Fig. 4. Water flow records from the lagoon, bay and wave-swept sites, measured at the approximate height of a crab (0.06m above the substratum). Mean and maximum velocities measured for the trials shown were 0.02ms^-1, 0.04ms^-1 (lagoon), 0.21ms^-1, 0.40ms^-1 (bay) and 0.30ms^-1, 0.91ms^-1 (wave-swept site).