. A number of these are uncommon or extremely rare, including the water milfoil
Myriophyllum robustum, the clubmoss
Lycopodium serpentinum, and the critically endangered swamp helmet orchid Anzybas carseii, now found nowhere else in the world. Baumea
spp., mānuka
(Leptospermum scoparium) and wire rush
(Empodisma minus) are the dominant vegetation of the peat bogs while greater species diversity is found in the mineralised swamp zones, including introduced species such as grey willow (Salix cinerea) and crack willow (Salix fragilia). Moss
es and lichen
s are also well represented in the wetland.
These diverse ecosystems provide habitat to a wide range of native wetland birds, including the Australasian bittern/matuku
(Botaurus poiciloptilus). Approximately 20 percent of New Zealand's breeding bittern population can be found in the Whangamarino. The wetland is also an important site for a number of other rare or threatened wetland birds, including spotless crake/pūweto
(Porzana tabuensis plumbea), marsh crake/koitareke
(Porzana pusilla), North Island fernbird/mātātā
(Bowdleria punctata vealeae), and New Zealand dabchick/weweia (Poliocephalus rufopectus). Occasionally the Whangamarino is visited by other unusual birds such as royal spoonbill/kōtuku-ngutupapa
(Platalea regia) and Japanese snipe
(Gallinago hardwickii), which helps keeps amateur ornithologists interested in the site.
The wetland provides habitat for a diverse range of native freshwater fish, including a significant population of the threatened black mudfish/waikaka
(Neochanna diversus). It is also home to longfin and shortfin eel/tuna
and other galaxiid species. Introduced invasive fish species are also present in Whangamarino Wetland; koi carp
(Cyprinus carpio) and brown bullhead
catfish
(Ameiurus nebulosus) are a particular problem as their aggressive feeding behaviour stirs up bottom sediments, effecting bank stabilisation and aquatic plant life. A study of koi carp otiliths undertaken by University of Waikato MSc student Jennifer Blair found that Lake Waikare and the Pungarehu Stream appear to be a source of recruits, with koi carp moving from these areas into the Waikato River and Lake Waahi.
is a driving component of wetlands, with many plants and animals uniquely adapted to the seasonal wet/dry cycle. Whangamarino Wetland is fed by a catchment
area of approximately 48,900 hectares. During the 1960s the hydrology of the Whangamarino was significantly impacted by the implementation of the Lower Waikato-Waipa Flood Control Scheme managed by Waikato Regional Council, and has also been impacted by the extraction of sand and hydro-power generation on the Waikato River
.
The flood control scheme is intended to replicate the natural water storage function of Lake Waikare
and Whangamarino Wetland in a highly manipulated and more controlled way. To do this, the direction of the Te Onetea Stream was reversed to transport water from the Waikato River into Lake Waikare during high river flows, while the level of Lake Waikare was lowered by one metre. The lake is kept to a strict fluctuation regime of approximately 0.3 metres and flood gates control the movement of water into the Whangamarino Wetland via the artificial Pungarehu Canal. Water is then stored in the Whangamarino until it is released back into the Waikato River via flood gates on the Whangamarino River
.
In 1994 the construction of a rock rubble weir
on the Whangamarino River was commissioned by the Department of Conservation and the Auckland/Waikato Fish and Game Council. The weir maintains minimum summer water levels in approximately 1,400 hectares of the mineralised wetland and helps recreate a seasonal hydrological cycle.
are the benefits (usually to humans) provided by natural ecosystems. They include provisions such as clean drinking water, supporting processes like the decomposition
of wastes, and cultural benefits such as spiritual or recreational opportunities.
Wetlands provide an astonishing array of ecosystem services for the local community. These include mitigating the effects of flood and drought, replenishing groundwater
, helping filter sediment and nutrients and purify water, providing reservoirs of biodiversity
and wetland resources, providing for cultural values, recreation and tourism, and climate change mitigation and adaptation. The Lower Waikato-Waipa Flood Protection Scheme has been estimated to save the Waikato Region $5.2 million (in 2007 dollars) by limiting damage to surrounding farmland during times of peak flood events.
Farmers are a particular benefactor of wetland ecosystem services. On good quality wetland margins, damp soils and dense pockets of native rushes and sedges are effective in:
iwi (tribe) and is considered a taonga
(treasure) by local hapū
. Early Māori utilised the wetland as a source of eel/tuna and birds for food, and flax/harakeke
(Phormium tenax) for traditional cultural purposes. The rivers of the wetland were used for travel and recreation and the peat margins were used to preserve taonga such as waka
, tools and weapons. Dense vegetation inhibited further use of the wetland, although it was used as a sanctuary during times of war.
