The Whangamarino Wetland in the

Waikato District Waikato District is a territorial authority of New Zealand, in the northern part of Waikato region, North Island. Waikato District is administered by the Waikato District Council, with headquarters in Ngāruawāhia. The district is centred to t ...

is the second largest wetland complex of the North Island of

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

. Encompassing a total area of more than 7200 hectares, the

Department of Conservation An environmental ministry is a national or subnational government agency politically responsible for the environment and/or natural resources. Various other names are commonly used to identify such agencies, such as Ministry of the Environment ...

''Te Papa Atawhai'' manages 5,923 hectares of

peat bog A bog or bogland is a wetland that accumulates peat as a deposit of dead plant materials often mosses, typically sphagnum moss. It is one of the four main types of wetlands. Other names for bogs include mire, mosses, quagmire, and muskeg; a ...

swamp 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 ...

, mesotrophic lags, open water and river systems listed as a wetland of international importance under the

Ramsar Convention The Ramsar Convention on Wetlands of International Importance Especially as Waterfowl Habitat is an international treaty for the conservation and sustainable use of Ramsar sites (wetlands). It is also known as the Convention on Wetlands. It i ...

Fish and Game New Zealand Fish & Game New Zealand is the collective brand name of 12 regional fish and game councils and the New Zealand Fish and Game Council which administer sports fishing and gamebird resources in New Zealand (apart from within the Taupo Fishing Distric ...

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 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 syste ...

(peat bog, swamp, mesotrophic lags, open water and river systems); one of the features that lent support to its designation under the Ramsar Convention. 239 species of wetland plants are found in the Whangamarino, 60 percent of which are

indigenous Indigenous may refer to: *Indigenous peoples *Indigenous (ecology), presence in a region as the result of only natural processes, with no human intervention *Indigenous (band), an American blues-rock band *Indigenous (horse), a Hong Kong racehorse ...

. A number of these are uncommon or extremely rare, including the

water milfoil ''Myriophyllum'' (water milfoil) 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 (37 endemic). These submersed ...

''Myriophyllum robustum'', the

clubmoss Lycopodiopsida is a class of vascular plants known as lycopods, lycophytes or other terms including the component lyco-. Members of the class are also called clubmosses, firmosses, spikemosses and quillworts. They have dichotomously branching s ...

''Lycopodium serpentinum'', and the critically endangered swamp helmet orchid '' Corybas carsei'', now found nowhere else in the world. ''

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 in ...

'' spp.,

mānuka ''Leptospermum scoparium'', commonly called mānuka, () mānuka myrtle, New Zealand teatree, broom tea-tree, or just tea tree, is a species of flowering plant in the myrtle family Myrtaceae, native to New Zealand (including the Chatham Islands ...

(''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 Grey willow or gray willow may refer to: *''Salix atrocinerea'', a species of willow native to Europe commonly called grey willow *''Salix cinerea'', a species of willow native to Europe and western Asia, also occasionally called grey sallow *''Sal ...

(''Salix cinerea'') and

crack willow Crack frequently refers to: * Crack, a fracture in a body * Crack, a fracture (geology) in a rock * Crack, short for crack cocaine Crack may also refer to: Art, entertainment, and media * ''Cracks'' (film), a 2009 independent thriller * Crac ...

(''Salix'' × ''fragilis'').

Moss Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) '' sensu stricto''. Bryophyta (''sensu lato'', Schimp. 1879) may also refer to the parent group bryophytes, which comprise liverworts, mosses, and hor ...

es and

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship. 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 The Galaxiidae are a family of mostly small freshwater fish in the Southern Hemisphere. The majority live in Southern Australia or New Zealand, but some are found in South Africa, southern South America, Lord Howe Island, New Caledonia, and the ...

species. Introduced invasive fish species are also present in Whangamarino Wetland;

koi carp or more specifically , are colored varieties of the Amur carp (''Cyprinus rubrofuscus'') that are kept for decorative purposes in outdoor koi ponds or water gardens. Koi is an informal name for the colored variants of ''C. rubrofuscus'' kept ...

(''Cyprinus carpio'') and

brown bullhead The brown bullhead (''Ameiurus nebulosus'') is a fish of the family Ictaluridae that is widely distributed in North America. It is a species of bullhead catfish and is similar to the black bullhead (''Ameiurus melas'') and yellow bullhead (''Ame ...

catfish Catfish (or catfishes; order Siluriformes or Nematognathi) 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 three largest species alive, ...

(''Ameiurus nebulosus'') are a particular problem as their aggressive feeding behaviour stirs up bottom sediments, affecting bank stabilisation and aquatic plant life. A study of koi carp

otoliths An otolith ( grc-gre, ὠτο-, ' ear + , ', a stone), also called statoconium or otoconium or statolith, is a calcium carbonate structure in the saccule or utricle of the inner ear, specifically in the vestibular system of vertebrates. The sa ...

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

Hydrology Hydrology () is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and environmental watershed sustainability. A practitioner of hydrology is calle ...

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 A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, the ...

