How Do Nutrients Cycle in Coral Reefs?

On the reef, fish are at the top of the food chain.

Corals are marine structures composed of millions of small organisms called polyps. According to the National Oceanic and Atmospheric Association, polyps secrete CaCO3 to form a hard skeletal structure that grows into sections of reef. Reefs are then inhabited by other marine creatures.

Reef Inhabitants

Reefs can be home to algae, fish, and many kinds of invertebrate marine life, all sharing and creating the reef ecosystem.

Interdependence

All of the creatures living within a reef are dependent upon it and one another for survival. The reef interacts with these creatures on several levels.

Zooxanthellae

A complex reef structure

Polyps in a coral reef have a symbiotic relationship with photosynthetic organisms called zooxanthellae, which supply their hosts with carbon.

Zooplankton

Polyps can also trap zooplankton from the water to help supply themselves with energy and nutrients.

Invertebrates

Sponges and other invertebrates fill over 60 percent of reef cavities, and contribute to the nutrient cycle in the greater reef ecosystem by filtering the water and excreting inorganic nutrients.

Fish

Coral fish are brightly colored and built for maneuverability on the reef.

Fish are at the top of the food chain in coral reefs, with different varieties of fish deriving nourishment from different sources, such as algae, invertebrates, smaller fish, or even the reef polyps themselves.

References

• Coral Reef Biology: NOAA
• Coral Reef Facts and Information
• Science Daily: Hidden Sponges Determine Coral Reef's Nutrient Cycle

Resources

• National Coral Reef Institute (NCRI)
• NOAA: About Coral Reefs