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Study finds that deep ocean dwellers are full of microplastics

Microplastics are everywhere. In our homes, bloodstreams, and even in human placentas. New research shows these pesky plastic particles have even reached the deepest parts of the ocean – and they’re being eaten by sea creatures.

Considering humans have been using non-biodegradable and non-recyclable plastic since the early 60s, there probably isn’t a single part of the planet that hasn’t been touched by fossil-fuel based materials.

Various kinds of plastic have been found everywhere, from the summit of Mount Everest to the most remote parts of our oceans. Pieces sized 5mm or smaller – also known as microplastics – are commonly identified inside the bodies of human adults and newborn babies.

Still, scientists were shocked to find that microplastics can be found in great quantities inside the deepest-dwelling ocean creatures. This is especially the case for animals that stay in the deep and do not migrate up to shallower waters.

Published in Limnology and Oceanography, the study delved deeper into data collected during the DEEPEND deepwater survey of fish and other marine organisms. Looking at the stomach contents of sea creatures, the group found that 29 percent of crustaceans and 26 percent of fish they sampled had eaten at least one microplastic particle.

Surprisingly, animals sampled from 4,000 to 5,000 feet deep had ingested more microplastics than any other group.


What does this tell us?

The authors of the paper describe an ugly truth.

‘These non-migratory organisms, that are thought to remain relatively [stagnant] at depth for their entire life, are being exposed to plastic,’ said postdoctoral Harvard student Ryan Bos.

In other words, you would think these animals – spending all their time at the bottom of the ocean – would be unscathed by the activities taking place on land or at the surface of the water.

However, they have it the worst. Microplastics swept to sea by strong winds and pollution float down the ocean’s water column and settle in sediments on the ocean floor. As small animals feed, they ingest the tiny plastic particles which are covered in various kinds of bacteria.

The type of plastic most commonly found in the stomachs of ocean bottom-dwellers is cellophane, the thin film we see used most often in food and cosmetic packaging. Cellophane can also be used as resin paint on ships.

Big fish usually ingest larger pieces of plastic while crustaceans tend to feed on smaller microplastics.

How does this affect their health?

Though there has been little research into the long-term health effects ingesting plastic has on smaller ocean organisms, we can look to the abundant research on large marine animals to understand what the consequences may be.

First, there is the reality that ingesting bits of plastic – no matter the size – has potential to cause physical harm to small ocean creatures by tearing soft tissues inside their bodies.

After digestion, the documented health effects in larger animals include reduced swimming speed, impaired reproduction rates, increased stress levels, reduced absorption of nutrients, and death.

It’s also unclear how chemicals used to improve the performance and appearance of plastic – including dyes and flame retardants – affect animals once they are broken down during digestion.

Finally, there is an extremely high likelihood that microplastics are never fully broken down and are passed up throughout the food chain, causing all predators and prey health problems… including humans.

Though it may seem like our planet is irrevocably ruined by plastic, studies like this one are helping to build a stronger case for global bans on single-use plastics for good.

Until then, we can all do our part by limiting the amount of plastic we use on a daily basis. If you’re looking for some simple ways to start, check out our guide to a plastic-free lifestyle here.