Words by Smiley Team
Mussels could be the key to keeping our ocean cleaner, as they can filter out microplastics through their faeces. Yes, you read that right.
When they feed, they suck anything from their surroundings – including microplastics – out of the water. And then when they poo, the microplastics are excreted in a way that makes it easy for people to collect them and remove them from the ocean.
This unique project is being run by scientists at Plymouth Marine Laboratory. Earlier this year, with financial support from the Waitrose ‘Plan Plastic’ Fund, the scientists conducted experiments that showed a cluster of 300 mussels (5kg) could filter out over 250,000 microplastics per hour.
Importantly, the plastics are unlikely to cause the mussels any harm. The microplastics are either rejected by the mussels within ‘pseudofaeces’ or ejected in their normal faecal matter.
[Read More: How to protect animals during a heatwave]
Additional experiments showed that, even when they contain high levels of buoyant plastic, the mussel faeces will rapidly sink out of the water. This means they can be collected for removal, taking microplastics out of the system entirely.
To test the process further, a series of trials have now begun in the Plymouth Sound using clusters of mussels in large submersible ‘baskets’ with net-like receptacles which collect the faeces (and the microplastics) which can then be hauled in and removed from the seawater.
“The trials so far have been extremely promising and we’re very excited about the positive impact systems like these could potentially have on estuarine areas, particularly in places where microplastics might accumulate such as marinas, harbours or near wastewater treatment works,” said Professor Pennie Lindeque, head of science - marine ecology and biodiversity.
“Each year, an estimated eight million tonnes of plastic end up in the ocean – the equivalent to a full truckload dumped into the sea every minute. Of course, prevention is better than cure but we are very encouraged to see that a nature-based solution using the humble mussel could have a key role to play in the war on microplastics, a growing threat to our world’s oceans.
"The mussels, with their highly evolved filtration system, effectively collect up and leave the recycling out for us to dispose of. It’s amazing to consider how far this could be taken.”
Image credit: Don Pablo / Shutterstock
