There are 5 trillion pieces of plastic floating around in the Earth’s oceans, many of which are microplastics no larger than 5 mm large. These tiny particles are being gobbled up by fish and killing them faster than they can reproduce. A new study found that consuming the plastic pieces also slows fish down and interferes with their natural abilities to sense oncoming predators.
The study, published in Science, observed perch larvae and their eating habits. When in the presence of microplastics, such as microbeads, the little guys actually preferred eating these harmful morsels over their usual meals of plankton. Ingesting the plastics slowed down development and interfered with the chemical signals the fish rely upon to sense when deadly predators are near. When pike were introduced into habitats where perch had been munching on microplastics, the perch were four times more likely to be eaten than those in a more natural environment.
Not only does ingesting plastic impede digestive systems with the fish, as well as with seabirds and other creatures, it seems there are longer-lasting effects on how the fish behave. All of these effects combined lead to increased mortality rates. In fact, all of the fish exposed to microplastics in the study were dead within 48 hours. Oona Lönnstedt, one of the study’s authors, told The Guardian, “If early life-history stages of other species are similarly affected by microplastics, and this translates to increased mortality rates, the effects on aquatic ecosystems could be profound.”
Via The Guardian