Coastal and Freshwater news

4 October 2018

Cawthron research shows that our rivers need regular health check-ups

New research by Cawthron Institute is aimed at ensuring that the right things are measured when it comes to the health of New Zealand’s rivers, lakes and streams.

Making sure we gather the right information and ask the right questions is vital – whether it’s for our own health or that of our environment,” says Dr Joanne Clapcott, Cawthron Institute Freshwater Ecologist.

The wellbeing of New Zealand’s freshwater ecosystems is under threat from agricultural intensification, urban development, water abstraction, invasive species, and climate change. There is considerable public interest and concern relating to these threats, says Dr Clapcott.

“There is also confusion around what the different indicators mean, how they link with community values, and how to determine what a ‘healthy waterway’ is. Cawthron’s latest research is a step towards ensuring that the things New Zealanders care about are included in freshwater health measurement and reporting.”

According to Dr Clapcott, a healthy river will support the range of species that are expected to live there and the ecological functions they perform. It will also provide for society’s expectations, whether these be for swimming, fishing, or aesthetics.

Indicators are used to provide information about how a waterway is functioning and to diagnose its overall health. Ideally, these indicators will give an early warning of impending concerns, show whether conditions meet acceptable limits, and help diagnose the causes of poor health. However, a single indicator will never fulfil all these purposes.

“A complete river health check-up that contains several indicators is needed,” says Dr Clapcott. “We have traditionally focused on water quality measures, but a complete picture requires indicators of biological community composition, ecosystem processes and functioning flow regime, and physical habitat structure. Indicators can identify if conditions are improving or degrading.”

In the report, What is a healthy river?, Dr Clapcott says, “aggregate indices that combine information from all these elements show promise, but we must ensure that information isn’t lost in the mix. In addition, results must be intuitive and easy to understand. To this end, ‘report cards’ are becoming an increasingly popular approach to presenting information on river health.”

Further use of kaupapa Māori frameworks for assessing river condition may help recognise the interconnections between ecological and human values. There are also potential gains to be made through empowering citizens with the tools to collect information and contribute to a better understanding of river health.

“We have the opportunity to embrace new technologies that will provide better information and help ensure we have rivers for future generations to enjoy,” says Dr Clapcott.

This latest research into waterways was funded by Cawthron Foundation through its bequest programme. “New Zealanders are passionate about their rivers, lakes and streams; many see the ability to swim and fish as an iconic part of being a New Zealander,” says Cawthron Foundation Chair Dr Morgan Williams.

“Our aim with this research was to address some gaps and provide the public with some more easily understandable, robust scientific information so they can become actively engaged in the discussion.”

“We want the report to be debated. We want people to get involved and make a difference to their local rivers and become engaged in monitoring programmes that new technologies will make easier and in real time. Waterways in virtually every country face an array of threats, and only through our active involvement can we ensure their health in the years ahead.”

Download the full report here and watch the accompanying video below.