Microplastics Discovered in the World's Deep Seas: Four Billion Fibers Litter Each Square Kilometer

Microplastics in the world's oceans are on the rise and now, it seems as if even the deep sea isn't safe. Scientists have found that about four billion microscopic plastic fibers could be littering each square kilometer of deep sea sediment around the world.

Plastic is swept into the ocean by rivers, runoff and even just dumping. Because it takes so long for plastic to degrade, its presence has greatly impacted wildlife, tourism and shipping. While monitoring for these plastics has increased, though, it seems as if their concentration hasn't increased at the sea surface or along shorelines. So where is the plastic going?

"The puzzle for marine scientists has been to establish where plastic debris is going," said Lucy Woodall, one of the researchers, in a news release. "Part of the answer is that much of this waste is breaking down into fibers invisible to the naked eye and sinking to the sea floor. It is alarming to find such high levels of contamination, especially when the full effect of these plastics on the delicate balance of deep sea ecosystems is unknown."

In order to assess exactly how much plastic might be present, the researchers focused on deep-sea sediment and coral samples from 16 sites in the Mediterranean Sea, Atlantic and Indian Oceans. In the end, they found that

"The deep sea habitat extends to more than 300 million square kilometers globally, so the discovery of previously under-reported microplastics suggests there may be even greater accumulation than was previously suspected," said Richard Thompson, one of the researchers. "A range of shallow water organisms are known to ingest microplastics, and the extent of their harmful effects will likely be influenced by their relative abundance. The discovery of substantial quantites in deep-sea sediments is of considerable relevance to our understanding of the potential of these particles to cause harm in the marine environment."

In fact, the researchers found that microplastics were abundant in all samples. Rayon contributed to about 56.9 percent of the total fibers, with polyester, polyamides, acetate and acrylic among the others.

The findings reveal that plastics are present even in the deep ocean. This could have major impacts on deep sea life. That said, more studies need to be conducted in order to find out exactly what these impacts might be.