Data for McAfee, Leung, Connell. Improving ecological function of polluted coasts under a tide of plastic pollution. Frontiers in Ecology and the Environment (FEE21-0330.R1).

This file contains the raw data for the oyster filtration experiments that are presented in the main manuscript (i.e., Figure 1) and the supplementary files (Panel Figure 1 and 2) of this paper (FEE21-0330.R1). No ethics approval was required for this work. <br> <em>Experiments for Figure 1 and Panel Figure 1 and 2</em>: Experiments were conducted using Australian Flat oysters (<em>Ostrea angasi</em>; ca. 2 years old) that were acclimated to controlled aquarium conditions (21.0 ± 0.5 °C; day/night cycle: 16/8 hr). Individual oysters were placed into experimental tanks (34 × 28 × 22 cm) filled with 17 L filtered seawater and cultivated microalgae (<em>Isochrysis </em>sp<em>.</em>) at an initial concentration of ~5 × 10⁵ cells mL^–1, and exposed to experimental treatments consisting of either 0, 10, or 100 µg L^–1 of polystyrene microspheres (diameter: 10 µm) crossed with either 0, 1, 2, 4 or 8 mg L^–1 of nitrigen fertiliser. Crossing all combinations of microplastic (three levels) and nitrogen (five levels) concentrations, 15 treatments were run both with and without oysters (<em>n</em> = 3 replicate tanks). Each of the 90 tanks were run in a temperature-controlled room (21.0 ± 0.5 °C) over four days under UV lights to stimulate continual growth of the microalgae. Changes in microalgae concentrations were measured per tank before and after the four-day exposure. From each tank, four aliquots (5 mL) were extracted, fixed with Lugol’s solution, and the microalgae concentration quantified using a haemocytometer under a light microscope. These four values were averaged to provide a single value per tank, with the process repeated for each replicate tank (<em>n</em> = 3 per treatment). <br> <em>Experiment for Panel Figure 2</em>: For the shock experiment, an individual oyster was placed in a tank (34 cm × 28 cm × 22 cm) filled with 7.5 L filtered seawater at one of four microplastic concentrations (0, 10, 100, or 1000 µg L–1; <em>n</em> = 5 replicate tanks per microplastic concentration). The oyster was allowed to rest for 2 hours, followed by adding algal suspension into the tank to obtain an initial microalgae concentration at ~5 × 105 cells mL–1. The oyster then fed for 9 hours. The final microalgae concentration was measured using a haemocytometer using the same method as described above. <br> Note¹: the microplastic discharge data was extracted from Schmidt et al. 2017 (data accessible here: https://pubs.acs.org/doi/abs/10.1021/acs.est.7b02368), wheras the river water discharge values were extracted from: Milliman and Farnsworth (2011) River Discharge to the Coastal Ocean: A Global Synthesis. Cambridge University Press, Cambridge.