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 Sand mining is the extraction of sand, mainly through an open pit (or sand pit) but sometimes mined from beaches and inland dunes or dredged from ocean and river beds. Sand is often used in manufacturing, for example as an abrasive or in concret ...

and hydro-power generation on 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 ...

. The flood control scheme is intended to replicate the natural water storage function of

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. It covers . Due to its ...

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 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. The main trib ...

. In 1994 the construction of a rock rubble

weir A weir or low head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in a change in the height of the river level. Weirs are also used to control the flow of water for outlets of l ...

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. The single-track

North Island Main Trunk The North Island Main Trunk (NIMT) is the main railway line in the North Island of New Zealand, connecting the capital city Wellington with the country's largest city, Auckland. The line is long, built to the New Zealand rail gauge of and ser ...

railway line crosses the wetland, and it has been proposed that two million tonnes of spoil from the Auckland

City Rail Link The City Rail Link (CRL) is a rail project currently under construction in Auckland, New Zealand. The project consists of a 3.5 km long double-track rail tunnel underneath Auckland's city centre, between Britomart Transport Centre and M ...

could be used to double-track the busy section of line which is a bottleneck on the section between Auckland (Papakura) and Hamilton.

Ecosystem services

Sometimes known as 'nature's benefits’,

ecosystem services Ecosystem services are the many and varied benefits to humans provided by the natural environment and healthy ecosystems. Such ecosystems include, for example, agroecosystems, forest ecosystem, grassland ecosystems, and aquatic ecosystems. Th ...

are the benefits (usually to humans) provided by natural ecosystems. They include provisions such as clean drinking water, supporting processes like the

decomposition Decomposition or rot is the process by which dead organic substances are broken down into simpler organic or inorganic matter such as carbon dioxide, water, simple sugars and mineral salts. The process is a part of the nutrient cycle and is e ...

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 is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidate ...

, helping filter sediment and nutrients and purify water, providing reservoirs of

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'') l ...

and wetland resources, providing for cultural values, recreation and tourism, and

climate change mitigation Climate change mitigation is action to limit climate change by reducing Greenhouse gas emissions, emissions of greenhouse gases or Carbon sink, removing those gases from the atmosphere. The recent rise in global average temperature is mostly caus ...

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 Surface runoff (also known as overland flow) is the flow of water occurring on the ground surface when excess rainwater, stormwater, meltwater, or other sources, can no longer sufficiently rapidly infiltrate in the soil. This can occur when th ...

and leaching to nitrogen gas which is returned to the atmosphere (

denitrification Denitrification is a microbially facilitated process where nitrate (NO3−) is reduced and ultimately produces molecular nitrogen (N2) through a series of intermediate gaseous nitrogen oxide products. Facultative anaerobic bacteria perform denitr ...

); * Trapping sediments that flow over land, helping to prevent infilling and

sedimentation Sedimentation is the deposition of sediments. It takes place when particles in suspension 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 ...

; * 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-Tainui Waikato Tainui, Waikato or Tainui is a group of Māori people, Māori ''iwi'' based in Waikato, Waikato Region, in the western central region of New Zealand's North Island. It is part of the larger Tainui confederation of Polynesian settlers who ...

iwi (tribe) and is considered a

taonga ''Taonga'' or ''taoka'' (in South Island Māori) is a Maori-language word that refers to a treasured possession in Māori culture. It lacks a direct translation into English, making its use in the Treaty of Waitangi significant. The current d ...

(treasure) by local

hapū In Māori and New Zealand English, a ' ("subtribe", or "clan") functions as "the basic political unit within Māori society". A Māori person can belong to or have links to many hapū. Historically, each hapū had its own chief and normally opera ...

. Early

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 C ...

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 Waka may refer to: Culture and language * Waka (canoe), a Polynesian word for canoe; especially, canoes of the Māori of New Zealand ** Waka ama, a Polynesian outrigger canoe ** Waka hourua, a Polynesian ocean-going canoe ** Waka taua, a Māori w ...

, 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 The Invasion of the Waikato became the largest and most important campaign of the 19th-century New Zealand Wars. Hostilities took place in the North Island of New Zealand between the military forces of the colonial government and a federation ...

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 The word pā (; often spelled pa in English) can refer to any Māori village or defensive settlement, but often refers to hillforts – fortified settlements with palisades and defensive terraces – and also to fortified villages. Pā sites o ...

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,

ecohydrology Ecohydrology (from Greek , ''oikos'', "house(hold)"; , ''hydōr'', "water"; and , '' -logia'') is an interdisciplinary scientific field studying the interactions between water and ecological systems. It is considered a sub discipline of hydrology, ...

and

peat Peat (), also known as turf (), is an accumulation of partially decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, moors, or muskegs. The peatland ecosystem covers and is the most efficien ...

oscillation, water quality, vegetation monitoring and monitoring of mammalian predators.

References

{{Reflist, 2

External links

Whangamarino Wetland
Department of Conservation
The economic values of Whangamarino Wetland
Department of Conservation
National Wetland Trust

Whangamarino Wetland
at Te Ara Encyclopaedia of New Zealand Wetlands of Waikato Ramsar sites in New Zealand Waikato District