Science ship documents plastic debris near Greenland; northern Europe eyed as source
Scientists aboard a German research vessel say they’ve started documenting plastic debris on the surface of the Arctic Ocean, creating new problems for marine life in the environmentally sensitive region.
Plastic has already been reported from stomachs of resident seabirds and Greenland sharks. The plastic litter reported from the Fram Strait could be leaking from a new garbage patch forming in the Barents Sea, the researchers concluded in their study, published in the scientific journal Polar Biology.
The scientists said it remains unclear how the litter made it so far north. They documented the pollution as the research icebreaker Polarstern traveled through the Fram Strait, the area between East Greenland and Svalbard in July 2012.
Altogether the “litter watch” spotted 31 pieces of litter along the the 5,600-kilometer route. Although this number may sound low, it confirms that there is indeed litter floating in the remote Arctic Ocean.
“Since we conducted our surveys from the bridge, 18 metres above sea level, and from a helicopter, we were only able to spot the larger pieces of litter. Therefore, our numbers are probably an underestimate,” said marine biologist Dr. Melanie Bergmann, with the Alfred Wegener Institute. It is well-known that, with time, plastic breaks down into small fragments at sea, which can only be detected properly by analysis of net tows.
The sixth patch in the Barents Sea is most likely in the early stages of formation. Bergmann believes it may be fed by the densely populated coastal regions of Northern Europe.
“It is conceivable that part of that litter then drifts even farther to the north and northwest, and reaches the Fram Strait,” Bergman said. “Another cause for litter in the Arctic could be the retreat of the Arctic sea ice. As a result more and more cruise liners and fish trawlers are operating further north, following the cod. Most likely, litter from the ships intentionally or accidentally ends up in the waters of the Arctic. We expect this trend to continue,” she added.
In a previous study, Bergmann analysed photographs from the deep Arctic seafloor for signs of plastic, glass and other types of litter, concluding that the amount litter in the deep sea has doubled in the last 10 years, with densities in a similar range to those from southern Europe.
In fact, the litter density on the deep seafloor of the Fram Strait is 10 to 100 times higher than at the sea surface.
“On the deep Arctic seafloor, we found an average of 2.2 to 18.4 pieces of litter per kilometre of our route. This indicates that the deep seafloor may be the ultimate sink for marine litter,” Bergmann suggested.
The litter floating in the Arctic is particularly detrimental to seabirds, which feed at the sea surface. A recent study from the nearby Isfjorden fjord on Spitsbergen showed that 88 percent of the northern fulmars examined had swallowed plastic. These birds spend their entire life at sea. Even Greenland sharks are swallowing plastic litter: Researchers found plastic litter in the stomachs of up to eight percent of the sharks caught south of Greenland.
Bergmann said the litter data for her latest study were collected in the course of a study on marine mammals and seabirds on board of RV Polarstern.
“We just took advantage of these surveys to count marine litter.” Scientists refer to chances such as this one, where valuable scientific data is gathered during expeditions of a different purpose, as “ships of opportunity”. “Since it’s reasonably easy to count litter from a ship in motion, it makes sense to use ‘ships of opportunity’ more often in the future to help us to learn more about the global distribution of floating litter, especially in remote areas. This could be done during patrol flights and voyages with research ships, cruise ships, coast guard, merchant and fishing vessels,” Bergmann said.