Together with colleagues from the Alfred Wegener Institute and the Johann Heinrich von Thünen Institute, Senckenberg scientists Serena Abel and Angelika Brandt examined sediment samples from the Kuril-Kamchatka Trench for the presence of microplastics. In their study, which was recently published in Environmental Pollution, the researchers show that 1 kilogram of sediment contains between 14 and 209 microplastic particles. Overall, the team was able to document 15 different types of plastics in the samples.

Overall, the research team identified 15 different types of plastics in the samples. All sediments contained polypropylene, a standard plastic commonly used in packaging materials. In addition, 75 percent of the samples contained polyethylene, and about 63 percent contained polyester. “All microplastic particles showed sizes below 375 micrometers, and the vast majority were smaller than 125 micrometers, i.e., about one-eighth of a millimeter,” adds the marine researcher from Frankfurt.

The scientists were able to discover the minute microplastic particles by means of the so-called Micro-FTIR method, a special variant of a spectrometer.

“We do not know exactly how much plastic is present in the deep sea; however, our results show that the trenches on the ocean floor, in particular, can serve as plastic sinks. Global estimates of the incidence of microplastics in our oceans indicate that there must be a portion that exists outside the water column and is missing from these estimates. The accumulation of microplastics in these areas could represent this ‘missing’ share,” says Brandt in conclusion. “Microplastics in the deep sea also mean that the basis of the food chain is affected, since many invertebrates feed on sediments, including the microplastic particles. Therefore, future generations unfortunately will have to deal with the consequences of today’s environmental pollution for a long time to come.”