Threats to wetlands
Human activity provides most threats to New Zealand's remaining wetlands. This includes
Wetland in the Te Anau area
- Sand and gravel extraction changes water levels, damages existing vegetation and provides access for weeds.
- Reclamation of lake and river margins, lagoons and estuaries, and draining of farm swamps, reduces wetland areas.
- Wetlands are polluted by excess run-off of sediment and nutrients from farmlands.
- Plant and animal pest invasion.
- Stock grazing in wetlands and surrounding catchments damages vegetation, decreases soil stability and contributes to pollution.
- Careless recreation practices, including misuse of jet-skiing, hunting, kayaking, power boating and whitebaiting, disturbs plant and animal life and may destroy parts of the physical wetland environment.
- Forest harvesting close to wetlands may damage wetland vegetation and cause erosion.
- Loss of vegetation in surrounding catchments allow excess sediment to run directly into wetlands.
- Pine forests draw water away from ground water systems leaving depleted supplies, and poorly managed farming practices cause sediment and/or fertiliser run-off.
- Wetlands drained for urban or rural development.