The great Barrier reef
Information
The Great Barrier Reef is one of the seven wonders of the natural world, and pulling away from it, and viewing it from a greater distance, you can understand why. It is larger than the Great Wall of China and the only living thing on earth visible from space.
The marine park stretches over 3000km (1800 miles) almost parallel to the Queensland coast, from near the coastal town of Bundaberg, up past the tip of Cape York. The reef, between 15 kilometres and 150 kilometres off shore and around 65 Km wide in some parts, is a gathering of brilliant, vivid coral providing divers with the most spectacular underwater experience imaginable.
A closer encounter with the Great Barrier Reef's impressive coral gardens reveals many astounding underwater attractions including the world's largest collection of corals (in fact, more than 400 different kinds of coral), coral sponges, molluscs, rays, dolphins, over 1500 species of tropical fish, more than 200 types of birds, around 20 types of reptiles including sea turtles and giant clams over 120 years old.
Animals
stats
The largest living structure on the planet, the Great Barrier Reef is incredibly rich and diverse.
Stretching 2300 kilometres, this natural icon is so large it can even be seen from outer space.
While it’s known mostly for its large maze of colourful reefs, its intricate architecture also provides a home for a huge number of plants and animals.
Some of these, such as turtles and crocodiles, have been around since prehistoric times and have changed little over the millennia.
The breathtaking array of marine creatures includes 600 types of soft and hard corals, more than 100 species of jellyfish, 3000 varieties of molluscs, 500 species of worms, 1625 types of fish, 133 varieties of sharks and rays, and more than 30 species of whales and dolphins.
The Great Barrier Reef is also unique as it extends over 14 degrees of latitude, from shallow estuarine areas to deep oceanic waters.
Within this vast expanse are a unique range of ecological communities, habitats and species – all of which make the Reef one of the most complex natural ecosystems in the world.
The Great Barrier Reef Marine Park:
covers 344,400 km2 in area
includes the world’s largest coral reef ecosystem
includes some 3000 coral reefs, 600 continental islands, 300 coral cays and about 150 inshore mangrove islands
extends south from the northern tip of Queensland in north-eastern Australia to just north of Bundaberg
is between 60 and 250 kilometres in width
has an average depth of 35 metres in its inshore waters, while on outer reefs, continental slopes extend down to depths of more than 2000 metres
was created in 1975 through the Great Barrier Reef Marine Park Act
extends into the airspace above and into the earth beneath the seabed.
While coral reefs initially made the Great Barrier Reef famous, they only comprise about seven per cent of the Marine Park and the World Heritage Area.
The rest of the Marine Park is an extraordinary variety of marine habitats, ranging from shallow inshore areas – such as seagrass, mangroves, sand, algal and sponge gardens, and inter-reefal communities – to deep oceanic areas more than 250km offshore.
Rather than having one level of protection throughout the Marine Park, the area is instead divided into different zones. Each zone has different rules outlining permitted activities and those that are prohibited.
Fish
Fish of the Great Barrier Reef
Home to over 1500 different species of tropical fish and other variants, the Great Barrier Reef is an incredible natural location teeming with life. From the smallest kinds of bait fish up to some of the largest varieties of sharks on earth, the environment of the Great Barrier Reef is home to those on all ends of the fish spectrum. The sheer volume and density of fish varieties which can be found within a small area make the reef a diver and snorkeler‘s paradise, as it is not uncommon to encounter hundreds of different species of fish within a single, relatively small area of ocean. Despite the staggering quantities of fishes that dwell within its waters, the fish of the Great Barrier Reef are divided up in to surprisingly few main families, each with significantly differing characteristics that mark the difference from one family to the next. There are several main factors that signify each major group, including (but not limited to) their size, colour, shape and behaviour. Thus, the major families of fish species that can be found in the waters of the Great Barrier Reef include:
Angelfish
Known for their distinctive shape and often strikingly colourful markings, Angelfish are one of the more numerous species of fish in the Great Barrier Reef, with over 80 different species in the family in total. Typical characteristics of the Angelfish include their beauty, inquisitive nature, and tendency to be found in all levels of the upper reef, from the surface to the base of the area’s coral formations. Patterns which can be found on Angelfish range from thin, vivid stripes to multi-coloured speckled patterns that make no two fish of the families look exactly alike, and they form a bulk of the subjects for underwater photography for enthusiasts on the Great Barrier Reef.
