Figure 1

Feeding on polystyrene particles. (a–e) Surface plots of the amount of ingested particles (1, 10 and 90 µm) per hour by Daphnia magna (a), Chironomus riparius (b), Gammarus pulex (c), Physella acuta (d) and Lumbriculus variegatus (e) at different particle concentrations (3–3 000 P mL⁻¹). n = 6. (f) Floating bars (min to max, line at mean) illustrating the number of ingested particles (1, 10 and 90 µm) per hour by D. magna, C. riparius, G. pulex and P. acuta exposed to 300 P mL⁻¹. The lower case letters refer to statistical significant differences between the organism and D. magna (letter m) and C. riparius (letter r) at same particle size. *p < 0.05, ***p < 0.001. n = 6.