The Ocean Impacts of Plastic You Didn’t Even Know Were Happening

Thanks to the likes of Blue Planet 2, increasing environmental coverage in the news and the work of individuals establishing campaigns such as the 2 minute beach clean, our society is more clued up on our environmental impact than ever before. The sight of some of our most intelligent and charismatic species being washed up, shrouded in fishing nets and supermarket packaging, is continually heart-breaking, but what about the species that are largely forgotten by our headline news?

Macroplastics often spark interest in the media, with 1960s crisp packets still floating ashore alongside 5 million pieces of Lego from a lost container in 1997. However, for some species of whale and shark, microplastics (those pieces of plastic under 5mm) pose the greatest threat. Baleen species use a filter feeding system made of thousands of small hair-like structures to filter krill from the surrounding water. The Mediterranean Fin Whale can swallow up to 70,000 litres of water in one gulp, leaving krill, and now microplastics, clogged in their mouths, thereby reducing the effectiveness with which they can feed. It is estimated that the sea holds 50 trillion microplastic particles as old pieces of litter are broken down by the sun and waves, leaving more tiny particles in our blue planet than stars in our galaxy.

From gentle giants to thumbnail-sized critters, microplastics’ impact seemingly knows no bounds. Salps are small jellyfish-like creatures which eat algae packed full of carbon dioxide at the sea surface. Once salps have filled up, their dense faeces sink to the seabed, taking with it carbon dioxide emissions from our planes, trains and cars for safe storage. However, with salps now confusing seaweed-cloaked microplastics as food, the buoyant human debris is making their faeces lighter, causing them to float at the surface, re-releasing emissions back into our ever-warming atmosphere. Apparently gassy cows are not the only thing global warming should be worrying about.

Alongside global warming, habitat loss is a major concern, yet the ‘plastisphere’ is increasingly considered a new ecosystem, with this hardy particle housing enthusiastic organisms, allowing them to circumnavigate the globe as they effortlessly bob across the ocean. This spreads invasive species to our vulnerable remote islands whilst also complicating feeding for fish as our disguised litter smells and looks near identical to their natural prey.

Yet for corals, selecting the correct natural food source isn’t a problem. They actually enjoy eating our synthetic waste! Recent research has shown that corals happily devour our plastic litter in favour of natural sand and microbes with the cocktail of chemical additives contained within them creating a tasty treat. This creates a recipe for disaster as even plastic bags merely entangling themselves in spiky coral branches increases the risk of disease and bleaching by 20 times. Loss of coral reefs is not only devastating for the fish nurseries which thrive there, but also for humans as our colourful underwater jungles are worth $375 billion a year to tourism, fishing and flood protection, particularly to those regions with already vulnerable populations.

If this wasn’t enough, our beloved shorelines, home of the quintessential family holiday, are filled with ‘plastic pebbles’ as melted plastic, sand and seaweed mix to masquerade as ancient stone, while our last arctic wildernesses store 12,000 particles in each litre of sea-ice, trapped in a natural glassy museum case. The list of plastic’s endeavours may seem endless, but we can all make a simple change in our local area to reduce rubbish through kerbing use and cleaning streets to protect our resident creatures, great and small.

By Neve McCracken-Heywood