Research conducted by UFZ has revealed the presence of microplastics in remote marine protected areas. Once plastic enters the ocean, it slowly breaks down into smaller pieces through weathering and decomposition. These small particles, if consumed by marine creatures, can significantly harm their health. Therefore, large accumulations of plastic can disrupt the biological balance of marine ecosystems. So which areas were particularly affected?

In a recent study, a research team from the Helmholtz Center for Environmental Research (UFZ) in collaboration with the Alfred Wegener Institute (AWI) found large amounts of plastic waste and microplastics in a remote marine protected area in the Pacific Ocean. These amounts were similar to those found in one of the world’s largest known landfills. Researchers emphasize that plastic is much more common than expected.

The entire ocean ecosystem is under threat. Therefore, they are calling for an end to the global release of plastic into the oceans as soon as possible. The study was published on: Environmental Science and Technology.

Scope of the problem and research results

“Plastic in the ocean is a serious problem. Every year millions of tonnes of plastic enter and remain in the oceans through rivers and wind, as well as shipping and fishing. The consequences for the ocean ecosystem are still difficult to assess,” says UFZ environmental chemist Professor Annika Jahnke, coordinator of the MICRO-FATE project, which made the study possible. .

What is the distribution of plastics in the oceans? Which areas were particularly affected? Are there plastic-free zones? So what properties does plastic have near the source or far from the open ocean? Jahnke and his research team explored these questions.

During a five-week expedition aboard the German research vessel Sonne in 2019, researchers sampled surface waters in the North Pacific Ocean between Vancouver, Canada, and Singapore. The team selected sampling stations along the cruise path based on the University of Hawaii’s predictive model of surface currents from a diagnostic model (SCUD). This model calculates the amount of plastic likely to be in a given marine area.

“We chose stations with predicted high and low plastic loads for our studies,” says Jahnke. “Some of the stations were located in previously well-explored areas, such as the Great Pacific Garbage Patch. We also wanted to explore largely unexplored areas in the open ocean. For example, we sampled from a marine sanctuary in northwest Hawaii, the Papahanaumokuakea Marine National Monument.”

The team used two different methods to measure the amount of plastic in surface water. The first was a wreck survey in which teams of two scientists aboard Zonne counted plastic objects visible to the naked eye as the ship passed and documented their shapes and sizes. The second involved neutron networks pulled to the surface to collect samples from nine stations.

“The size of the hole was 0.3 millimeters. This allowed us to collect not only large objects but also small plastic particles to quantify microplastics less than five millimeters in diameter,” says UFZ researcher Robbie Reinek, lead author of the study. “The plastic particles in each sample were sorted and counted by size. We then used a special form of infrared spectroscopy to chemically analyze the particles and assess their weathering state based on their appearance.”

The longer plastic is exposed to sun, wind, waves and seawater, the more it weathers and deteriorates. Other studies have shown that larger plastic fragments and undecomposed particles mostly form where plastic washes into the sea. The further the particles are transported, the more they are exposed to weathering and the finer they become.

“This is exactly what we showed in our research. And as expected, we found the highest amounts of plastic in samples taken from the area known as the Great Pacific Garbage Patch,” says Rynek. “But the objects in no way form a plastic carpet that covers the entire surface. This is important when we are talking about plastic removal technologies that need to cover very large areas to collect significant amounts of plastic. Co-author Dr. Melanie Bergmann from AWI explains that most of the plastic is small pieces that slip through the nets or simply It can be harvested through significant “bycatch” of animals, which is why reducing plastic emissions is so important, he says.

Implications and future directions

“The most surprising, and also most alarming, result of our study is that we found similarly large amounts of extremely small microplastics in a remote marine protected area in northwestern Hawaii. We did not expect this. According to the prediction model’s calculations, there should be much less plastic in this area,” says Rynek.

“Most likely microplastics are much more dispersed in the oceans than previously thought. In fact, we found plastic at all our sampling stations. There were no samples without plastic. So we cannot assume that plastic is causing problems mainly in known accumulation areas; the problem is much larger and actually affects the entire ocean ecosystem,” says Jahnke .

This year, UN member states plan to adopt a legally binding global plastic agreement to stop plastic pollution in the oceans. “As independent scientists, we are part of the Coalition of Scientists for an Effective Plastics Pact to make recommendations to UN member state delegates,” says Bergmann.

In addition to significantly reducing plastic production by avoiding unnecessary plastic products and promoting reuse systems, many researchers believe that the chemistry of plastic products should be simplified and improved. This is the only way to ensure safe reuse and higher recycling rates.