The Waikato War of 1863-1864 saw several major battles take place in the Whangamarino area, including the fierce land battle at Rangiriri. A small remnant of Rangiriri pā
remains today; further north visitors can walk up a short track to Te Teoteo's pā and the Whangamarino Redoubt at the confluence of the Whangamarino and Waikato Rivers. Here, visitors can stand at the site where two forty-pound Armstrong guns fired on Māori entrenchments at Meremere pā and also obtain a good scenic view looking south over the northern part of the wetland.
and peat
oscillation, water quality, vegetation monitoring and monitoring of mammalian predators.
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
. Encompassing a total area of more than 7200 hectares, the Department of Conservation Te Papa Atawhai manages 5,923 hectares of peat bog
Bog
A bog, quagmire or mire is a wetland that accumulates acidic peat, a deposit of dead plant material—often mosses or, in Arctic climates, lichens....
, swamp
Swamp
A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. A swamp generally has a large number of hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation. The two main types of swamp are "true" or swamp...
, mesotrophic lags, open water and river systems listed as a wetland of international importance under the Ramsar Convention
Ramsar Convention
The Ramsar Convention is an international treaty for the conservation and sustainable utilization of wetlands, i.e., to stem the progressive encroachment on and loss of wetlands now and in the future, recognizing the fundamental ecological functions of wetlands and their economic, cultural,...
. Fish and Game New Zealand
Fish and Game New Zealand
Fish and Game New Zealand is a statutory body set up to advocate for recreational hunting and fishing in New Zealand.It was set up under the Conservation Act 1987 with the statutory responsibility for the sports of freshwater sport fishing and gamebird hunting...
are the second largest landowner, managing 748 hectares of the wetland primarily as gamebird hunting habitat.
The site is also one of three of New Zealand’s foremost wetlands included in the Arawai Kākāriki wetland restoration programme, which aims to “enhance the ecological restoration of three of New Zealand’s foremost wetland/freshwater sites, making use of strong community involvement and promoting research into wetland restoration techniques”.
Ecosystems and biodiversity
Whangamarino Wetland consists of a rich and representative variety of wetland ecosystems (peat bog, swamp, mesotraphic lags, open water and river systems); one of the features that leant support to its designation under the Ramsar Convention. 239 species of wetland plants are found in the Whangamarino, 60 percent of which are indigenousIndigenous (ecology)
In biogeography, a species is defined as native to a given region or ecosystem if its presence in that region is the result of only natural processes, with no human intervention. Every natural organism has its own natural range of distribution in which it is regarded as native...
. A number of these are uncommon or extremely rare, including the water milfoil
Myriophyllum
Myriophyllum is a genus of about 69 species of freshwater aquatic plants, with a cosmopolitan distribution. The center of diversity for Myriophyllum is Australia with 43 recognized species...
Myriophyllum robustum, the clubmoss
Lycopodiopsida
Lycopodiopsida is a class of plants often loosely grouped as the fern allies. Traditionally the group included not only the clubmosses and firmosses, but also the spikemosses and the quillworts...
Lycopodium serpentinum, and the critically endangered swamp helmet orchid Anzybas carseii, now found nowhere else in the world. Baumea
Baumea
Baumea is a genus of the sedge family, which includes around 30 species native to Madagascar and the Pacific Islands, with 15 species in Australia. All are perennial rhizomatous herbs, with leaves and stems very similar in appearance. The inflorescence is terminal, with the flowers tightly...
spp., mānuka
Leptospermum scoparium
Leptospermum scoparium is a shrub or small tree native to New Zealand and southeast Australia. Evidence suggests that L. scoparium originated in Australia before the onset of the Miocene aridity and dispersed relatively recently from Eastern Australia to New Zealand. It is likely that on arrival...
(Leptospermum scoparium) and wire rush
Restionaceae
Restionaceae, also called restiads, is the botanical name for a family of rush-like flowering plants native to the Southern Hemisphere.- Description :...
(Empodisma minus) are the dominant vegetation of the peat bogs while greater species diversity is found in the mineralised swamp zones, including introduced species such as grey willow (Salix cinerea) and crack willow (Salix fragilia). Moss
Moss
Mosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems...
es and lichen
Lichen
Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...
s are also well represented in the wetland.
