Samples were approximately 25.4 mm segments cut from each straw. This length was chosen because it achieved a starting mass of at least ~100 mg for each straw material. This initial mass ensured that the accuracy for mass measurements by our analytical balance (Mettler Toledo AG245; readability of 0.1 mg; repeatability of 0.1 mg) would be ≤0.5% for the duration of the mass loss seawater incubation experiments. The thickness of each straw type was measured using digital calipers (Mitutoyo CD-6" ASX; uncertainty of 0.02 mm, resolution of 0.01 mm) (Table ).