Facts: The study
The study was conducted on 60 fish that were placed five each in 45-liter aquariums.
Their behavior was filmed and analyzed, and towards the end of the study, the fish were euthanized, measured, weighed, and liver and brain samples were taken.
The study is published in the scientific journal Science of the Total Environment.
When young perch were exposed to bioplastic in the fish food for six months, their behavior changed significantly. They became worse at forming shoals, moved less and reacted differently to danger.
The PLA plastic is often described as environmentally friendly and is used in disposable cutlery, 3D printers and food packaging.
“We see that there is something in the PLA plastic that causes a change in the fish, but we cannot see what,” says PhD student Azora König Kardgar in a press release.
The perch received two percent PLA in their fish food.
“We see that PLA is not harmless to the fish, so it should not be sold as an environmentally friendly alternative to ordinary plastic. It should be considered ordinary plastic,” says Azora König Kardgar.
Another group was fed fish food with the same amount of kaolin, a type of white clay used for porcelain. That group was also affected, among other things regarding the male sex hormone and possibly disturbances in the fish’s endocrine system.
The two fish groups were compared with a third control group that received fish food without additives.