Marine pollution is among the most prominent concerns of scientists and environmental activists. Due to the development of technologies, the expansion of maritime transportation hubs and routes, and the increase in waste volume, human impact on the environment has become drastic. According to Arias and Marcovecchio (2017), changes in marine and ocean conditions can directly affect the global climate because of their close connection to the planet’s energy fluxes and biogeochemical cycles. Furthermore, marine pollution affects natural ecosystems, marine and coastal animal life, and human well-being and health. This paper examines the causes of this environmental problem, primarily related to anthropogenic factors, and considers its consequences. It also discusses global responses and solutions adopted at the level of governments and international organizations, designed to mitigate and prevent adverse impacts.
Causes of Pollution
The primary cause of marine pollution is global human industrial activity, which has reached tremendous proportions in the 21st century. The most dramatic cases of ocean pollution are related to the emission of fossil fuels into water areas due to accidents or improper manufacturing. According to Arias and Marcovecchio (2017), oil provides about 40% of all energy used by modern civilization, making it a major natural resource and a severe threat to the environment. Vessel crashes or accidents can result in the emission of large amounts of oil into the sea and contamination of bottom sediments with oil products. Researchers state that in the present years, the “average number of oil spills above 700 tonnes” is about “3.7 per year” (Karim, 2016, p. 44). The effects of such large spills are long-lasting, especially in northern climates, and can potentially disrupt the ecosystem in the region.
An additional pollution factor is climate change caused by excessive CO₂ emissions into the atmosphere, primarily due to oil and coal combustion. Arias and Marcovecchio (2017) state that the “ocean’s health is threatened by the resulting temperature increase and acidification of oceanic waters” (p. 95). An abnormal change in the biochemical indicators of marine waters can be considered a significant pollution factor that endangers flora, fauna, and humans.
Other types of anthropogenic pollution also contribute to the environmental problems in the world’s oceans. According to Xanthos and Walker (2017), “5.25 trillion plastic particles (weighing 269,000 tons) are floating in the sea,” and “plastic debris accounts for 60–80% of marine litter” (p. 17). It is stated that plastic is resistant to moisture and has a very long service time, and therefore its lifespan in natural conditions can reach hundreds and thousands of years (Xanthos & Walker, 2017). Therefore, plastic does not dissolve in the ocean but forms vast accumulations generated by special currents. There are currently five large concentrations of garbage patches – two each in the Pacific and Atlantic Oceans, and one in the Indian Ocean (Xanthos & Walker, 2017). They mainly consist of plastic waste generated by dumping from the densely populated coastal zones of the continents. These garbage patches are highly dangerous for marine and some other animals and cause pollution in coastal areas. Besides, microplastics, whareh is increasing abundantly in both the aquatic environment and animal organisms, may subsequently have an adverse impact on human health.
Over the past decades, there has been an increase in the number of hazardous chemicals in the marine environment, including heavy metals and pesticides, which can disrupt the ecological balance. According to Arias and Marcovecchio (2017), the emissions of contaminant sources reach the ocean “through the atmosphere and watersheds, and human-built structures such as pipelines and outfalls” (p. 99). Generally, they are highly toxic to various animal species, and can even cause abnormal mutations.
Each type of anthropogenic marine pollution is disastrous to the health of living organisms. Heavy metals, hazardous chemicals, and microplastics, for example, can reduce life expectancy and even kill marine flora and fauna (Mearns et al., 2018). They can also cause adverse mutations, intoxications, and infections in living species. Researchers also revealed that pollution stressors affect lifestyle patterns of organisms, including metabolism, nutritional status, population density, reproductive and developmental peculiarities, and others (Mearns et al., 2018). For instance, global garbage patches in the world’s oceans interfere with the usual routes of fish and marine mammals and cause the death of many of them. According to Xanthos and Walker (2017), “entanglement of species by marine debris can cause starvation, suffocation, laceration, infection, reduced reproductive success and mortality” (p. 18). As a result, animals are forced to change their typical routes, disrupting well-established ecosystem processes.