Butterfly Fish
A close relative of the Angelfish, Butterfly Fish share many physical characteristics but are typically distinguished from Angelfish due to their more elongated, thinner “noses” which tend to jut out from their main body. Similarly vibrantly coloured and patterned (with the dominant colour usually a bright yellow), they add yet more colour to what is already a vivid tapestry of rainbow-coloured marine creatures. The bodies of Butterfly Fish are very thin, which help them navigate through smaller passages so that they can dine on their usual diet of coral polyps or algae growing on the reef. Butterfly Fish are also known for being incredibly loyal to their mates, and stay with them for life.
Cardinal Fish
A small, elusive species, Cardinal Fish have large eyes and mouths for their size and are notable to having their dorsal fin separated from a single protrusion into twin fins, a relative rarity among reef-dwelling fishes. Cardinal Fish are nocturnal and typically bury themselves within gaps in coral or caves during the daylight hours before emerging at night to get their fill of their typical shrimp and crab based diet. In terms of coloration, those of the Cardinal Fish are often relatively inconspicuous (such as the common Pajama Cardinal Fish), especially in comparison to the gaudy colours of most of the reef’s other inhabitants; this is a contributing factor to their ability to evade the many larger predators that inhabit the same waters.
Clown Fish
Also known as Anemone fish, Clown Fish have recently sprung to international fame due to providing the basis for the starring character of Disney/Pixar’s hit CGI movie Finding Nemo. Anemone fish are extremely popular with the diving community, and Clown Fish in particular are characterised by their highly recognisable markings, typically with a bright orange colouring coupled with a glowing white or light blue band. Their habitats are the sea anemones from which they derive their name, having built up an immunity to the otherwise poisonous tentacles of these soft ocean plants via coating themselves in a layer of mucous. This in turn acts as a natural defence system against passing predators, as the Clown Fish can nestle itself amongst the anemones which will poison any overaggressive threats to the fish – a truly symbiotic relationship. While they are small in size, Clownfish are also popular for being one of the most accessible species of fish in the Great Barrier Reef due to their tendency to inhabit shallower waters, making them often visible by snorkelers without needing to dive down further into the reef’s depths.
Damselfish
From stunning bright colours to drab, muted hues, Damselfish are so numerous that they range from all ends of the spectrum; as one of the most common species found in the Great Barrier Reef they can be seen virtually everywhere. Small fish that are surprisingly territorial for their size, Damselfish are extremely diverse in terms of behaviour as well as coloration and typically stake out a designated “home” amongst the coral reef which they will then defend with their lives (often against predators much larger than themselves.) Depending on subspecies their diet consists of either plankton or algae, with the plankton eaters typically having brighter colours and the algae feeders being duller shades of orange and brown.
Gobies
Gobies are a huge family of fish that are mostly tiny in size and with short lifespans, with some members of the species being among the smallest in the world, however there are also larger types that can reach up to 30cm in length when fully grown. Unfortunately for the Gobies, they perform a sympathetic yet essential function within the ecosystem of the Great Barrier Reef as they act as prey for a large number of predators within the same habitat. Gobies mainly reside at the bottom levels of the reef and typically travel either alone or in small groups so as to avoid detection from predators.
Groupers and Cods
These large, slow, plodding reef dwellers are characterised by their stout bodies and large mouths, and are some of the largest fish that can be found in the Great Barrier Reef, with the largest members growing to a length of up to 270 centimetres and weighing in at over 400 kilograms. Fortunately they are harmless and actually fairly social creatures, making for great photo opportunities for scuba divers dating back to recent memory. While visually they are usually quite subdued in colour consisting of mainly speckled greys and browns, their sheer size and docile nature more than makes up for it – and their numerous quantity means that venturing into some of the reef’s deeper areas will almost surely yield an encounter with a grouper of some description.
