Alarming 40% of our ocean is filled with plastic debris. If we don’t change our lifestyle, we will have plastic more than fish in the oceans by 2050. Although the current situation is pretty bad, there is still hope. Learn the real size of the problem and possible solutions to address it.
The plastic era
The invention of plastic changed our lives. It is cheap, flexible, and durable. The début of plastic occurred in the 19th century, with the creation of polystyrene (PS) and polyvinyl chloride (PVC). With a massive need for metal for military purposes in the Second World War, plastic industry flourished. In the 1950s, plastic mass production started and continued growing ever since. In 2010, world production was 265 million tons, with an estimated consumption per capita of 100 kg.
The path to the sea
Inappropriate waste management, improper human behavior, and incidental pollution send part of this production to the sea. Pollution can originate from nautical or land-based activities. A study published last year in the journal Science estimated an input from 4.8 to 12.7 million metric tons of plastic every year resulting from inland activities. However, it not possible to know how much trash marine activities produce. This type of trash can involve abandoned fishing gear, lost containers, or illegal ship discharge.
An old problem
Plastic is everywhere, buried in Arctic ice and the deep sea, floating on the ocean surface and washed ashore affecting even the most remote beaches. If the situation is not good, the perspectives are even worse, with an estimate of a 10-fold increase in the next decade.
The problem is not new. Back in 1975, reports of plastic pollution in the oceans calculated a plastic mass of 5.8 million metric tons in the oceans. In 1997, Captain Charles J. Moore discovered in North Pacific the first garbage patch, a 15-m long island of trash floating on the ocean. Circular ocean currents and winds trap debris in central stable areas, creating garbage islands composed of all sorts of items, from plastic bottles to tiny particles. Apart from plastic, these rotating currents, known as gyres, concentrate plankton, seaweed, and marine animals.
The five Garbage Gyres
Currently, five known gyres are trapping plastic debris in the ocean:
North Pacific Gyre
South Pacific Gyre
North Atlantic Gyre
South Atlantic Gyre
Indian Ocean Gyre
How big is the problem?
Data gathered from 24 expeditions held from 2007 to 2013 revealed 268,940 tons of plastic afloat at sea, the equivalent of 1% of the annual production. The samples contained 233,400 ton of macroplastic and 35.540 ton of microplastic. The expeditions sampled 1,571 locations using net tows and survey transects.
The garbage gyres concentrated 7,000 to 35,000 tons of plastic debris. Due to its larger size, the North Pacific Gyre concentrates 33-35% of the debris. In addition to the five subtropical gyres, the team sampled gulfs, bays, and densely populated coastlines.
Although plastic waste is not biodegradable, solar exposure makes it more brittle by photo-oxidative reactions, so it breaks down into smaller and smaller particles. Most of those microplastic particles remain suspended in the water column resembling a cloudy soup, with a predominance of 1-5 mm fragments. A substantial part of those microplastics disappear from the surface, probably due to shore deposition, sinking, nanofragmentation, ingestion, or biofouling (accumulation of organisms).
Sea life threatened
Plastic can be very dangerous for sea life. According to the United Nations Organization, over one million birds and 100,000 mammals and sea turtles die every year because of plastic. Turtles mistake plastic bags for jellyfish. Albatrosses confound plastic resin with fish eggs and use it to feed their chicks. Many birds die from starvation or rupture of internal organs after eating plastic. Marine mammals die with plastic blocking their digestive tract. Seals, whales, and turtles get entangled in ghost nets (abandoned fishing nets) and drown. Researchers found the most unusual sort of materials inside marine animals: cigarette lighters, toys, magic markers, and washing gloves to cite some examples.
In addition to the physical damage, plastics can also be toxic to sea life. They contain additives, such as bisphenol A (BPA), pigments made of lead and chromium, and flame retardants.
Plastics also absorb hydrophobic chemicals present in the surrounding water, such as pesticides. When animals ingest plastic debris, these toxic substances can leach from the plastic into their digestive fluids and penetrates cell membranes causing toxic effects. Toxic substances can act as endocrine disruptors and produce infertility, carcinogenic and neurotoxicological effects.