Furthermore, marine pollution causes alterations in the temperature and biochemical composition of water. Numerous studies have confirmed that the amount of anomalous micromaterials and harmful and toxic substances in sea and ocean water, including arsenic, lead, mercury, chromium, insecticides, and pesticides, has increased significantly in recent decades (Mearns et al., 2018). This leads to many negative consequences, some of which may be irreversible by a certain point. First, the state of the ocean affects climate conditions, and its pollution, among other things, leads to climate change, which is also a global environmental problem. Second, the biochemical changes in the marine areas lead to specific issues, such as water blooms, negatively affecting its suitability for living organisms (Arias & Marcovecchio, 2017). Thus, marine pollution has adverse effects on the entire global ecosystem.
Influence on Humanity
The consequences of marine pollution on flora and fauna unavoidably affect people whose health and life are closely connected with nature. When animals consume and retain anthropogenic pollutants and toxins that they cannot digest or excrete, they accumulate these substances in the organism. The number of accrued contaminants increases as species move up through the food chain. Accordingly, the highest concentrations of toxic substances are found in the bodies of major marine predators. This process is referred to as biomagnification and primarily threatens human health, as people are at the top of the food chain (Mearns et al., 2018). Marine food products may be harmful to health even after heating.
In addition to food problems, contaminated water also causes many other threats to human health. It can cause or exacerbate various infectious and oncological diseases and lead to deterioration of the human body through excess toxins or parasitic bacteria (Arias & Marcovecchio, 2017; Mearns et al., 2018). Marine pollution also has detrimental effects on the human economy and the condition of inhabited areas. For instance, according to Xanthos and Walker (2017), “stranded plastic along shorelines creates an aesthetic issue, which has negative impacts for tourism,” and adversely affects “shipping, energy production, fi,shing and aquaculture resources” (p. 18). Thus, this environmental problem affects the most vital areas of human existence.
Effective Responses and Solutions
Marine pollution is recognized as one of the most significant environmental concerns and is addressed by a range of policies at the level of governments and international organizations. The 1982 UN Convention on the Law of the Sea defines as pollution any substances that result or are likely to result in detrimental effects on marine life (Arias & Marcovecchio, 2017). The principle of likelihood prevents possible contamination even in the absence of scientific data. A specialized agency named International Maritime Organisation (IMO) was also established within the UN to monitor, assess, and regulate marine pollution issues, including through international agreements. For instance, it provides “machinery for co-operation among governments for the prevention and control of pollution of the marine environment from vessels” (Karim, 2016, p. 1). International maritime law and related agreements allow states to agree on rules and penalties for accidents, shipwrecks, and waste emissions into the marine environment.
Furthermore, states establish similar norms and standards in national law. Domestic legislation generally sets quotas and limits on the discharge of waste into the water for any industrial facility. Numerous non-governmental organizations are conducting research on marine pollution and carrying out social activities to raise public awareness in this regard (Xanthos & Walker, 2017). They are also making considerable efforts to organize coastal and marine clean-up activities with the help of volunteers and government support. Thus, various endeavors are being made at all social levels. Nevertheless, the situation continues to deteriorate, and humanity needs more consolidated and proactive measures to confront marine pollution.
It may be concluded that the leading cause of marine pollution is anthropogenic factors, including vessel wrecks and accidents, and excessive emissions of industrial waste into the marine environment. The problem is fraught with disastrous consequences for entire marine ecosystems composed of different species of flora and fauna and has adverse implications for human health and other areas of life. Despite international regulations and organizations, national laws and measures, and the efforts of non-governmental organizations, the problem requires higher priority.
Arias, A. H., & Marcovecchio, J. E. (Eds.). (2017). Marine pollution and climate change. CRC Press.
Karim, M. S. (2016). Prevention of pollution of the marine environment from vessels. Springer International Publishing.
Mearns, A. J., Reish, D. J., Bissell, M., Morrison, A. M., Rempel‐Hester, M. A., Arthur, C., Rutherford, N., & Pryor, R. (2018). Effects of pollution on marine organisms. Water Environment Research, 90(10), 1206-1300.
Xanthos, D., & Walker, T. R. (2017). International policies to reduce plastic marine pollution from single-use plastics (plastic bags and microbeads): a review. Marine Pollution Bulletin, 118(1-2), 17-26.