How to Explore Tidepools

Exploring tidepools on the Pacific Coast and how the tidal zones affect what you will see in a tidepool.

Difficulty: Easy

Instructions

Things You'll Need:

• Non-skid waterproof shoes

1. 
    
   An ochre sea tar clings to a rocky shoreline

   The rocky outcroppings of the Pacific Coast offer a glimpse into the marvelous wilderness of the underwater world. Exploring tidepools is fun and educational and is something easy to do for both young and old.
   
   It all starts with the rise and fall of the tides. Twice a day pounding surf surges in and beats against the rocky shoreline, whipping up an agitated froth. Six hours later the waters retreat, leaving the area exposed and life within it on hold until the sea returns.
   
   In a tidepool at Corallina Cove in Montana de Oro, deep pockets in the rock layers hold pools of water filled with colorful life. Ochre sea stars, some orange and some purple, stand out against the deep green sea lettuce. Small black and brown turban snails pepper the pools. Some of these shells actually contain hermit crabs that scurry around hunting for food. Green anemones wave their tentacles trying to capture minute organisms to drag into the depths of their bodies. A pretty rose-colored scale called coralline algae covers most of the rocks under water and lends the cove its name. Harbor seals haul out and rest on the exposed rocky ledges. Closer to the breaking waves are sea urchins, more crabs and sea stars.

2. 
    
   Coralline algae makes for a colorful display in the mid-tide zone.

   There are several tidal zones beginning with the splash zone, which receives the blast of the waves at high tide, and proceeding through the high-tide, mid-tide and low-tide zones. Each of these sections has its own creatures and plant life that manage to exist in both the turbulent water and when high and dry.

3. 
    
   The rocky ledges of a typical tidepool terrain.

   The high-tide zone remains moister than the splash zone and is where you will see barnacles, mussels, rock crabs, anemones and chitons.
   
   The mid-tide zone is uncovered at normal low-tide levels. Small fishes, shrimp, sea stars, hermit crabs and nudibranchs live in this environment. Of these the shell-less snail, the nudibranch, is probably the most colorful, often having flowing plumes on their backs. They dine on sponges; hydroids, colonized plant-like organisms that cling to rocks; and bryozoans, moss-like creatures similar to coralline algae.
   
   Uncovered only at the lowest tides each month, the low-tide zone harbors anemones, sponges, sea urchins, tube worms, sun stars, sea cucumbers and thick beds of seaweed.

4. Gazing into these many small ponds at low tide, you will be privileged to see a miniature realm in complete detail. If you go tidepooling, please leave the areas as you found them. Replace rocks and creatures exactly as they were and handle everything gently. Remember that everything you see is protected by law.