Field Trip Notes
The class is enjoying a normal day at the beach until Ms. Frizzle discovers a letter from Uncle Shelby. He needs the class to look after his beachfront property. The kids soon discover that his supposedly luxurious accommodation is actually a tiny spot on the shoreline. Why would anyone live in a spot where youre battered by waves at high tide and baked by the sun at low tide? To find out the answer, Ms. Frizzle turns the kids into...mussels!

Life in the Intertidal Zone

Going Hands-on

Time: 20 minutes for tide; 45 minutes for tidal zone
Group Size: 4

Ms. Frizzles class explores the intertidal zone as mussels. Your class simulates a tide, and then populates a tidal zone.

What You Need

• 18 inches of clear plastic aquarium tubing
• Glass of water
• Food coloring
• Rectangular glass casserole dish
• Rocks, sand
• Tape
• Copies of LIFE IN THE INTERTIDAL ZONE page

For each group:

• 1 animal model from activity sheet
• Books, magazines about intertidal critters Ahead of time: Gather a Between-the-Tides library of pictures, shells, books, other material.

Talk About it

Ask: What are tides? (twice-a-day rise and fall of ocean waters) Do they affect ocean shore critters? (They cover the uncover them, batter them with waves.)

What To Do 

Create a Tide

1.  Create a “shoreline” in the dish. Prop it to make a sloping “beach.” Arrange rocks and sand in dish for a shore.
2. Create a “tide.” Color the water. Position the glass so that the glass water level is near the bottom of the beach dish - “low-tide zone.”
3. Put one end of the tubing in the glass. Tape in place. Suck on the tube to fill it with water. Pinch shut while you place it in the dish. Tape in place.
4. Raise or lower the glass to siphon water to or from the dish, creating “tides.” Ask: Are shore animals always covered with water? How can they survive tide changes? (experiment graphic) Raise and lower glass for tides.

Create an Intertidal Zone

1.   Assign each group an activity-sheet critter.
2.  Arrange furniture to create an intertidal zone - floor, low zone; chairs and tables, mid-zone; chalkboard, high and splash zone. 
3. Let groups arrange their animals in the proper part of the intertidal zone. Ask: Why is this the best place for you? How do you survive when the tide is out?

Next Stop

Have groups select another intertidal zone animal to learn about and draw. Add it to your intertidal zone tableau.