Parrotfish
What could a fish possibly have in common with a parrot? Upon seeing a Parrotfish the first time, it will immediately become apparent – their mouths have a distinct resemblance to a parrot’s beak, which they use to bite off hard sections of coral. Being basically a “medium-sized” reef dwelling fish and with multiple bright coloured patterns on their bodies being the norm, they are one of the most visible species in the Great Barrier Reef and help fill the waters they inhabit with a bevy of additional colour. Contributing to their conspicuous nature is the fact that they live in relatively shallow sections of the reef’s waters, making them a frequent sight spotted by snorkelers adventuring in the Great Barrier Reef. Parrotfish also have one peculiar habit that helps contribute to the development and growth of the reef itself – they use their beaks and teeth to grind up coral and then excrete it as sand which helps in time to create small islands and sandy beaches throughout the world.
Sharks
While the wide range of sharks that can be found in the Great Barrier Reef – over 160 species inhabit its waters and reefs – they are sometimes unfairly labeled as dangerous predators as despite their reputation they rarely seek to attack humans. While they can indeed be efficient killing machines, this is usually only the case when seeking their prey, and not all kinds are as efficient as the stereotype of the Great White Shark. The most common species of shark found in the Great Barrier Reef is the White-tipped Reef Shark, a generally passive kind that grow to a maximum of around two metres. Another species that is far more recognisable is the Hammerhead, due to its – you guessed it – elongated hammer-shaped head that provides the shark with enhanced vision when seeking prey. Hammerheads can grow up to four metres in length and may rarely attack swimmers although they are not overly aggressive; that title in the Great Barrier Reef falls to the Tiger Shark. Tiger Sharks can reach lengths of five metres, and they are opportunistic predators at the top of the food chain that take whatever they may come across including large fish, mammals and even birds.
Surgeonfish
Some of the most visually striking fish in the entire Great Barrier Reef, with vivid colours combined with patterns and stripes being the norm with the species and as a result are highly popular fish for people to keep in home aquariums. Surgeonfish derive their name from their spiked blade and venomous fin spines which protrude from their bodies and they use to protect themselves from both predators and fellow members of the same species when engaging in territorial disputes. Large, colourful schools of surgeonfish are a frequent sight on the reef and are the subject of many postcards and magazine photo shoots looking to promote the reef, and with good cause – a school of surgeonfish swimming in unison is the equivalent of an ocean-dwelling, moving rainbow!
Triggerfish
Brightly-coloured and with a distinctive, “pouty” mouth, Triggerfish are one of the most easily recognisable species of fish on the Great Barrier Reef. Lines, spots and a myriad of other patterns that vary from one fish to another are a hallmark of the Triggerfish family, and as such much like Surgeonfish they are another popular feature of aquariums the world over. Aside from their appearance, Triggerfish are (in)famous for their tempers, being overly aggressive and often biting fish and even people that dwarf them in size. They have strong jaws which they use to feast on a diet of such hard-bodied sea entities as molluscs, sea urchins and other crustaceans, and thus their bite can pierce quite deeply when biting down on human skin.
Trout
Coral Trout are one of the most popular catches for fisherman dropping a line in the Great Barrier Reef’s waters due to their ability to fetch a high price on overseas markets as well as their taste. Coral Trout rank fairly high on the reef’s food chain themselves, with a diet that includes many other smaller fish (with Damselfish being a particular favourite.) One of the most visually stunning attributes of the Coral Trout is the male’s ability to instantly change its colour when putting on displays of courtship attempting to land a female, an amazing spectacle to witness when scuba diving. Depending on species, Coral Trout typically grow anywhere from 70 to 120 centimetres in size, and thus are one of the larger common denizens of the Great Barrier Reef.
Wrasse
The most common species of Wrasse found in the Great Barrier Reef is the Humphead or Maori Wrasse, a fish with a very distinctive feature – the large hump on their forehead from which they derive their name. They are one of the largest fish found in the reef and can be identified by not only the forehead lump but also their thick “lips”. Maori Wrasse are also one of the longest-lived fish in the entire Great Barrier Reef, with many known to live upwards of 30 years of age, but in spite of this fact are currently listed as an endangered species due to their reputation for being a delicious meal and thus previously heavily fished. Maori Wrasse can grow up to two metres in length, and combined with their unique colouring and distinctive forehead are one of the most sought-after fish for divers in the reef’s waters off the coast of such destinations as Cairns and Port Douglas.
www.gbrma.gov.au/about-us/message-from-the-chairmen
New Caledonia Barrier Reef
About the Area
New Caledonia's marine waters harbour the second longest double barrier reef in the world, which reaches a length of 1,500 kilometers.
