Between Sand and Sea

The next time you’re at the beach, try to look for a special place called the intertidal zone. You can find it anywhere the ocean meets the land, but it is unlike any other environment in the world. Why? It is the one place that has four different seasons happening at the same time in one day!

These different seasons affect how the intertidal zone’s animals and plants live and move. It is a wonderful place for scientists to study because every season teaches something new about the many depths of the ocean. These important lessons tell us about how unique creatures adapt to fast changes in temperature, water movement, and salinity.

The first season is called the spray zone. You can spot this zone if you see bubbles or splashes of water on the shore where the sand is wet. It is closest to the land, never fully covered by the ocean, and is exposed to air, rain, sun, and even cold frost. While very few plants grow here, small animals like periwinkles, whelks, and barnacles make this place their home. These animals can breathe air, stay underwater for a short time, and move along on the sand just like you and me!

The second season is known as the high intertidal zone. It is flooded once or twice a day during ocean high tides but is exposed to land and air for the rest of the day. Most of the animals and plants here - like green algae, isopods, and brittle stars - are used to living above the water surface, but not deep underwater or high above on dry land.

Go out into the deeper waters and you will find the mid intertidal zone. Unlike the spray zone or high intertidal zone, it usually sits underwater except for a short time during the ocean low tide. Creatures such as sea anemone, barnacles, and snails live here because they cannot breathe outside the water!

The last season is the low intertidal zone. It is the hardest one to find because it is usually deep underwater and is exposed to the air only when the tides are very low. The plants and animals here, such as sea cucumbers, tube worms, and sea urchins, cannot survive out of the water for too long.

As you can see, the seasons in the intertidal zone are very different even if they exist at the same time. What is one thing they all have in common? Well, the organisms that live in the intertidal zone all have to adapt to quick changes in their environments. Sometimes there are storms and strong waves that make the waters move faster. While it’s fun for us to splash in the waves, it’s very hard for tiny sea creatures and plants to live with. Sea stones, rocks, and pebbles that move with the tides can also damage the sands that animals live in. The ocean is always busy, so the intertidal zone is always changing.

But don’t worry! The animals and plants have adapted to these conditions over many years. For example, barnacles build solid homes on big rocks so they don’t get carried away. Also, mollusks, which are small animals with hard shells on their backs, have flexible bodies and can stick to surfaces. Sea grass and algae are able to push their roots deep into the sand while they sway with the currents.

So, the next time you’re at the beach, go on an adventure and look for the intertidal zone! There are many fascinating and wonderful things you can find here, from sea anemones to green algae and snails. The intertidal zone gives us a big picture of the big ocean and is an important part of the natural ecosystem; make sure you treat it and its inhabitants with care!