Sobering stats on the state of our freshwater – expert reaction

The Ministry for the Environment and Stats NZ have released the latest national report on the state of our freshwater.

Our Freshwater 2023 details the key pressures on New Zealand’s lakes, rivers, streams, wetlands and aquifers, and the impact of declining water quality on the economy, the environment, and our physical and cultural health. An interactive webpage also explores the state of the environment through the eyes of a tuna (longfin eel).

The Science Media Centre asked experts to comment.

  • Drs Neale Hudson, Manager –National Freshwater Centre, and Clive Howard-Williams, Emeritus Scientist, at NIWA:

“In Our Freshwater 2023, the Ministry for the Environment has taken advice from the Parliamentary Commissioner for the Environment to add pressures such as land use and climate change to the reporting framework.

“In previous reports, the narrow focus on freshwater state was unbalanced, like a medical doctor focusing on the symptoms of an illness without considering the causes. The new report is a good start, but there is a long way to go. The PCE advised ‘adding’ pressures, with no direction about how information about pressures should be used. Simply listing multiple pressures serves to increase the number of disconnected sets of information in the new report. A better use of pressure information is to establish clear, evidence-based relationships between changes in freshwater state and the pressures that cause them. This is a logical step forward, if we are to reverse environmental degradation by reducing pressure levels. Despite the logic, evidence for cause-and-effect relationships is rarely included in environmental reports. Our Freshwater 2023 cites a single study that attributes water quality trends to changes in land use and climate. This work needs to be greatly expanded, and it needs to be a major component of future environmental reports.

“On a closely related issue, Our Freshwater 2023 treats the potential impacts of pressures such as land use, climate change and invasive species separately, and does not address the fact that virtually all freshwater ecosystems are affected by multiple, interacting pressures. Among the challenges ahead for the science community are accurately relating environmental degradation to multiple pressures and developing the tools that stakeholders need to manage multiple pressures effectively.

“NIWA has carried out repeated analyses of national-scale freshwater state and trends for the last two decades. The general state of freshwater described in Our Freshwater 2023 has not changed appreciably over that period: persistent and widespread ecological degradation. This situation is a matter of great and long-standing concern for the New Zealand public.

“Our Freshwater 2023 indicates that work is underway to improve monitoring and reporting, which is laudable. However, a narrow focus on improved monitoring is likely to help us better document degraded conditions, rather than driving improvements. What else is needed to turn the situation around? In our view, there is a critical need for tools for predicting the environmental effects of land use human activities, in advance. These tools currently exist in the form of mathematical models. Our Freshwater 2023 mentions models, but mainly in the context of assessing historical water quality. We are advocating the use of models as predictive tools to help answer fundamental questions like: Which policies and regulatory actions will have beneficial outcomes for freshwater without unnecessarily disadvantaging communities? How can finite water resources be used while minimising adverse environmental impacts And where will mitigation actions such as wetland creation and erosion control be most effective?”

No conflicts of interest.

  • Roland Stenger, Principal Scientist, Environmental Research Group, Lincoln Agritech:

“Our freshwater 2023, in a compact manner, ‘brings current freshwater indicators together with what we know from past reports and insights from the research literature’. Accordingly, the reader won’t find substantial new insights into freshwater pressures, states and impacts in this report, but a few points are noteworthy.

“It recognises that climate change adds additional complexity to the pressures caused by our rural and urban land use history and modification of our waterways (e.g. by flow regulation). As for freshwater states, it gives more emphasis to integrative measures (e.g. the macroinvertebrate community index, MCI) rather than classical water quality indicators (e.g. nitrogen and phosphorus concentrations). This can be seen as a step towards a ‘freshwater ecosystem health framework’, which is currently still unachievable due to lacking monitoring data. By incorporating a location-specific cultural component developed by iwi or hapū, it might ultimately be feasible to assess the mauri of waterbodies around the country. This would directly relate to freshwater impacts, as it is increasingly recognised that the health and well-being of wai is closely linked to the health and well-being of people.

“However, enabling such a holistic assessment system would require substantial investment into freshwater research to close a range of critical knowledge gaps, some of which are outlined in the final section of the report. Giving impetus to addressing these research questions could be the report’s most beneficial effect.”

No conflict of interest.

