Can geo-engineering rehabilitate shallow lakes? Dr Ben Woodward and Dr Deborah Hofstra, NIWA
Many shallow lakes are highly eutrophic and have ‘flipped’ from a clear-water state with submerged plants to being turbid and dominated by phytoplankton. This degraded state is perpetuated by phosphorus recycling from lake sediments. This project uses lab and fi eld experiments to validate selected geo-engineering products as tools for rehabilitating Waikato shallow lakes. The team discovered that allophane is an effective flocculant.
The project is funded by NIWA SSIF, Waikato River Authority, Dairy NZ and Waikato Regional Council, with in-kind support from the University of Waikato and support from local landowners.
Development of a groundwater health Index Dr Brent Gilpin and Dr Louise Weaver, ESR
Increasing demand for freshwater and land-use intensification has led to an increased risk of contamination entering groundwater supplies. Contaminants have an unknown effect on the groundwater communities present in the aquifer, yet these communities are the underground food web that protects our drinking water supply.
There is little known about the complex processes that take place below ground to remove contaminants, and no knowledge of cumulative and chronic effects of contaminant addition into groundwater.
This SSIF-funded research is aligned with the Groundwater health project. The team identifies organisms across the domains of bacteria, archaea, fungi, protozoa and macroinvertebrates present in groundwater, focusing on the shallow alluvial aquifers in Canterbury and Southland. The aim is to produce a simple-to-use, tiered assessment of the groundwater quality related to the presence or absence of the keystone species.