Far from being just a figure of speech, the existence of microplastics spread throughout the ocean is unequivocal for specialists on the topic.

A favorite of industry due to its flexibility, durability and low production costs, plastic’s virtues are crumbling not unlike a 500-milliliter bottle transforming into millions of fragments in the marine environment.

Drifting at sea and subject to wind, ultraviolet rays and maritime currents, a small bottle thrown down on the beach will deteriorate over the years into particles measuring less than 5 millimeters (0.2 inches). These particles can become part of the food chain, contaminating algae, crustaceans, fish and, eventually, humans.

Yet, studies on the consequences for the environment, sea life and human health, as well as the reach of the contamination, are still scarce.

In Brazil, where more than 12 million tons of plastics are produced every year, making it the planet’s fourth-largest plastics producer, two important studies are in the laboratory analysis phase to map out regions, calculate the pollutant load, categorize the types of plastics and, finally, learn how the trash made it’s way to the Atlantic Ocean.

The MICROMar project is coordinated by Professor Guilherme Malafaia of Goiano Federal Institute and involves researchers from numerus state and federal universities. For a year and a half, MICROMar collected sand and seawater samples from 1,212 beaches and 211 municipalities along 7,500 kilometers (4,660 miles) of the Brazilian coastline.

The 10,000 samples currently under analysis will make MICROMar the largest diagnosis of plastic pollution ever carried out in Brazil.

This study aims to identify and quantify the residue according to different uses of the coastline, taking into account the population density of each region, how much tourism goes on there and climate characteristics like precipitation and wind direction, all of which are considered, together with outfall from large rivers, to be major factors in carrying pollutants to the ocean.

“The project’s major contribution will be to create a thorough analysis that maps out the most critical regions. We all know that microplastics are everywhere — they’re omnipresent. The maps will enable us to see how the pollution is distributed and understand just how extensive and serious the contamination is along our coastline,” Malafaia says.

According to this biologist, preliminary observation indicates that microplastics contamination is a reality on nearly every beach studied, from far-north Goiabal Beach in Calçoene, Amapá, down to Barra do Chuí, in Rio Grande do Sul state on the Uruguay border. Even the lakes dispersed between the Lençóis Maranhenses sand dunes (which were recently recognized by UNESCO as a World Heritage Site) hold significant amounts of microplastics.

“The most polluted beaches are those in the south and southeast. But, in general, many beaches, including famous northeast beaches like Ceará’s Jericoacoara and Recife’s Praia de Boa Viagem, showed high pollution loads, indicating that there is contamination not only in tourist areas but also in more remote locations,” Malafaia says.

Food safety

Another project, Voice of the Oceans, focuses on food safety. The initiative finished a 70-day overland expedition in July this year to farmers markets and small groceries along the Brazilian coast, measuring the presence of microplastics in the marine animals eaten by the people there.

Voice of the Oceans is a result of a partnership between the Schurmann family (who were the first Brazilian family to circumnavigate the globe in a sailboat) and the University of São Paulo (USP), with funding from UNEP, the U.N. Environment Programme. Samples of seven mollusk species including oysters and mussels were collected in 17 cities in 15 Brazilian states ranging from Itajaí, Santa Catarina, in the south to Belém, Pará, in the north.

Bivalves (which have two shells, or valves) are excellent bioindicators for marine environment pollutants because they filter organic material from the water with their gills.

Aside from involuntarily filtering microplastics when they eat, bivalves are also effective biomarkers for pollutants in the food chain because they eat plankton, which live at the bottom of the food chain. The fact that they are prey for animals from the bottom of the ocean up through the entire water column (the space between the bottom and the surface) also makes them effective biomarkers.

“In the lab, we will measure the size and density of each particle as well as identify its composition — whether it is polyethylene, PVC, polypropylene — and then categorize the profile of the microplastics being eaten by these animals,” says marine biologist Marília Nagata, who led the Voice of the Oceans expedition.

Polyethylene, used in single-use food packaging, is made from oil and natural gas and is the most widely manufactured plastic in the world, with volumes amounting to 103.9 million metric tons per year.

USP’s Oceanographic Institute will create the laboratory to classify and count the microplastics with special technology able to identify particles smaller than a cell. The study is led by Professor Alexander Turra with funding from Brazil’s National Council for Scientific and Technological Development. The measuring instrument was donated by Shimadzu and is the first of its type dedicated to research in Brazil.

“My main aim in creating this laboratory is so we will be able to train people in Brazil and create more opportunities for increased infrastructure so analyses can be carried out in all the coastal states,” says Turra, who also holds the UNESCO Chair for Ocean Sustainability.

Contaminated oysters

Turra also led a bivalve study in the Paranaguá Estuarine Complex, located on the Paraná coast, which is home to Latin America’s largest grain seaport.

