New study confirms the harmful effects of microplastics in aquatic ecosystems. The findings show larval fish preferring microplastics over zooplankton as a food source in contaminated environments.
The scientific journal "Science" published the findings Friday, raising concern on how these changes can affect the ecosystem. Especially since larval fish feeding on microplastics lose anti-predatory instincts, increasing their vulnerability and affecting the sustainability of the fish population.
Fight Or Flight Instincts Altered
In the study, Perch fish were contained with their natural predators, Pike. An experiment confirmed that baby fish that eat microplatic particles lose their flight instincts. Perch that were exposed to microplastics were caught four times faster than those reared in uncontaminated environments.
The vulnerability is credited to the fishes' relative inactivity and an apparent inability to smell predators, should have prompted their survival instincts. If this increases mortality rates in fish population, the consequences could upset the balance of aquatic biodiversity in contaminated waters.
Microplastics As Fish Feed
Professor Peter Eklöv , co-author of the study, also noted the fishes' acquired preference for microplastics as a food source. "This is the first time an animal has been found to preferentially feed on plastic particles and is cause for concern," Eklöv stated in an article by UPPSALA University.
Microplastics involve particles smaller than 5mm, as by-products of the breakdown of plastic waste. Microplastics are also manufactured for a variety of uses, such as microbeads mixed into personal care products. The waste accumulates and makes its way into oceans, rivers and lakes, before concentrating on shallow waters.
The study's lead author Oona Lönnstedt also noted that contaminated larval fish have reduced hatching rates, contributing to the problem of unsustainable fish populations. In a Christian Science Monitor report, Lönnstedt said this observation is consistent with findings around the world.
"The microplastic particle levels tested in the current study were similar to what is found in many coastal habitats in Sweden and elsewhere in the world today." The study illustrates the need to consider the effects of microplastics and also the urgency of finding biodegradable alternatives.