‘Worrying’ Remote Ocean Plastics Study Troubles Scientists

When you think of plastic in the oceans, you might think of the Pacific Garbage Patch being the worst of our problems.

However, it turns out there are many more areas of pollution throughout the Pacific that contain just as much plastic and are therefore just as much of an issue, a new paper in the journal Environmental Science & Technology reveals.

There are large numbers of plastic waste and microplastics gathered across the Pacific, including in a remote marine protected area northwest of Hawaii known as Papahānaumokuākea Marine National Monument, indicating that plastic might be more distributed in the oceans than we first thought.

“Plastics in the ocean are a serious problem. Every year, millions of tons of plastics end up in the ocean via rivers and wind as well as from shipping and fishing—and it remains there. It is still difficult to assess the consequences for the ocean ecosystem,” study author Annika Jahnke, an environmental chemistry professor at the Helmholtz Centre for Environmental Research (UFZ) said in a statement.

Plastic pollution can harm marine life through ingestion and entanglement, as many marine animals mistake plastic debris for food, leading to internal blockages, starvation, and death. Additionally, animals such as sea turtles, dolphins, and seabirds can become entangled in plastic debris, causing injuries, drowning, or hindering their ability to hunt for food. Ocean plastics can also disrupt entire ecosystems, smothering coral reefs and introducing non-biodegradable materials and toxic chemicals.

To worsen matters, the longer plastic pollution is exposed to the elements at sea, the smaller and smaller it is broken down, becoming microscopic flecks of microplastics. These can be ingested by marine organisms and enter the food chain. As a result, humans who consume seafood may inadvertently ingest these microplastics, potentially exposing themselves to harmful chemicals and toxins associated with plastic pollution.

The paper describes how researchers from the UFZ, in collaboration with the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI), went on a five-week expedition aboard the German research vessel “Sonne” in 2019, where they investigated the levels of plastics floating on the surface of the North Pacific Ocean between Vancouver and Singapore.

The researchers sampled the water at several locations and used a model to predict how many plastics were likely to be present in a given area of ocean based on their measurements.

“We selected stations with predicted high and low plastic loads for our investigations,” said Jahnke. “Some stations were located in areas that had already been well researched, such as the so-called Great Pacific Garbage Patch. We also wanted to investigate zones in the open ocean that had hardly been explored. For example, we took samples in a marine reserve northwest of Hawaii, the Papahānaumokuākea Marine National Monument.”

They used both naked-eye observations of the ocean surface and neuston net samples of the water, where they could count the plastic contents.

“The mesh size was 0.3 millimeters. This allowed us to collect not only larger items but also small plastic particles to determine the amount of microplastics, which are less than five millimeters in diameter,” study author UFZ researcher Robby Rynek said in the statement. “The plastic particles from each sample were sorted by size and counted. We then used a special form of infrared spectroscopy to chemically analyze the particles and estimate their weathering state based on their appearance.”

They found the most plastic in the water in the Great Pacific Garbage Patch—but also a significant amount in other regions, including protected marine reserves.

“This is exactly what we showed with our investigations. And as expected, we found the highest quantities of plastics in the samples we took in the area known as the Great Pacific Garbage Patch,” says Rynek.

“The most surprising and, at the same time, most worrying result of our study is that we found equally large quantities of particularly small microplastics in the remote marine protected area north-west of Hawaii. We hadn’t expected that. According to the calculations of the forecast model, there should be considerably less plastics in this area,” Rynek explained.

The Great Pacific Garbage Patch is located across several sites in the Pacific, formed by ocean currents. Some reports claim that the patch may be over twice the area of Texas, though the exact size and bounds of the patch remain unclear.

Unfortunately for efforts to remove the plastic, much of the plastic found in the oceans by the expedition is extremely spread out, not clustered together

“However, the items do not in any way form a carpet of plastic that covers an entire surface in a dense manner. This is important when thinking about plastic removal technologies, which would have to cover vast areas in order to be able to collect significant amounts of plastic. Most plastics are small fragments that escape nets or which can only be collected with considerable animal ‘by-catch,'” co-author Melanie Bergmann of the AWI said in the statement.

Many of the plastics were tiny microplastics, making it even harder to remove the pollution from the waters.

“Microplastics are most likely distributed much further across the oceans than previously assumed. We actually found plastics at all of our sampling stations. There were no samples without plastics. So, we can’t assume that plastics are causing problems mainly in the known accumulation areas—the problem is much bigger and actually affects the entire ocean ecosystem,” said Jahnke.

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