Recently published by Turra’s Ph.D. student Suzane de Oliveira, the study analyzed oysters in their natural habitat throughout the region, including in Superagui National Park, an important conservation unit on the state’s northern coast.

The results showed that more than 90% of the oysters collected were contaminated by some amount of microplastics. At some collection sites near the port, in urban centers and at the mouths of rivers, 100% of the oysters analyzed carried contaminants in their bodies.

Large quantities of microplastic fibers were found inside the organisms’ digestive tracts, most likely derivatives of the laundering of synthetic clothing, nylon used in fishing nets and rubber residue from tires on the trucks that drive on the Estrada da Graciosa, the highway leading to the port.

“The number of particles identified in Superagui National Park was surprising because it’s the farthest point from the port and an environmentally protected area. This just shows how much we need to learn about the processes that generate microplastics, which will lead us to their origin,” Turra points out. He adds that the serious problem of plastic threads that come off of synthetic clothing could be mitigated by prewashing processes at manufacturing mills before the fabrics are sold to clothing manufacturers.

Turra says the fibers are released and lost after 10 wash cycles in normal Brazilian washing machines, and that prewashing can reduce the amount of these fibers by 70%.

3.4 million tons of plastic in the oceans

Another important project working to identify the sites where the most plastic is being leaked into the ocean along the Brazilian coastline is part of the Blue Keepers program, a joint project between the UNESCO Chair and ONU’s Global Compact together with the University of São Paulo Oceanographic Institute.

According to two studies already completed by the project, Brazil dumps 3.44 million tons of plastic into the ocean every year, meaning that a third of the plastic produced in the country could reach its seashores. It is estimated that between 86 million and 150 million tons of plastic residue have accumulated in the ocean

The study also revealed that there are 600 sites in Brazil where plastic pollution is discharged into the Atlantic Ocean. The main entryways identified are the basins of the Amazon River (some 160,000 tons/year) and the Rio São Francisco (230,000 tons/year), Guanabara Bay (216,000 tons/year) and the Rio da Prata (with more than 1 million tons per year). Together, these sites are responsible for 67% of the plastic that Brazil sends to the sea.

However, the coastal zones are not where the most microplastic particles are found. A study carried out by Australia’s National Science Agency and the University of Toronto revealed that the amount of plastic on the sea floor may be a hundred times greater than what is floating on the surface.

The first scientific record of deepwater garbage in Brazil was published recently in Marine Pollution Bulletin by researchers from USP’s Oceanographic Institute.

The study was initially focused on biodiversity, seeking to identify deep-sea fish species during Deep-Ocean Project expeditions, financed by FAPESP, the São Paulo Research Foundation. But to the scientists’ surprise, the net they used for collecting fish also collected large quantities of food wrappers, plastic shopping bags, bottles, cans and fishing gear. Plastics composed more than half of these items, which were found at all the study’s collection sites. The trash was retrieved from depths ranging from 200-1,500 meters (650-5,000 feet) and at around 200 km (125 mi) from the São Paulo and Santa Catarina coastlines.

In 2023, 430 million tons of plastic were produced worldwide, 40% of which were single-use plastics. Only 9% of the plastics used on the planet are recycled.

In Brazil, this number doesn’t even reach 2%. Since 2022, people have been awaiting approval in Congress of Bill 2524/2022, which seeks to reduce the generation of disposable plastic residues and promote the circular plastics economy.

Proposal for a global treaty

There are no frontiers to the extent of microplastic dispersion carried on maritime currents to the farthest reaches of the globe.

There are high hopes for the Global Plastics Treaty, which is being discussed by 175 U.N. member nations. The final meeting to write the definitive text will be held in November 2024 in South Korea.

The goal is to significantly reduce pollution caused by disposable single-use plastic through a legally binding accord (enforceable by law).

The first obstacle is to reach a consensus on restrictions for the production of new plastics. The measure, seen as primordial by environmentalists, has met with strong resistance from nations connected to large oil and natural gas producers.

At the recent meeting held in Canada, Peru and Rwanda presented a proposal to cut production by 40% between 2025 and 2040, gaining support from nearly 30 countries including France, Norway, Chile and Senegal. Brazil and the United States both declined to support the proposal.

According to Larissa Godoy, the TerraMar Project’s national coordinator and substitute general coordinator of coastal management for the ocean department and of coastal management in the environment ministry, Brazil has required that the global accord be binding according to PNUMA’s proposal and that there be a fair transition to the circular plastics economy respecting the most fragile links in the chain (like the individuals who collect recyclable materials) and also workers in the plastics industry, whose health and integrity must be protected.

Godoy says that “without real support for the circular economy, for recycling and for the demand for virgin raw materials, there will be no reduction of plastic.”

This story was first published here in Portuguese on Oct. 15, 2024.