A pioneering study by the Millennium Institute of Coastal Socio-Ecology (SECOS) revealed the first evidence of microplastics in estuarine sediments in southern Chile. The research, published in the journal Environments, confirms the presence of these particles in the estuaries of Lenga and Tubul-Raqui, in the Biobío region.
Although the concentrations are lower than those recorded in highly industrialized estuaries in countries like China, India, or France, scientists interpret the finding as an early warning that demands preventive measures to protect these vital ecosystems.
Microplastics: a global environmental challenge
Plastic pollution is one of the planet’s biggest environmental problems. Millions of tons of waste degrade in the ocean into microplastics, particles less than 5 millimeters that invade every marine corner, from the water column to the bottom sediments.
Dr. Ricardo Barra, a researcher at SECOS and the Faculty of Environmental Sciences at UdeC, explained the motivation for the study:
“Research on microplastics has overlooked the study of estuaries, key ecosystems at the interface between the continent and the sea. This is the first report of microplastics in estuarine sediments in Chile.”
Two estuaries, two realities
The analyzed estuaries represent contrasting scenarios:
- Lenga, in San Vicente Bay, highly industrialized.
- Tubul-Raqui, where artisanal fishing predominates.
The results reflected this difference:
- Lenga recorded 106.9 particles per kilo of sediment.
- Tubul-Raqui reached 49.3 particles per kilo.
The study identified fibers, fragments, foams, and films as the most common types. Using infrared spectroscopy (FTIR), researchers determined the chemical composition:
- In Lenga, polyamide (PA) (35%) predominated, followed by polyester and polyurethane, materials present in technical clothing, fishing nets, and industrial uses.
- In Tubul-Raqui, the most abundant polymer was polyvinyl chloride (PVC), widely used in pipes, packaging, and construction.
Good news or warning?
While the concentrations are dozens of times lower than in other countries, researchers warn that this should not be interpreted as good news.
Barra, also director of the EULA-UdeC Center, noted:
“This represents an early warning. We must now investigate what this contamination causes in the organisms living in the estuary. The call is to prevent, to improve the management of plastic waste.”
Academic Marco Lardies, from UAI and a SECOS researcher, added that the estuaries of central-southern Chile act as reservoirs and seasonal sources of microplastics, with increases of up to 20 times in winter.
“Although the levels are lower, there is a growing risk if local mitigation measures are not implemented. These particles can directly affect benthic and fishing species, alter their habitat, and release toxic additives and heavy metals that spread in the food web.”
An urgent call for prevention
Since microplastics come from the fragmentation of larger plastics, their removal from the environment is practically impossible. Therefore, researchers emphasize the need to prevent their entry through:
- Better waste management.
- Reduction of single-use plastics.
- New public policies focused on coastal ecosystems.
Chile has advanced with laws like Law 21.368, which regulates single-use plastics, and the framework of Extended Producer Responsibility (EPR). However, experts argue that specific measures for estuarine ecosystems are still lacking, where impacts can extend to biodiversity and human health.
The finding of microplastics in the estuaries of Lenga and Tubul-Raqui marks a turning point in environmental research in Chile. Although concentrations are low, they represent an early warning signal that demands strengthening prevention and expanding oversight.
Estuaries, essential for biodiversity and the local economy, already show signs of contamination that could worsen if not acted upon quickly. Science provides the evidence: now it is up to society and public policies to respond with concrete solutions.
