Answer: When the tide recedes, organisms are exposed to the air.
Intertidal zone represent the part of the marine ecosystem, which exhibit shallow water and the marine organisms are partially exposed. This zone is exposed to high and low tides.
Sea stars have thick skin, mussels have hard shells, and rockweed algae have a rubbery exterior all these adaptations are beneficial when the tides recedes, organisms are exposed to the air. The animals in the intertidal zone are exposed to danger of being eaten by land predators. Therefore, these adaptations provide them protection from being eaten and hunted by the land predators.