While concerns are common about the consumption of plastics by fish, studies by researchers at Memorial University of Newfoundland show encouraging results.
These researchers have identified a species, silver hake, which consumes no plastic material.
Another surprise awaited these researchers. By reviewing the existing literature, they realized that 41% of the fish species studied did not seem to ingest plastics.
Max Liboiron, an assistant professor of geography at Memorial University and a specialist in environmental pollution, studied the gastrointestinal contents of 134 silver hake fished in 2014 and 2015 in the Grand Banks of Newfoundland.
The hake studied was feeding where there is plastic that contaminates the waters off the south coast of Newfoundland. But none of his fish ate.
It is not a species that eats plastic.
Max Liboiron, Memorial University of Newfoundland
It is important for researchers to determine the amount of plastics that fish consume. These plastics can be contaminated with pesticides or methylmercury. If the fish eats plastic, it can absorb these contaminants. The fish is then eaten by humans or other animals.
Endocrine disruptors in some plastics have been linked to certain health problems in humans, from fetal cancer to obesity and thyroid problems.
Inconclusive results for salmon and capelin
Max Liboiron also studied salmon and capelin caught in Newfoundland waters, and found that they also did not consume plastics. It states, however, that these observations were made at a very specific period in the life of these species.
“When we catch capelin and salmon in this province, it is generally in full reproduction, and many fish do not eat during this period. So we do not know if they ever eat plastic, or if they do not consume only when they are at the end of their spawning period,” she says.
On the other hand, research has revealed that silver hake, through all periods of its life, does not consume plastics.
Samples too small
By consulting 211 other existing studies on plastic consumption by fish, researchers have found that silver hake may not be as unique as they originally thought.
Ms. Liboiron indicates that 41% of the species studied do not consume plastics, according to these studies.
Another cautionary note is that two-thirds of these studies did not examine a sample large enough for the results to be conclusive, according to Ms. Liboiron.
Low levels of plastic ingestion in Newfoundland and Labrador
Nevertheless, Max Liboiron is of the opinion that studies whose conclusions are less alarmist tend to go under the radar.
According to Ms. Liboiron, the plastic intake rate of many fish in Newfoundland and Labrador is low.
For example, it has been shown that only two out of every 100 cod consumed plastics.
“Most scientists are encouraged to publish more spectacular, more exciting, more distressing results,” she says.
Brenda Ryu is a reporter for Island Daily Tribune. After graduating from University of Prince Edward Island, Brenda got an internship at CBC News Atlantic and worked as a reporter and sound producer. Brenda has also worked as a reporter for Huff Post Canada. Brenda h covers entertainment and community events for Island Daily Tribune.