Fig. 2.

(A) A comparison of in situ shear strength measurements in low and high salinity wetlands (low salinity n = 53, from six sites; high salinity n = 47, from six sites) (see Fig. S1). The arrows indicate that the soil shear strength exceeded the vane maximum, as our objective was to examine minimum shear strengths. A less sensitive torque head was used to determine the maximum values occurring in the saline marsh at only one site. A two-tailed Welches t-test shows that the low and high salinity populations are significantly different (P < 0.0001, α = 0.02). (B) Shear strengths of the low salinity wetland including both lab (n = 30) and field data (n = 53). Note the minimum in average strengths around 30 cm depth. The arrows at the base of the diagram indicate wave shear stress from scenarios A, B, C, and D in Fig. 3.