A reduction in the number of plastic bags found in seabeds around the United Kingdom suggests that initiatives to deal with this kind of pollution are working, a new study has found.
"We observed sharp declines in the percentage of plastic bags as captured by fishing nets trawling the seafloor around the U.K. compared to 2010," Thomas Maes, co-author of the study, said in a statement, "and this research suggests that by working together we can reduce, reuse and recycle to tackle the marine litter problem."
There has, however, been an uptick in fishing debris in the same waters, the 25-year study found. The levels of other forms of plastic, deep-sea litter remained constant across the survey period.
Paying for plastic bags
The study, conducted by the U.K.'s Center for Environment, Fisheries and Aquaculture Science (Cefas) and published in the journal Science of The Total Environment, analyzed data from 1992 to 2017 from 2,461 trawls from 39 boats that trawled for plastics in the Celtic Sea and the Greater North Sea. While 63 percent of the trawls contained some form of plastic litter, the levels of such litter began to decline after 2010, culminating in a 30 percent reduction in plastic litter compared to the pre-2010 levels.
A number of factors could be responsible for the decline, according to Maes' team, including manufacturing changes in the bags themselves that results in them breaking down more quickly, changes in water flows and a 5-pence charge on plastic bags England introduced in October 2015.
England was the last country in the U.K. to introduce such a levy on plastic bags, with Wales rolling out its levy in October 2011, Northern Ireland in April 2013 and Scotland in October 2014. Each also charges 5 pence for a single-use plastic bag. Since the fee was instated, England's plastic bag use has dropped by 85 percent.
British Prime Minister Theresa May made reducing plastic waste, like bags and cups, part of a "national plan of action" earlier this year. Part of that plan included extending the 5-pence charge to all retailers as opposed to those with more than 250 employees, which is the current regulation.
Other attempts to combat plastic in England have been less successful. A so-called "latte levy" that would have imposed a 25-pence charge on to-go cups didn't get government backing, and a deposit return plan for plastic bottles proposed in December 2017 has yet to be implemented.
What about other plastics?
Plastic washes up a beach in Branscombe, England. Levels of plastic waste on the seafloor have improved since this photo was taken in 2008, but there's still work to be done. (Photo: Matt Cardy/Getty Images)
This study gives credence to the need for other solutions. Plastic bags were the only form of pollution that saw a decline. Plastic bottles held steady. Plastic sheeting used in packaging saw an uptick in all regions.
Fishing gear, including lines, cables and crates, also saw an increased presence. Other fishing accoutrements, like nets and lines, remained constant. The study's authors propose that the North Sea's busy shipping traffic and international fishing grounds could be in part responsible for this "abundance of litter."
But the researchers caution that it's "difficult to make firm conclusions in relation to marine litter" thanks to the variety of factors involved, including the decline in plastic bags. They cite, as an example, that the strong water flows of the English Channel may be pushing litter out of the channel itself before it can be observed there.
The researcher further suggest that the amount of litter found in the seabed, between the flows of water and other reasons, is not static, and they encourage international cooperation and data sharing among countries that share sea borders so that pollution detection can improve.