Ammoniacal nitrogen levels in rivers
Effluent, particularly from humans and farmed animals, such as sheep and cows, is the primary source of ammoniacal nitrogen. Elevated levels of ammoniacal nitrogen contribute to excessive overall nutrient levels, and can also be toxic to fish and other aquatic animals.
Ammoniacal nitrogen levels are measured monthly at the 77 sites in the National River Water Quality Network. Some of the ammoniacal nitrogen data for the national network may be affected by problems with laboratory analytical procedures. This data will be reviewed and posted once it has been quality assured.
Regional councils also monitor ammoniacal nitrogen levels in many other rivers and streams throughout New Zealand. Regional council data shows that urban streams have the highest ammoniacal nitrogen levels, followed by rivers and streams in predominantly pastoral catchments. On the other hand, rivers in unmodified catchments have the lowest levels of ammoniacal nitrogen.
What can you do?
- Fence off streams and river banks to help protect our waterways. Planting native vegetation or other plants enhances water quality by filtering sediment, faecal bacteria and nutrients from surface water run-off.
- Farmer? Prevent stock from entering rivers, lakes and wetlands.
- For more advice on stream and wetland protection contact your local or regional council or the New Zealand Landcare Trust.
- Follow urban design and industry best practice guidelines to reduce contaminants getting into waterways.
- Boat owner? Before entering a lake or river, remove all weeds, flush out jet units and wash your boat down to avoid introducing new aquatic pests into the waterway. Visit www.biosecurity.govt.nz for more information on stopping the spread of pest species.
This information has come from the latest state of the environment report Environment New Zealand 2007.
Return to main river water quality page.
Last updated: March 2009
