Microplastics Threaten To Destroy Fish Populations, Study Finds Perch Love Eating Plastic Over Natural Food

Microplastics, often found in many products like face wash and toothpaste, are dumped into the water and eventually end up in the world’s oceans. Studying the environmental impact of the plastic pollution, scientists recently discovered young fish love eating the microbeads much the same as teenagers love fast food.

Led by Dr. Oona Lonnstedt, a team of researchers analyzed the influence of polystyrene, a type of synthetic polymer, on the early life stages of fish. After exposing newly-hatched European perch to microplastics, they found the fish would rather eat the plastic over natural food.


By preferring the plastic, the fish were unknowingly starving themselves, Dr. Lonnstedt told BBC News.

“They all had access to zooplankton and yet they decided to just eat plastic in that treatment. It seems to be a chemical or physical cue that the plastic has, that triggers a feeding response in fish. They are basically fooled into thinking it’s a high-energy resource that they need to eat a lot of.”

The experiment involved three groups of young perch. One group grew up in water free of any microplastics, while another group lived in water containing a concentration of about 10,000 particles per cubic meter. The third group was exposed to an aquatic environment comprised of 80,000 particles per cubic meter.

The researchers noted the perch that ate the plastic were generally smaller and slower than the fish not exposed. In addition, the stunted perch were eaten by predators much faster than the ones born in clean water.

In the wild, perch detect chemical changes in the water that alert them when another fish is attacked by a predator. The plastic-eating fish seemed to lack this ability, especially the ones born in the highest concentration of microplastics.

The researchers introduced pike, a natural predator, into the perch environments. After 24 hours, 54 percent of the plastic-free perch were eaten, while 66 percent in the second group were gone. The third group, the fish exposed to the highest plastic concentration, were completely gone within the same time period.

Based on their study, the researchers are convinced the decline of some fish species like perch and pike in the Baltic Sea over the past 20 years is likely linked to increased fish deaths while they are young. As the fish are more susceptible to predators, they never develop long enough to reproduce.

Perch and pike are not the only aquatic life in danger. Previous research has shown microplastics hinder the reproduction cycle of oysters, as well as harm other sea creatures like mussels and marine worms. Some have even suggested the microbeads are killing coral by blocking the digestive systems of coral polyps.


Since the tiny plastic particles remain in the environment for quite some time, they are eventually passed up through the food chain. As reported by the Inquisitr last month, the United Nations released a report indicating that plastic has reached the human dinner table. According to their statistics, 25 percent of the fish at markets in California and Indonesia contain plastic.

While the United States has banned microbead use in many personal care products, the prohibition does not include detergents and many leave-on cosmetics. The U.K. and Europe have done little to combat the problem.

“It’s body care products, it’s not just toothpaste and scrubbers; some mascara and some lipsticks have plastic in them too,” said Dr. Lonnstedt. “It’s a silent threat that we haven’t really thought about before. We need to ban the products that have microbeads in them.”


However, the microplastics found in the environment do not always come from cosmetic products. Much of it starts out as large pieces of non-biodegradable plastic, like bags, that eventually break down into smaller bits through sun and water exposure.

While the study has helped the scientists understand how microplastics may be adversely affecting the population of certain fish species, they now have plans to study the impact of specific types of plastic. If they can identify certain chemical products, then it may be easier to persuade lawmakers and manufacturers to eliminate the most dangerous ones.

[Photo by Joe Raedle/Getty Images]