Freshwater pressures rising
The Ministry for the Environment and Statistics New Zealand have released the latest national report about the state of freshwater.
The report - Our fresh water 2017 - shows New Zealand's rivers and lakes are under increasing pressure, with nitrogen levels getting worse at over half the measured river sites and 72 per cent of monitored native fish species threatened with extinction.
Waterways Centre for Freshwater Management director Professor Jenny Webster-Brown said the report "conclusively confirms that the overall quality of our freshwater environment is declining... rapidly".
"In the last 10 years we have begun to address the problem through policy changes and law amendments, but a greater investment of time, funding and effort is needed in action and innovation before we will be able to halt, and if possible, reverse this trend."
Our Land and Water National Science Challenge director Ken Taylor said there had been a "beneficial shift in thinking around water quality, which means that no-one is now denying that there's a problem".
Taylor, who was part of the report's technical advisory group, said that with plenty of evidence showing there is a problem "we now need to focus on finding solutions".
Though much of the recent public focus has been around 'swimmability', the report highlighted a range of other issues facing freshwater ecosystems.
Niwa freshwater research manager Dr Scott Larned, also part of the advisory group, said some of the biggest issues were wetland loss and degradation, nutrient enrichment in lakes, estuaries and lowland rivers, and invasive non-native species.
With several data gaps identified by the report, Professor Richard McDowell said one reason for this is because we only have general data about land use, such as fertiliser application and stocking rates, meaning any land use signature was "averaged-out".
Prof McDowell, chief scientist for the Our Land and Water challenge, said "the data is there, but privacy concerns rightly prevent it being used".
"The solution may be to anonymise the data such that these links can be made and therefore quantitative solutions found."
The SMC gathered expert reaction to the report.