These diverse ecosystems provide habitat to a wide range of native wetland birds, including the Australasian bittern/matuku
Australasian Bittern
The Australasian Bittern , also known as the Brown Bittern, is found in south-western and south-eastern Australia, Tasmania, New Zealand, New Caledonia and Ouvea. Populations in Australia and New Zealand have declined in the 20th century.It is a large bittern, patterned and streaked brown, buff...
(Botaurus poiciloptilus). Approximately 20 percent of New Zealand's breeding bittern population can be found in the Whangamarino. The wetland is also an important site for a number of other rare or threatened wetland birds, including spotless crake/pūweto
Spotless Crake
The Spotless Crake is a species of bird in the rail family, Rallidae.It is found in American Samoa, Australia, the Cook Islands, Fiji, French Polynesia, Indonesia, Micronesia, New Zealand, Niue, Papua New Guinea, the Philippines, Pitcairn, Samoa, Solomon Islands, and Tonga.-References:* BirdLife...
(Porzana tabuensis plumbea), marsh crake/koitareke
Baillon's Crake
The Baillon's Crake is a very small waterbird of the family Rallidae.-Distribution:Their breeding habitat is sedge beds in Europe, mainly in the east, and across Asia. They used to breed in Great Britain up to the mid-19th century, but the western European population declined through drainage....
(Porzana pusilla), North Island fernbird/mātātā
Fernbird
The Fernbird is an insectivorous bird endemic to New Zealand. The Māori names are Kōtātā or Mātātā. It is a rich brown above and white below, with brown spots on both the throat and breast. Early settlers called it the "Swamp Sparrow" no doubt because of its colouration. The tail feathers are...
(Bowdleria punctata vealeae), and New Zealand dabchick/weweia (Poliocephalus rufopectus). Occasionally the Whangamarino is visited by other unusual birds such as royal spoonbill/kōtuku-ngutupapa
Royal Spoonbill
The Royal Spoonbill, Platalea regia, also known as the Black-billed Spoonbill, occurs in intertidal flats and shallows of fresh and saltwater wetlands in Australia, New Zealand, Indonesia, Papua New Guinea, and the Solomon Islands. It has also been recorded as a vagrant in New Caledonia...
(Platalea regia) and Japanese snipe
Latham's Snipe
Latham's Snipe, Gallinago hardwickii, also known as Japanese Snipe, is a medium-sized , long-billed, migratory wader.-Identification:...
(Gallinago hardwickii), which helps keeps amateur ornithologists interested in the site.
The wetland provides habitat for a diverse range of native freshwater fish, including a significant population of the threatened black mudfish/waikaka
Black mudfish
The black mudfish, Neochanna diversus, is a galaxiid of the family Galaxiidae, found only in swamps and wetlands in the northern half of the North Island of New Zealand, from Kaitaia in the north to the Mokau River in the south. Its length is up to 12 cm.-References: Database entry includes...
(Neochanna diversus). It is also home to longfin and shortfin eel/tuna
Eel
Eels are an order of fish, which consists of four suborders, 20 families, 111 genera and approximately 800 species. Most eels are predators...
and other galaxiid species. Introduced invasive fish species are also present in Whangamarino Wetland; koi carp
Koi
or more specifically , are ornamental varieties of domesticated common carp that are kept for decorative purposes in outdoor koi ponds or water gardens....
(Cyprinus carpio) and brown bullhead
Brown bullhead
The brown bullhead, Ameiurus nebulosus, is a fish of the Ictaluridae family that is widely distributed in North America. It is a species of bullhead catfish and is similar to the black bullhead and yellow bullhead...
catfish
Catfish
Catfishes are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the heaviest and longest, the Mekong giant catfish from Southeast Asia and the second longest, the wels catfish of Eurasia, to detritivores...
(Ameiurus nebulosus) are a particular problem as their aggressive feeding behaviour stirs up bottom sediments, effecting bank stabilisation and aquatic plant life. A study of koi carp otiliths undertaken by University of Waikato MSc student Jennifer Blair found that Lake Waikare and the Pungarehu Stream appear to be a source of recruits, with koi carp moving from these areas into the Waikato River and Lake Waahi.
Hydrology
HydrologyHydrology
Hydrology is the study of the movement, distribution, and quality of water on Earth and other planets, including the hydrologic cycle, water resources and environmental watershed sustainability...
is a driving component of wetlands, with many plants and animals uniquely adapted to the seasonal wet/dry cycle. Whangamarino Wetland is fed by a catchment
Drainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...
area of approximately 48,900 hectares. During the 1960s the hydrology of the Whangamarino was significantly impacted by the implementation of the Lower Waikato-Waipa Flood Control Scheme managed by Waikato Regional Council, and has also been impacted by the extraction of sand and hydro-power generation on the Waikato River
Waikato River
The Waikato River is the longest river in New Zealand. In the North Island, it runs for 425 kilometres from the eastern slopes of Mount Ruapehu, joining the Tongariro River system and emptying into Lake Taupo, New Zealand's largest lake. It drains Taupo at the lake's northeastern edge, creates the...
