- Scientists and Indigenous Skolt Sámi knowledge holders have detected microplastics in the lakes and rivers that the Indigenous Sámi communities have used for generations.
- The concentration of microplastics was small, researchers found, but it was still higher than the quantity expected, given that the area is thought to be pristine.
- The average size of the microplastics was 100 micrometers and concentrations ranged from 45 to 423 microplastic particles per cubic meter.
- While the source of the microplastics is unknown, researchers say one of the sources could be from the transboundary pollution accumulated in fish that come from the ocean to the freshwaters for spawning.
In Finland’s freezing Arctic, lakes and rivers have nourished the lifeways of Indigenous Skolt Sámi communities for generations as they fished and herded reindeer. But three years of research undertaken by Sámi traditional knowledge holders and scientists have, for the first time, detected another presence in their waters: microplastics.
“The plastic concentrations were really small, but they were definitely there in higher quantity than it was thought to be,” said Tuomo Soininen one of the study authors and a PhD scholar at the department of technical physics in the University of Eastern Finland. “It’s really pristine when you observe these areas, and you don’t see big plastic debris anywhere.”
The research found that the average size of the microplastics was 100 micrometers (μm) and that concentrations ranged from 45 to 423 microplastic particles per cubic meter (35.3 cubic feet). They sampled both freshwater and marine water that are part of the Finnish Skolt Sámi traditional use: Lake Inarijärvi (Inari), Näätämö river catchment and the Neiden Fjord in the Barents Sea. The Näätämö River in Lapland, Finland’s northernmost region, flows and drains into the Neiden Fjord, before continuing into the Barents Sea. Neighboring Lake Inari was also sampled as a lake ecosystem but it is not in the same basin.
The most common polymer types the researchers found were polyethylene, polypropylene and polyethylene terephthalate. Microplastic concentrations were lower in the fjord compared to the catchment area of Näätämö River or Lake Inari.
The source of these microplastics is unknown. However, the authors hypothesize that it could be carried by transboundary pollution from the ocean, blown in by the wind into the mouth of the Näätämö River, or accumulated in the fish returning from the ocean to spawn in the river.


Traditional Sámi knowledge as key leads?
Among these once-pristine water systems, the Näätämö River, spread across both Finland and Norway, is one of few salmon rivers that are accessible to the Skolt Sámi. The river is not only a source of their livelihood, but also a repository of traditional knowledge and a means to nurture their socio-spiritual harmony with nature, sources told Mongabay.
Pauliina Feodoroff, a Skolt Sámi leader, said she was 12 when she caught her first salmon in the Näätämö River. She recalled how fishing was a part of the essential trade with Norway and that salmons were traded for butter, flour, sugar and tea. Although communities now have cut down on salmon fishing and trading, she said, people have observed fish population has receded over the years.
“Not only the [fish] numbers, but many Sámi people noticed the presence of invasive species, mainly pink salmon [Oncorhynchus gorbuscha] and new algae in the water systems,” Feodoroff told Mongabay.
To document the changes while using their traditional knowledge, Skolt Sámi in northern Finland developed the Skolt Sámi Climate Events Database. They collaborated with scientists and local NGO Snowchange Cooperative and a network of Indigenous peoples and communities around the world. Microplastic detection was just one part of the project and was part of collaborative management efforts since 2011.
“It’s not a news piece that microplastics are everywhere but the study was significant in the sense that Indigenous Sámi and scientists collaborated to collect samples in wilderness areas that look pristine and were least expected of microplastics,” said Tero Mustonen, one of the study authors and a researcher at Snowchange Cooperative. “And this is possible with the database and the knowledge gathered from the Indigenous Sámi women.”
Research on microplastics in these waters kicked off because of the observations Sámi women made of the waters they traditionally use, Feodoroff said. “The water no longer smelled and tasted like before. We would feel a mild burning sensation in our throats when we consumed it, but the water still looked clean.”
Because local knowledge helped spur the study, she said, scientific research was needed to know what was actually changing in their rivers and landscapes, to be more prepared for possible implications.
Following the detection of microplastics, Feodoroff said, “Instead of growing worried, the Skolt Sámi community people are actively planning to monitor the wilderness areas, place trash bins in the areas and recycle them.”


What’s the source of the microplastics?
While the research detected the presence of microplastics, Soininen said it’s unlikely that there are immediate effects of these concentrations of plastics on human health. However, regarding species that are on the bottom of the food chain, he said, “We don’t know when a switch can happen. If there’s some bigger effect on some small plankton species, we still don’t know the effects on the food chain. So, there might also be global effects coming.”
Given the Arctic is a sink for plastics, Mustonen said he’s also worried about more plastic and pollution coming into these waters due to climate change.
“We know that the ice on the North Pole, which used to be permanent, [now] has a lot of microplastics concentrated. We don’t know if climate change will melt most of the ice in a few decades to leave behind a lot of plastic debris, and also other pollutants like persistent organic pollutants,” said Mustonen. A 2023 study in Nature found that the Arctic is melting four times faster than the rest of the world.
The authors of the microplastics research said the interconnectedness between the waters could be a source of microplastic pollution in the river — transboundary pollution from the oceans accumulating in the anadromous fish returning for spawning in the Näätämö River. The Nätämö river basin is important because it is currently the only river of the Skolt Sámis’ where the Atlantic salmon (Salmo salar) comes to spawn. Since the river is connected to the Arctic Ocean and to the fjord ecosystem, it provides a link between the northern oceans, Arctic seas, and interconnected freshwater habitats.
Rivers everywhere discharge into the seas, transporting plastics and microplastics that originate from land-based sources, said Maiju Lehtiniemi, a research professor at the Finnish Environment Institute (SYKE) who was not involved in the study. “But it could be possible, of course, that migrating fish can transport microplastics they have ingested in the sea to the rivers during spawning migrations.”
One caveat and factor affecting the concentrations of detected microplastics, said Lehtiniemi, could be the volume of water sampled for the microplastic analyses.

“In the research, the volume was not that high, and it would be good to filter a cubic meter or more to obtain reliable particle concentration of the particles that are not high in concentration as the filtered water volume may be one of the factors affecting the concentrations obtained.”
According to Lehtiniemi, the fact that lower concentrations of microplastics were found at the fjord where the river discharges could be because discharged microplastics are spread out more widely to a larger volume of seawater. “And also because microplastics tend to sink down to the sediments, it could be that the concentrations are lower in the water surface or column.”
She also said that she believes microplastics in fish in these waters are still so low, making it safe to eat them. “The impacts of microplastics in the northern ecosystems are still low but, over time, if nothing is done about plastic waste and microplastics entering the northern waters there can be effects to be seen.”
Banner image: Researchers on one of the field visits to the Näätämö River, remote wilderness areas and the fjord at the outflow to the Arctic Ocean. Image courtesy of Snowchange Cooperative.
Plastic pollution talks end & Arctic peoples return home to a ‘sink’ of plastic