Coral Reefs

The term "coral reef" generally refers to a marine ecosystem in which the main organisms are corals that house algal symbionts, called zooxanthelae, within their tissues. The algae photosynthesize and share this energy with the corals in exchange for protection and access to light. Coral reefs are some of the most diverse ecosystems in the world and are therefore often refered to as the "rainforests of the ocean".  Because coral reefs are sensitive to such factors as water temperature, salinity and other chemical and physical factors, they can serve as indicators of environmental changes.

Image: Nick Hobgood

  • Ocean acidification troubles Featured Article Ocean acidification troubles Ocean acidification troubles

    The seas in which corals and other calcifying species dwell are turning acidic, their pH slowly dropping as Earth's oceans acidify in response to increased carbon dioxide... More »

  • Banded butterflyfish Featured Article Banded butterflyfish Banded butterflyfish

    The Banded butterflyfish (Chaetodon striatus) is a member of the butterflyfish family (Family Chaetodontidae) that lives on coral reefs in the Western Atlantic Ocean and... More »

  • French angelfish Featured Article French angelfish French angelfish

    The French angelfish (Pomacanthus paru) is a member of the angelfish family (Family Pomacanthidae) that lives among coral reefs in the Atlantic Ocean. ... More »

Recently Updated
Greater St Lucia Wetland Park, South Africa Last Updated on 2014-07-10 16:27:07 The Greater St. Lucia Wetland Park (32°06’25’’E to 32°56’46’’E. and 26°51’26’’S to 28°29’07’’S) is a World Heritage Site. There are few comparable protected coastlines within the tropics as pristine as St. Lucia's. The Park is one of the outstanding natural wetland sites of Africa. It lies on a tropical-subtropical interface with a wide range of terrestrial, wetland, estuarine lake, coastal and marine environments, which are scenically beautiful and basically unmodified by people. These include coral reefs, long sandy beaches, coastal dunes, lake systems, swamps, and extensive reed and papyrus wetlands, critical habitat for a range of species from Africa's sea, wetlands and savannas. The interaction of these environments with major floods and coastal storms in the Park's transitional... More »
How coral reefs are built Last Updated on 2014-07-02 16:08:56 A variety of marine creatures ultimately contribute to the complex structure of coral reefs. However, most of the underlying solid framework of coral reefs is constructed by the slow, cumulative efforts of just one particular group of simple, tiny animals called the hard (Scleractinian) corals. In these corals, the body of each individual animal (called a polyp) is encased in a hard external skeleton composed of calcium carbonate and formed by the animal itself from substances extracted from seawater. Another quite different type of coral (commonly called fire coral) sometimes also substantially contribute to the framework of shallow Caribbean reefs. As adults, hard corals typically exist as parts of large cohesive assemblages called colonies, in which only the outermost layer is composed of living polyps. Each coral colony is composed of many genetically identical... More »
National Oceanic and Atmospheric Administration (NOAA), United States Last Updated on 2014-06-30 19:00:15 The National Oceanic and Atmospheric Administration (NOAA) is a federal agency within the United States Department of Commerce.  As a science-based operational agency tasked with monitoring climate and changes in the environment, NOAA is responsible for the study of the atmosphere and the oceans.  The agency issues daily weather forecasts and storm warnings, restores coastline, aids the flow of marine commerce, and manages fisheries.  NOAA's activities facilitate weather- and climate-sensitive economic activity that account for roughly one-third of the country's gross domestic product (GDP)[1]. The agency also responds to natural and man-made maritime disasters, operates a complex network of oceanographic, meteorological and atmospheric data-collecting products and services, and manages marine mammals, marine endangered... More »
Common coral reef fishes of Bimini Last Updated on 2014-06-18 16:33:48 Bimini is an island in the  Bahamas  in the West Indies.  Over 320 species of reef fishes have been identified during REEF Fish Surveys in Bimini. The following ranking is based on the results of 1672  REEF Fish Surveys covering a bottom time of 1552 hours and 11 minutes. (REEF Geographic Zone Report.  June 4, 2009).  The species are ranked by the percentage of surveys in which a species was observed.  Abundance of fishes in REEF Fish Surveys are estimated using the following categories: 1- single =1 individual, 2-few = 2- 10 individuals, 3-many = 11-100 individuals, and 4-abundant > 100 individuals.        The mean numeric abundance (ranging from 1 - 4) was calculated for each species..  The mean abundance category is determined as follows: mean abundance category 0... More »
Common coral reef fishes of French Cay Last Updated on 2014-06-18 16:19:54 French Cay is one of the  Turks and Caicos Islands  in the West Indies.  Over 220 species of reef fishes have been identified during REEF Fish Surveys in French Cay. The following ranking is based on the results of 344  REEF Fish Surveys covering a bottom time of 328 hours and 15 minutes. (REEF Geographic Zone Report.   June 3, 2009).  The species are ranked by the percentage of surveys in which a species was observed.  Abundance of fishes in REEF Fish Surveys are estimated using the following categories: 1- single =1 individual, 2-few = 2- 10 individuals, 3-many = 11-100 individuals, and 4-abundant > 100 individuals.      The mean numeric abundance (ranging from 1 - 4) was calculated for each species..  The mean abundance category is determined as follows: mean abundance... More »