DEN HELDER, The Netherlands -- Marine plastic pollution now commands worldwide attention. This wasn't the case 40 years ago, but Jan van Franeker, a young oceanic biologist at the time, began finding ominous signs of pollution in the bodies of northern fulmar birds back then while studying their evolutionary process.
Van Franeker, now 64, continues his research at the Wageningen Marine Research Institute here atop a peninsula jutting into the Northern Sea. It was back in the late 1970s that he noticed something strange: There were often pieces of plastic in the seabirds' bodies.
The birds were provided by his research colleagues who were trying to find the impact of oil pollution on the species. They agreed that Van Franeker would dissect the birds to see if oil was found in their bodies. "Occasionally, I did find some oil, but much more plastic," said the researcher.
Van Franeker began to record every foreign object he found in northern fulmars. As the records piled up, his concerns about plastic pollution deepened. It was in 1985 that Van Franeker published the results of his research, pointing out that the birds took in a "considerable" amount of plastics, and that their intake included poisonous materials. Similar research results warned about abnormal changes occurring in seabirds.
Now 93 percent of northern fulmars in the North Sea have plastic in their bodies, according to a study by Van Franeker and his colleagues of 525 of the birds from 2010 through 2014. Some 58 percent of sampled birds had taken in 0.1 grams or more. Pushing this ratio down to 10 percent or less is the goal of the signatories to the OSPAR Convention, designed to protect the marine environment of the Northeast Atlantic.
Northern fulmars fly near the sea surface and eat fish. They are thought to take in floating plastic waste or plastics eaten mistakenly by fish. The average amount of the material found in a bird's body is 0.31 grams. Much of the plastics originate in plastic products that have become unidentifiable after breaking into tiny pieces, or pellets for industrial purposes.
"If one imagines a northern fulmar of the size of a human, the plastics it takes in is about this amount," says Van Franeker, showing a lunch box-sized container filled with plastics.
-- Plastic pollution extends to arctic regions
In September 2015, Australia's Commonwealth Scientific and Industrial Research Organisation and other bodies published the results of a study in the Proceedings of National Academy of Sciences, a leading American scientific journal. It warned that 99 percent of seabirds in the world could possibly take in plastic waste by 2050.
The study was based on research on the eating habits of seabirds since the mid-1960s. Using the data, the researchers estimated the impact of marine plastic pollution on the global environment.
In the early 1960s, less than 5 percent of marine birds took in plastics; by the mid-2010s, the proportion is estimated to have shot up to nearly 90 percent. During the period, world plastic production ballooned twentyfold, and plastic products including items for one-time uses such as wrapping spread into the daily lives of ordinary people. Plastic products that drift into the oceans are broken into pieces by the movement of waves or sunlight, but they never vanish and continue to float on the water.
The study revealed that the southern hemisphere had suffered greater damage compared to the north. The researchers don't know how many of the birds died because of plastic intake. In one extreme case, waste weighing 8 percent of the weight of a seabird was found inside its body. This amounts to 5 kilograms in a human weighing 62 kilograms.
The Arctic Sea, despite its pristine image, is among the waters affected by plastic pollution. According to Susanne Kuhn, 31, a research associate with Van Franeker and a specialist on fish species in the Arctic Sea, two out of 72 young polar cod, or 2.8 percent of the total, were found to have microplastics in their bodies. Plastic fibers were excluded from the finding as they drift in the air and could have mistakenly become mixed up with the samples.
Polar cod, which lay eggs under the sea ice, are considered to be an important yardstick in judging the impact of plastic pollution on the Arctic Sea ecosystem. Kuhn said that 2.8 percent might not seem like a lot, but pointed out that the figure really should be zero.
Other research efforts have shed light on plastic pollution in the Arctic Sea. In April this year, a research team at the Alfred Wegener Institute, which leads a German study of the Arctic, reported that up to 12,000 pieces of microplastics had been found in one liter of sea ice taken from the Arctic Sea by a research vessel.
According to study results published in the British scientific journal Nature Communications, the count was two to three times higher than past counts since 2005. The plastics included materials for food wrappings and cigarette filters while parts of fishing equipment and fishing boat paints were identified, leading the research team to estimate that fishing activities in the Arctic Sea were partially responsible for the pollution.
Nearly 70 percent of the detected plastic pieces were no bigger than 50 micrometers -- one-twentieth of a millimeter -- in diameter. Their size makes them easier to be absorbed by crabs and shrimps or small animals, says the research team. Ice in the Arctic Sea is melting due to global warming, and as this happens and the ice moves, researchers fear more plastic pieces will be released into the sea.
(Japanese original by Kosuke Hatta, Brussels Bureau)