Fill a shoebox with items found in the ocean. Include stones, sand and shells. Check grocery store produce sections for dry seaweed to add to the sea life box. Find ceramic or plastic representations of coral where aquarium supplies are sold. Toy sea animals are available at teacher supply or department stores. Ask the children to open the sea life box and name each object inside. Make a set of word cards to match with objects in the box.
Fill two bowls with tap water and set them side by side. Pour regular table salt into one of the bowls. Use one cup of salt for every two cups of water. Stir until the salt dissolves. Explain that one bowl contains fresh water--found in springs and lakes and the other contains salt water--found in the sea. Let each child taste the two types of water by dipping Popsicle sticks in the bowls, then tasting. Also, gather heavy and light objects from the classroom to float in the water bowls. If an object sinks in fresh water, try to float it on salt water. The salt water floats objects that sink in fresh water. Record findings on paper and make copies to send home with the children.
It is difficult for youngsters to visualize the enormity of the largest ocean dweller, the blue whale. A blue whale's average span is 80 feet but they can grow to reach 100 feet in length. Demonstrate this size to children who are learning about the ocean. Bring a 100-foot length of twine to class. Designate a student to hold one end of the twine while another class member unrolls it. Let the children walk from one end to the other.
Fill a bowl with water and tint it with two or three drops of blue food coloring. Explain to the children that the bowl of water will represent the ocean. Pour half a cup of oil on top of the water. Tell the class that when oil spills into the ocean, people try to remove it. Pass pieces of paper towels or cotton balls to class members and instruct them to skim the materials over the water to remove the oil. Ask another student to pull the oil from the water with an eye dropper. Let one or two students attempt to dip the oil from the water surface with a spoon. Encourage the children to come up with other ideas to clean up the oil spill, then try the more plausible ideas. Teach the class that sea animals need a clean habitat and that oil spills threaten their survival.