Do Intertidal Organisms Use the Color of Light to Find Different Depths?

Peabody Charter School
Teacher: Claire Poissonniez
Scientists: Shinichi Asao, Robin Pelc and Gerick Bergsma

Introduction:

The project we did was about intertidal organisms going to deep or shallow water. The question is, do animals use the color of light to find different depths?

Hypothesis:

High-intertidal animals will move towards red light, and low-intertidal animals will move toward blue light.

Methods:

This project was done by using a big tub, half-way filled with water from the ocean. This project was also done by putting two different colored squares of cellophane over the tub. The colors were red and blue, the colors of deep and shallow water. Then we put three different kinds of interitdal animals in the very middle of the tub. The intertidal animals were a sea star, an urchin, and a few snails. After we put the animals in the middle and saw which way they went. All the animals went to the red.

Results:

Most of the animals went to the red side of the tub. Only one animal didn't go to the blue. That was the hermit crab.

Discussion:

The animals went to the red because that is the shallow water. The reason is because you can see the reds in shallow water and they get faded away in deep water. I think that we should have used yellow instead of blue because the animals that we used didn't want to go that deep.

Conclusion:

Most of the animals went to the red because the animals live in shallow water.

The intertidal organisms use the color of light to tell if they are in shallow water or deeper water.