Every year, the amount of plastic in the world’s oceans increases by between five and 13 million tonnes. Over time, plastic breaks down into micro and nanoparticles that are invisible to the naked eye. Researchers at Lund University have investigated how these small plastic particles affect organisms in aquatic ecosystems.
They found that some species of grazing zooplankton, daphnia, which are an important source of food for fish, were particularly vulnerable. Phytoplankton diatoms were also severely impacted. However, other types of algae, such as blue-green algae (cyanobacteria), which contribute to algal blooms, were completely unaffected.
“We don’t yet know why some collapse while others continue to thrive as usual. If the concentrations of nanoplastics increase, even those that can handle a few particles at present will also likely suffer,” says Lars-Anders Hansson, professor of aquatic ecology.