A new study, conducted in the United States, confirms the presence of microplastics in fish and shellfish, highlighting however how some species are more at risk of contamination than others
The microplasticsvery small fragments of plastic that pollute the environment, are now an omnipresent element, even in our food chain. In fact, it is now sadly known that, due to environmental pollution, these small debris can be ingested by marine animals, thus ending up on our tables through the consumption of fish (and unfortunately this is not the only channel).
A recent study, conducted by a team from Portland State Universityconfirmed this scenario, revealing the level of microplastic contamination present in the most consumed fish species in Oregon, United States, species that are actually widespread and popular elsewhere.
More specifically, the research analyzed the content of microplastics in 6 Pacific Northwest fish and shellfish speciesvital to the local economy, including king salmon, cod, black rockfish, pink shrimp, Pacific herring and Pacific lamprey.
Experts focused on how trophic levels (a fish’s position in the food chain) can impact microplastic contamination and the difference between samples taken from fishing boats and those from supermarkets.
The results of the study, published in the journal Frontiers in Toxicologyshowed the presence of 1,806 suspicious particles in 180 of the 182 samples analyzed. Fibers were the most common particles, followed by fragments and films.
But which species were most contaminated?
The most contaminated fish
Below is the list of species analysed, starting from the most contaminated one and moving down, according to the study which – we underline – was conducted on samples from a specific area. It should be noted that the results may vary from area to area, but are nevertheless interesting as they offer a useful indication for identifying fish at greatest risk of contamination:
But why are shrimp the most contaminated by microplastics? According to the study, the reason lies in their eating behavior. In fact, they feed by filtering the water near the surface, where plastic particles accumulate. Because these particles resemble zooplankton, they are easily ingested by shrimp.
Although increased contamination due to seafood processing and packaging was expected, the researchers noted that rinsing fish and shellfish, a common home practice before preparation, significantly reduced additional contamination that might settle on the surface during fish processing. However, the problem of upstream contamination remains.
And the matter, as experts have underlined, is particularly relevant.
In fact, the study provides evidence of the widespread presence of particles in the edible tissues of Oregon marine and freshwater species. Susanne Brander, an ecotoxicologist and associate professor in the College of Agricultural Sciences at Oregon State University, said:
It is very concerning that microfibers appear to move from the gut to other tissues such as muscles. This has broad implications for other organisms, potentially even humans.
