Intertidal Zone: Definition, Characteristics & Facts

Intertidal Zone: Definition, Characteristics & Facts
Coming up next: Language & Language Regions: Definitions & Dialects

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:02 Definition
  • 0:33 Characteristics
  • 1:08 Life
  • 1:48 Facts
  • 2:42 Lesson Summary
Add to Add to Add to

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up


Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Josh Corbat

Josh has taught Earth Science and Physical Science at the High School level and holds a Master of Education degree from UNC-Chapel Hill.

Sea stars, anemones, and crabs, oh my! In this lesson, learn about the zone of the ocean where these creatures can be found. Discover some key characteristics and facts of this zone, then test your knowledge with a quiz.


If you have ever walked along the beach, wind blowing in your hair, maybe the sun setting in the background, and reached down to pick up a shell or sea star, you have interacted with the intertidal zone of the ocean. The intertidal zone is the area of the ocean between the high tide and low tide lines, usually on the beach at the water's edge. If you think of the line created at high tide as the upper limit and the line created at low tide as the lower limit, the intertidal zone is everything between those lines.


The defining characteristic of the intertidal zone is that it is submerged with water during high tide and exposed to the air during low tide. The zone can take many forms, from sandy beaches to rocky cliffs. It is common for the intertidal zone to change frequently, since it is constantly battered by crashing waves.

This changing nature of the zone makes it a somewhat harsh environment for living things. Normally, environments on Earth are either completely dry or completely wet, but the fact that the intertidal zone is always changing leads to organisms that are uniquely adapted to live there.


Common lifeforms found in the intertidal zone are sea stars, crabs, mussels, barnacles, and various corals. Many of these lifeforms are adapted to live part of their lives submerged in water and part of their lives exposed to open air.

A great example of how some organisms are adapted for this type of environment is in barnacles. Barnacles are submerged in water during high tide and are open, exposing parts that take in vital food and nutrients. Then, during low tide, the barnacles are exposed to the air and are closed, maintaining an interior environment in which they can survive. Otherwise, they would dry out when exposed to the open air.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create An Account