Animals that live in the intertidal zone have to deal with exposure to air, as well as strong currents. Many organisms such as sea stars or sea urchins have developed what are called tube feet. Tube feet help to secure them to their rock. So some form of anchoring themselves. To deal with sun exposure, snails such as periwinkles and oyster drills . This forms a watertight seal around the shell, protecting them from the sun. So here, it would be moisture control.