This barrier reef is of outstanding biogeographical interest and serves as a regional center of endemism in the south pacific.
Much of the enormous species diversity in New Caledonia is yet unclassified as new species of fish and invertebrates are being discovered regularly.
The reefs provide one of the main nesting sites for the Green turtle (Chelonia mydas), and house several rare crab and endemic mollusk species.
Local Species
Fish diversity is high with at least 1,000 species documented. These fish include the endemic Sea bass (Luzonichthys williamsi) and numerous species within the families Labridae, Pomacentridae, Gobidae, Serrandiae, Chaetodontidae, and Apogonidae.
Major commercial fish include representatives from the families of Serranidae, Lutjanidae, Lethrinidae, Mullidae, and Labridae.
New species of fish and invertebrates are being documented, including a new species of an extremely rare amphipod (Didymochelia ledoyerisp), and a palaemonine shrimp (Brachycarpus crosnieri).
Other species of interest include the dugong (Dugong dugon), a diverse population of water striders (Xenobates spp. and Halovelia spp.), two species of giant clams (Tridacna gigas and Hippopus hippopus), over 600 species of sponges, 5,500 species of mollusks, 5,000 species of crustaceans, and over 350 species of algae.
Twenty-three known species of marine birds breed here, including the Red-footed booby (Sula sula), Sooty tern (Sterna fuscata), Lesser noddy (Anous tenuirostris), and Brown noddy (A. stolidus). Marine turtles include Green turtles (Chelonic mydas), Hawksbill turtles (Eretmochelys imbricata), Loggerhead turtles (Carettta caretta), and Leatherback turtles (Dermochelys coricea).
The reef system is home to at least 15,000 species of marine animals, including some 800 species found nowhere else on the planet! - See more at: http://www.culturalsurvival.org/take-action/new-caledonia-protect-coral-reef/new-caledonia-protect-coral-reef#sthash.wXafTvUp.dpuf
Red Sea Coral Reef
Red Sea Coral Reefs
Red Sea coral reefs are the northernmost in the Indian Ocean. Most of the Red Sea coast is rimmed by shallow submarine shelves and extensive fringing reef systems, by far the dominant reef type found here.
Red Sea fringing reef platforms are over 5000 years old, and the entire coastal reef complex extends along some 2,000 km (1,240 miles) of shoreline.
Most such reefs grow directly from the shoreline. The dominant, most actively growing corals include most notably highly branched species of the genera Acropora and Porites.
Red Sea coral reef
The Red Sea also contains numerous offshore reefs that defy classic reef type categorization.
Included in this catch-all category are atoll-like rings of coral, elongated coral ridges that rise abruptly from considerable depths on both sides, and peculiar complex reef patterns of odd shapes.
Such Red Sea coral reef formations are almost certainly the result of the active and unusual tectonic forces that have been at work here for millennia and continue today.
There are a few true atolls in the Red Sea (several off the coast of Sudan), but no true barrier reefs.
Characteristics of Red Sea Coral Reefs
The geological history of the Red Sea region is distinctive, and there is only slow and restricted water (and larval) exchange between this sea and the remainder of the Indo-Pacific region as a whole.
Thus, Red Sea reefs have developed a number of features that distinguish them from reefs found throughout most of the rest of this vast oceanic area.
Particularly important in the light of global warming predictions is the fact that Red Sea corals have developed an unusually high tolerance to the extreme temperatures, salinity, and occasional turbidity (caused by huge seasonal dust storms) that occur in the region. Such conditions that would be lethal or highly damaging to most hard corals found elsewhere.
Also, water clarity is exceptional in the Red Sea because of the lack of river discharge and low rainfall. Thus, Red Sea reefs are not heavily impacted by the suspension and dissipation of fine sediments that plague reefs in tropical oceans near large land masses.
The Al Wadj Bank, Saudi Arabia. Courtesy NASA.
Red Sea coral reefs are particularly well developed in the north and central portions (off the coasts of Egypt, Saudi Arabia, Sudan), with large sizable offshore reef complexes containing small islands, fringing reefs, and a variety of reef-associated habitats (see photo, above).
Endemic Red Sea reef fish (Chaetodon semilarvatus). © Fotolia.
