New evidence on how microplastics hit wildlife: ‘Affects whole ecosystems’

There are examples of aquatic animals that grow more slowly or quickly because they live in environments affected by microplastics.

- The effect of microplastics on the whole freshwater ecosystems is something we have suspected but had little evidence of until now, says Ze Hui Kong, a PhD student at the Department of Aquatic Sciences and Assessment, SLU.

Microplastics are small particles that include fragments and fibres from plastic materials in sizes between 0.001 and 5 millimetres (a common hair is 0.05 millimetres in diameter).

Ze Hui Kong's study highlights many of the effects of microplastics.

- Microplastics affect entire ecosystems. It starts with microorganisms being exposed and then eaten by larger animals. Ultimately, this has the potential to reach the top of the food chain and the perch and pike we like to fish and eat, says Ze Hui Kong.

Ze Hui Kong has also investigated the different ecosystem effects of microplastic particles with different particle types. Some forms of microplastic particles are easier for microorganisms to grow on. This changes the way the plastic moves in the water and can cause the pieces to become heavier and sink to the bottom.

- We tested spheres, fibres and fragments - but also different types of plastic polymers. It turned out that the important thing was not necessarily particle shape or polymer, but its concentration, says Ze Hui Kong.

The thesis provides a scientific basis for future environmental monitoring strategies.

- The impact of microplastics on animals, microorganisms and ecosystems are obvious. It is clear that efforts are needed to rapidly reduce the amount of microplastics in our waters, says Ze Hui Kong.