Wetlands are the natural boundary between land and water. They are permanently or intermittently wet areas, shallow water and land water margins that support plants and animals adapted to wet conditions.
Wetlands are often located in the margins of lakes and rivers, but also occur on flats, slopes and basins,and on the margins of estuaries where they are often influenced by the tides. They may also be known as a bog, fen, swamp or marsh, indicating the different wetland types. Different types are determined primarily by their nutrient status and acidity, water source and the level of the water table and the different substrates. This determines the broad vegetation types that occur in each wetland.
No two wetlands are exactly alike. Wetlands vary widely because of regional and local differences in:
- water chemistry
- other factors including human disturbance.
Wetlands may also change over time as environmental conditions alter.
Why are wetlands important?
Wetlands are important but diminishing ecosystems around New Zealand including the Bay of Plenty.
Wetlands are important:
- as aquatic and semi-terrestrial habitats for important native flora and fauna, including rare and endangered indigenous species. Even small wetlands, such as raupo swamps, often provide habitats for indigenous fauna, and many of these species are found only in wetlands
- as traditional Māori sources of food, fisheries, paru (mud dye), urupa, weaving resources and mahinga kai
- for amenity, natural character and landscape values
- for natural heritage as a representative of the full range of ecosystems
- for water quality improvement due to the filtering of nutrients and sediments by plants in the wetland and other natural biological processes
- for flood mitigation due to detention of water in the wetland and its gradual release during dry periods.
- for unique and rare geothermal wetland ecologies, and habitats for indigenous flora and fauna species adapted to geothermal areas.
Why are wetlands under threat?
Wetlands are very sensitive to changes in climate, water availability, disturbance and land use and they are extremely vulnerable to the effects of human activity.
Approximately 90 percent of New Zealand's freshwater wetlands have been lost in the last 150 years. The Bay of Plenty region has lost more than the national average - an estimated 97 percent of wetlands have been lost in our region. Most of these wetlands were in areas very desirable for the development of farmland. Draining, burning and clearing of vegetation for farmland, together with the reclamation of wetlands for urban and industrial uses, have been the principal agents of wetland destruction.
The factors that can impair the functions and values of wetlands in the Bay of Plenty include:
- inappropriate land use management and development
- drainage and/or infilling associated with the pressure to develop economically productive land
- grazing, pugging and wallowing by stock
- built structures
- lack of ongoing maintenance
- pest animals and plants. Invasive weeds, such as parrot feather, are evident in some of the wetlands in the Bay of Plenty
- burning of vegetation
- discharges of contaminants, including diffuse discharges of nutrients and sediment from land use activities.
What can you do to help restore and protect wetlands?
- fence off any wetlands on your property and encourage others to do the same
- avoid creating drainage ditches near wetlands
- get involved with your local care group
- legally protect your wetland, e.g. Queen Elizabeth II National Trust Covenant
- actively manage and restore your wetland by controlling pest plants and animals
How can Bay of Plenty Regional Council help you restore and protect wetlands?
Our Land Management Officers work directly with landowners and the community to actively manage wetlands. They can provide advice on:
- Environmental Enhancement Fundproject funding
- resource consent requirements
- Wetland Management Agreements, a voluntary agreement to help protect, maintain or enhance wetlands on private land
- wetland creation, enhancement, restoration or protection, especially regarding wetland design, planting advice, maintenance, fencing and long-term management
- possible funding assistance.
- legal protection, such as QEII National Trust Covenant
- existing wetland care groups.
Examples of current wetland restoration projects
Wetland Restoration Guide
Download the Wetland Restoration Guide (1.21MB, pdf). The Bay of Plenty Wetland Restoration Guide was prepared by the Bay of Plenty Wetlands Forum (comprising the Department of Conservation, Bay of Plenty Regional Council and Fish & Game New Zealand).