Further south, coral growth is somewhat inhibited by the influx of nutrient laden water where the Indian Ocean enters the Red Sea. This surface waters of the more southerly areas are also subject to far greater mixing with deeper water caused by strong winds coming off a high mountainous coast.
In general, the marine biota of Red Sea coral reefs is characterized by high endemism. For example, of the 1200 or so coral reef fish species recorded, about 10% are endemic (found nowhere else).
About 300 hard coral species have been recorded from the Red Sea as a whole. The Egyptian coast alone supports about 200 species of reef building corals belonging to almost 50 genera. This represents about four times the hard coral diversity found on Caribbean reefs, and is comparable to the coral diversity found in the Maldives and Seychelles in the Indian Ocean.
Nonetheless, the biodiversity of Red Sea reefs does not rival that of reefs of the richest parts of the Indo-Pacific region.
Status Of Red Sea Reefs
Despite the extreme conditions characteristic of the region, Red Sea coral reefs are generally healthy. Coral reefs range widely in condition and cover, with up to 85% living coral cover at the best sites and over 50% live coral cover at many other locations. There is usually minimal coral bleaching evident, although some localized outbreaks are reported from time to time.
A fringing reef rims the shore of Egypt's Ras Mohammed National Park. © Fotolia.com
Still, many Red Sea coral reefs situated near urban centers and other developed parts of the coast have been heavily damaged or lost due to the predicatable effects of poorly planned or regulated population expansions and coastal development, along with associated declines in water quality.
In some of the once most pristine reef areas, insufficiently managed dive tourism (damage from anchors and recreational scuba divers) has also taken its predictable toll on the reefs.
Studies of diver effects on reefs suggest that continued dive tourism expansion at some of the more popular tourist destinations would be ill-advised and will inevitably lead to serious reef degradation.
A growing number of marine number of protected areas (MPAs) have been established in the Red Sea to help alleviate some of these problems. Ras Mohammed National Park was established by Egypt in 1983 and includes miles of healthy fringing reefs. The Red Sea Marine Peace Park in the Gulf of Aqaba was founded in 1994 by the governments of Jordan and Israel to preserve and protect the area's coral reefs.
Red Sea Geography and Oceanography
The Red Sea is an extension of the Indian Ocean, lying between the Arabian Peninsula and Africa, with a surface are roughly equal to the US state of California.
Map of the Red Sea and surrounding region
The only natural connection between the Red Sea and the rest of the Indian Ocean is Bab el Mandeb, a narrow strait that transitions into the Gulf of Aden.
To the north, the Red Sea splits into two narrow branches (the Gulf of Suez and the Gulf of Aqaba) that flank the Sinai Peninsula.
Overall, the Red Sea is a comparatively shallow body of water with an average depth of only about 1600 feet. However, it is in reality a young ocean in the early stage of formation.
As the African and Arabian continents slowly rift apart, new oceanic crust is formed and slowly but surely the Red Sea is gradually widening. The tectonic forces at work are most evident in the deep narrow trench (Rift Valley) that runs most of the length of the sea at its center, reaching a maximum depth of over 8,600 feet (2,600 m) below sea level.
The region surrounding the Red Sea is one of the hottest, driest areas on earth. The extreme air temperatures result in very high levels of evaporation, making this one of the hottest and saltiest bodies of seawater in the world.
The average salinity is 40 parts per thousand (ppt), as compared to about 35-36 (ppt) in the tropical Indian, Pacific, and Atlantic Oceans. Recent measurements found surface water temperatures to be 28 degrees C. (82 degrees F.) in winter and up to 34 degrees C. (93 degrees F.) in summer.
Exploring Red Sea Reefs
Scuba diving and snorkeling on the fringing reefs of the Red Sea became popular soon after the publicity, books, and films of the expeditions of Hans Hass and Jacques Cousteau in the 1950s and 1960s were widely disseminated.
Shallow reefs, clear water, and abundant marine life make for excellent Red Sea reef exploration © Fotolia.
Today, the most popular dive destinations along the northern coast of the Gulf of Aquaba (known as the "Red Sea Riviera") include Eilat in Israel and Aqaba in Jordan. Other popular destinations in the Gulf of Aquaba on the the Egyptian side of Sinai are Dahab and Taba.
