Many of us had a penchant for fast food as teenagers, and some of us still do – we knew it was bad for us, but you know, it was convenient and everyone else was eating it. But according to recent research, fish actually prefer to eat micro-plastics rather than established food sources that provide them with the nutrition they need.
Researchers at Uppsala University in Sweden exposed perch larvae to different concentrations of micro-plastics, namely polystyrene, and found it had a significant effect on successful hatching – 96% hatched in the absence of micro-plastics, while only 81% did so in water containing large quantities of plastic pollution. Of the latter, many were born slower and smaller, making them more vulnerable to predators.
Most interestingly, those exposed to high quantities of plastic preferred eating the micro-plastics to conventional food sources. “They all had access to zooplankton and yet they decided to just eat plastic ... They are basically fooled into thinking it's a high-energy resource that they need to eat a lot of. I think of it as unhealthy fast food for teenagers, and they are just stuffing themselves," Dr Oona Lonnstedt, the study’s lead author, told the BBC.
It’s estimated that an average of eight million tonnes of plastic pollution is deposited in the world’s oceans annually. While larger debris is a significant problem – this study estimates that 90% of seabirds have ingested plastic at some point – much of the plastic in the ocean is broken down into micro-plastics over time and consumed by smaller animals, as are micro-beads from cosmetics.