In a world of fish-eating fish, microplastics are a confusing issue. These tiny plastic particles are eaten by small fish, which are then eaten by larger fish, passing the pollutant up the food chain, to humans.

Scientists know that many microplastics come from the modern, massive use of plastic packaging, which breaks down into small grains that are swallowed at sea. A source not previously considered is synthetic rope used by many maritime vessels, including boats. fishing.

It is found to contribute “substantial amount of microplastic contamination” to the environment, report researchers from the International Marine Litter Research Unit at the University of Plymouth in England. Published in the peer-reviewed journal Total environmental science, a new study shows that aging plastic ropes and nets are a major source of this pollution, reports Ben Coxworth of New Atlas.

Researchers have found that new and one-year-old synthetic ropes can release about 20 fragments of microplastic for every meter carried in the ocean, and that number increases exponentially with older equipment. Two-year-old ropes emit 720 fragments per meter while ten-year-old ties can lose 760 units per meter, reports Technological networks.

According to the report, fishing vessels use around 220 meters of rope during a typical haul. Based on a careful 50-yard line, the researchers estimate that a new string can release up to 2,000 microplastic fragments each time, while the old string could reach levels of 40,000 units.

“For centuries, most everyday items, including ropes and nets used in the maritime industry, have been produced using natural resources,” said study co-author. Richard Thompson, professor at the University of Plymouth, in a statement. “However, the large-scale increase in plastic production since the 1950s has resulted in the gradual replacement of plastics with their natural counterparts. The durability of plastic, however, has created a major environmental challenge once items reach the end of their shelf life or, as in this study, when they dispose of microplastics.

For the study, the researchers conducted laboratory simulations and field experiments. Estimates were based on hauling a weight of 5.5 pounds on a 50 yard rope. Senior scientist Imogen Napper, a postdoctoral researcher at the university, warned that these numbers are considerably lower than what would be used on real fishing boats.

“Most maritime activities would carry much heavier loads, creating more friction and potentially more fragments,” she said in a statement. “It highlights the urgent need for standards on the maintenance, replacement and recycling of ropes in the maritime industry. However, it also shows the importance of continuous innovation in the design of synthetic ropes with the specific aim of reducing microplastic emissions.

The researchers used the UK fishing fleet of around 4,500 active vessels as the basis for this study. Based on that total, they estimate that 326 million to 17 billion pieces of microplastic could enter the ocean each year from this source alone, according to a press release from the University of Plymouth.

“A greater appreciation of the issues within society at large is starting to make a difference,” Thompson concludes in the statement. “However, this study highlights a previously unquantified but substantial source of microplastics and strengthens the level of collaboration required to achieve lasting and positive change.”