Plants and animals in the rocky intertidal zone constantly interact with each other and their environment.

The rocky intertidal zone is the part of the shore where the tides come-and-go over rocks that peek out at the coast.

It may look like a still-life painting at low tide--when nothing seems to be moving, but plant and animal inhabitants interact and affect each other in many ways. There is keen competition for space, light and food. There is predation--one animal eating another. There are animals living on other animals and even inside other animals!

Life in the tidepools also interacts with its environment. Some animals can only survive where the waves pound the rocks, others need the relative shelter of deeper water. Plants and animals can dry out if exposed for too long at low tide. Some animals cut holes in the rock for themselves to sit in, leaving behind habitats for other animals. Eveyone who's there has managed to find a way to stay alive.

Whether amongst living things or with their environments, many interactions are so slow that we can't see them happening, even when it takes place right before our very eyes--unless we have the right tools for the job.

At the Ocean Institute
Students and visitors at the Ocean Institute can use three different digital video tools to discover the less-than-obvious interactions that take place in rocky intertidal environments. These techniques include:

• Time-Lapse photography - To speed up observation of slow processes
• Counting using photoquadrats - To make an estimate when there are too many to count one-by-one
• Infrared imaging - To see in the dark