Microplastics are a huge threat to both human and planetary health. Apart from reducing production and dismantling our dependence on plastics, how might we creatively start to remove these contaminants from our environment? Chloe Moriarty explores some of the nature-based solutions capable of tackling microplastic pollution, including some small heroes that could have a big impact in this global fight.
Microplastics. If you’ve managed to avoid hearing about these tiny, persistent particles by now, you certainly haven’t managed to avoid coming into contact with them. Formed through the gradual breakdown of larger plastic items such as bags and bottles, microplastics are ubiquitous in the environment. Air, blood, and water- all are contaminated with minuscule remnants as a result of global plastic use; microplastics have penetrated the very fabric of life.
With microplastics seeping into every corner of our world, the issue of how to remove these long-lasting particles from the environment has become of pressing concern for scientists and policymakers alike. Many ideas have been posited, tested, shelved, or implemented, from magnets to membranes, but a widespread and cost-effective solution continues to evade experts. In the attempt to tackle this mounting problem, researchers have turned to nature for inspiration- and in doing so, microplastics may have met an unlikely match - mussels.
You might be more familiar with the mussels that turn up on your plate at a seafood restaurant, but these unassuming creatures could hold the secret to microplastic filtration. Credits: Wilson44691 via Wikimedia Commons.
Mussels are not one species, but rather a collective of bivalve invertebrates (their spineless shells are split into two halves, or ‘valves’) that inhabit lakes, rivers, and seas worldwide. Whilst they might look unassuming in your local rockpool, mussels have a secret weapon- their immense water filtration capacities.
Filtering up to 150,000 litres of water in one day, small mussel beds (around 1m2) can act as a vital tool for combatting the microplastic crisis. Researchers at Plymouth Marine Laboratory set out to harness this power, first testing how mussels respond to microplastics in a controlled lab environment before installing ‘bioreefs’ in highly polluted waters to ascertain the larger potential for mussel filtration. The results were incredible- the blue mussels consumed around 66%of the microplastic particles in the water around them, excreting the filtered substances for scientists to collect. With other species of mussel also known to be strong biofilters, the researchers are hopeful that a large mussel bed could filter up to 250,000 microplastics each hour, around 4% of the output from polluting rivers.
Although this is a promising solution, mussels offer only part of the solution to this gargantuan problem- the sheer size of mussel beds required to filter the volume of microplastics in our oceans is unseen in the natural world. However, we can draw inspiration from other elements of the Earth, both big and small, to help us tackle microplastics on all fronts; wetlands, bacteria, algae, and beetles, are just some of the candidates put forward to lead the fight against microplastics.
Wetlands offer a nature-based solution for microplastic removal, filtering stubborn pollutants out of streams and rivers with incredible efficiency. Credits: A.Savin via Wikimedia Commons.
Covering just over 5% of Earth’s land, wetlands are vibrant habitats that teem with life. They support around two fifths of the world’s animals and plants and are crucial to flood reduction and water purification; these wet mosaics of flora and fauna create an impact that far exceeds their size. In South Gloucestershire, wetlands were found to play a vital part in filtering wastewater discharge, effectively removing microplastics and reducing harmful concentrations of phosphorus, nitrogen, and ammonia. These findings have been backed up by other scientists around the world, some of whom have found that constructed wetlands can filter out microplastics with up to 90% efficiency. Both mussel beds and wetlands therefore serve as amazing examples of the natural value of our oceanic and terrestrial ecosystems; nature offers both large-scale and small-scale opportunities to tackle microplastic abundance whilst building more resilient and biodiverse communities.
If wetland filtration is a feat of natural engineering, then using egg whites to remove microplastics is certainly a feat of biochemical engineering. Offering one of the more unique solutions to the microplastic mess, Princeton University scientists have discovered that egg whites can be turned into a gel that is capable of filtering seawater microplastics with 99% efficiency. Yet this is not the only weird and wonderful solution to the plastic dilemma; straws that remove per- and polyfluoroalkyl substances (chemicals believed to cause cancer) alongside microplastics are now being sold, squid bone derivatives have been used to filter 95% of the particles from plastic-polluted waters, and fungi have been found to voraciously ‘chomp’ through synthetic sponges. Whilst these proposals might not provide the much sought-after golden solution to our plastic woes, each out-of-the-box idea brings us one step closer towards a world in which plastic no longer chokes our oceans, our Earth, and our bodies.
Plastic waste is found all over our world, severely harming our wildlife and inhibiting the natural functioning of our ecosystems. Credits Captain Darwin via Wikimedia Commons.
If one thing is clear from these scientific discoveries, it’s that we still have a microplastic mountain looming over us. But what is also clear is that by looking to nature, we might find a way to navigate through a world that is slowly shifting to a very ‘unnatural’ state, burdened with the weight of all the plastics ever produced. There are thousands of bright minds devoting their research to the tall task of microplastic removal; thousands of solutions offering us the all-important hope of a better future. The journey will be long and arduous, but warm light glows beyond the mountain; a vibrant and healthy world tenderly calls out to us from beyond the shadows of the rugged peak. The fight is not lost yet.
After all, when you combine nature’s unique lifeforms with the marvels of human ingenuity, who knows what magic you might create?
About the Author: Chloe Moriarty is a final-year BSc Geography with Proficiency in Law student at the University of Exeter, with a keen interest in historic extinctions, human-wildlife conflicts, and environmental law. She runs an environmental campaign on campus, and volunteers as a youth advisor for an environmental charity. You can find out more and connect with Chloe via her LinkedIn.
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