December 19, 2019

Study Finds Ocean Microplastics “Far Outnumber” Previous Estimates

News Source: SDG Knowledge Hub

Author(s): Catherine Benson Wahlén

Researcher at the Scripps Institute of Oceanography have published a study that suggests previous estimates of plastic in the ocean may be “off by five to seven orders of magnitude.” The US National Science Foundation (NSF) provided financial support for the study.

The study developed and tested a new method for collecting and counting tiny microplastics in the ocean. They measured mini-microplastics in the guts of salps, a planktonic species that transports carbon and particles from the sea surface to the deep sea. Every salp the researchers examined had ingested plastic.

The study found much higher concentrations of tiny microplastics in the ocean and suggests that the traditional method for estimating marine microplastics is “likely missing the smallest particles.” The study estimates the ocean contains 8.3 million pieces of mini-microplastics per cubic meter of water. Nearshore samples had higher plastic concentrations than samples from the open ocean.

Despite significant interest in microplastics, “we are just beginning to understand the scale and effects of these ocean contaminants” NSF’s Division of Ocean Sciences program director, Dan Thornhill, observed. He said the study “demonstrates that marine plastics are far more abundant than anyone realized and can be found potentially everywhere in the ocean,” resulting in consequences for the environment and human health.