Plastic, what a versatile material! It’s everywhere and most of us could not imagine a life without it. But what exactly is plastic, or rather plastics? They are synthetic or semi-synthetic polymers that are lightweight, cheap and resistant to most interactors and processes, hence their popularity. Because they are suitable to so many applications, their production has increased by about 200% from the mid 50s according to scientists. Sounds good so far? Yes, but there is a catch: the fact that they are causing trouble in our oceans, where they easily end up.
Two forms of plastics are found in the environment: macroplastics, the more obvious component and microplastics, the part that results from the breakdown of larger plastics mainly due to exposure to sun and seawater. Some microplastics, however, are manufactured to be tiny (the ones you would find in your exfoliating facial cleanser for example). Macroplastics, while seemingly more visible and obvious to humans, can easily be confused for prey by seabirds, sea turtles, cetaceans and fish. Frequent studies report on beached animals with stomachs full of plastics that cannot be digested and cause starvation. Researchers have documented an astounding 700 marine species known to be affected by plastics. Li and colleagues, from the Hong Kong Institute of Education, took it upon themselves to review the issue of plastic pollution in 2016 and synthesize the research done on the incidence, sources, and effects of plastic debris in the ocean.
Jambeck, from the University of Georgia, and her colleagues from other American and Australian universities and research centers estimated in 2015 that the release of plastics in the ocean is around 4 to 12 million tons annually. Eighty per cent of plastic debris originates from land-based sources, and not surprisingly from the more densely populated areas, particularly after severe weather events. In fact, the countries of South East Asia have been shown to be a major hotspot of plastic release into the oceans, due to their high and increasing populations as well as their inadequate waste management systems. While most people are usually aware of this phenomenon as it has generated a lot of media attention lately, people usually do not realize that the remaining 20% of plastic debris comes from the ocean itself, especially through the loss of gear in commercial fisheries. Both land-based and marine debris tend to accumulate in areas with specific oceanographic conditions, carried there by currents affecting whole ocean basins. You might have heard of the Great Pacific garbage patch for example.
The consequences of the presence of plastics in the marine environment are two-fold, resulting from either entanglement or ingestion. Ingestion of macroplastics can cause blockage of the digestive tract and reduce feeding activity as the affected animals ‘feel full’ because of the amount of debris in their gut. Researchers are discovering more insidious effects of ingested plastics, which include hormonal issues and reproductive failure.
Not all species or individuals react equally to marine debris. For example, animals feeding at the surface as well as those feeding on animal plankton, and juveniles in some species, show the greatest occurrence of plastic ingestion. As seabirds regurgitate food to their chicks, the younger generations are affected as this part of the population does not have the choice or potential to avoid plastics. Furthermore, because the decomposition of plastics in the gut can create a build-up of gas, animals such as sea turtles have been shown to lose the ability to dive and thus feed, as they cannot escape the surface of the water. Lastly, some plastics contain toxic chemicals that are released in the gut during plastic decomposition and can contaminate the animals that have ingested them. Subsequently those contaminants cause hormonal issues in seabirds and fish, as well as behavioral changes.
Entanglement is the other way plastics can kill marine wildlife, either directly or indirectly. ‘Ghost fishing’ is a term describing animals getting entangled or trapped in fishing equipment at depth. This often results in drowning. However, researchers have shown that plastics can have longer-term effects, including an increase in energy spent to move through the water for streamlined aquatic animals that carry around extra materials, including pieces of nets and lines. In these conditions, affected animals can be more vulnerable to predation as they cannot escape as fast as they normally could. Wounds resulting from plastics constricting limbs can also get infected or lead to necrosis.
The issue of plastic pollution negatively affects marine creatures, but also has the potential to influence human health through consumption of contaminated sea products. This is especially concerning when consuming species higher in the food chain, as they accumulate pollutants when they eat prey that are themselves contaminated. Researchers are currently quantifying how much this will affect us. In addition, plastics are dangerous for a wide range of animals outside the sea. Creatures inhabiting freshwater and land ecosystems are similarly being negatively influenced by plastic pollution. It is, therefore, time to act. The good news is: each and every one of us can do little things at home every day to contribute to the addressing of this important environmental issue.
This is shocking! What can I do to help?
Of course, clean-up programs are great and if you live in an area with such programs and have a bit of spare time, do get involved! Adequate recycling of all household products, including plastics, and avoiding littering are other ways to help. However, it now seems more urgent to try to reduce our plastic consumption, rather than try to deal with waste in a more clever way. While it requires a bit of effort and some planning ahead, there are a lot of things each of us can do to address this reduction; in some ways, this will save you money and will probably help make you healthier too! Buying items in bulk, including food, cosmetics and cleaning products is a great way to reduce plastic consumption because you can either bring your own containers and fill them up, which is more efficient, or buy items in recycled paper bags. You can also check with your local deli if they will allow you to bring your own container to use when buying meals. If shopping in supermarkets is more convenient for you, you could also pledge to avoid food items wrapped in unnecessary plastics. A lot of products, including veggies and fruit, come covered in plastic, and it is up to consumers to express their frustration regarding this issue by avoiding buying such products and by contacting companies to ask them to reduce packaging. It is also best to buy items that come in plastic when the containers are reusable and can be used at home to store meals. Plastic bags are also increasingly being banned from shopping outlets; having your own reusable bags is therefore a better choice for shopping. Taking political action by, for example, requesting plastic bag bans is another great way to be involved. The most common plastic items that cannot be re-used and can easily be avoided include for example straws, plastic bottles and take away cups.
You can challenge yourself to say no by signing up for initiatives such as Plastic Free July. If you want to challenge yourself even further, why not give Zero Waste living a go? There are great resources online that will help you determine the different steps you can take to make such changes in your life. Why not try to make some of the products you use at home, including household cleaners, shampoos, lotions and make-up? It is probably easier than you think and will help you avoid nasty chemicals! Lastly, the effects of plastic pollution still need to be better understood and because it is such a global issue, chances are you will be exposed to it and can get involved in sharing information. More and more universities are setting up platforms to collect citizen science data. If you live close to the coast and come across plastic debris in the environment as well as animals affected by plastics, you can report your observations and help scientists quantify the extent of the problem in your area. Finally, educating your friends and family about the issue is absolutely crucial if you want to make progress reducing plastic pollution and its impact on the marine environment.