Samantha Ladewig: Plastic pollution - another nuclear-free moment?

New Zealand is part of the push for change, but we need to maintain our commitments, writes Samantha Ladewig. Photo / 123rf

OPINION

During the 2017 election campaign, former Prime Minister Jacinda Ardern said that climate change was her generation’s “nuclear-free moment”. Just six years later, the need to combat plastic pollution means we may be facing another one.

According to the most recent figures from the United Nations, the world produced more than 200 million metric tons of “short-lived” plastic – mostly packaging and consumer products - in 2020. Less than a quarter of it was recycled. More than half was “mismanaged” – left to float around in the air or in waterways, and ultimately, the sea.

The UN’s latest report says that plastic pollution is estimated to cost the world economy between $466 billion and $730b a year worldwide. That’s approximately two to three times the total value of New Zealand’s economy.

Fortunately, the world is no longer ignoring the problem. Last year, the United Nations voted to negotiate an international treaty to end plastic pollution, with a target for completion by the end of 2024.

The next round of talks on the proposed treaty will be in the Kenyan capital, Nairobi, in mid-November. The 30-page first draft highlights the effects of plastic pollution on the ocean, with a section specifically addressing the issue of lost and discarded fishing gear.

New Zealand’s Ministry for the Environment is taking an active part in the process. Its solutions include bans or phase-outs of single-use and hard-to-recycle plastics, like coffee stirrers, plastic-stemmed cotton buds, some PVC and polystyrene food packaging, and tableware, produce bags, and straws designed to be used only once.

Other jurisdictions are also working on combating the problem. The European Union has just followed New Zealand and many other countries in outlawing plastic microbeads and has gone further with a ban on plastic glitter and grains used on artificial sports surfaces.

The UN treaty’s strategy aims to cut plastic pollution by 80 per cent by 2040. The report estimates that with adequate investment in “circular economy” measures of reuse, recycling and reorientation, the world could save between 650 billion and almost a trillion dollars per year by 2040.

The effect on our much-touted “100 per cent pure New Zealand” has been quantified in numerous studies of microplastics in marine fauna, including some of our most iconic food species, like hoki and yellowbelly flounder.

Yet effects on individual marine fauna such as these only make up a small portion of the billions of dollars that plastic pollution costs the world today. In fact, the wider, marine ecosystem-level effects, including flora, fauna, and sediment properties, from plastic pollution are where our dollars are largely wasted.

Ecosystem-level effects concern not only human provisions from the environment, but also environmental regulation, and even care of our cultures. University of Auckland ecologists have demonstrated in several studies over recent years that plastic pollution impairs these services that the marine ecosystem provides us.

Fortunately, the world is no longer ignoring the plastic problem. Photo / Michael Craig

In particular, microplastic fibres can alter the amount of oxygen, nitrogen, and carbon that marine environments naturally cycle and the way our marine ecosystems cycle these life-sustaining elements.

Fortunately, these studies have identified areas of hope that could fuel practical solutions. Ecosystem-level effects caused by microplastic pollution are dependent upon the environment they are in. For example, the amount or type of flora, fauna, or sediment properties can change the intensity or the type of effect on the ecosystem caused by plastic pollution.

This means that marine plastic pollution environmental issues can be mitigated if we can manage to protect the ecosystems that are at risk. Specifically, they found that ecosystem-level effects are enhanced in muddy estuaries, suggesting that protection efforts should be focused on these areas or even that we protect our estuaries from becoming muddier.

Additionally, they found that marine plastic pollution ecological effects are not only dependent on environmental properties but also the time the plastic spends in the environment. They found that plastic-bound additives can dissipate in marine sediment after only a week or two. Once dissipated, the ecosystems recovered.

With the recent United Nations report stating that about 3500 substances associated with plastics have “one or more hazardous properties of concern”, University of Auckland chemists are investigating bio-based additives to combat issues with fetal development, male fertility and other intergenerational effects from the use of harmful additives.

Scientists around the country are hard at work to end plastic pollution in Aotearoa New Zealand, with research focused on plastic downcycling, biodegradable polymers, eco-friendly additives, and plastic-degrading microbes, all of which are relevant to the UN treaty.

With a growing tide of plastic waste accumulating in our ocean, and major concerns about effects on the health of humans, animals and ecosystems, the need for international action is urgent.

New Zealand is part of the push for change, but we need to maintain our commitments, both through international cooperation and campaigning, and making sure that our own laws and practices contribute to the solution.

• Samantha Ladewig is a researcher with the Ocean Boundaries Hub project at the University of Auckland