Assessing Contaminants with Stream Order

How can the research be used? Ka pēhea e whai take ai te rangahau?

• We discovered that fencing only large streams to exclude stock would have less effect on freshwater quality than originally thought. Small, steeply sloping streams contribute, on average, 77% of the load of freshwater contaminants. This work was covered in all major newspapers, and radio and TV stations.
• Farm environment plans and tools such as MitAgator can help farmers target strategies to mitigate contaminant losses from critical source areas. This means that cheaper strategies than fencing can be used to keep livestock out of smaller streams, for better effect.
• The results challenge proposed government stock exclusion regulations.
• This research is now being used by regional government to determine policy to improve the quality of freshwater. For example, Taranaki Regional Council has committed to fencing more streams than those covered by central government’s proposed stock exclusion regulations.
• This research is being used internationally. The paper Assessing the Yield and Load of Contaminants by Stream Order was awarded JEQ Best Paper 2019, for the best paper produced in the prior three years, as awarded by the editors of the American Tri-Societies, whose members number over 20,000 North American scientists covering the primary and environmental sectors.