Japanese researchers have confirmed that tiny plastic marine debris has spread to the Southern Ocean, posing a threat to the Antarctic ecosystem, the Environment Ministry announced.

“The findings indicate that contamination has spread globally,” said Tadashi Tokai, a professor of marine resource study at the Tokyo University of Marine Science and Technology, who is a member of the team. “What is important is to proceed with measures to prevent discarded plastics from leaking into the sea while urging states to take countermeasures against it based on the latest data.”

According to the ministry’s Sept. 26 announcement, scientists from Kyushu University and the Tokyo University of Marine Science and Technology surveyed the Antarctic Ocean by trawling a net with a vessel and found 44 pelagic microplastics--tiny pieces of plastic measuring 5 millimeters or less--at five locations.

Based on the number of microplastics found in the sample locations, wind speed and other factors, they estimated that 286,000 microplastics per square kilometer exist at the most contaminated areas in the ocean.

Pelagic microplastics are generated when plastic bottles and bags floating in the seas or elsewhere are degraded and broken down into tiny pieces. The contaminant easily absorbs hazardous substances and is difficult to decompose.

There are concerns that if microplastics are consumed by fish there could be damaging effects to ocean ecosystems. The latest survey was conducted as part of efforts to study waters that are less likely to be affected by human activities.