As fish ingest large amounts of plastics, they are also affected. Although no study documented the consequences for fish health, we know higher trophic levels can achieve higher toxic concentration, through biomagnification. This problem affects us directly, as we eat fish. Humans are at the top of the food web. Therefore, it is very likely that we absorb all plastic toxins, becoming victims of the very poison we created.
A further problem concerning plastic pollution includes marine rafting. Algae, mussels, and microorganism can travel with floating plastic and colonize new areas, which can unbalance the ecosystems of affected areas.
Another worrisome issue is that high accumulation of plastic debris can block the sun, preventing marine plankton and algae from receiving enough sunlight to produce nutrients. As these photosynthetic organisms are the base of the marine food chain, the whole chain in endangered.
There is still hope
Cleaning the ocean is a difficult task, but with time, money, and energy it is still possible. The solution to the problem involves several fronts:
Prevention: Prevent more plastic from reaching the ocean. A proper waste management and the cleaning of rivers can help in this task.
Legislation: The sea is an international area. Hence, currently no nation takes responsibility for a cleaning action. This mindset should change with the creation of laws to protect the ocean in which all countries take their share of responsibility.
Alternatives for plastics: Incentives for the creation and use of biodegradable plastics made from renewable sources, which are less harmful to the environment. Some examples are the Polylactic Acid (PLA) and the Plastarch, both non-toxic options made from plants.
Recycling: As plastic cannot degrade naturally, recycling is the correct destination. The proper discharge of plastic is paramount to avoid more trash in the oceans. Plastic can also be turned into oil and degraded by selected microbial strains.
Cleaning the ocean: Many actions are aiming to remove the garbage from the sea, from local initiatives, such as ‘Fishing for Litter’ to global initiatives, such as ‘Clean-up the World’, which work with volunteers from 120 different countries.
New technology: Cleaning the ocean also counts on the creativity of brilliant minds that created innovative devices to remove trash. The young Boyan Slat, from the Ocean Clean-up (Netherlands) in an example. He invented a fixed platform to remove garbage from the sea and, together with his team, plans to test it this year. Another example is the inventors from Sussex, England. They presented their creation, Sea Vax solar power vacuum, at the Innovate 2015, a fair for innovations held in London last November. Both projects show self-sufficient devices able to remove garbage from the water without harming marine life.
Education: The throwaway culture should stop, or there is no point in cleaning the sea. The practice of the good old 3Rs: reduction, reuse, and recycling, is still valid.
Commitment of plastic producers: manufacturers should be responsible for the entire product cycle and provide its proper discharge or collection.
Suggestions for further reading:
Cózar, A., Echevarría, F., González-Gordillo, J.I., Irigoien, X., Úbeda, B., Hernández-León, S., Palma, Á.T., Navarro, S., García-de-Lomas, J., Ruiz, A. and Fernández-de-Puelles, M.L., 2014. Plastic debris in the open ocean. Proceedings of the National Academy of Sciences, 111(28), pp.10239-10244.
Eriksen, M., Lebreton, L.C., Carson, H.S., Thiel, M., Moore, C.J., Borerro, J.C., Galgani, F., Ryan, P.G. and Reisser, J., 2014. Plastic pollution in the world’s oceans: more than 5 trillion plastic pieces weighing over 250,000 tons afloat at sea. PloS one, 9(12), p.e111913.
Hammer, J., Kraak, M.H. and Parsons, J.R., 2012. Plastics in the marine environment: the dark side of a modern gift. In Reviews of environmental contamination and toxicology (pp. 1-44). Springer New York.
Jambeck, J.R., Geyer, R., Wilcox, C., Siegler, T.R., Perryman, M., Andrady, A., Narayan, R. and Law, K.L., 2015. Plastic waste inputs from land into the ocean. Science, 347(6223), pp.768-771.