More than any other time in history, the salty water of our oceans is littered with millions of bits of plastic waste. These non-biodegradable scourges often become torn and consumed by marine creatures, working their way up the food chain.
This misfortune has spread to nearly every corner of our oceans, turning once pristine ecosystems into habitats mottled with microplastics. Now, it seems a tiny type of amphipod is making matters worse.
A team from the University of Plymouth, UK, found that the creature can shred a single-use plastic bag into around 1.75 million microscopic fragments. Yes, you read that right – the tiny crustacean unwittingly breaks the bag down into millions of fragments no larger than a grain of rice, between 0.3 and 5 millimeters thick. This is worrisome as already at least 51 trillion microplastic particles float in our oceans, according to the UN.
The crustacean, officially called Orchestia gammarellus, is native to the coasts of northern and western Europe. It grows to a whopping 1.8 centimeters (0.7 inches), but its diminutive size belies its impact. The team warn that its behavior may also not be a one-off, since a “variety of other organisms also have the potential to shred plastic”.
The study, published in Marine Pollution Bulletin, notes that when the plastic was covered in biofilm, a natural matter that builds up on the surface, the critters tore at it four times faster. This suggests the amphipod’s act is the result of feeding behavior, or at least an attempt to do so.
Enticed as many marine dwellers are by the plastic bags, the crustacean tears and stretches the plastic, with debris found in and near their fecal matter. To make matters worse, laboratory and shoreline monitoring suggest that the type of plastic had no influence on whether the mini denizens ate the rubbish – conventional, degradable, and non-biodegradable waste were all up for grabs.
“Amphipods play an important role in the breakdown of organic matter on the shoreline and in the organization of benthic marine communities in temperate regions worldwide,” write the authors. “Estimates suggest that up to 70 percent of plastic debris settles onto the benthos with significant accumulations in intertidal habitats worldwide. Therefore, detritivores such as amphipods are likely to regularly come into contact with plastic debris.”
Around 120 million tonnes (132 million US tons) of single-use plastic items are produced each year, with much ending up in our oceans. Every year, around 8 million tonnes (8.8 million US tons) of plastic litter our oceans.
We already know that sea turtles often mistake plastic bags for jellyfish, birds can become strangled by debris rings, plastics can pierce an animal’s stomach lining, and whales have been found with their stomachs filled with plastic bags rather than proper food.
To help combat some of this, England implemented a 5p charge for all single-use bags a few years ago. This reduced sales by more than 85 percent in the first six months, and has resulted in more than 9 billion fewer bags since its introduction. To truly turn things around, however, more needs to be done.
Plastics “already represent a potential hazard to marine life, but this research shows species might also be contributing to the spread of such debris,” said Richard Thompson, a marine biology professor from the University of Plymouth, in a statement. “It further demonstrates that marine litter is not only an aesthetic problem but has the potential to cause more serious and persistent environmental damage.”