As the tides ebb and flow the conditions in the intertidal change dramatically, challenging the organisms that live there to monotonous cycles of temperature, aerial exposure (drying) and immersion, water pressure, depth, salinity and turbulence and even UV light exposure. These regular (and therefore predictable) cues synchronise the internal tidal clocks of these organisms to the environment. Daily, or circadian cues such as light and dark, as well as lunar-related cues are also experienced by these animals.