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Nutrient reduction bioassays in the Waikato River

TR 2018/45

Report: TR 2018/45

Author: Dr Max Gibbs, Glenys Croker (NIWA)

About this report

This report was commissioned by the Technical Leaders Group for the Healthy Rivers Wai Ora Project Report No. HR/TLG/2015-2016/3.5

NIWA conduct a nutrient reduction bioassay on Waikato River water to determine whether reducing either N or P concentrations would cause a reduction in phytoplankton growth.

Read or download the report

Nutrient reduction bioassays in the Waikato River [PDF, 1.7 MB]


1 Introduction
2 Methods
2.1 Experimental design
2.2 Nutrient depleted water
2.3 Treatments
2.4 Biology
3 Results
3.1 Zooplankton
3.2 Phytoplankton
3.3 Nutrients
3.4 Bioassay
4 Summary and Discussion
4.1 Hypothesis 1
4.2 Hypothesis 2
4.3 Hypothesis 3
5 Conclusions
6 Recommendations for future bioassays
7 Acknowledgements
8 References