In all, 383 plastic particles were found in the gastrointestinal tract and gills of 67 out of 68 fish collected in streams of riverside communities in Pará.
A study carried out by the Federal University of Pará (UFPA) found, on average, six pieces of plastic inside the 98% body of fish collected by a group of researchers in springs and streams in the amazon.
In all, 383 plastic particles were found, 201 in the gastrointestinal tract and 182 in the gills (respiratory organ of aquatic animals, also known as gills) of 67 of the 68 fish analyzed by the research group from the Laboratory of Ecology and Conservation (Labeco), from UFPA.
Researchers claim that plastic ingestion can cause the death of these fish or affect their reproduction and lead to an imbalance in the food chain; or even that this synthetic material can ultimately end up in the human body.
This type of pollution shows signs of being spread throughout the Amazon basin. In January 2019, a group of researchers led by ichthyologist Marcelo Andrade, also linked to UFPA, identified the presence of plastic in Amazonian fish for the first time. On that occasion, they found particles in the gastrointestinal tract of almost 25% from fish collected in the Xingu River, including the red piranha (Pygocentrus nattereri).
A study published in the journal Nature Communications in June 2017 estimates that 39,000 tons of plastic are dumped into the ocean each year via the Amazon River — which passes through Peru, Ecuador, Colombia and Brazil.
ecological imbalance
Previous studies had already investigated this type of pollution in fish that live in other parts of the water course, such as rivers and oceans, and are consumed by humans.
The difference in this work, carried out by a group of freshwater fish researchers and published in July in the scientific journal Environmental Pollution, is to point out the extent of the damage to the animals' respiratory system and that this environmental problem affects the sources of rivers and streams, where the fish are, on average, 10 cm long in adulthood, are not usually consumed by humans and face greater risks of ecological imbalance.
Fourteen species of fish collected from 12 sites in the Guamá river basin, in the municipality of Barcarena in Pará, and in the Acará-Capim basin, in the municipalities of Ipixuna do Pará, Concórdia do Pará and Tomé Açu, were analyzed.
These two riverside regions do not have sewage treatment and use these springs and streams both as a leisure space and to dispose of waste.
In these places, these smaller fish play a fundamental role in the ecological balance of the region. They can be responsible predators, for example, controlling insects or serving as food for frogs.
“Without the future presence of one of these species that consume insect larvae, for example, there could be an explosion in the population of mosquitoes and the unbridled spread of diseases”, explains researcher Danielle Ribeiro-Brasil, one of the authors of the article and member of the UFPA research group, in an interview with BBC News Brasil.
One of the animals studied is the Crenicichla regani, also known as jacundá or ladybug. The fish of this species are predators that feed on small crustaceans and insect larvae and can show aggressive behavior. With good nocturnal vision, they often feed in the dark and sometimes are not even noticed by people in the environment, since they do not usually exceed 8 cm in length in the adult stage.
This species, analyzed in the UFPA study, contained more plastic in its gills and in its gastrointestinal tract than the others.
According to her, the next studies will analyze the impact of this pollution on the loss of species or the reduction of these communities. The origin of these particles must also be analyzed, but the main hypothesis is that these pieces found in Amazonian streams and springs came from synthetic clothes. Of the total, 93% of the particles found in animals are fibers.
In general, these particles originate from different sources, such as clothing, tires, paint and toothbrushes. It is estimated that between 2% and 5% of all plastic produced per year ends up discarded in the seas, but the real dimension of the problem is not known.
A study by the United Kingdom's National Oceanography Center, released this week, estimates that the amount of plastic floating in the Atlantic Ocean is capable of filling more than a thousand cargo ships, totaling 21 million tons (an amount ten times greater than if thought).
As these materials deteriorate, they end up being consumed by marine animals, entering the food chain - a path that ultimately brings plastic into the human body.
This week, another study, by researchers at the University of Arizona, in the USA, showed for the first time plastic microparticles in human lung, liver, kidney and spleen tissues.
There is still no conclusive information on the impact of this type of pollution on people's health, but it is already known what the presence of plastic inside the body can cause to fish.
These particles can attack two central points of fish in streams: the gills and the digestive tract. In the first, plastic interferes with the physical fitness of the animal, affecting its energy to capture food and reproduce. In the second, these particles can give the fish a false sense of satiety or even injure it to death.
According to the study, the fish that live in these analyzed streams consume proportionately more plastic than those found in rivers.
“Not all fish ingest plastic. This is also related to his behavior in the environment. If you are a carnivore, for example, you actively search for food and may mistake the piece of plastic for something you can eat,” says Ribeiro-Brasil.
Other studies point out that these plastics are ingested by some species not only because they look like food but also because they smell like food.
According to scientists at the Royal Netherlands Institute for Marine Research, these plastic particles in the ocean are quickly colonized by a thin layer of microbes, often called the “plastisphere,” which release chemicals that make plastic smell and taste like food for some animals. marine.
For the group of UFPA researchers, actions to prevent the increase in plastic contamination in the Amazon basin require the involvement of the local population, environmental education initiatives on solid waste management and the engagement of public and private institutions, among other points.
They defend, for example, incentive measures to reduce the consumption of single-use plastics, such as cotton swabs and straws, and regulation to guarantee the preservation of these ecosystems affected by pollution.
Source: https://g1.globo.com/natureza/noticia/2020/08/19/pesquisadores-acham-plastico-dentro-de-98-dos-peixes-analisados-em-estudo-na-amazonia.ghtml
