Just How Much Plastic Is In Our Oceans?

Plastic pollution is the most widespread problem affecting the marine environment, which isn’t that surprising since annual plastic production has surpassed most other man-made materials. As most of us will be aware, the main sources of marine plastics are land based and I’m sure some obvious culprits jump to mind; plastic bags, bottles, food containers and wrappers. Since 80% of global litter is dominated by food and beverage items you would be correct in thinking this. However, there are many other ways that plastics enter our ocean. We need to take a look at some of our everyday products to see if they contain hidden plastics. For example polyethylene is one of the most commonly used microplastics in cosmetic products, (microplastics are plastics under 5mm in size). Microplastic can be found in different household items, many of which we wash down the drain. 

Going back to the cosmetics, when we wash these products off our skin these microplastics go down the drain which usually end up in a water treatment facility. Wastewater treatment can effectively remove more than 90% of microplastics but that still means that a small percentage of microplastics are remaining in the water. Some facilities release the treated water into freshwater and so microplastics can end up in our oceans via our freshwater. The same goes for our clothes, a lot of our clothes are made from synthetic fibres; synthetic fibres actually make up 14% of global plastics production

When we wash our clothes these fibres fragment and release microfibres (which are considered a type of microplastic). Approximately 3 million metric tons of synthetic microfibers have entered water bodies from apparel washing between 1950 and 2016. When we consider these other aspects of plastic use, alongside our more obvious habits, plastics are sneaking their way into our oceans in more ways than we might think.


                                                                                                                                Image from oceanconservancy.org

In 2020 alone The International Coastal Cleanup (ICC) collected over 5 million pounds of trash from our shorelines. The ICC has been running shoreline cleanups all over the world for 35 years, and from their data we can see just how much plastic is in our coastal areas. Here are a few of their findings to put things into perspective; 

  • The total weight of trash removed during the 35 years of the ICC is equal to 1,148 blue whales (344,521,233 pounds)
  • 35 years’ worth of plastic bottles arranged end to end would stretch from Lisbon, Portugal to Moscow, Russia 
  • The straws and stirrers collected over 35 years would stretch the entire length of the Himalayas

These stats say it all;
last year over half a million plastic bottles were collected. And this is only the plastic that we can get a hold of on land. We have to consider what’s still in the ocean. 

I’m sure most of us have heard of the Great Pacific Garbage Patch but did you know there are actually 5 garbage patches in our oceans? Garbage patches are where all our trash collects in the ocean, from litter to fishing gear. Gyres, which are large systems of circulating ocean currents, pull debris into one location. When litter gets caught in a gyre it continues to move within this circulating current, thus causing the garbage ‘patches’. ‘Patches’ can be a bit misleading.

These are not simply floating islands of trash but the debris is spread from the surface all the way to the ocean floor. There are 5 main gyres in our oceans hence why there are actually 5 garbage patches. The largest of the 5 being the Great Pacific Garbage Patch, hence its notoriety. It covers an estimated surface area of 1.6 million square kilometres- which is three times the size of France! Within this patch there are approximately 1.8 trillion plastic pieces floating in the patch – a plastic count that is equivalent to 250 pieces of debris for every human in the world. Remember these figures are for just one of the garbage patches! 

                                                                                                                                             Picture from worldatlas.com

Plastics in the ocean will slowly start to break down and eventually become microplastics. When they get this small they are very difficult to remove and often mistaken for food by marine animals and plants such as plankton. You might think that the rainforests are responsible for the majority of the world’s oxygen but scientists estimate that 50-80% of the oxygen production on Earth comes from the ocean, the majority of this production is from oceanic plankton. Plankton can attach themselves to microplastics and this can have many serious impacts. Microplastics can block out the sun, preventing the plankton from photosynthesising; using carbon dioxide, water and sunlight to create energy and releasing oxygen as a byproduct. When it cannot photosynthesise it dies and so its oxygen production stops.

Since the 1950s there has been a 40% diminishment in phytoplankton population, if plankton populations continue to decline this will have serious impacts not only as our oxygen source but also as a food source for marine life. If plankton is attached to microplastics then the animals that feed off the plankton will be ingesting microplastics too. Unfortunately marine animals aren’t picky in the size of plastics they consume, larger pieces of plastic including plastic bags are often mistaken for food. Sea turtles that have been caught (accidentally) by fisheries that operate near the Great Pacific Garbage Patch have been found to have up to 74% (by dry weight) of their diets composed of ocean plastics.

Once plastic enters the marine food chain, there is a possibility that it will contaminate the human food chain as well. Even if you don’t eat seafood I’m afraid you can’t escape ingesting microplastics as they have been identified in honey, beer, salt and even tap water; further study is needed to understand the effects of this on human health. But surely ingesting plastics isn’t doing us much good, right? In addition to marine and human health, marine plastics are costing governments billions of dollars; in the US yearly economic costs are estimated to be between $6-19bn USD. The costs stem from its impact on tourism, fisheries and aquaculture, and (governmental) cleanups.

                                                                                                            Picture from nationalgeographic.com

A comprehensive study called Breaking the Plastic Wave outlines that if we don’t take action now the estimated 11 million metric tons of plastic waste that enters the ocean every year will nearly triple by 2040. That’s the same as dumping 110 pounds (50 kilograms) of plastic on every meter of coastline around the world. This aligns with the analysis back in 2016 that there could be more plastic than fish in the ocean by 2050.  If governments and industry around the world take immediate action, rates of plastic pollution can be reduced by nearly 80% in the next 20 years. At the heart of this New Plastics Economy is a vision of a circular economy for plastic in which it never becomes waste. To do this we need to; 

  • Eliminate all problematic and unnecessary plastic items. 
  • Innovate to ensure that the plastics we do need are reusable, recyclable, or compostable.
  • Circulate all the plastic items we use to keep them in the economy and out of the environment

This might seem a bit hopeless to us as individuals if governments and industries are the ones who need to make these big changes. However, as consumers we have the power to show these big corporations what we want from our products. Unfortunately money is what makes the world go round and if plastic products aren’t making anyone money, these companies will have to make a positive change. Necessity is the creator of invention and a lack of profits from plastic certainly equals necessity. The amount of plastic in our environment is overwhelmingly high, but we can still have a voice; vote with your wallet.

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