The tide is the rise and fall of the sea as it is affected by the gravitational pull of the moon and sun. We do not tend to think much about the tides. Certainly not about their role in keeping certain animals alive. Yet, they play a critical role not only in the lives of fish but of creatures great and small all over the planet.
Many fish depend on the tide to feed. Fish around coastal areas wait on the tide to wash smaller fish out to sea or to pull them into areas where food is abundant. For example, on the southern U.S. coast, the high tide floods rivers and marshlands with more than a foot of water. Crabs and fish use this opportunity to feed on smaller fish and water creatures that live in the marshlands. At low tide, oyster rocks and tide pools are exposed, also allowing crabs to feed.
Tide Pool Creatures
Tide pools are rock formations that are filled and emptied of water depending on the tide. There are sometimes hundreds of creatures living in a single pool. These creatures depend on the sea water for nutrients, protection and to move about. At low tide, many of these creatures are exposed to the air, leaving them at risk of predator attacks and oxygen depletion. The whole eco-system of the tide pools would simply not exist without the constant movement of the tides.
Many seabirds also catch fish depending on the tides. Many fish migratory patterns depend on the tides as do some of their feeding patterns. Birds have discovered this and, like fisherman, will follow the tides to catch fish.
In many parts of the world, thousands of female sea turtles propel themselves ashore during high tide to lay their many eggs in the sand. When the babies hatch, the tiny turtles scramble down to the surf, the tidewater washing them into the ocean. The sheer number of baby turtles ensures that at least a few will make it to adulthood.