Plastic debris in the ocean

03.10.2013 15:08 by firmm Team

Text: Nina Bircher, Alicia Lipsky, volunteers for firmm; Photos: Nina Bircher, Alicia Lipsky, Jörn Selling and from Internet

In March 2012 a dead sperm whale got washed ashore on the coast of Andalusia. Researchers found 17 kilos of plastic debris in its stomach, part of it were tarpaulins from the nearby greenhouse industry. It was assumed that the animal died of starvation or stomach injuries caused by the ingestion of larger plastic pieces. Plastic debris increasingly poses a hazard for marine animals. With this blog we would like to give a broad overview about the problem.

Plastic and its applications

Nowadays plastic is used for almost everything: In the packaging- and building industry, vehicle construction, medicine, for sport and leisure articles, electronics and agriculture and many things more – everywhere plastic plays a major role (1). This widespread use of plastic is possible because of its many advantageous properties like small weight, acid resistance and flexibility. The material is also named after the latter: The term plastic is derived of the Greek words 'plastikos' (ready to form) and 'plastos' (formed) (1). Moreover, plastic production is very cheap (2).

Plastic is a general term for many different synthetic materials. Synthetic plastic materials are gained from oil, gas or coal and consist of long chains of molecules, so called polymers, which are produced through the consistent linkage of the same unit (monomer). Refined oil (naphtha) is the most common original material (2,3). These chemical bonds are very stable and not biodegradable. The most common types of plastic materials produced are the so called mass production plasticsPolyethylene, Polypropylene, PVC, Polystyrene, PET and Polyurethane. They are all made of oil and count for about 80% of the European plastic production (2). Many other compounds such as plasticizers, stabilizers, colorants, filling materials, reinforcing agents, flame retardants and antistatic agents are added to the original material to give it specific properties. Many of them are harmful and not permanently bounded to the plastic – they ooze into the environment (3).

The triumph of plastic started in the 1950s when its widespread usage began to develop. In 1950 about one million tones of plastic were produced worldwide (1). Today it’s already 250 million tones every year (2). In north America and western Europe about 100 kg of plastic were used per year per capita in 2005 and in 2015 it will be 114 kg. About 38% of the total plastic consumption in Europe is caused by the use of packaging material and therefore by the use of products, that are thrown away again very soon. If not disposed properly, plastic can contaminate the environment for hundreds of years as it is not biodegradable (4). Even in Europe with its relatively well developed waste management only about one quarter of all plastic garbage is recycled (2).

Carelessly thrown away plastic is often transported to the oceans through rivers. According to estimates worldwide about 675 tones of garbage get in the oceans every hour and about one half of it consists of plastic (3). Because of wind, waves and UV radiation plastics disintegrates into small fragments and is transported by ocean currents over large distances even in to very remote areas such as the artic and Antarctic. Because of the global ocean currents plastic debris has tendency to accumulate in some subtropical convergence zones or gyres (4). An area in the North Pacific with a very high concentration of plastic debris has gotten much attention in the media and was referred to as “great pacific garbage patch” or “the seventh continent” (5). These names are somewhat misleading as this “plastic area” is a cloudlike, drifting accumulation of mostly small plastic particles and not a “plastic carpet” which could be seen at the surface or on satellite images (4). At exposed beaches of the Hawaii islands in the middle of the pacific large amounts of plastic debris get washed ashore: At the as “Plastic Beach” well known Kamilo Beach at the south western point of Big Island more plastic particles than natural sand can be found (5).

This enormous plastic pollution in the oceans poses a great threat to marine life.

Effects of the plastic pollution

The marine fauna is heavily affected by plastic pollution. At least 270 different species are threatened by garbage (3). They get entangled in it and drown, suffocate, starve because they can not absorb food as well anymore or die because of strangulation or injuries. Entanglement is especially a problem for sea lions and seals. More than 58% of all seal and sea lion species regularly get entangled and some populations have been heavily decimated as a result (7). Unfortunately fishermen often loose or get rid of nets and fishing linesand these continue fishing even tough they are not in use anymore. This phenomenon is called “ghost fishing” and it leads to large amounts of marine organisms being trapped and in some areas it is yet another serious threat for fish populations.

