Plastic pollution is arguably one of the most challenging forms of pollution that we are faced with today, negatively impacting terrestrial, freshwater and marine ecosystems, and the organisms that live in these habitats.
Discarded plastic not only looks unsightly; it kills. Wildlife often become entangled in plastic bags or other discarded plastic debris, which can impair their ability to forage or hunt for food and evade predators.
In many cases it slowly cuts into the victim’s flesh, causing open wounds that lead to a slow, agonizing death as wounds become infected or as the animal is slowly strangled to death.
Effect of Plastic Pollution on WildlifeBirds, fish, reptiles and mammals have all been known to eat discarded plastic items that they mistake for food, which over time accumulates in the animal’s gut as it is not readily digested. This may result in a blockage, or may cause the animal to stop eating as it does not feel hungry. Either way, the hapless animal is likely to slowly starve to death.
Seabirds such as albatrosses, many of which are already endangered, mistakenly feed plastic objects and pellets to their chicks, who eventually die as a result. Predators higher up the food chain accumulate plastic that they unwittingly consume when they feed on prey that has consumed plastic, and they too will have problems digesting and processing it.
Does Plastic Persist in the Environment?
Plastic is a man-made material that is designed to be durable and to withstand the elements; consequently, it does not break down readily in the environment, but rather persists for a very long time. When it does eventually start to break down, it doesn’t disappear, but rather breaks down into smaller and smaller pieces, eventually resulting in gazillions of tiny plastic fragments – or microplastics – measuring less than 5mm.
While plastic pollution on land has always been recognized as a huge environmental problem, only recently has the extent of marine plastic pollution become truly apparent. This is partly because plastic tends to sink to the ocean depths, out of sight and out of mind. But as more and more plastic debris washes up onto beaches around the world, and people become increasingly aware of the existence of the Great Pacific Garbage Patch – an extensive area where plastic debris converges in the middle of the ocean – conservationists are beginning to sit up and alarm bells are beginning to sound. Microplastics are an emerging pollutant that has scientists particularly concerned. Due to their tiny size, they have until recently slipped under the radar. But recent oceanic surveys have revealed that these tiny particles are abundant in all the world’s oceans, and scientists are particularly concerned about the impact on marine animals and higher predators, especially man, who relies heavily on the world’s ocean for a source of protein food.
The level of microplastics in the world’s oceans has steadily increased over the last couple of decades in line with an increase in the use of plastics, and continues to increase further still. What is more problematic is the fact that more and more plastic is being discarded into the environment, yet the existing plastic is not disappearing.
The result: an ocean that is accumulating more and more plastic, and rapidly becoming a plastic soup, spiralling out of control. A study (1) conducted in the north Pacific Central gyre in 2001, revealed that microplastics outweighed zooplankton by a ratio of 6:1!
Microplastics do not only originate from plastics that have broken down into tiny fragments, but also comprise tiny resin pellets that are shipped in bulk to manufacturers who use them to produce plastic products. Very often there is spillage en-route to their destination, and they are added to the environment before they are even used in the manufacturing process. Other forms of microplastics include minute plastic beads (< 1mm) used in cosmetic products, such as shower gels and facial scrubs, that eventually make their way into the environment where they persist.
These plastic particles attract and accumulate carcinogenic pollutants such as POPs (persistent organic pollutants), PCBs (polychlorinated biphenyls), brominated flame retardants, and DDT – an extremely hazardous pesticide that is now banned in most countries of the world, yet still persists in the environment – at levels that are 100 thousand to 1 million times greater than the levels found in the surrounding seawater. POPs accumulate in the organs and fatty tissue of animals that consume them. Top predators, such as predatory fish, marine mammals, and humans are even more vulnerable, as POPs bioaccumulate and become more concentrated in animals further up the food chain. Furthermore these pollutants continue to accumulate throughout the lifetime of the animal, so more and more toxins build up within their (read our) system, where they can cause adverse health effects, reproductive problems, growth defects, immune deficiencies and cancer.
What Can You Do?
Sir David Attenborough on Plastic Pollution
- Moore, C.J., Moore, S.L., Leecaster, M.K., and Weisberg, S.B., 2001. A Comparison of Plastic and Plankton in the North Pacific Central Gyre. Marine Pollution Bulletin 42, 1297-1300. DOI:10.1016/S0025-326X(01)00114-X