Figure 2
Field measured marsh shoreline erosion rates 2010–2016 (m yr−1). Data are means with 90% confidence intervals, n = 5 for Reference, 9 for Oiled-Untreated, 5 for Oiled-Manual, and 2–6 for Oiled-Mechanical treatments (n = 14–20 for Oiled sites combined) depending on year. Due to missing values, the desire to use as much data as possible, and the lack of clear differences among cleanup treatments, we pooled the oiled site data for statistical analysis. Marsh erosion rates differed among Reference and Oiled sites (F1,17 = 9.751, p = 0.006); among years (F2.32,39.40 = 2.703, p = 0.072); and for the interaction of oiling and year (F2.32,39.40 = 2.648, p = 0.076). Pairwise differences (Tukey’s test) among Reference and Oiled sites were observed for 2010–2011 (p = 0.003) and 2011–2012 (p = 0.001), but not for other years. See Supplementary Table S1 for detailed two-way mixed ANOVA results.
