Scientists create biodegradable shoes that sea creatures can eat

By Pol Allingham via SWNS

Scientists have developed shoes that biodegrade in seawater enough for sea creatures to eat them.

They say that the replacement for plastic could tackle pollution plaguing the world’s oceans by degrading enough to become consumed by sea life.

Footwear is an important focus-point - shoes make up a huge percentage of plastic waste in the world’s water and landfill, and plastic-based flip-flops are the world’s most popular shoe.

Currently, plastic polluting our seas never degrade and instead break up into smaller and smaller particles until they become microplastics that live on for centuries.

But an interdisciplinary team at University of California San Diego have created materials that start to degrade after just four weeks.

To test their new creation in the water the group met up in an aquarium with marine biologist and scientific diver Samantha Clements at Scripps Institution of Oceanography.

They took biodegradable polyurethane materials they had previously developed to biodegrade in land-based composts - which have already been turned into the first biodegradable shoes available to buy, from their spinoff company Blueview.

Working at the Ellen Browning Scripps Memorial Pier and Experimental Aquarium allowed them to trial the biodegradable polyurethane materials in an ecosystem near the shore, a classic environment for rogue plastics to gather.

The group discovered all sorts of marine organisms colonized on the polyurethane foam and biodegrade the material back to their original chemicals, which are then consumed as nutrients by the same microorganisms in the ocean.

Data in the study published in the journal Science of the Total Environment reveals a mixture of bacteria and fungi form the microorganisms living throughout the natural marine environment.

“No single discipline can address these universal environmental problems but we’ve developed an integrated solution that works on land—and now we know also biodegrades in the ocean," said UC San Diego biologist Stephen Mayfield is who worked on the study.

“I was surprised to see just how many organisms colonize on these foams in the ocean. It becomes something like a microbial reef.

“We’ve shown that it’s absolutely possible to make high performance plastic products that also can degrade in the ocean.

“Plastics should not be going into the ocean in the first place, but if they do, this material becomes food for microorganisms and not plastic trash and microplastics that harm aquatic life.”

In an interdisciplinary collaboration the group of experts from biology, polymer, and synthetic chemistry, and marine science tracked the samples and found the material began to degrade after just four weeks in the sea.

After that, the researchers identified the microorganisms from six sites across San Diego that are capable of breaking down and eating the material.

In 2010 researchers estimated 8 billion kilograms of plastic end up in the ocean each year, and a steep rise is predicted by 2025.

When it enters the water plastic waste disrupts marine ecosystems and migrates together to form giant mounds of trash, such as the 1.6 million square kilometer Great Pacific Garbage Patch.