Fig. 4. Dissolved inorganic nitrogen concentrations in water.

Concentrations (µM) of NO₃⁻ a, NO₂⁻ b, and NH₄⁺ c are shown for each microplastic treatment and control microcosms after 7 and 16 days of incubation (n = 3 per treatment). Error bars are standard error and CON is the control treatment. Initial community (n = 1) concentrations are 0.072, 0.527, and 3.44 µM for NO₃⁻, NO₂⁻, and NH₄⁺, respectively. Statistical analyses can be found in Supplementary Tables 2–4.