Sunday, August 31, 2008

Besides the White Pox Diease mentioned in one of the previous post, there are also many other Coral diseases.Below are information on the other diseases.







Sea Fan Browning & Fungus


1995 was the year REEF RELIEF's Craig Quirolo observed that the majority of purple sea fans were turning brown. The filter feeders appear to be "stuffed" with particulate matter. Some have lesions that create gaping holes while others were infected with a fungus that causes deep purple spots on the sea fan. Quirolo shared his data with Drew Harvell of Cornell University, who is studying the sea fans along with Kio Kim (Un Buffalo), and Garriett Smith (Un-N.C.). They have learned that the fungus attacking the fragile gorgonians is aspergillus, typically found in soil. Sea fans in Puerto Rico, the Bahamas and Jamaica are also turning brown.



Blackband Disease
Blackband disease has attacked boulder corals like the lesser and greater star corals for many years, but an acceleration of diseased coralheads began in the late 1980's at Keys reefs. The leading edge of the disease is a cyanobacteria. Healthy coral growth appears to mushroom up and around the dead area over time. Harold Hudson of the Florida Keys National Marine Sanctuary developed a method of preventing its spread by vacuuming the disease off corals and applying protective clay to the affected tissue. Since the disease is high in phosphates, REEF RELIEF introduced and fought hard for passage of a phosphate ban on soaps and detergents used throughout the Florida Keys that is one of the strongest phosphate bans in America.
source:http://reefrelief.org/Image_archive/diseases/index.shtml

Importance of coral reefs.

Coral reefs are important for many reasons.They provide shelter and protection for many different species of fish.They also protect coasts from strong currents and waves by slowing down the water before it gets to the shore.Coral reefs contain the largest variety of species of marine life in a very tiny area, and produce more living biomass than any other marine ecosystem. Coral reefs provide many free economic and environmental services, which make them the most valuable of all marine ecosystems in most countries . They are very important in controlling how much carbon dioxide is in the ocean water. Without them, the amount of carbon dioxide in the water would rise dramatically and that would affect all living things on Earth,not only that,fishes will also be left homeless.

The Great Barrier Reef is the only living thing on earth that can be seen from outer space!
600 continental islands and 350 coral cays are spread throughout the reef.
There are approximately 3400 individual reefs that make up the Barrier Reef.
That the Great Barrier Reef was declared World Heritage on 26th October 1981.
The reef stretches for more than 2300 kilometres, from near Fraser Island off the coast of Queensland Australia to the Papua New Guinean coastline.
Not all coral is hard,in fact some are soft and spongy.

coral facts

World's first coral reefs occurred about five hundred years ago,their first close relative developed in Europe 230 million years ago.The Great Barrier Reef is relatively young at just 500,000 years old. The current reef's structure is much younger at less than around 8,000 years old.most reefs have formed on hard surface ,like a base of an old reef that died when the sea level is low,or on the edge of a rocky island. It depends on how the reefs start out, several types of reefs can form. Coral reefs form in the deep ocean and are called atolls. The theories on how coral reefs form were first put forward by Charles Darwin (of The Origin of Species fame) who proposed that atolls form around the edges of high volcanic islands that gradually submerge beneath the sea with changes in sea level or subsidence of the land. Hence,an atoll starts life as a fringing reef, then it becomes more of a ring growing on the shrinking land-mass, until the land disappears and just the coral circle remains. In some cases, the coral growth is unable to keep pace with the sinking island, and sunken dead reefs have been found.

Formations of coral reefs

Formations
Coral reefs can take a variety of forms, defined in following:
Fringing reef – a reef that is directly attached to a shore or borders it with an intervening shallow channel or lagoon.
Barrier reef – a reef separated from a mainland or island shore by a deep lagoon (see Great Barrier Reef).
Patch reef – an isolated, often circular reef, usually within a lagoon or embayment.
Apron reef – a short reef resembling a fringing reef, but more sloped; extending out and downward from a point or peninsular shore.
Bank reef – a linear or semi-circular in outline, larger than a patch reef.
Ribbon reef – a long, narrow, somewhat winding reef, usually associated with an atoll lagoon.
Atoll reef – a more or less circular or continuous barrier reef extending all the way around a lagoon without a central island; see atoll.
Table reef – an isolated reef, approaching an atoll type, but without a lagoon
source:http://en.wikipedia.org/wiki/Coral_reef

Reef-building or hermatypic corals are only found in the photic zone (above 50 m depth), the depth to which sufficient sunlight penetrates the water for photosynthesis to occur. The coral polyps do not photosynthesize, but have a symbiotic relationship with single-celled algae called zooxanthellae; these algal cells within the tissues of the coral polyps carry out photosynthesis and produce excess organic nutrients that are then used by the coral polyps. Because of this relationship, coral reefs grow much faster in clear water, which admits more sunlight. Indeed, the relationship is responsible for coral reefs in the sense that without their symbionts, coral growth would be too slow for the corals to form impressive reef structures. Corals can get up to 90% of their nutrients from their zooxanthellae symbionts
source:http://en.wikipedia.org/wiki/Coral_reef

Coral reefs are aragonite structures produced by living organisms, found in marine waters with little to no nutrients in the water. High nutrient levels such as those found in runoff from agricultural areas can harm the reef by encouraging the growth of algae.[1] In most reefs, the predominant organisms are stony corals, colonial cnidarians that secrete an exoskeleton of calcium carbonate. The accumulation of skeletal material, broken and piled up by wave action and bioeroders, produces a massive calcareous formation that supports the living corals and a great variety of other animal and plant life. Although corals are found both in temperate and tropical waters, shallow-water reefs are formed only in a zone extending at most from 30°N to 30°S of the equator. Tropical corals do not grow at depths of over 50 m (165 ft). Temperature has less of an effect on the distribution of tropical coral, but it is generally accepted that they do not exist in waters below 18 °C.[2]. However, deep water corals can exist at greater depths and colder temperatures. Although deep water corals also form reefs, very little is known about them.[3]
source:http://en.wikipedia.org/wiki/Coral_reef