Science, Tech, Math › Animals & Nature Tidal Pool Share Flipboard Email Print magnetcreative/E+/Getty Images Animals & Nature Marine Life Marine Habitat Profiles Marine Life Profiles Sharks Key Terms Amphibians Birds Habitat Profiles Mammals Reptiles Wildlife Conservation Insects Forestry Dinosaurs Evolution View More By Jennifer Kennedy Marine Science Expert M.S., Resource Administration and Management, University of New Hampshire B.S., Natural Resources, Cornell University Jennifer Kennedy, M.S., is an environmental educator specializing in marine life. She serves as the executive director of the Blue Ocean Society for Marine Conservation. our editorial process Jennifer Kennedy Updated January 11, 2020 A tidal pool, also commonly called a tide pool or rock pool is water left behind when the ocean recedes at low tide. Tidal pools can be large or small, deep or shallow. Tide Pools You'll find tidal pools in the intertidal zone, where land and sea meet. These pools usually form where there are areas of hard rock, and parts of the rock have eroded away to form depressions in the rock. At high tide, ocean water collects in these depressions. As the water recedes at low tide, the tide pool temporarily forms. What's in a Tide Pool Kelly Mooney/Getty Images There are many marine species found in tide pools, from plants to animals. Animals Although vertebrates such as fish occasionally inhabit a tide pool, the animal life is almost always composed of invertebrates. Invertebrates found in tide pools include: Gastropods such as periwinkles, whelks, and nudibranchsBivalves such as musselsCrustaceans such as barnacles, crabs, and lobstersEchinoderms such as sea stars and sea urchins. Seabirds also frequent tide pools, where they wade or dive for prey. Plants Tidepool plants and plant-like organisms are important for food and shelter in a tide pool. Coralline algae may be found encrusting over rocks and the shells of an organism such as snails and crabs. Sea palms and kelps may anchor themselves to bivalves or rocks. Wracks, sea lettuce, and Irish moss form a colorful display of algae. Challenges of Living in a Tide Pool Animals in a tide pool must deal with changing moisture, temperatures and water salinity. Most also can face rough waves and high winds. Thus, tide pool animals have many adaptations to help them survive in this challenging environment. Adaptations of tide pool animals may include: Shells: animals such as snails, barnacles, and mussels have strong shells, crabs, lobsters, and shrimp have hard exoskeletons. These structures protect these animals from predators and help keep their bodies moist in dry conditions.Clinging to rocks or to each other: Sea urchins and sea stars cling to rocks or seaweeds with their tube feet. This keeps them from being washed away as the tide goes out. Some animals, like barnacles and periwinkles cluster together, which provides greater protection from the elements.Hiding or Camouflage: Sea urchins can camouflage themselves by attaching rocks or weeds to their spines. Crabs bury nearly their whole body in the sand. Many nudibranchs blend in well with their surroundings. Sometimes, octopuses are found in tide pools and they can change color to camouflage themselves. Advantages of Living in a Tide Pool Amanda Nicholls/Stocktrek Images/Getty Images Some animals live their entire lives in one tide pool because tide pools are full of life. Many of the animals are invertebrates, but there are also marine algae, which provide food and shelter, plankton in the water column, and fresh nutrients delivered regularly by the tides. There are also plenty of opportunities for shelter for animals such as sea urchins, crabs, and baby lobsters, who hide in seaweeds, under rocks, and burrow in sand and gravel. Don't Remove Them From Their Home Tidepool animals are hardy, but they won't survive for long in a beach pail or your bathtub. They need fresh oxygen and water, and many depend on tiny organisms in the water to feed upon. So, when you visit a tide pool, quietly observe what you see. The quieter and calmer you are, the more likely you will be to see more marine life. You can pick up rocks and view the animals underneath, but always put the rocks back gently. If you pick the animals up, put them back where you found them. Many of these animals live in a small, very specific area. Tide Pool Used in a Sentence He explored the tidal pool and found sea urchins, starfish, and crabs. References and Further Information Coulombe, D.A. 1984. The Seaside Naturalist. Simon & Schuster: New York.Denny, M.W., and S.D. Gaines. 2007. Encyclopedia of Tidepools and Rocky Shores. University of California Press: Berkeley.Gulf of Maine Research Institute. Tidepool: Window into the Sea. Accessed February 28, 2016.