Diversity and

Distribution of coral reefs

By Robyn and Taylor

Corals are marine animals related to jellyfish and anemones. They

catch plankton and other suspended food particles with

arm-like tentacles, which feed a centrally located mouth. These

algae provide them with an additional food source through

photosynethis

Coral reefs are one of the most biologically diverse ecosystems on earth, rivaled only by tropical rain forests. They are made up not only of hard and soft corals, but also

sponges, crustaceans, mollusks, fish, sea turtles, sharks, dolphins and much more. Competition for resources such as food, space and sunlight are some of the primary

factors in determining the abundances and diversity of organisms on a reef. Each component of a coral reef is dependent upon and interconnected with countless other plants, animals and organisms. This means that fluctuations in the abundance of one

species can drastically alter both the diversity and abundances of others. While natural causes such as hurricanes and other large storm events can be the stimulus for such

alterations, it is more commonly anthropological forces that effect these types of shifts in the ecosystem.

Even though they cover only a tiny fraction (less than .2 percent) of the ocean's bottom, coral reefs contain more

than 25 percent of all marine life.

There are two main types of coral: hard coral, the major reef-building species; and soft coral, such as sea

whips and sea fans.

coral reefs are normally found in the tropical and semitropical areas of

the world where water temperatures range between 16

and 30 degrees Celsius

Coral reefs are classified into three types: barrier reefs, fringing reefs, and

atolls. Barrier reefs occur offshore separated by water from the mainland. Fringing reefs are

continuous with the land mass, and atolls are islands made of coral surrounding a central lagoon.

Not all coral produce reefs. Those that do are called hermatypic.

THE GREAT BARRIER REEFmeasuring 1,243 miles, is the

largest living structure on EarthIt can be seen from the Moon.

This is also the world’s largest coral reef, which is made up of approximately 900 islands and

3000 coral reefs

It was formed around 18 million years ago

30 species of whales, 215 species of beautiful birds, 6 species of sea turtles, 125 species of sharks and stingrays, 49 species of pipefish, 17 species of sea

snakes and around 1,500 types of fish

One of the largest pearl was found in such a clam and was reportedly sold in New

York for $10 million

Most coral are colonial; that is, coral are made up of many individual polyps connected by living tissue. Each polyp has a cuplike shape with a ring of tentacles

around a central opening. The tentacles are tipped with stinging cells used for defense and to capture zooplankton for food. The tiny polyps are the actual living coral tissue.

Coral reefs occupy less than one percent of the Earth’s marine environment, but are home to more than a quarter of all known marine fish species and tens of thousands of

other species found nowhere else on earth. Reefs also serve as a buffer against incoming storm surges, protecting local populations.

Coral reef distribution has been derived from a wide range of sources at various levels of scale and quality. In mast cases, the source maps plot emergent reef crest or shallow

reef and reef flat areas. In order to show reef distribution on this world map, it has been necessary to scale up the area of reef that exists in most countries.

Coral reefs are among the ocean's most complex and biologically diverse marine ecosystems.  They are

underwater communities that are very important to the food chain.  In certain areas of the ocean, not too far under the surface where sunlight can still penetrate, are beautiful gardens of coral and other organisms in

all the colors you can imagine. 

Threats to the world's coral reefs include: Pollution Disease

Over-fishing Dynamite and cyanide fishing

Sedimentation Bleaching caused by rising ocean

temperatures