  • Professor Jenny Webster-Brown, President of NZ Freshwater Sciences Society; and Director of Our Land and Water National Science Challenge/ Toitū te Whenua, Toiora te Wai:

“The most recent update on the state of Aotearoa’s freshwater environment, Our Freshwater 2023, reinforces the observations made in previous such assessments (2017 & 2020), while providing a more robust analysis of trends where further monitoring data is now available. Sadly, as the knowledge of our freshwater environments improves, there is little good news. One of the new statistics is that nearly 70% of our indigenous freshwater birds are now threatened with extinction or at risk of becoming so threatened. As with other ecosystem indicators of environmental health and taonga, this signals that we are still failing to reduce the key pressures on these species; poor water quality, reduced habitat and introduced predators and competitors.

“Such a dismal state of the environment assessment should be able to galvanise the stewards of our environment into action. We know what needs to be done to reverse these trends. I fear this report will not do this. The report is short, around half the length of the previous reports, little of the data is updated beyond 2017 or 2020 and there is a somewhat muddled presentation of educational narratives and numerical state/trend monitoring data. The 2023 report also lacks the informative graphs and graphics used to clearly present monitoring data in previous reports. Finally, the summaries (including an executive summary) used to highlight the most critical findings in previous reports are missing.

“Consequently this is an interesting, if demoralising, read but does not clearly point to or inspire the actions most needed now. Consistent reporting on particular indicators or combined indices of freshwater environmental health and mauri, every three years, would greatly simplify and focus this report, and make its key messages clearer. I appreciate that this is not a new idea, and the development and choice of such indicators/indices is problematic, but it is needed. Secondly, the educational component of this report would be greatly strengthened by profiling actions taken to improve freshwater environments in particular catchments, and their efficacy. There has to be light at the end of the tunnel, before we will move forward.”

No conflict of interest declared.

  • Marnie Prickett, Research Fellow, Department of Public Health, Otago University, Wellington:

Our freshwater 2023 is another sobering reminder of how unhealthy Aotearoa’s water has become and the impact this has on our communities and natural world. It also highlights that it is time to consider how such reporting could support national restoration efforts, rather than document decline of the natural environment we love and rely on.

“Much of the report reads as a list of poor decision-making and its consequences. We have put too much pressure on freshwater, we face further extinctions of fish and other wildlife, further consequences to the health and well-being of our communities, amplified flooding and drought from draining wetlands and restricting river channels, and more. The intensification agriculture has been particularly damaging in recent decades; driven by increases in irrigation, fertiliser use, imported feeds, and resulting in increases in cattle numbers and stocking rates.

“It is significant and welcome that the report emphasises the impact on people’s health and well-being from polluted, degraded waterways. Communities are not independent from the water around them, they are intertwined. When waterways are degrading, our physical and mental health suffers.

“In 2019, the Parliamentary Commission for the Environment identified serious issues and gaps in national environmental monitoring and reporting. This 2023 report acknowledges this, and its own (substantial) limitations, and says there is an overhaul of environmental reporting on the cards. The question for me is how could this not only support better understanding and evidence-based decision making but also drive our national restoration efforts? For example, we could measure and report on area and quality of restored wetland. How many more hectares since the last report? And is fertiliser use reducing in a significant way? Can we build momentum for protection and restoration, which are the goals of our national freshwater policy, through our national reporting?”

Conflict of interest statement: Marnie is an organiser for a volunteer campaign called Choose Clean Water that advocates for improvements in freshwater policy for healthy waterways for people and nature.

  • Mike Joy, Senior Researcher, Institute for Governance and Policy Studies, Te Herenga Waka – Victoria University of Wellington:

“I was pleased to see that the Our Freshwater 2023 (OF23) report unflinchingly identifies the appalling state of lowland freshwaters of Aotearoa. I applaud the progression with each of these reports to more honest and direct reporting, with less fudging of the causes and effects, there are however still serious issues around reporting and data gaps that urgently need addressing.”

Statistical reporting issues:

“It is discouraging that the most recent data used in the 2023 report is only up to 2020, despite the more recent data being available. Another troubling issue is that despite having been previously criticised for the use of short time periods when analysing trends because of the statistical problems this can create, they are still used in this report.

“For example, the report states that for lake and groundwater sites “we present 10-year trends because there was limited data to determine longer trends across the monitoring networks”. Worryingly MfE for almost a decade now has used the same reasoning for using only ten years (so the records are now close to 20 years) plus I have the data and know that this statement is no longer correct.

“The use of short time-period data in trend testing is problematical because the statistical trend tests are very sensitive to the number of samples analysed. For example, if analysis of a 20-year dataset showing a clear statistically significant trend is reduced to 10 years, the trend will often no longer be statistically significant. Thus, using short time periods can and often does give the false impression of no change. This effect is well known and reports highlighting this issue have been done by statisticians for MfE and the last thing we need is false impressions of improvement.”

