Adam Canning: Clean river promises have been swept away

It appears the Science and Technical Advisory Group recommendations on reducing nutrient run-off have been ignored, says Dr Adam Canning. Photo / Janine Baalbergen, file

Opinion

COMMENT

The health of our nation's rivers, lakes and estuaries was one of the top election issues in 2017. When Labour formed its Government, Prime Minister Jacinda Ardern said, "It's our job to step in when rivers are dying."

Ardern vowed to set high standards, recognising that the task will be no small feat, stating: "We will not accept that it is too hard. We will not accept that, and we will not accept a position that we simply sit back and allow this degradation to continue. We have set our standards and our sights higher, no matter how hard that proposition might be."

Environment Minister David Parker has just announced the array of policy decisions that will shape the future of our freshwater ecosystems. The programme has two goals: To stop rivers getting worse and to restore them to a healthy state within a generation.

For the first goal of stopping rivers getting worse, I would give the Government's policy a B+ grade.

The new rules would cap very high levels of fertiliser application on farms; require intensive agriculture to fence cattle and pigs out of large streams with a small buffer (even though most pollution comes from the small streams); mandate that water quality cannot decline further; restrict the conversion of land to more environmentally harmful uses; and introduce rules on intensive winter grazing. Though, undesirably, the latter still mean cows will be standing in 20cm of mud.

Environment Minister David Parker and Agriculture Minister Damien O'Connor announcing the plan to stop the degradation of our waterways in September 2019. Photo / Mark Mitchell

Despite being set too high, the fertiliser cap, in particular, is an important step forward in environmental management in New Zealand. It acknowledges that controlling the source of pollution could be more effective than working backwards from the effects. It is basically saying: we're going to look at stopping the causes of pollution before they have an effect on waterways, rather than issuing a penalty when they do.

On the goal of restoring rivers to a healthy state within a generation, the proposal lacks ambition in terms of achieving the health of rivers most Kiwis desire, and I would give it a D grade.

While a range of new measures proposed by the Science and Technical Advisory Group (STAG) for both ecological and human health have been included in the policy, they are only there in non-statutory form and with no deadline for when they have to be achieved.

That means no one can take legal action to enforce the improvement of poor rivers, and councils could set achievement of goals for the year 2300. Even though 76 per cent of our native fish are threatened or at risk of extinction, and STAG proposed a metric and bottom line for native fish, it has been included without a bottom line, so there is no trigger for rivers with poor fish habitat to improve.

Perhaps one of the most disappointing decisions was not to accept the STAG recommendations on managing nutrients (nitrogen and phosphorus). The Government has said it will revisit these in 12 months.

Nutrients can substantially disrupt freshwater food webs and make rivers slimy – it's the silent and invisible killer. The politicians claim more work is required to contemplate whether nitrogen bottom lines should vary across the country, despite the majority of STAG stating, "We believe that there is sufficient evidence available now … to support the introduction of nationally applicable bottom lines and thresholds for DIN and DRP."

Adam Canning. Photo / supplied

Instead, they opted to increase the standard of nitrate toxicity to 2.4 mg/L (2.4 times higher than the 1 mg/L of DIN recommended by the majority of STAG). The majority of STAG stated "We are very uncomfortable with the use of nitrate toxicity data … as a basis for nutrient limits."

The criteria lack scientific robustness, are arbitrary, are based on conditions never seen in NZ waterways, and only include one NZ native fish alongside tolerant and undesired species, like catfish. A respected international review of nitrogen also recommended that nitrogen stay below 0.5-1 mg/L to keep rivers healthy.

Adopting a limit of 2.4 mg/L instead of 1 mg/L means only 5 per cent of monitored rivers will require improvement, instead of the 16 per cent required under the 1 mg/L limit. This is probably welcomed by polluters, as it's perceived as having lower economic impact. This is despite Ardern stating, "I have never accepted that we have to choose between a clean environment and a prosperous economy."

The large majority of the 17,500 public submissions on the policy were strongly supportive of ambitious proposals, and while some parts of the policy are a good step forward, others are still window-dressing.

• Dr Adam Canning is a research scientist at James Cook University and member of the Essential Freshwater Science and Technical Advisory Group.