.
The flood control scheme is intended to replicate the natural water storage function of Lake Waikare
Lake Waikare
Lake Waikare is the largest of several shallow lakes in the upper floodplain of the Waikato River in New Zealand's North Island. It is a riverine lake, located to the east of Te Kauwhata and 40 kilometres north of Hamilton...
and Whangamarino Wetland in a highly manipulated and more controlled way. To do this, the direction of the Te Onetea Stream was reversed to transport water from the Waikato River into Lake Waikare during high river flows, while the level of Lake Waikare was lowered by one metre. The lake is kept to a strict fluctuation regime of approximately 0.3 metres and flood gates control the movement of water into the Whangamarino Wetland via the artificial Pungarehu Canal. Water is then stored in the Whangamarino until it is released back into the Waikato River via flood gates on the Whangamarino River
Whangamarino River
The Whangamarino River is a lowland river of the Waikato Region of New Zealand's North Island, draining the Whangamarino Wetland and associated farmland catchment. The river converges with the Waikato River just north of Meremere...
.
In 1994 the construction of a rock rubble weir
Weir
A weir is a small overflow dam used to alter the flow characteristics of a river or stream. In most cases weirs take the form of a barrier across the river that causes water to pool behind the structure , but allows water to flow over the top...
on the Whangamarino River was commissioned by the Department of Conservation and the Auckland/Waikato Fish and Game Council. The weir maintains minimum summer water levels in approximately 1,400 hectares of the mineralised wetland and helps recreate a seasonal hydrological cycle.
Ecosystem services
Sometimes known as 'nature's benefits’, ecosystem servicesEcosystem services
Humankind benefits from a multitude of resources and processes that are supplied by natural ecosystems. Collectively, these benefits are known as ecosystem services and include products like clean drinking water and processes such as the decomposition of wastes...
are the benefits (usually to humans) provided by natural ecosystems. They include provisions such as clean drinking water, supporting processes like the decomposition
Decomposition
Decomposition is the process by which organic material is broken down into simpler forms of matter. The process is essential for recycling the finite matter that occupies physical space in the biome. Bodies of living organisms begin to decompose shortly after death...
of wastes, and cultural benefits such as spiritual or recreational opportunities.
Wetlands provide an astonishing array of ecosystem services for the local community. These include mitigating the effects of flood and drought, replenishing groundwater
Groundwater
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock...
, helping filter sediment and nutrients and purify water, providing reservoirs of biodiversity
Biodiversity
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...
and wetland resources, providing for cultural values, recreation and tourism, and climate change mitigation and adaptation. The Lower Waikato-Waipa Flood Protection Scheme has been estimated to save the Waikato Region $5.2 million (in 2007 dollars) by limiting damage to surrounding farmland during times of peak flood events.
Farmers are a particular benefactor of wetland ecosystem services. On good quality wetland margins, damp soils and dense pockets of native rushes and sedges are effective in:
- Converting nitrogen from surface runoff and leaching to nitrogen gas which is returned to the atmosphere (denitrification)DenitrificationDenitrification is a microbially facilitated process of nitrate reduction that may ultimately produce molecular nitrogen through a series of intermediate gaseous nitrogen oxide products....
; - Trapping sediments that flow over land, helping to prevent infilling and sedimentationSedimentationSedimentation is the tendency for particles in suspension to settle out of the fluid in which they are entrained, and come to rest against a barrier. This is due to their motion through the fluid in response to the forces acting on them: these forces can be due to gravity, centrifugal acceleration...
; - Filtering and trapping effluent particles;
- Trapping bacteria and other harmful micro-organisms, which then are killed by exposure to sunlight or are retained by the soil;
- Retaining water by maintaining the ground water table and soil moisture levels;
- Protecting land from flood damage by absorbing and slowly releasing water during high rainfall, overland or river flows.
