Pollution
Marine plastic pollution is not only a problem of larger marine debris, but also when it breaks down into smaller particles called microplastics and even smaller nanoplastics. Just one plastic bottle can break into so many pieces that bits of it can be found on every beach in the world [1]. Microplastics are also found in things like soaps, body creams and toothpaste. These tiny plastics end up in the ocean through sewage waters, where they are eaten by marine animals. It is difficult to study the harm these particles do, but there are signs that it can increase the risk of diseases [2] and biomagnification of pollutants.
Bioaccumulation is the increase of harmful chemicals (such as heavy metals and pesticides) in an organism over time. These chemicals stick to fat, accumulating in the animals’ bodies as they eat contaminated prey. As bigger animals eat smaller ones, the chemicals move up the food chain and become even more concentrated and dangerous, in a process called biomagnification. This can lead to dangerously high levels of pollutants in top predators like marine mammals, which are often long-lived and at the top of the food chain. Despite efforts to reduce pollution, some chemicals are still a big problem, with studies linking high contamination to reproductive failure in harbour porpoises, killer whales, and bottlenose dolphins [8, 9].
References
[1] International Whaling Commission (IWC). (2020). Report of the IWC Workshop on Marine Debris: The Way Forward, 3-5 December 2019, La Garriga, Catalonia, Spain. SC/68B/REP/03. Available at https://archive.iwc.int/pages/view.php?ref=17025&k=
[2] Nelms, S. E., Barnett, J., Brownlow, A. et al. (2019). Microplastics in marine mammals stranded around the British coast: ubiquitous but transitory? Scientific Reports, 9, 1075. https://doi.org/10.1038/s41598-018-37428-3
[3] Jambeck, J. R., Geyer, R., Wilcox, C., Siegler, T. R., Perryman, M., Andrady, A., Narayan, R., & Law, K. L. (2015). Plastic waste inputs from land into the ocean. Science, 347(6223), 768–771. https://doi.org/10.1126/science.1260352
[4] Kosior, E., & Crescenzi, I. (2020). Solutions to the plastic waste problem on land and in the oceans. In: T. M. Letcher (Ed.), Plastic waste and recycling (pp. 415–446). Academic Press. https://doi.org/10.1016/B978-0-12-817880-5.00016-5
[5] James, N. A., & Große, A. (2023). Marine Mammals and Interactions with Debris in the Northeastern Atlantic Region: Synthesis and Recommendations for Monitoring and Research. In: Grimstad, S.M.F., Ottosen, L.M., James, N.A. (Eds.), Marine Plastics: Innovative Solutions to Tackling Waste. Springer, Cham. https://doi.org/10.1007/978-3-031-31058-4_1
[6] Jepson, P. D., & Law, R. J. (2016). Persistent pollutants, persistent threats. Science, 352(6292), 1388–1389. https://doi.org/10.1126/science.aaf9075
[7] Borrell, A. (1993). PCB and DDT in blubber of cetaceans from the northeastern north Atlantic. Marine Pollution Bulletin, 26(3), 146–151. https://doi.org/10.1016/0025-326x(93)90125-4
[8] Jepson, P. D., Deaville, R., Barber, J. L. et al. (2016). PCB pollution continues to impact populations of orcas and other dolphins in European waters. Scientific Reports, 6, 18573. https://doi.org/10.1038/srep18573p
[9] Murphy, S., Barber, J. L., Learmonth J. A. et al. (2015). Reproductive Failure in UK Harbour Porpoises Phocoena phocoena: Legacy of Pollutant Exposure? PLoS ONE, 10(7), e0131085. https://doi.org/10.1371/journal.pone.0131085
Did you know that...
- At least 8,000,000,000 kg of plastic every year enters the ocean worldwide [3]
- 80% of all plastic in the ocean originates on land, but is carried gets to the sea through by wind, rivers, and sewage [4]
- At least 60% of all marine mammal species in the North East Atlantic have suffered from ingestion of marine debris or entanglement [5]. This happens for example when marine mammals become wrapped by marine debris.
- The use of some chemicals has been strictly regulated since the 80s, but they continue to harm marine mammals today [6]. An example of this is the pesticide DDT, that was used to kill insects and increase crops from 1940 to 1970. This pesticide can still be found in marine mammals’ blubber [7]
Discuss
When a plastic bottle is improperly disposed of, is the consumer who purchases the bottle or the company that manufactures it more accountable for the environmental impact?























































































































