There was a mistake in the Matlab code we used to generate time series solutions of our model, Eqs. (16)-(18). The corrected text below replaces one paragraph on p. 7, and the figures below replace Fig. 4 , Fig. 5 on p. 8. There is no qualitative change to our results. However, there is a quantitative change in the initial dead oyster shell volume B ( 0 ) needed for reef survival. The corrected threshold B ( 0 ) , about 0.40 m3 per m2 of sea floor, is more consistent with a recently experimentally estimated threshold of 0.30 m (Colden, Latour, and Lipcius, Mar Ecol Prog Ser 582: 1–13, 2017) than was our old incorrect threshold of about 0.12 m3.