Groundwater reporting issues:

“A key failure in the report’s groundwater section is the trend results for nitrate. The changing percentages are based on a very small, and crucially non-randomly selected subset of the total number of groundwater monitoring sites.

“The devil is in the detail. The positive sounding statement in OF23, ‘Nitrate-nitrogen levels at 49 percent of sites (128 of 262) were likely or very likely improving, and 35 percent (92 of 262) were likely or very likely worsening,’ while likely to sound encouraging to readers, does not stand up to scrutiny.

“Only 262 sites are used for reporting trends. I’m flabbergasted that they can choose to report national groundwater trends based on such a tiny, non-random subsample, when there are at least 1000 sites monitored nationally.

“To put this in context, most of the 16 individual Regional Councils in Aotearoa monitor far more sites than 262 sites. Canterbury Regional Council for example monitor more than 300 sites and they report more than two/thirds are getting significantly worse.”

Recommendations in OF23:

“I’m in total agreement with many of the recommendations the report makes particularly in the ‘Data and Research Gaps’ section. Gaps identified in OF23 as “critical gaps” are the gaps me and others in the NGO space have been highlighting for years, so it is great to see them in this report.

“These issues include – collecting and using mātauranga Māori evidence, seeing freshwater in a holistic interconnected way, better understanding pressures, pollution lags times and tipping points. As well as the more recently identified threats of rising nitrate in drinking water with its implications for human health in relation to cancers and birth defects.

“While it is heartening to see these appear in this report its frustrating to see how long this recognition has taken. Crucially however, most of these recommendations are self-recommendations. If only the Minister and/or Ministry staff would read this report and take their own advice, then commission and fund the research needed to fill these gaps! I would hate to see future reports just reiterating the need for these gaps to be filled and no change as we have seen to this point.

“Overall, I would give this report a B+, trying harder but still some big issues to address.”

No conflict of interest.

  • Dr Tim Chambers, Department of Public Health, University of Otago:

Our Freshwater 2023 provides a sobering snapshot of the state of Aotearoa’s freshwater. The report outlines the core pressures that have led to substantial degradation of our freshwater, which have serious economic, socio-cultural and health implications.

“The report notes that Aotearoa has experienced one of the highest rates of agricultural land intensification over recent decades internationally. For example, dairy cow numbers have increased nationally from 3.4 million in 1990 to 6.3 million in 2019, with Canterbury and Southland seeing ten-fold and sixteen-fold increases during this same period, respectively. Irrigated land has doubled during a similar period, with around 75% of this increase attributable to dairy intensification.

“The report highlights some of the potential direct health impacts of the pressures on our freshwater. The national ground water monitoring programme shows that 68% and 19% would fail the drinking water standards for bacterial and nitrate contamination, respectively. For bacterial contamination, 82% of all sites are either getting worse (50%) or showing no improvement (32%). For nitrate, 51% are either getting worse (35%) or not improving (16%) (baseline 2009). An estimated 45% of our river length is not suitable for swimming due to bacterial contamination. In 2017, 1200 people got sick after reporting contact with recreational water.

“The report also highlights what we do not know and where research investment is required. These areas include better investment in national monitoring and reporting, research into the health impacts of key contaminants and mātauranga Māori.

“The report is focused on documenting the pressures and state of freshwater, thus it does not detail potentially policy mechanisms to reverse degradation. The report does clearly show that further action is required to protect our freshwater for our physical and economic wellbeing.”

Conflict of interest statement: Dr Tim Chambers was a peer-reviewer of the report. 

Professor Richard McDowell, Chief Scientist, Our Land and Water National Science Challenge: 

“We know that water quality is declining, but what can we do to fix this? Recent analyses have shown that by implementing all known mitigations we can reduce nutrient losses from farmland by about a third. However, this may still not be enough to make water quality at some sites acceptable. Additional reductions in nutrient and contaminant losses could be achieved through land use change.

“We estimate that we can maintain primary exports and meet water quality (and greenhouse gas) objectives through a mix of mitigations and land use change with a <1% decrease in profit. However, improvement will not be instant as lag times between making changes and better water quality varies from about 5 years (on average) in rivers to several decades in deeper groundwater. Nevertheless, through the right mix of industry guidance and policy (and market demands) we can begin changing now.”

No conflict of interest.

Source: Science Media Centre 

Author: Bob Edlin

Editor of AgScience Magazine and Editor of the AgScience Blog