Microplastics, the poison of the sea

A group of researchers extracts plastics from the stomach of a sperm whale located off the coast of Granada in March 2012. Ebd-csic

Plastic poisons marine fauna and, ultimately, everyone.

A part of each washing machine that is started up, of each abandoned waste, of each gram that is not recycled or filtered in the treatment plants reaches the sea, where between 4.8 and 12.7 million metric tons accumulate, according to different studies.

This pollution, multiplied by 10 in the last 40 years, affects 86% of turtles, 44% of birds and 43% of marine mammals.

"It has become a major global problem," concludes the study by Margarita López Rivas, a doctor in marine biologist at the Research Center for Scientific Collections at the University of Almería (Cecoual)

"There are solutions, but there has to be political will and there hasn't been so far," he adds.

López Rivas and a group of collaborators, with the support of the Biodiversity Foundation and the Ministry for the Ecological Transition and the Demographic Challenge (Miteco), have carried out an analysis, published in

of 112 investigations on the effects of this contamination in sea turtles, cetaceans and fish, both pelagic (which inhabit the most superficial areas) and benthic (typical of the bottom of aquatic ecosystems).

The presence of plastics and their components has been identified in all the species studied.

In addition to constituting a death trap, as in the case of abandoned fishing gear, known as “ghost nets”, or other types of smaller volume waste, “plastics are entering the food chain through their ingestion by part of marine organisms ”, warns the doctor in marine biology.

And in that chain is humanity.

The study reveals that the highest ingestion of plastics by marine fauna collected in the Mediterranean and the northeast Indian Ocean varies depending on the species and the differences in color and type of prevalent polymers.

In sea turtles, the most frequent are white plastics (66.60%), fibers (54.54%) and low-density polymers or LDPE (39.09%);

in cetaceans, whites (38.31%), fibers (79.95%) and polyamides (49.60%);

and in fish, transparent (45.97%), fibers (66.71%) and polyester polymers (36.20%).

"In general, clear fiber microplastics are probably the most prevalent types ingested by marine megafauna worldwide," the paper concludes.

The prevalence of fiber residues is mainly due to residues from laundry;

the different polymers, to the degradation of the most common plastics;

and the rest, mainly, from the dragging to the sea of ​​the waste

The prevalence of fiber residues is mainly due to residues from laundry;

the different polymers, to the degradation of the most common plastics;

and the rest, mainly, from the dragging to the sea of ​​the waste.

"The main source of contamination is terrestrial, from boulevards full of garbage affected by climatic events, or from emissaries", the researcher details.

López Rivas explains that the presence of plastics in marine organisms is due to the fact that the fauna mistakes them for their usual food, such as gelatinous species, which ingest them at the same time as they feed or because they are already present in the prey.

The highest concentrations detected in marine specimens are recorded in the Pacific Ocean.

According to the study, this could be because 51% of the world's plastic in 2018 was made in Asia, where China produced 30% and is also the largest recipient of foreign waste.

The Asian continent is also home to the most polluted rivers and these represent 86% of the world's plastic pollution.

But the problem is global.

The oceanic circulation extends the problem and the presence of large accumulations of garbage is not limited to areas of high population density, but also occurs in the most remote areas of the planet, from the open ocean to the Arctic or the abyssal depths, according to warns the investigation.

“The impacts of marine pollution by garbage, mainly plastic waste, call for urgent strategies and a global vision.

Preventive measures to minimize the release of these pollutants into the oceans and seas should be a priority for the conservation of the world's marine ecosystems ”, the study concludes.

“We must change the recycling systems.

The companies associated with this work are not working and some countries are taking steps ”, adds López Rivas, who is now going to study the specific effects of microplastics on species of interest to fisheries and marine vertebrates.

Up to the brain

This study is of great importance due to its direct consequences on human nutrition.

An investigation of the University of Lund (Sweden), carried out by the chemist Ceder Tommyval, has demonstrated the disintegration capacity of plastic into nanoparticles.

These extremely small fragments reach all parts of living organisms.

A work from the same university proved that plastic particles can reach the brain of fish.

"It is no longer that they are in the digestive tract, but that they may be in any organ, so it would not be worth cleaning the fish," says López Rivas.

"Microplastics absorb organic and metallic pollutants as they travel through water and release these dangerous substances into the aquatic organisms that eat them, causing them to accumulate up the food chain," says Shaobin Wang, professor of chemical engineering. at the University of Adelaide (Australia), which is investigating formulas to mitigate this damage, according to a study on reducing waste generated by cosmetics.

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