Recreation
Whangamarino is a popular duck hunting location and recreational fishers targeting koi carp, rudd, catfish, goldfish, eel and mullet are regularly seen in the wetland. Bow hunting for koi carp is increasing in popularity, while bird watching and kayaking are also commonly undertaken activities. 748 hectares of the wetland is owned by the Auckland/Waikato Fish and Game Council and thousands of gamebirds frequent the wetland annually, attracting hunters from Auckland and the greater Waikato area. The Fish and Game Council and gamebird hunters are working together with the Department of Conservation to improve wetland habitat and control predators around popular hunting sites.Cultural importance
Whangamarino is located within the rohe (area) of the Waikato-TainuiWaikato (iwi)
Waikato is a Māori iwi from the Waikato region of the North Island of New Zealand. Actually a confederation of smaller tribes, it is also part of the larger confederation of Tainui, consisting of tribes descended from Polynesian migrants who arrived in New Zealand on the Tainui canoe...
iwi (tribe) and is considered a taonga
Taonga
A taonga in Māori culture is a treasured thing, whether tangible or intangible. Tangible examples are all sorts of heirlooms and artefacts, land, fisheries, natural resources such as geothermal springs and access to natural resources, such as riparian water rights and access to the riparian zone of...
(treasure) by local hapū
Hapu
A hapū is sometimes described as "the basic political unit within Maori society".A named division of a Māori iwi , membership is determined by genealogical descent; a hapū is made up of a number of whānau groups. Generally hapū range in size from 150-200 although there is no upper limit...
. Early Māori utilised the wetland as a source of eel/tuna and birds for food, and flax/harakeke
Phormium tenax
Phormium tenax is an evergreen perennial plant native to New Zealand and Norfolk Island that is an important fibre plant and a popular ornamental plant...
(Phormium tenax) for traditional cultural purposes. The rivers of the wetland were used for travel and recreation and the peat margins were used to preserve taonga such as waka
Waka (canoe)
Waka are Māori watercraft, usually canoes ranging in size from small, unornamented canoes used for fishing and river travel, to large decorated war canoes up to long...
, tools and weapons. Dense vegetation inhibited further use of the wetland, although it was used as a sanctuary during times of war.
The Waikato War of 1863-1864 saw several major battles take place in the Whangamarino area, including the fierce land battle at Rangiriri. A small remnant of Rangiriri pā
Pa (Maori)
The word pā can refer to any Māori village or settlement, but in traditional use it referred to hillforts fortified with palisades and defensive terraces and also to fortified villages. They first came into being about 1450. They are located mainly in the North Island north of lake Taupo...
remains today; further north visitors can walk up a short track to Te Teoteo's pā and the Whangamarino Redoubt at the confluence of the Whangamarino and Waikato Rivers. Here, visitors can stand at the site where two forty-pound Armstrong guns fired on Māori entrenchments at Meremere pā and also obtain a good scenic view looking south over the northern part of the wetland.
Conservation management
Whangamarino Wetland has been subject to intensive biodiversity management, research, and community awareness campaigns by the Department of Conservation as part of the Arawai Kākāriki wetland restoration programme. Conservation measures taken to maintain or improve biodiversity include controlling weeds, particularly grey willow, aquatic grasses, yellow flag iris, alligator weed and gorse, and mammalian pests, including mustelids, rodents, cats and possum. The Whangamarino weir was repaired in 2010 and is now operating as it should to help maintain minimum summer water levels in the wetland. Fencing to exclude stock from wetland areas and restoration plantings have also taken place. Monitoring of Australasian bittern/matuku and other cryptic wetland birds including spotless crake/pūweto, marsh crake/koitareke, and fernbird/mātātā is regularly carried out, as is monitoring of black mudfish/waikaka and threatened plants such as Anzybas carseii and Lycopodium serpentinum. The Auckland/Waikato Fish and Game Council have also implemented a number of projects to enhance wetland habitat in the Whangamarino for gamebirds. Research carried out to date includes studies on sediment sources and accumulation rates, ecohydrologyEcohydrology
Ecohydrology is an interdisciplinary field studying the interactions between water and ecosystems. These interactions may take place within water bodies, such as rivers and lakes, or on land, in forests, deserts, and other terrestrial ecosystems...
and peat
Peat
Peat is an accumulation of partially decayed vegetation matter or histosol. Peat forms in wetland bogs, moors, muskegs, pocosins, mires, and peat swamp forests. Peat is harvested as an important source of fuel in certain parts of the world...
oscillation, water quality, vegetation monitoring and monitoring of mammalian predators.
External links
- Whangamarino at the Department of Conservation
- The economic values of the Whangamarino Wetland
- National Wetland Trust
- Whangamarino Wetland at Te Ara Encyclopaedia of New Zealand