Since Blue Planet 2 aired, the world has opened its eyes to the impacts of marine plastics and the UK has erupted into an ‘Anti-plastic frenzy’. From coffee shops implementing incentives of reusable coffee cups, to stores across the UK plotting to minimise packaging and single use plastics.
Our modern-day society is built on the need for convenience, ease and speed. A product that fulfils this requirement in a growing population of over 7 billion people, is plastic. Use of plastic is increasing from an annual global usage of 260 million tonnes in 2009, to 322 million tonnes in 2015. Just look around the room and pick out every object that is composed of plastic. It is used in everything from food packaging to toothbrushes, and furniture to the construction of homes. The biggest downfall of such a versatile material is its lack of degradation. Plastics do not degrade, instead they break down into smaller pieces. Such broken down plastic pieces have been classified into size categories: micro <5mm, meso 5-25mm and macro >25mm.
Plastics have now polluted all of our ecosystems, both on land and in the ocean. Studies have found them from Pole to Pole, and everywhere in between (tropics, deep sea and open waters). Plastics form one of the most extreme habitat of all. Why? Because unlike the deepest depths of the Deep Sea, or the freezing waters of the Antarctic, no organism is adapted to life in a plastic ocean and we ourselves do not know the overall effects of this man-made habitat.
The “Island of Trash” and “The Trash Isles” are what the media has dubbed the Great Pacific Garbage Patch (GPGP) in recent years. The media have misinformed the public into believing the GPGP is something that humans can walk on. However, the majority of the plastic found is actually of micro- and meso- size, scattered freely throughout the water column. It is not a solid accumulation. The GPGP is actually two separate aggregations of debris, one located in the West Pacific and one in the East Pacific. The currents are responsible for the movement of plastic debris all around the Northern Pacific Gyre, where they are often drawn in to its stable centre. This has led to an accumulation of debris, according to a recently published study an estimated 79,000 tones of debris have been estimated to be floating around a 1.6 million km2 area, which is 2-4x bigger than scientists previously predicted. It was found that the majority of this, 46% was discarded fishing net. Microplastics however were found to account for only 8% of total weight, yet 1.8 trillion microplastic pieces were estimated to be floated in the area. However it is important to note that this data is based on a study over aa limited period of time.
How low can they go?
Plastics aren’t just floating upon the surfaces of the ocean or round gyres, they accumulate at other hotspots too. Despite accumulations on the surface and in the photic zone there is still a missing plastic quota. Although little research has been carried out in this field, scientists have discovered that the deep sea is also a ‘sink’ for plastic. Such research has discovered that although most plastics are positively buoyant in water, they often become negatively buoyant over time due to biofouling, resulting in a sink of the plastic (biofouling is an accumulation of plants/algae/microorganisms on wet surfaces). From this limited research microplastic accumulations have been found all across the deep sea, up to depths of 3500m in copious amounts. This brings into question how such a complex ecosystem with specially adapted organisms will cope with a compound; we do not yet know the chemical, biological or toxicological impacts.
Plastic for tea?
We’re constantly seeing widespread images across social media showing the effects of plastic on marine life. Whales with plastic bags in their stomachs, seals with fishing ropes around their heads, a turtle with a straw up its nose. Laboratory studies have been carried out on a wide variety of organisms, with the aim of seeing how these specific organisms cope with plastic in their environment and the consequences of plastic pollution. One notable organism for study is Mytilus edulis, more commonly known as the blue mussel, which are commonly consumed by humans . Researchers have found that M. edulis is able to translocate (move to other cells in the body) microplastic particles and retain them for 48 days. A further study found that trophic level transfer of microplastic was possible through M. edulis to their predator the common crab, Carcinus menas, causing concern about possible entry ways of plastic into human food chains. The latest published work (as of May 2018) into plastic within mussels was focused both on wild mussels situated along the coast, and those possible to buy in supermarkets for human consumption. It was found that all coastally sampled mussels (from 8 locations around the UK) were found to contain microplastics. Supermarket bought mussels were found to have a microplastic abundance that was higher in pre-cooked mussels than within those freshly supplied.
What can be done?
It’s pretty simple in terms of future plastic. We could move to alternative more “earth friendly” products. Some brands have already started rolling these out, a notable change came from Johnsons and Johnsons Co., who changed their plastic stick cotton buds to more eco-friendly paper rolled ones. Other changes come from plastic bag tax and coffee companies implementing incentives of money off when a reusable cup is brought. The biggest step is to cut out single-use plastic (plastic that is only used once, like plastic bottles and straws) as these are the biggest plastic polluters. For the average consumer like most of the people likely to read this, the best things you can do are refuse single use plastic, in favour of alternative products, or cut out single-use plastics/plastics all together. If that isn’t quite viable for you then the next best thing is to Re-use, Reduce and Recycle!
But for plastics already in our ecosystems, there isn’t a guaranteed solution to our issue, especially with plastic found in deep sea ecosystems. However, organisations such as the The Ocean Cleanup Project exist. They are an Nonprofit Organisation(NPO) with the goal of cleaning up half of the Great Pacific Garbage Patch in 5 years. They plan on using money from the sale of the plastic collected at the GPGP to fund cleaning all 5 of the ocean gyres. Other organisations like 4Ocean sell recycled bracelets and use the profit to take plastic from the ocean. Since their founding in January 2017 they’ve already removed 700,000 pounds (as of June 2018) of plastic from the ocean.
Plastics are becoming highly problematic in our ecosystem. Primarily because we don’t know their overall effects, both chemically within the water and the biological affects they’re having on marine species. However it is clear we need to make a conscious change in society to prevent further damage from occurring.
Until next time,
(please note this blog post was previously published as part of my university module over on extrememarine.org.uk, edits have been made to keep up with current research)
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