Most of us, and definitely those who are concerned with the marine environment, know about the problem of plastic in our oceans. This debris poses all manner of threats to animals, from accidental ingestion to entanglement. Plastics also release toxins into the water as they degrade. And while large-scale plastic debris, such as the now infamous Great Pacific Garbage Patch, draws headlines, new research indicates that the problem might be much more insidious that we first thought — keep in mind that when small animals consume small pieces of plastic, those animals are in turn eaten by larger animals, until the plastic works its way up the food chain and eventually ends up in human food.
Danish researchers working on the Danish Technological University’s (DTU) Aqua faculty have just published findings from a new plastic research project in the publication Marine Pollution Bulletin. For the first time, scientists have been able to measure and detect plastic down to 1/100 of a millimeter, so-called microplastic, which was previously far too small to be measured. Until now the smallest plastic debris that scientists were able to measure was 0.3 millimeter.
On average, the researchers found one item of plastic per two liters of seawater, and much more during tests conducted closer to shore. The tests were done during 2004, in numerous locations from the Sargasso Sea to the U.S. East Coast. Samples were taken in water up to 20 feet deep.
Professor Torkel Gissel Nielsen of DTU says that new measuring and sampling techniques allowed the researchers to update their findings, and the results are worrying.
“Using special analysis techniques, we’ve deliberately targeted plastic down to 1/100 of a millimeter, and when doing that, a whole new picture emerges,” he says. “Suddenly you see just how ubiquitous plastic is in the oceans. It’s really quite scary.”
One of the primary problems with microplastic, as stated above, is that due to the minute sizes of the pieces, it may enter the food chain as it is consumed by marine animals.
“The smallest pieces of plastic we’ve examined are so small that they have been proven to be absorbed by animal plankton during lab trials,” says Robin Lenz, a research assistant from DTU who has worked on the project. “Because of this, it is realistic to assume that they have already entered the marine food chain.”
But the problem doesn’t end with the plastic itself being consumed; it’s further aggravated by what goes with the plastic.
“A range of other chemicals that find their way into the oceans are able to bind with the plastic,” says Nielsen. “This includes oils, brominated flame retardants and phthalates (such as BPA), used as softening agents in plastic products. That way, microplastic can become little, chemical missiles.”
Microplastic sources can be anything from larger plastic items that have broken down over time to small plastic beads added to cosmetics as exfoliators, which are washed down countless bathroom sinks every day. California recently banned the use of plastic exfoliators in all cosmetic products sold in the state beginning in 2020, a step that other states and nations are urged to emulate. You can help prevent more plastic entering our oceans with choices small and large — don’t buy single-use plastic items or products with microbeads, and when you do buy plastic, make sure it’s recycled properly.