Coral

Acropora millepora red and green color morphs

How corals control their colour

Using the staghorn coral Acropora millepora as a model, scientists from the University of Southampton have found that the fluorescent pigments that are mostly responsible for coral colours act as sunscreens for the symbiotic algae that live in the coral tissue. These alga require light to produce sugars, which they can contribute to the nutrition of the corals in return for the shelter and the supply of nutrients that are provided by the coral host.

Staghorn coral found off South Florida

Forests of rare staghorn coral discovered off South Florida

A scientist from Nova Southeastern University's Oceanographic Center found the coral while doing a survey for the environmental agency, which wanted a better map of shallow reef system.

The department of environmental protection wanted a better map of the coral's locations to improve the management of beach-widening, coastal development and other activities that could harm corals, as well as improve responses to incidents such as oil spills and illegal boat anchoring.

Green-coloured encrusting sponge is well distributed within the coral reef system of Palinurus Rock

Large coral reef discovered off Iraq

Joint expeditions performed by scientific scuba divers from MSC Basrah (Iraq) and SDC Freiberg (Germany) carried out in September 2012 and in May 2013, revealed the existence of a true live coral reef in Iraqi coastal waters for the first time ever.

The Iraqi coast at the northern end of the Persian Gulf is dominated by the large swampy river delta of the rivers Euphrates, Tigris and Karun, merging into the Shatt al-Arab that represents the main outflow in the Arabian/Persian Gulf.

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Iraq reef
How can physical barriers, such as isolation on a particular island, lead to the formation of new species through the process of natural selection?
How can physical barriers, such as isolation on a particular island, lead to the formation of new species through the process of natural selection?

How do new species of coral form in the ocean?

In a recent publication in the Proceedings of the National Academy of Sciences, or PNAS, Hellberg and his graduate student Carlos Prada investigate how corals specialize to particular environments in the ocean.

It is very well known that physical barriers and reproductive isolation can lead to the formation of new species on land, especially among plants and animals with short generation times such as insects and annual plants.

Kyra Hay sorting Coral samples

Deep corals discovered on Great Barrier Reef

The coral Leptoseris is living 410 feet (125 meters) below the ocean's surface, a discovery that expedition leader Pim Bongaerts of the University of Queensland called "mind-blowing."

Bongaerts and his colleagues received funding from insurer the Catlin Group Limited to explore the Great Barrier Reef as part of an effort to understand how climate change is altering the oceans.

Electron micrograph of Bacteriophages (vira) in the process of infecting a cell. This is not the virus or bacteriophage in question but a generic photo

A vaccine for corals

White syndrome' is a name given to a number of diseases exhibiting similar symptoms, such as such as white pox, white band and white plague disease. The causes of white syndrome are in many cases unknown. White syndrome has increased in abundance 20-fold in the last five years, with increases on inner, mid-shelf and outer-shelf reefs along the length of the Great Barrier Reef. It also had a major impact on Caribbean reefs. In areas of the Great Barrier Reef surveyed, white syndrome, along with skeletal eroding band, was the most common disease.

Miriam Weber measures the oxygen concentration
Miriam Weber measures the oxygen concentration

Rapid coral death by a deadly chain reaction

Scientists at the Max Planck Institute for Marine Microbiology from Bremen together with their colleagues from Australia, Sultanate of Oman and Italy have investigated how and why the corals die when exposed to sedimentation. According to their findings, oxygen depletion, together with an acidification of the environment, creates a chain reaction that leads to coral death.

(Filephoto) Butterfly fish

A Holistic Approach to Coral Reef Health

However, at locations were there was excessive adverse impact (like pollution), the corals did not recover fully, even after eight years.

“You can imagine that when you are recovering from a sickness, it will take a lot longer if you don’t eat well or get enough rest,” said Jessica Carilli, a graduate student at Scripps Institution of Oceanography at UC San Diego.

“Similarly, a coral organism that must be constantly trying to clean itself from excess sediment particles will have a more difficult time recovering after a stressful condition like bleaching.”

Disease and overfishing also affected coral health. In places where there is overfishing, the population of bigger fishes like groupers are either significantly reduced or have vanished.

In the absence of these predatory fishes, other fish species thrive. One such species is the butterflyfish, which feed on coral and appear to be responsible for disease transmission amongst the corals.

In a study, scientists compared seven Marine Protected Areas [MPAs] where fishing had been banned for at least five years, and another seven neighbouring sites with similar diversity.

They discovered that the corals at the latter sites suffered more diseases; in some cases, the difference was twice as many. In addition, many butterflyfish were found at the sites where fishing was allowed, leading to a higher incidence of coral disease.

Coral reef (DI02213) Photo by Kathy Krucker
Corals are highly sensitive to both warming ocean temperatures and ocean acidification brought about by increased atmospheric carbon dioxide

Deepfreezing corals to save the reefs

A recent meeting of minds in Denmark saw scientists and politicians alike acknowledge that global emissions of carbon dioxide (CO2) are rising so fast that we are losing the fight to save the coral reef and most reefs will not survive even if tough greenhouse gas regulations are implemented.

Preserving samples of coral species in liquid nitrogen would enable scientists to reintroduce them to the seas in the future – if global temperatures can be stabilised by then.

Geradia (gold) coral. Some deep-sea coral are now believed to have lifespans in excess of 4,000 years.
Geradia (gold) coral. Some deep-sea coral are now believed to have lifespans in excess of 4,000 years.

Deep-sea coral found to be over 4000 years old

A black deepsea coral found about 400 meters from Oahu and the Big Island in Hawaii is more than 4,000 years old — making it the oldest marine organism ever found, according to researchers from Lawrence Livermore National Laboratory, Stanford University and the University of California, Santa Cruz.

Using a manned deep-sea research submersible samples were collected at the Makapuu and Lanikai deep-sea coral beds off the coast of Oahu, Keahole Point deep-sea coral bed off the coast of the Big Island and Cross Seamount about 100 miles south of Oahu.