Fragile Reefs

Fragile Reefs lesson plan

Adjust your goggles and tighten your swim fins! Dive beneath the ocean surface to explore breathtakingly beautiful coral reefs and the thousands of species they shelter. Create a coral reef ecosystem in your own undersea diorama.

  • 1.

    A coral reef resembles a large, busy city, with more species of sea creatures and plants than anywhere else in the ocean. Although a coral reef looks like a colorful rock formation on the sea floor, it’s really millions of tiny coral polyps living together in huge groups. Polyps are small, soft-bodied animals, about 1/4 inch wide. Some of them grow hard outer structures called exoskeletons. When the polyps die, they leave behind their exoskeletons. Live polyps attach themselves to the exoskeletons of dead polyps and so the reef builds. It takes about a year for a coral clump to grow outward 1 inch, so it takes a long time for a coral reef to form! There are about 230,000 square miles of coral reef in the world.

  • 2.

    Polyps need warm, shallow, sea water to grow, so coral reefs are often near land. There are three main types of reefs. A fringing reef is attached to the shore. An atoll is a ring of coral formed around a sunken volcano. A barrier reef has a channel of water between it and the shore. Although all types of coral polyps grow in similar ways, the many different polyps form more than 2,500 different kinds of coral! It may resemble tree branches, the human brain, tiny pipes, fans, feathers, lace, or mushrooms. It may be bright pink, glowing orange, rich purple, or brilliant yellow. The warm, sunlit water and many hiding places of a coral reef attract thousands of different animals. Learn more about the creatures who live in a coral reef and then use your imagination to create your own diorama using ideas like these.

  • 3.

    Use Crayola® Scissors to cut paper to fit inside a recycled box. With Crayola Markers, create the shallow, light-reflecting water you might find near a coral reef. Use Crayola Erasable Colored Pencils to draw small, brightly colored fish. Color with markers, cut out, and glue in several group formations, or schools, with Crayola School Glue. Glue the paper inside the shoe box, covering the sides, top, and bottom.

  • 4.

    Create a coral reef with Crayola Model Magic. Use the neon and white modeling compound to create spirals and folds. Imprint interesting textures into the modeling material with household items. Create layers of textured and sculpted coral. The compound will stick to itself when fresh from the pack or may be glued after air drying. Use markers to create brightly colored shrimp, sea horses, or other tiny creatures. Cut out and glue to the coral. Add larger sea animals, such as angel fish or an octopus, to your seascape. Glue them around the edges of the box to add more depth to your diorama.

  • 5.

    Explain to classmates, other students, or your families how coral reefs are in danger today due to overfishing, tourist activity, pollution, and global warming. Decide, as a group, on a possible course of action to prevent the loss of this very valuable h


  • Students research to learn how coral reefs form, where they are located, and what plant and animal species find shelter in the reefs.
  • ?Students build and display a diorama to represent coral and animals that live in a coral reef.
  • ?Students participate in a discussion about what could be done to preserve the possible extinction of coral reefs.


  • Find The Great Barrier Reef on a world map. It runs alongside the northeast coast of Queensland, Australia, and is the largest coral reef in the world. It stretches for 1,260 miles and is home to 4,000 species of shell fish, 2,000 species of fish, 500 spe
  • There are more kinds of animals in coral reefs than in any other earth habitat except rain forests. Choose different species to research, including microscopic algae and plankton, tiny animals like polyps, small animals, medium animals, and the largest pr
  • Assessment: Set aside a day on which dioramas are displayed around the perimeter of the room. Students walk around the room to see and hear each other’s diorama presentations that include: the type of coral reef depicted (atoll, fringing, or barrier), the type of coral, and the species of sea life represented. Allow time for students to ask questions of one another.