Discovered in the late eighties, the Great Pacific Garbage Patch is a floating farrago of ocean debris, made up of tens of thousands of tons of plastic, mostly abandoned fishing devices, including nets and other commercial shipping gear.
Published Thursday in the journal ‘Scientific Reports,’ a recent study conducted by scientists at the Ocean Cleanup Foundation has revealed that the Great Pacific Garbage Patch, also known as the Pacific Trash Vortex, has some 80,000 metric tons of marine trash – 16 times more than earlier estimates.
Six universities and an aerial sensor company also took part in the survey, which utilized 30 vessels to traverse the patch, in addition to an aircraft equipped with advanced sensors for 3D mapping of the floating trash trove.
The study shows that abandoned fishing nets, also referred to as ghost nets, account for 46 percent of the overall tonnage, with about 20 percent of the total floating trash mass believed to be debris from the 2011 Japanese tsunami.
The rest is an assortment of other commercial fishing gear, including eel traps, oyster spacers, crates, ropes and baskets.
An estimated 1.8 trillion pieces of plastic of varying sizes make up the 1.6 million-square-kilometer trash vortex, out of which 94 percent are microplastics, which actually works out to just 8 percent of the entire mass.
“We were surprised by the amount of large plastic objects we encountered,” the expeditions’ chief scientist Dr. Julia Reisser said in a statement.
“We used to think most of the debris consists of small fragments, but this new analysis shines a new light on the scope of the debris.”
It must be mentioned that some 100,000 marine animals, including whales, seals, and turtles fall prey to ocean plastics, year after year.
“The prevalence of ghost nets and discarded fishing gear is well documented, so this is not necessarily surprising,” said Angelicque White, an oceanographer at Oregon State University, who was not part of the research team.
“But the authors have done an excellent job of using a variety of survey methods to quantify this debris,” White added.
Ironically, it is consumer stuff like plastics bottles or packaging plastics that draw much of the headlines today with little or no attention given to the offending fishing industry, observes George Leonard, chief scientist at the Ocean Conservancy.
“The interesting piece is that at least half of what they’re finding is not consumer plastics, which are central to much of the current debate, but fishing gear,” he said.
“This study is confirmation that we know abandoned and lost gear is an important source of mortality for a whole host of animals and we need to broaden the plastic conversation to make sure we solve this wedge of the problem,” he added.
Laurent Lebreton, an oceanographer with the Ocean Cleanup Foundation and lead author of the study, said that the percentage of fishing gear found was way more than what the research team had bargained for.
“I knew there would be a lot of fishing gear, but 46 percent was unexpectedly high,” Lebreton said. “Initially, we thought fishing gear would be more in the 20 percent range. That is the accepted number [for marine debris] globally—20 percent from fishing sources and 80 percent from land.”
Britta Denise Hardesty – principal research scientist for the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia – who wasn’t a part of the new study group, says that the findings may show that ghost nets account for nearly half of the total tonnage of the patch, but there are other factors that need to be considered as well.
“It’s not fair to just blame it on the fishermen or the top 20 countries for mismanaging waste,” said Hardesty. “Instead we need to look at the true value and cost of plastics, and factor in the costs of livelihood and tourism.”
An earlier study published in the journal Marine Policy last October, which Hardesty was actually part of, also discovered that fishing gear was a major contributor to this massive gyre of plastic pollutants. An estimated 600,000-plus tons of fishing paraphernalia is lost to the oceans every year.
“One thing that has been increasing over time, really, is plastic consumption on a global scale,” Lebreton correctly notes. “We are using more and more plastic in our societies. I think without the help of proper waste management infrastructures, we can expect more and more plastic to be released into the environment in general, and down the line into the marine environment.”
The good thing is that Boyan Slat, the Dutch founder of Ocean Cleanup Foundation and co-author of the study, is set to launch a $32-million clean operation sometime later this year.
The massive operation will involve the deployment of “long floating screens” that will serve as an artificial coastline, allowing the ocean currents to bring the debris to it, instead of chasing the plastic with vessels and nets – an almost impossible task considering the time and money it would entail.
If all goes according to plan, Ocean Cleanup is expected to remove half of the Great Pacific Garbage Patch in a matter of five years, which, if achieved, is pretty impressive, considering the mammoth scale of the operation.