We first validated that SA/V is a key control of the lifetime of CDA in the coastal environment, using solid CDA films (𝜌 𝑠𝑜𝑙𝑖𝑑 = 1.35 g/cm 3 ) of different thickness (1, 5, and 10 mil), (Figures , Supplementary Discussion 1). The relative mass loss rates of the films trended linearly with SA/V (R 2 = 0.996), being fastest for the 1 mil (SA/V = ~80) and slowest for the 10 mil (SA/V = ~8) (Figure ). Consequently, environmental lifetime depended on film thickness, scaling linearly with increasing thickness from ~12 to ~91 weeks for the 1 to 10 mil films, respectively (Supplementary Table ).