Researchers find grazing zooplankton severely affected by nanoplastic particles

Researchers from Lund University in Sweden have been studying how nanoplastics affect aquatic life in lakes and rivers. Their findings are surprising: for the first time, they have shown that while some species are becoming extinct, others, such as cyanobacteria that cause algae blooms, are completely unaffected.

The study is published in the journal Communications Earth & Environment.

Each year, the amount of plastic in the world’s oceans increases by 5 to 13 million tonnes. Over time, plastic breaks down into micro- and nanoparticles that are invisible to the naked eye. Researchers from Lund University investigated how these tiny plastic particles affect organisms in aquatic ecosystems.

The researchers found that several species of herbivorous zooplankton, water fleas, which are an important food source for fish, were particularly vulnerable. Phytoplankton diatoms were also severely affected. However, other types of algae, such as blue-green algae (cyanobacteria), which contribute to algal blooms, were not affected at all.

“We don’t yet know why some collapse while others continue to thrive as normal. If concentrations of nanoplastics increase, even those that can currently handle small amounts of particles could be affected,” says Lars Anders Hansson, professor of aquatic ecology.

The researchers conducted their study in constructed wetlands that were designed to mimic natural systems as closely as possible, so their findings are likely applicable to natural ecosystems. Differential effects on different organisms can lead to significant changes in food webs and ecosystem processes, such as declines in plant-eating zooplankton and algal blooms.

“The concentrations of nanoplastics we used are low and very close to the concentrations already present in our oceans,” Hanson said.

The researchers plan to continue conducting experiments to see how these insidious nanoplastic particles, which can penetrate cell membranes, affect different species in lakes and rivers.

“From a broader perspective, our research provides knowledge and a basis for future decision-making on how to address the obvious problems posed by plastics, even though they are an excellent material for many aspects of everyday life,” says Lars Anders Hansson.