The Tidepool World

The environment along the seashore is ever changing. With each incoming and receding tide, the land is transformed. When the tide flows out, it leaves behind sea water trapped in low places between rocks along the shore, called tide pools. As the tides ebb and flow, animals and plants are also washed among the rocks and into the tide pools, which become world of their own. Unlike land or deep-sea creatures, these shoreline inhabitants must be adaptable to living on both the land and the sea. Living along the shoreline presents uniquely harsh conditions, such as being left to bake in the hot sun by a receding tide only to be picked up by the next tide and abruptly washed back into the ocean.

Tidepool Zones

The coastal areas where tide pools form are generally divided into four horizontal bands, called intertidal zones. The area above the high tide water line is called the splash or spray zone because its water cover consists of sea spray or occasional storm tides. The high zone is covered by almost all high tides, while the mid-tide zone is usually covered twice a day. The low-tide zone is under water most of the time. Sometimes included as a fifth intertidal zone is the lowest area which is always underwater and called the sub-tide zone.

Tides

Ocean tides are the recurring rises and falls of sea level, accompanied by the horizontal flow of water caused by the interaction of gravity between the earth, moon and sun. Daily tide highs and lows are the result of gravity exerted by the moon as it causes the oceans to bulge toward it. Since the earth is rotating, this occurs twice each day. The monthly cycles result from a combination of gravity from the sun and the moon. When the earth, moon and sun are aligned during the full moon and new moon, a very strong tide called a spring (having nothing to do with the season) tide occurs. During quarter moons, very weak neap tides occur as the gravitational pull of the sun and the moon partly cancel each other out. This regular cycle of tides directly affects life and the environment in tide pools.

Tide pools are teeming with life. Both vertebrates and invertebrates call this intriguing place home. Invertebrates, animals without a backbone, such as sponges, anemones, and hydroids, make up the largest animal populations in tide pools.

Invertebrates

Vertebrates

Other

Safety and Viewing Tips

Dress Appropriately – Long pants will protect your legs. Wear enclosed shoes, not sandals, with good treads. Some of the creatures you’ll see can cause cuts to vulnerable skin.

Don’t Go it Alone – Be sure you have a good field guide for your explorations, they’re readily available.

Low Tide is the Time to Explore – You’ll see the most when the tide is at its lowest. A tide chart can give you this information, so you’ll know when to plan your tide pool visit. Generally, you’ll go when there’s a full moon or a new moon.

Look for the Lowest Pools – The best places to see the inhabitants of a tide pool is in the exposed low, deep pools.

Keep Your Hands to Yourself – Handling can harm the animals. If you force an animal from its spot, you can pull its feet off or squash it. Be patient. By watching quietly you’re much more likely to see the animals moving and going about their business. If seaweed floating on top of the water is blocking the view, try moving it carefully and slowly aside so you can see beneath the surface without disturbing the animals.

Keep Your Feet to Yourself – Watch where you step to avoid harming exposed animals. These sea creatures are tough enough to withstand the baking sun and strong waves, but can be crushed by a careless step. Of course you should never put your foot in a tide pool.

You Can’t Take it With You – Everything you see – animals, plants, rocks and shells – are part of the tide pool ecosystem. Even if something looks as if it wouldn’t be missed if you took it, think again. You could be doing harm and violating the strict laws that protect these areas. The only thing that should be removed is litter that someone left behind. Always carry a plastic bag to place any trash.

Don’t Block The Exit– Even at low tide, an incoming tide can cut off the route back to safety on the shore fairly quickly, so be alert and watch the water level.

Be Careful Walking on the Rocks – Watch where you’re walking. Never jump from rock to rock. Instead, look for good footholds and step between bigger rocks. Avoid stepping on seaweed since it can be very slippery.

Don’t Trust the Ocean – Sometimes a really large wave comes along that can sweep inattentive explorers into the water and away from shore.

Related Pages