Further south, along the western shore of the Red Sea, reef diving is well supported at Marsa Alam, El Gouna, Safaga, and Hurghada.
The very popular Egyptian reef diving center of Sham-el-Sheikh, located on the southern tip of the Sinai, has undergone rapid expansion recently.
In the most southerly portions of the Red Sea, recreational diving (or tourism of any kind) is presently considered risky because of the presence of pirates originating from uncontrolled zones of Somalia. The situation is even worse in the Gulf of Aden between Somalia and Yemen.
Actinopterygii (ray-finned fishes) > Perciformes (Perch-likes) > Acanthuridae (Surgeonfishes, tangs, unicornfishes) > Acanthurinae
Etymology: Acanthurus: Greek, akantha = thorn + Greek, oura = tail (Ref. 45335).
Environment / Climate / Range Ecology
Marine; reef-associated; depth range 5 - 100 m (Ref. 28016), usually 5 - 45 m (Ref. 27115). Tropical; 23°C - 28°C (Ref. 27115); 35°N - 24°S, 32°E - 143°W
Size / Weight / Age
Maturity: Lm ? range ? - ? cm
Max length : 50.0 cm TL male/unsexed; (Ref. 3145)
Short description Morphology | Morphometrics
Dorsal spines (total): 9; Dorsal soft rays (total): 24-26; Anal spines: 3; Anal soft rays: 23 - 24. Body brown; head banded; fins brown. Capable of changing color to pale bluish overall. Behind eye a yellow area and 2 yellow bands extending anterior from eye. A single, sharp, forward-pointing erectile spine which folds down into a horizontal groove on each side of the caudal peduncle; spine in white sheath. Gill rakers 13-15 in both anterior and posterior rows. Scales minute.
Distribution Countries | FAO areas | Ecosystems | Occurrences | Introductions | Faunafri
Indo-Pacific: Red Sea south to Natal, South Africa and east to the Marquesan and Tuamoto islands, north to southern Japan, south to the southern Great Barrier Reef and New Caledonia.
Biology Glossary (e.g. epibenthic)
Inhabit steep slopes, often in turbid waters, generally in the vicinity of coral reefs (Ref. 58652) or rocky bottoms. Form resident spawning aggregations (Ref. 27825, 48637). Adults often seen in schools, feeding mid-water on plankton (Ref. 48637). Feed on zooplankton. Marketed fresh. Flesh is almost never poisonous (Ref. 4795).
This fish is also known as the Sohal Surgeonfish and Red Sea Clown Surgeon, and less commonly the Zebra Surgeon, Majestic Tang, Majestic Surgeon, Zebra Tang, and Arabian Tang. It is found in the Red Sea, to the Persian Gulf, and the Arabian Sea, sometimes in large aggregations, but usually in solitude. These fish commonly inhabit the reef plateau just before the slope, and are generally found in depths of less than 20 meters (65'). Wild Sohal Tang specimens can grow to 16 inches; in an aquarium the adults will normally grow from 7 to 10 inches.
The Sohal Tang is hardy, but susceptible to a disease known as Lateral Line erosion, or Hole in the Head. A vegetarian diet high in vitamins, especially beta-carotene can aid in the prevention of development of the disease. Stray voltages are also thought to contribute to this disease and the grounding probe may be beneficial.
Sohal Tangs are very aggressive. They should not be kept with other Tangs or Wrasse species. They tend to be well-behaved with old tank mates, but try to kill any new additions. They are only suited for large aquariums with other aggressive fish. They do fairly well in very large reef systems with no other Tangs, and plenty of swimming room.
Although Tangs will eat meaty foods along with the other fish in the aquarium, it is important that they are offered plenty of marine based seaweed and algae.
Just about everything to do with the Yellowfin Surgeonfish is extensive and big. They are the largest of the Acanthurus genus, reaching up to over 27 inches. They are found over the largest geographic area of the globe and at some of the greatest depths, having reportedly been observed by submarines at 295 feet (90 meters) deep. Their diet consists of about the widest variety of foods for the surgeonfish, and they are said to be one of the few that will take bait from a fisherman.They are capable of enormous changes in color pattern and they grow very quickly.
Not much is known of their personality as they are not generally kept in captivity, but as with other Acanthurus the Yellowfin Surgeonfish is probably not overly aggressive, except toward its own genus.
