In recent weeks there has been a major environmental disaster on the northwest coast of Spain. Millions of small plastic balls, so-called “pellets” or pellets, are appearing on the beaches of Galicia, causing concern among residents and the scientific community.
This phenomenon occurred after more than 26 tons of this material was dumped in Portuguese waters by the merchant ship Toconao and sparked a heated debate about the risks posed by this waste.
Pellets are a refined form of plastic that is used as a raw material to make a variety of products, from packaging to toys, and can come in many different shapes.
Direct impact of pellets on nature
The presence of plastic particles on the Galician coast, although chemically harmless (not yet proven), represents a direct and immediate threat to marine fauna.
Previous research on this material has shown that sea creatures, including fish and birds, often mistake these pellets for their natural food.
This mix-up can lead to accidental ingestion of these particles, especially in high concentrations. One of the problems when they enter the body is that they block the digestive system of marine animals, causing exhaustion, poor health and, in severe cases, death.
On the other hand, the accumulation of these plastics in the digestive tract of larger animals, even in the absence of serious obstacles, leads to a limitation in their ability to absorb essential nutrients, negatively affecting their health, growth and reproduction.
However, the dangers are not limited to swallowing this pellet. There is an additional risk that this plastic, once decomposed, becomes microplastics, which can easily be consumed by smaller organisms such as plankton and then transmitted to fish and other predators of other meat species, including humans, and are therefore present in foods throughout the food chain .
Plastic doesn't come about by chance
The chaff scattered along the coast appears to be composed primarily of polyethylene, which is commonly used in food preservation materials and is chemically harmless.
But these materials do not come alone; to produce granules, several chemical compounds are used that act as stabilizers, antioxidants and filters, protecting the plastic from light. Many of these substances are highly toxic to aquatic life in free form and although they do not pose a problem under normal conditions or in plastics, these “pellets” are not designed to withstand the marine environment.
Sea water, movement and constant exposure to sunlight lead to completely different conditions than those normally found in products made from this material. The conditions lead to erosion and material destruction with serious consequences in the medium and long term. In addition to this ability to release toxic substances, there is also the ability of plastic particles to absorb substances dissolved in the environment.
According to Alicia Herrera Ulibarri, researcher at the University of Las Palmas de Gran Canaria of SMC Spain: “Chemical pollutants are present in the environment in very low concentrations, but they adhere to the walls of particles and cause them to decompose. They concentrate there, making them more dangerous to marine life that ingests them.“ These substances can include heavy metals, pesticides or UV filters used in cosmetics. This exposure can cause a variety of health problems in marine life, ranging from endocrine disruption to direct damage to vital organs.
Combined with bioaccumulation, this process increases the toxic effects of contaminants in the food chain, increasing the risk to more species, including the end consumer. A study by Ricardo Beiras, researcher at the Marine Research Center of the University of Vigo, shows that the toxicity of microplastics is mainly due to the leaching of chemical additives and substances adsorbed by them, not to the microplastics themselves.
Of particular concern are the long-term effects of pollution from pellets containing pollutants. Since particles decompose under environmental influences such as ultraviolet radiation and mechanical stress, adsorbed pollutants can be released into the environment. This poses an ongoing threat to the health of marine ecosystems and potentially human health.
Chaff carries pathogenic microorganisms
The famous “pellets” not only pose a physical and chemical threat to marine ecosystems; They also pose a biological threat. Plastics (both meso-sized particles and degradable microplastics) provide ideal surfaces for the settlement and growth of microorganisms that form biofilms, also known as biofilms Biofilms.
These biofilms are layered collections of organisms covered by a matrix of secretions that can transport a variety of bacteria, algae, fungi and protozoa. The colony matrix protects microorganisms from adverse environmental conditions and antibacterial treatments.
There is concern that biofilms could serve as a reservoir for pathogenic bacteria, which pose medium and long-term risks to marine life and humans and should not be ignored. In addition, some microorganisms present in biofilms may be invasive species or produce toxins that have negative effects on native flora and fauna. The presence of these biofilms can alter natural ecological processes, particularly nutrient cycling in the marine environment.
And what is the best solution?
The best solution is of course prevention; But when an accident like the one that occurred in Portugal a few days ago occurs, this terrible experience should be a lesson for the future.
With the damage now done, there is an urgent need to remove plastic particles from the coast, but it is important that this process is carried out carefully and in a coordinated manner.
According to Zulema Varela, an ecotoxicologist at the University of Santiago de Compostela, some of the activities carried out on the Galician coast, certainly with the best intentions, can cause more problems than they can solve.
For example, the sand dunes in the affected area play an important role in coastal protection and are home to unique biodiversity. Cleanups that do not take into account the fragility of these ecosystems can result in dune erosion and vegetation loss, causing severe environmental damage beyond the locations where the pellets are located.
On the other hand, uncontrolled beach raking or sand filtering can harm very delicate benthic invertebrate communities, the preservation of which is essential to the health of the ecosystem. Invasive restoration methods can alter or destroy these habitats and impact the beach's food chain and ecological balance. In addition, if handled carelessly, pellet particles can be trampled and buried, making them difficult to remove and increasing their impact.
Faced with this difficulty, Zulema Varela explains how best to remove the chaff, saying that “it is very complicated” and that she does not know of an effective method. However, the researcher understands that a unique protocol is required to maximize effectiveness and minimize harm.
In this context, it is imperative that authorities implement this protocol as quickly as possible and engage conservation experts to guide and train staff and volunteers. An effective response requires close coordination between authorities, environmental organizations and local communities. The best way is to educate and raise awareness about the importance of protecting these ecosystems and eliminating pollution.
References:
- Arias-Andres, M. et al. 2018. Microplastic pollution increases gene exchange in aquatic ecosystems. Pollution (Barking, Essex: 1987), 237, 253-261. DOI: 10.1016/j.envpol.2018.02.058
- Battisti, C. et al. 2020. Small-scale environmental actions require a problem-solving approach: Applying project management tools to beach debris removal. Environments. DOI: 10.3390/environments7100087
- Beans, C. 2023. Do microplastics spread infectious diseases? Proceedings of the National Academy of Sciences, 120(31), e2311253120. DOI: 10.1073/pnas.2311253120
- Beiras, R. et al. 2020. The aquatic toxicity of chemically defined microplastics can be explained by functional additives. Hazardous Substances Journal, 406. DOI: 10.1016/j.jhazmat.2020.124338
- Camacho, M. et al. 2019. Organic pollutants in marine plastic waste on the beaches of the Canary Islands. Science of the Whole Environment, 662, 22-31. DOI: 10.1016/j.scitotenv.2018.12.422
- Oberbeckmann, S. et al. 2018. Environmental factors support the formation of specific bacterial accumulations on microplastics. Frontiers of microbiology, 8. DOI: 10.3389/fmicb.2017.02709
- Turner, A. et al. 2020. Metals and marine microplastics: adsorption from the environment versus addition during production, using lead as an example. Water research, 173. DOI: 10.1016/j.watres.2020.115577
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