What are wetlands?
Wetlands are areas where water is the primary factor controlling the environment and the associated plant and animal life. They occur where the water table is at or near the surface of the land, or where the land is covered by water, either permanently or temporarily. They come in many different guises, including streams, swamps, bogs, lakes, lagoons, estuaries, mudflats and flood plains.
Wetland, Lake Arthur Scenic Reserve,
Wetlands are among the world’s most productive environments. They are cradles of biological diversity, providing the water and primary productivity upon which countless species of plants and animals depend for survival. Many of these plants and animals have specially adapted to living in wet places.
Wetlands were a treasure trove for early Maori, providing abundant supplies of flax for clothing, mats, kits and ropes; raupo for thatching and dried moss for bedding; the eels, fish and birds which lived there were a good food source; and the feathers of birds like the pukeko and bittern were used to adorn cloaks and other garments. Waterways were an important means of access by waka (canoe).
The international significance of wetlands is reflected in the Convention on Wetlands (the Ramsar Convention). This convention is an intergovernmental agreement adopted on 2 February 1971 for the conservation and wise use of wetlands. See DOC's role in the Ramsar Convention.
An international report was launched by the Ramsar Convention on 1 February 2013 entitled The Economics of Ecosystem and Biodiversity (TEEB) for Water and Wetlands.
The report "urges a major shift in our attitudes to wetlands, to recognise their value in delivering water, raw materials and food essential for life and crucial for maintaining people's livelihoods and the sustainability of the world's economies".
Economics of Ecosystem and Biodiversity for Water and Wetlands on the Ramsar Convention website
Wetlands absorb water during heavy rain, releasing water gradually so flooding is reduced. Downstream water flows and ground water levels are also maintained during periods of low rainfall. Wetlands help stabilise shorelines and riverbanks.
As water moves into a wetland, the flow rate decreases, allowing particles to settle out. Plant surfaces provide for filtration, absorption of solids and add oxygen to the water. Growing plants remove nutrients. This cleansing role of wetlands protects downstream environments.
Boardwalk, Pukepuke Lagoon
Wetlands offer a wide variety of recreation activities including boating, fishing, swimming, bird watching, whitebaiting and hunting.
Tourism and education
Wetlands are attractive to visitors because of the large numbers and diversity of species they support. The popularity of wetlands is demonstrated by visitor numbers at the Sinclair Wetland near Dunedin and the Miranda Shorebird Centre at the Firth of Thames. Wetlands also offer many interesting education opportunities and the Department has produced a number of education kits for various wetlands.
A huge range of plants and animals inhabit wetlands. Wetland plants include 47 species of rush and 72 species of native sedge. Many of these plants have very specific environmental needs and are extremely vulnerable to change. A number of New Zealand’s endangered plant species depend totally on wetlands.
Wetlands support the greatest concentrations of bird life of any habitat in New Zealand and support far more species that a comparable forest area. Migratory species depend on chains of suitable wetlands. The survival of threatened species such as the Australasian bittern, brown teal, fernbird, marsh crake and white heron relies on New Zealand’s remnant wetlands.
Native fish need wetlands too. Eight of New Zealand’s 27 species including inanga, short-finned eels, kokopu and bullies are found in wetlands while the whitebait fishery depends on the spawning habitat offered by freshwater wetlands. The best whitebait runs are found on the West Coast of the South Island where extensive areas of forest and swamp remain. The decline in native fish populations is directly related to massive reductions in freshwater habitat.
Wetland plants and water quality video
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