Swallowing plastic debris is a huge problem for some marine animals too. This happens often because animals confuse garbage with food and especially plastic is swallowed often. Particularly sea turtles, birds and marine mammals mistakenly swallow plastic. This is dangerous, when plastic blocks the digestion and therefore also makes digestion of real food impossible. The animals then starve even though they have a full stomach (7). The sperm whale that got washed ashore in Andalusia in 2012 probably also died this way. Every year about 100´000 marine mammals and about one million birds die because of swallowing plastic debris. You can get an impression of the problems dimension when you watch this short movie: www.midwayfilm.com

Indirectly the plastic pollution also affects other marine animals and even humans. Plastic is not biodegradable and therefore just mechanically or through radiation falls in to small pieces. Thereby, suspended particles develop and toxic substances are set free. This substances include added compounds such as Nonylphenol, Bisphenol A (BPA), Styrene monomers or plasticizers (Phthalates) (UNEP Plastic Report). Phthalates have a similar effect as hormones and can therefore damage the sensitive hormone system. These toxic substances are absorbed by different organisms and thus get in to the food chain, accumulate there and eventually also are absorbed by humans (9). The risks posed by phthalates is still not well understood, but they possibly affect child development negatively, can cause cancer or lead to Infertility in men (3).

Another risk caused by small plastic particles is the tendency of toxic, not biodegradable substances such as DDT, DDE, PCB and other POPs (Persistent Organic Pollutants) to adhere to the surface of micro plastic. This way, these substances can accumulate in the food chain (8). That these substances accumulate in the food chain very strongly can be seen when one examines stranded whales, which should be deposed of as hazardous waste as their blubber contains such much toxic components (11).

What are we doing about it?

This whole plastic contamination problem is human made and therefore, we are responsible to clean up the oceans. So far we are not doing very well. Since the sea is mostly a public good and doesn’t belong to anybody, nobody feels really responsible for getting it clean. It would cause great costs and require relevant infrastructure on land to be able to recycle or get rid of the collected garbage properly. It seems as if the awareness about the plastic problem is still quiet small and therefore public pressure on governments not strong enough. Thus, no effective international agreements to avoid plastic pollution have been set up. To solve the problem of plastic pollution in the oceans, we need to both prevent plastic from getting into the sea and get plastic out of the sea. Both ideas are already being developed:

In the 1980s the international convention MARPOL (International Convention for the Prevention of Pollution from ships) was implemented, which prohibits the disposal of plastic of ships on sea. This is so far the most far-reaching international convention and it was ratified by 122 states. Unfortunately the situation still gets worse. This is the case because a control of compliance with these regulations is difficult to achieve in many countries. Furthermore, only 20% of the garbage present in the oceans is coming from ships but about 80% from land based sources. Even if MARPOL was completely successful, there would still a lot of plastic get in to the oceans (7).

It is also very important to clean up coastlines regularly. This can be a bit frustrating since plastic gets washed or is left ashore again and again, but each clean up counts and could save the life of an animal. The largest organized coastal clean up is ICC (International Coastal Cleanup). It is coordinated by the Ocean Conservancy and regular clean ups have been arranged since 1986 with the help of volunteers in 132 countries (8).

The firmm-volunteers were curious about what lies around at the beaches of Tarifa and organized their own mini coastal clean up. Three of us collected in only 2 hours and on less than 200m 4 large bags full of garbage. We found everything from an old bed, bathing tube and chairs to plastic bottles and plastic bags. We also saw carelessly thrown away grills and a whole shoes collection as well as fishing lines with the hooks still attached. Here some impressions:

About 10-30% of the by catch fishermen find in their nets is plastic. Unfortunately, space on board of a fishing boat is often too limited to take the garbage back on land and the infrastructure in harbours not sufficient for larger amounts of garbage. Moreover, it often requires a fee to get rid of waste in harbours. Thus this plastic is often just thrown back into sea. NABU (Naturschutzbund Deutschland) started 2011 the „Fishing for Litter“ project in Germany and introduced a free garbage deposit in harbours for fishermen. The environmental organisation KIMO is working on free infrastructure for waste management in European harbours since 2003 (9).

19 year-old student Boyan Slat is developing a project to clean up the oceans. His goal is to place floating filters at strategic spots in the oceans to collect garbage from the water without organisms and organic material. Afterwards he wants to recycle the collected plastic (10).

Many approaches have been proposed, but none has really made the situation better so far. For future, we all should work towards cleaner oceans and each and everyone can do his or her part:

The best thing you can do is to reduce your own plastic consumption:
- For example, you could get yourself a cool shopping bag and use it every time you go shopping
- Do you live in Switzerland? Participate in the refiller project (ww.refiller.ch). Otherwise, get a reusable coffee cup and drinking bottle.
- If you often buy “take away” food, try to use your own lunch box
- Cook with fresh ingredients more often and buy less packaged food
Always get rid of your garbage properly and separate waste carefully.
Talk about plastic pollution with others, it is important to create awareness.
If you see garbage lying around just collect it.