The intertidal zone—the area between the highest and lowest tide lines—is a challenging environment. Organisms that live here must survive crashing waves when the tide comes in, and exposure to sun and air when the tide goes out.

In the Internet Activities for this chapter, you'll find out how conditions vary in different parts of the intertidal zone. You'll also explore how intertidal organisms are adapted to survive in these challenging conditions. Click on Internet Activities at the left to begin.