Shallow Soft Bottom Habitats
I. Physical Features of Shallow Soft Bottom Communities (i.e. at Scuba depths, to 30-40 meters)

Movement of bottom sediments by large waves is a dominant physical process influencing the structure of benthic infaunal communities along the shallow Scuba-accessible continental shelf (Oliver et al. 1980). Wave action produces a coarse, poorly consolidated, well-sorted (i.e. low variation in grain size), and therefore easily moved beach deposit behind the surf zone. Large waves lift these surface sediments into a granular suspension tossed shoreward and then seaward by the passing waves (Bascom 1964, Clifton et al. 1971). Extreme storm waves can remove as much as a meter of surface sediments at water depths greater than 10 meters. The physical stability of the beach deposit increases with increasing water depth as wave-generated bottom currents decrease. As a result, bottom sediments grade from coarse to fine sand with increasing water depth and decreasing wave disturbance (Hodgson and Nybakken 1973, Oliver et al. 1980).