Microplastics in the Mediterranean Sea: Sources, Pollution Intensity, Sea Health, and Regulatory Policies is an excellent journal article detailing how tourism in the Mediterranean has led to plastic pollution and the many consequent effects [1].
The article first starts by mentioning the immense sources of plastic pollution, noting that approximately 208–760 kg per year of solid waste per capita, with tourist activities in the Mediterranean basin serving as the most significant contribution to increased marine litter. This is no surprise as the region, is the world’s largest tourism destination with >10,000 tourist spots and >100,000 hotels, accounting for 35% of international arrivals and 30% of tourism receipts [2].
Figure 1. Sources of plastic pollution in the Mediterranean Sea [3]
The World Wildlife Foundation (WWF) corroborates this problem, with 0.57 million tonnes of plastic annually entering Mediterranean waters. [3] They even have a neat diagram that displays the magnitude and large-scale nature of the problem, with plastic coming from several countries around the Mediterranean basin as seen in Figure 1. Furthermore, despite only containing 1% of the global water mass, the basin holds 7% of global microplastics, suggesting a significantly more polluted environment than the global average [4].
The article then notes that huge quantities of plastic debris undergo fragmentation into smaller pieces over time, suggesting some transformation of the pollution [1]. It does not go in-depth into this transformative process so I sourced for other data to supplement the article’s content.
Figure 2. How plastics are broken down in water systems [5].
The Plastic Action Centre (figure 2) states that plastics get weathered and degraded in environments, breaking down into smaller and smaller pieces and eventually reduced to microplastic particles which they note are no larger than 5mm in size.
The article notes the various environmental impacts of microplastics. The first is the consumption of microplastics by marine organisms. Marine biota that consumes the microplastics can result in toxicity, endocrine disruption, carcinogenicity, and physical injuries such as blockage and internal abrasion. Secondly, entanglement with plastics is common too. Various animals like the Caretta Caretta loggerhead sea turtle face high impacts from plastic sheets while the Chelonia Mydas green turtles’ main cause of death was entanglement in plastic bags and ropes. Lastly, plastic litter acts as a considerable stressor for coral reefs due to shading suffocation, with 19 Cnidarian species subject to suffocation [6].
These environmental stressors also have implications for human health. The article notes that over 55% of the 220 marine species reported to have ingested microplastics are of commercial importance like Norway lobster, Atlantic cod, and mussels among others. While research is still ongoing on the full effects on human health, the damage microplastics can cause is quite significant. One recent study noted that as microplastics are most commonly ingested by humans through food and drink, gastrointestinal problems like inflammation and intestinal diseases are most common. Beyond this, damage to the liver, reproductive systems, and nervous systems along with the emergence of cancer are a few other areas in that microplastics affect human health [6]. What is most concerning though is the potential toxicity of leaching additives. Plastics contain chemical additives that can cause harmful effects on humans through hazardous POPs transfers and the presence of heavy metals [7].
It is not all doom and gloom as the article does conclude with legislation that targets reducing single-use plastics and a circular economy for plastics which enables them to be reused/recycled and not dumped into the environment. Still, progress is slow and the present pollution in the Mediterranean will remain for many decades, all due to the huge tourist presence in the region.
Fig 3. Comic detailing the human causes of marine pollution [8]
As Figure 3 perfectly encapsulates, human activities are responsible for huge amounts of trash in the marine environment. Thus, the next time we are relaxing and enjoying the entertainment of our seaside holiday, we should be more mindful of the waste we produce and limit it as much as possible.
– Lucian Taft Kimbrell
References
[1] Sharma, S., Sharma, V., & Chatterjee, S. (2021, April 12). Microplastics in the Mediterranean Sea: Sources, pollution intensity, sea health, and regulatory policies. Frontiers. Retrieved February 26, 2023, from https://doi.org/10.3389/fmars.2021.634934
[2] Zibaoui, A. (2022, July). The New Normal for Mediterranean tourism. ASCAME. Retrieved February 26, 2023, from https://www.ascame.org/new/the-new-normal-for-mediterranean-tourism/
[3]WWF. (2019, June 7). Flawed plastic system hits the Mediterranean Sea and its economy. WWF. Retrieved February 26, 2023, from https://www.wwfmmi.org/?348053%2FFlawed-plastic-system-hits-the-Mediterranean-Sea-and-its-economy
[4] IUCN. (2022, July 14). Plastics in the Mediterranean. IUCN. Retrieved February 26, 2023, from https://www.iucn.org/our-work/region/mediterranean/our-work/marine-biodiversity-and-blue-economy/plastics-mediterranean
[5] Plastic Action Centre. (n.d.). How plastics breakdown into microplastics. How Plastics Breakdown into Microplastics | Plastic Action Centre. Retrieved February 26, 2023, from https://plasticactioncentre.ca/directory/how-plastics-breakdown-into-microplastics/
[6] Mamun, A. A., Prasetya, T. A., Dewi, I. R., & Ahmad, M. (2023). Microplastics in human food chains: Food becoming a threat to health safety. Science of The Total Environment, 858, 159834. https://doi.org/10.1016/j.scitotenv.2022.159834
[7] Campanale, Massarelli, Savino, Locaputo, & Uricchio. (2020). A detailed review study on potential effects of microplastics and additives of concern on human health. International Journal of Environmental Research and Public Health, 17(4), 1212. https://doi.org/10.3390/ijerph17041212
[8]Fuller, J. (2023, February 24). Jake-fuller-beach-trash-cartoon-CLR. Cayman Compass. Retrieved February 26, 2023, from https://www.caymancompass.com/2018/01/17/beach-trash/jake-fuller-beach-trash-cartoon-clr/