Marine plastic pollution is a problem with a far reaching consequences. We are likely familiar with the heart-wrenching image of a marine turtle having a plastic straw removed from its nose, but recent research reveals that plastic pollution in our ocean has sunk to a new low. The current record for how deep plastic debris is found in the ocean? A plastic bag found 10,898m deep in the Mariana Trench.

This was just one of the findings from a recent study published on April 2018 in the journal Marine Policy, which investigated the nature of deep-sea debris. Researchers at The Global Oceanographic Data Center (GODAC) of the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) carefully analyzed archived photographs and videos of deep sea debris that were collected by deep-sea submersibles and remotely operated vehicles. By looking at data from over 5000 dives since 1983, the researchers found that plastic formed the majority (33%, to be exact) of all the deep sea debris items recorded. The type of plastic they found is also notable – 89% of deep sea plastic debris they observed was from single-use products.

Plastic debris detected on the sea bottom at the Mariana Trench published in the study, from the JAMSTEC Deep-sea Debris Database (http://www.godac.jamstec.go.jp/dsdebris/e/).

These study findings run contrary to our perceptions of single-use plastics being lightweight and buoyant. Evidence of plastic debris was found for the first time in the hadal zone – the deepest region of the ocean. This zone is the part of the ocean that is beyond 6000m deep, and usually lies within oceanic trenches. In fact, the study found that plastic debris dominates relative to other waste types in the hadal zone.

Plastic debris was also found entangled with deep-sea ecological communities. 17% of images analyzed showed debris intertwined with at least one other organism. The presence of plastic debris amongst some of the most inaccessible ecosystems in the world should raise alarm bells. These wonders of the deep are teeming with life such as shrimp, tubeworms and anemones, and scientists are only just beginning to uncover its mysteries and sheer diversity. But the study found deep-sea organisms such as anemones attached to plastic bags on the muddy sea floor – we might not always like what we unearth.

Plastic debris alters deep-sea marine habitats for the long term. Given that there is little UV light and turbulence in the deep parts of the ocean, deep-sea plastic debris is estimated to remain for hundreds of years before being broken down. Beyond the potential chemical pollution from plastic disintegration, plastic can also act as a hard surface on which organisms might latch on to. This can potentially and permanently disrupt sensitive deep-sea ecosystems, as these deep sea critters might now make their home wherever plastic is available.

These findings shed new light on the relationship between land-based human activity and the deepest parts of the ocean. This only adds urgency to calls for stronger regulatory action against single-use plastics. It is estimated that more than 250,000 tons of plastic are currently in the world’s oceans, and that coastal countries generate around 275 million metric tons of plastic waste annually. With plastics being found in areas more than 1000 km off the coast of the mainland, it is clear that an international effort is needed to monitor and regulate both the production and disposal of plastics.