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glossary
photo courtesy of International Coral Reef Information Network

The complicated physical framework that reef-building coral provide makes it an ideal habitat for thousands of fish species. Consequently, many different fish species have evolved with the reefs in order to take full advantage of all the biological productivity available.

The reef creates a diversity of habitats and food sources for many different species of fish. Different fishes may feed on algae, living coral tissue, plankton, other fishes, and some small "cleaner fishes" actually feed on the parasites of larger fishes. These feeding habits contribute to the balance of nature in a reef ecosystem.

Reef fish dynamics are also very complex. Some fish may only live on the reef as juveniles, while other species use nearby mangrove and seagrass habitats for refuge and then migrate to the reef later in life. Then there are some fish species that only visit the reef occassionally.

Reef fishes contribute a large amount of biomass to reef ecosystems. They are vital in that they transport large quantities of inorganic and organic nutrients between different areas within a reef. Consequently, their presence, abundance, and diversity is integral to the health and success of a reef ecosystem.

(www.coral.noaa.gov/faq2.shtml; Sorokin, 1995; Montogomery, 1990; www.coralreef.org/resources/photobank.html)
 

Herbivory is a vital component to the ecological balance of coral reefs. Algae grows much faster than the slow-growing, reef-buiding corals. Herbivores maintain the reef by keeping the corals from being smothered and overgrown by algae, which would lead to coral mortality. The grazing also keeps physical space available for coral larvae to settle, mature, and calcify reef structures. Consequently, presence of herbivores is extremely important in a reef ecosystem.

Sea urchins and herbivorous fish compete for the available macroalgae. A healthy reef consists of a moderate abundance of sea urchins and diverse presence of herbivorous fish. Elimination or severe reduction of the herbivorous fish populations would lead the coral reef ecosystem to eventually rely exclusively on sea urchins to maintain the macroalgal growth.

Go to Human Activities Data for data on status of herbivorous fish.

(www.coral.noaa.gov/faq2.shtml; Glynn, 1990; Miller, and Gerstner, 2002)
photo courtesy of International Coral Reef Information Network
 

Sharks, barracudas, groupers, and other predatory fish help to control the number of omnivorous and herbivorous organisms. Severe reduction or elimination of this feeding level due to overfishing would result in increase of the herbivore populations. This would obviously alter the delicate balance of the reef ecosystem.

Go to Human Activities Data for data on status of predatory fish.

  1. How would elimination or severe reduction of predatory fish impact the coral reef ecosystem?


source: www.coral.noaa.gov/faq2.shtml; Jackson et al, 2001; www.coralreef.org/resources/photobank.html)
 
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This web site was created by Lynn Tran at the North Carolina State University, Department of Mathematics, Science, and Technology Education on 7/12/03. Faculty advisor Dr. David Eggleston, NCSU, Department of Marine, Earth, & Atmospheric Sciences. Last updated December 29, 2003 .