Microplastics are one of the most pernicious forms of plastic pollution threatening our oceans, so scientists are hard at work to find solutions that could help filter this ecological burden out of the marine environment.
Recently, we wrote about how sea squirts can help us monitor the steadily growing quantity of microplastics present in our oceans. Also turning to nature for help, another team of researchers is now investigating the potential of mussels to help rid our oceans of these tiny particles of plastic waste.
The solution is currently under trial in the waters of a marina near the Plymouth Marine Laboratory in England, where a group of mussels is filtering microplastics out of the water. As these bivalve mollusks feed, they suck bacteria, algae, and anything else in their surroundings, including microplastics, out of the water and into their gills. The mussels then excrete the microplastic together with other waste, in a way that makes it easy for people to then remove it out of the ocean.
Before being tasked with filtering the water in the Plymouth marina, the researchers behind the study completed research in a lab where 300 mussels (weighing about 11 pounds) were placed in a flow tank, which mimics currents, along with phytoplankton for food and microplastics.
In the experiment, the mussels filtered out more than 250,000 microplastics per hour or about 25 percent of the microplastics in the water. That plastic ended up encased in the mussels’ poop, which naturally sinks down to the water column, enabling the researchers to easily collect the excrement and dispose of it.
According to the team behind the study, there’s a possibility for the plastic-filled poop to one day be used as a biofuel, due to its carbon-rich consistency. In the field trials, the team uses nets with receptacles underneath to collect the waste, so that the plastic pieces don’t sink to the bottom of the ocean floor.