Microplastic pollution appears to affect creatures at the bottom of the food web the most. That’s one of the main takeaways from an analysis of 43 studies looking at the effects of microplastics on aquatic life.
Microplastics are tiny beads that get into waterways from our consumer products or tiny fibers that wash out of our clothing.
Tomas Höök is an associate professor at Purdue University, and he directs the Illinois-Indiana Sea Grant program. He says a lot of different aquatic creatures eat microplastics, and small fish and zooplankton can eat microplastics instead of their normal food.
“And that might be because they’re actually consuming microplastics, and those microplastics take up room in their guts and they’re not as hungry, or they spend time ingesting microplastics and that’s less time they can spend feeding on natural prey," he says. "Or maybe the microplastics just confuse them so they’re not as effective at foraging.”
He says studies showed microplastics reduced the growth, survival, and reproduction of zooplankton, and that could affect the fish that eat them.
The Sea Grant website sums up more of the study's findings:
* Considering all effect sizes together, on average, exposure to microplastics negatively affects consumption, growth and survival of aquatic animals.
* However, the results are highly varied and not all groups of animals were affected in the same ways.
* Microplastics significantly reduced growth, reproduction and survival of zooplankton.
* When exposed to microplastics, larval and juvenile fish see negative effects on natural consumption of other foods.