Microplastic encapsulation capacity of a cladoceran zooplankton Daphnia magna

Abstract

We examined the microplastic encapsulation capacity of a freshwater cladoceran zooplankton Daphnia magna, which is a typical species in the freshwater ecosystem. To read the possible relevance of encapsulation capacity to the food in the medium, and to understand under which condition the encapsulation capacity is higher, experiments were performed with 12 individuals of D. magna in each medium on 6 (3 of them contain ϕ=10 µm polystyrene microspheres) different media. After the experiment, the gut volume was measured with a digital microscope. Subsequently, the approximate number of particles in the gut was determined using the Kepler conjecture. The surface area of the plastic particles encapsulated was calculated in the diet range, suggesting that the total surface area of plastic particles in a Daphnia magna gut may reach around as much as that of two soccer balls.