There are many wastes, both solid and liquid, that are thrown into the sea. In this article we will talk about the main negative impacts caused by humans on beaches.
IndexPollution: impacts of human presencePollution of beaches by cigarette buttsImpact due to eutrophicationAccumulation of plastic waste
Pollution: impacts of human presence
It is not uncommon to go to the beach and find abandoned soda cans, bottles or cigarette butts. The situation is even worse after certain events that leave the beaches covered in plastic cups and bottles. Although some of this waste is removed, others are left abandoned in the sand, subjected to wear and tear due to the abrasion of the wind and, in the case of plastics, the sun. The movement of sediments makes it easier for these wastes to remain buried and makes their extraction difficult.
Pollution of beaches by cigarette butts
A study recently published by the Spanish Institute of Oceanography (IEO) has highlighted the problem posed by the cigarette butts we leave on the beach. It is estimated that around five billion cigarette butts are thrown into the environment each year, many of which end up in the sea or on beaches.
Cigarette filters are made of cellulose acetate, a material that is difficult to biodegrade and can remain in the ground for a long period of time. The study published by the IEO has shown that cigarette butts release heavy metals into the marine environment, mainly copper, which is toxic to many organisms.
It would, therefore, be a source of pollution to the marine environment that, according to researchers, could affect marine water-filtering organisms, such as oysters, and once within the food chain it could cause problems for other organisms.
Other types of pollutants that are released into the marine environment are fecal waste, both human and from livestock, and fertilizers containing nitrogen or phosphorus. This causes excessive growth of microorganisms and algae, which is known as eutrophication. Although the most dramatic effects of eutrophication are visible in lakes, lagoons and bodies of water with little renewal (such as the Mar Menor, in Murcia), marine ecosystems and beaches can also be affected.
Alterations in the marine microbiota can be harmful to health. For example, during red tides (a proliferation of microalgae that can occur naturally or due to eutrophication) the number of dinoflagellates and diatoms (microscopic, single-celled algae) in the water increases. These microorganisms release toxins that can be harmful if contaminated fish or shellfish are consumed.
Something similar can occur due to fecal waste, which causes the proliferation of bacteria that contaminate the water and the organisms that live in it, such as different types of seafood. Contact with this type of bacteria can cause everything from diarrhea to skin infections, which is why efforts have been made in recent years to ensure that all fecal waste is eliminated in treatment plants before the water is discharged into the sea.
Accumulation of plastic waste
Beaches are terrestrial ecosystems that act as a sink for plastic waste, since both those that we leave behind on the sand and those that are returned by the sea accumulate there. The joint action of water, sand moved by the wind and UV light degrades plastics, fragmenting them into small particles that have greater mobility and can reach other terrestrial ecosystems.
The problem with plastics is twofold. On the one hand, in marine ecosystems they are susceptible to being ingested by animals, causing their death. On the other hand, in terrestrial ecosystems they accumulate in the substrate, where they alter the physical and chemical properties of the soil, modifying the microbiota and plant growth, being an important source of pollution.
Ocean currents can transport plastics long distances, keeping them drifting away from the coast. The largest plastic “island” in the world is located between California and Hawaii, occupying an area of several million square kilometers and containing about 100 million tons of plastic.
For these reasons we must pay special attention to not leaving waste of any kind behind when we visit the beach, leaving everything as it was before our presence there. Otherwise, we can cause a lasting impact whose long-term consequences on ecosystems and our health are unpredictable.
- Santos-Echeandía et al. (2021). The role of cigarette butts as vectors of metals in the marine environment: Could it cause bioaccumulation in oysters? Journal of Hazardous Materials, Volume 416, 125816, ISSN 0304-3894.
- Auta et al. (2017). Distribution and importance of microplastics in the marine environment: a review of the sources, fate, effects, and potential solutions. Environment International, 102, 165–176. doi:10.1016/j.envint.2017.02.013
- Lawton and Codd (1991). Cyanobacterial (blue-green algae) toxins and their significance in UK and European waters. Journal of Soil and Water Conservation. 40(4): 87–97. doi:10.1111/j.1747-6593.1991.tb00643.x