Teach the children about the different types of ocean plants and their purposes. Have each child bring a shoe box or cardboard box to class with them. Help the children cut out windows from each of the shorter sides of the box and from one of the longer sides. Stretch plastic wrap across the window cutouts and tape it in place. Have the children spread clay in the bottom of their boxes and glue a piece of blue or green construction paper to the inside back of the box. Let the children draw, color and cut out seaweed, kelp and sea grass from pieces of paper. Have them glue the plants to craft sticks and insert them into the clay bottom of their boxes. Allow the children to add rocks, sand and fish cutouts to further decorate their aquariums.
After teaching your students about ocean plant life, have them create a small ocean in a bottle to take home and show their families. Have each student fill the bottom of a 20-oz. clear pop bottle with sand and rocks. Fill the bottles two-thirds of the way full with water and have the students add a few drops of blue food coloring. Help them cut a piece of tissue paper into narrow strips. Instruct them to gather three to four strips together and tie them in a not at the bottom. Tie the bottom end of the tissue paper seaweed around a small rock and drop it into the bottle. The rocks will weigh the tissue paper down so that it sinks to the bottom. Have the children add multiple seaweed clumps to their bottles. Give each child a small pinch of glitter to add to the water. The glitter will represent algae floating in the water. Provide each child with a few small plastic sea animals to add to their oceans. Help the children glue the caps onto their bottles.
Use a classroom bulletin board to teach children about ocean plant life. Cover the bulletin board with blue paper to create an ocean. Cut out waves along the paper at the top of the bulletin board. Decorate white pieces of paper with colored glitter and attach them in a strip along the bottom of the bulletin board to act as sand at the bottom of your ocean. Show your class pictures of ocean plants and share their names, characteristics and purposes. Have a larger replica of each plant created from green construction paper. As you talk about each plant, pin the paper replica to the bulletin board. Add cutouts of the animals that use the plants for food and shelters. After the lesson, have children draw, color and cut out their own versions of the ocean plants from colored paper. Help each child attach his plant to the ocean bulletin board.
This activity works well for younger children. Give each child a piece of paper and instruct her to color it blue to represent water. Teach the children about ocean plants and show them pictures. Have the children use finger paints to draw plants in their ocean. Help the children create a hand print in their ocean to represent a clump of seaweed or kelp. Write the children's names on their pictures and display them on a bulletin board.