- 1. Marine Protected Areas
- 2. What is the Coastal Zone?
- 3. The Formation and Biology of Coral Reefs
- 4. Coastal Zone Interactions and Threats
- 5. Human Impacts on Coral Reefs—Litter
- 6. Human Impacts on Coral Reefs—More
- 7. Animals on the Reef
- 8. Animal Interactions and Food Webs
- 9. Endangered Species
- 10. Glossary
8. Animal Interactions and Food Webs
Hundreds of different types of plants and animals live on coral reefs. All living things, plants and animals, need energy. What is energy? It is the ability to do any kind of work. To move, to grow, even to think takes energy.
We get our energy from the plants and animals that we eat but where do plants and animals get theirs from?
Plants are producers. They make their own food and create their own energy. Plants get their energy from the sun. On a coral reef it is the algae (seaweeds) living with the corals that catch the sun’s energy.
- A primary consumer is an animal that eats green plants. It is also called a herbivore. On a coral reef, surgeonfish (balagi) are herbivores. They feed on the algae growing on corals and rocks.
- A secondary consumer is an animal that feeds on smaller plant-eating animals. It is also called a carnivore. On a coral reef, groupers (kawakawa) are carnivores. They feed on the smaller fish swimming by.
On the reef, just as in other places, all living things feed on each other, passing energy from one source to the next. For example—in a lagoon, (shallow parts of the reef) seagrasses grow using the sunlight to make their food and energy. This is done through the process of photosynthesis (process where plants use the sun to make food) Seagrasses are the producers. The energy is then passed on to turtles which eat the seagrass. Turtles are the herbivores (plant eaters) and the primary consumers. Sharks prey and feed on turtles; the energy from the turtles is then passed on to the sharks. Sharks are the carnivores, the secondary consumers. This is called a food chain.
The energy moves through the food chain from one link to the next. At each stage the energy is used for many things, for example, turtles use their energy to swim around.
Food chains describe one feeding relationship. On a reef there will be many of these feeding relationships which will all connect together to make one big food web.
Activity
Match up the related items and make a coral reef food web!
- Sun
- Plankton
- Octopus
- Jellyfish
- Coral
- Parrotfish
- Shark
- Anemone
- Butterflyfish
- Crab
- Sea Turtle
Symbiosis
Many marine animals live side by side on a reef, working together and helping each other. Many form partnerships (groups) to make their lives a little easier or more comfortable. Each of the partners will benefit from the relationship. This is called symbiosis.
Let’s take a look at a few of these mutual symbiotic relationships on the reef:
Clownfish and anemone
Blind Shrimp and Goby
Clams and Zooxanthellae
Cleaner wrasses and cleaner shrimps at cleaning station
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