The world’s largest heap of ocean garbage is growing at an alarming rate.
The 600,000-square-mile collection of ocean plastic and trash floating halfway between California and Hawaii known as the Great Pacific Garbage Patch now contains four to 16 times more plastic than previously estimated, with pollution levels increasing exponentially, new analysis reveals.
It’s estimated some 1.8 trillion pieces of plastic weighing 80,000 metric tons are currently afloat in the area, and it is rapidly getting worse, according to a study published Thursday in the peer-reviewed journal Scientific Reports.
These conclusions are the result of a three-year mapping effort conducted by an international team of scientists affiliated with The Ocean Cleanup Foundation, six universities and an aerial sensor company.
In order to analyze the full extent of the Great Pacific Garbage Patch, researchers crossed the debris field with 30 vessels simultaneously supplemented by two aircraft surveys in what they say is “the most comprehensive sampling effort of the trash patch to date.”
Most vessels were equipped with standard surface sampling nets while the fleet’s mothership, RV Ocean Starr, trawled two six-meter-wide devices, which allowed the team to sample medium- to large-sized objects. To increase the surface area surveyed and to quantify the largest pieces of plastic, a C-130 Hercules aircraft was fitted with advanced sensors to collect multispectral imagery and 3D scans of the ocean garbage.
In total, the fleet collected a total of 1.2 million plastic samples, while the aerial sensors scanned more than 115 square miles of ocean surface.
“We were surprised by the amount of large plastic objects we encountered,” said Dr. Julia Reisser, Chief Scientist of the expeditions.
According to the study, the vast majority (92 percent) of the mass is represented by larger objects while the other 8 percent of the mass is contained in microplastics, defined as pieces smaller than 5 millimeters.
“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,” Dr. Reisser said.
By comparing the amount of microplastics with historical measurements of the garbage patch, researchers discovered that plastic pollution levels have been growing exponentially since measurements began in the 1970s.
“Although it is not possible to draw any firm conclusions on the persistency of plastic pollution in the Great Pacific Garbage Patch yet, this plastic accumulation rate inside the Great Pacific Garbage Patch, which was greater than in the surrounding waters, indicates that the inflow of plastic into the patch continues to exceed the outflow,” said Laurent Lebreton, the study’s lead author.
“These results provide us with key data to develop and test our cleanup technology, but it also underlines the urgency of dealing with the plastic pollution problem,” Slat added. “Since the results indicate that the amount of hazardous microplastics is set to increase more than tenfold if left to fragment, the time to start is now.”