Great Barrier
Reef - The Whitsundays - 
The Great Barrier Reef is said to be the
largest structure on earth ever created by living creatures.
The Great Barrier Reef World Heritage Area is 347 800 square
kilometres in area ( an area bigger that the United Kingdom,
Holland and Switzerland combined). It is the largest World
Heritage Area and marine protected area in the world.
The reef contains over 2,900 reefs which includes 760 fringing
reefs, and 300 coral cays.
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Amazing
Coral - Great Barrier Reef |
You can experience one the of the “7” wonders
of the world with a Day Trip to one of the pontoons with underwater
viewing platforms with optional Diving and Snorkelling or you
can experience the reef and islands on a Sailing and Diving
charter boat, “highly recommended”.
The Great Barrier Reef is the world’s largest and most complex expanse
of living corals reefs supporting varied forms of marine life. As the world’s
largest coral reef ecosystem, the Great Barrier Reef is home to over 1500 species
of fish, about 400 species of corals, 4,000 species of molluscs, 215 species
of birds, 6 species of sea turtles and a host of sponges, anemones, worms, crustaceans,
shells, sea stars, urchins…. Scuba diving and snorkelling are the most
popular ways to experience the unique and beautiful underwater world of the Great
Barrier Reef.
Most commonly asked questions
REEF FACTS AND FIGURES
The Great Barrier Reef Marine Park was
established in 1975, and it is the world largest marine protected
area in the world. It is approximately 348,700 square kilometres
in area and approximately 2,300 kilometres long, running from just
north of Bundaberg to the tip of the Cape York Peninsula. The reef
contains over 2,900 reefs which includes 760 fringing reefs, and
300 coral cays. There are also 618 continental islands, which were
once part of the mainland. As the world's largest coral reef ecosystem
the Great Barrier Reef is home to approximately:- 1,500 species
of fish 400 species of corals 4,000 species of molluscs 500 species
of seaweed 215 species of birds 16 species of sea snake 6 species
of sea turtle and some of the largest populations of dugong in
the world.
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WHAT FISH IS THAT ?
With over 1500 species of fish on the reef the answer to this question is not
an easy one. The use of identification books and underwater cards can be useful
in identifying commonly encountered species. Body and mouth shape are often
the best key features in identifying the type of fish. The reef fish section
of the marine biology manual will outline the features of the mostcommonly
encoungered families of fish. Aim to learn the name of just one fish every
time you visit the reef, and you will quickly know the most commonly encountered
species. |
ARE WE GOING TO SEE ANY SHARKS ?
If you see a shark while visiting the reef, consider yourself very lucky as sharks
are not frequently encountered by visitors. Of those which are seen the most
commonly encountered are the white tip reef and black tip reef sharks. Easily
identified by the white markings on the tips of the dorsal fins, they are often
found resting upon the sea floor. Like most sharks white tip's are extremely
timid and won't stay long around divers. Most sharks found on the reef are
fish eaters and therefore pose no threat to visitors. Do not harass or block
off a shark's exit as they may attack out of fear. |
WHAT ABOUT STINGERS ?
The box jellyfish is found in the coastal waters of North Queensland during summer
months (October to March). Visitors wishing to swim during this period should
only do so in protective swimming enclosures or wear protective clothing. The
box jellyfish is a coastal species and is not found out on the reef, but they
can sometimes be found around islands close to the mainland. Other stingers
that are sometimes encountered on the reef include the irukandji and blue bottle.
Both can cause a nasty sting, Vinegar can used on both box jellyfish and irukandji
stings but not on blue bottle stings. For blue bottles use cold water and ice. |
Box Jellyfish |
WHY ISN'T CORAL VERY COLOURFUL ?
Most visitors to the reef comment that the coral isn't very colourful as they
are used to seeing brightly coloured images in books and on television. Natural
white light is made up of all the colours of the rainbow; underwater, these
colours are filtered at different depths with red and yellow disappearing first.
This gives the reef a predominantly blue/green appearance. Photographs and
video are taken using lights to show the true colours of the reef. So the colours
are there, it's just that you need white light to see them. This is why night
diving on the reef is so spectacular. |
Colourful
corals
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WHAT ARE CORALS ?
Coral are made up of a thin layer of living animals called polyps, which secrete
a chalky, limestone skeleton as they grow. Coral colonies grow as the polyps
divide and multiply in a process known as budding. In addition to catching
planktonic prey with their tentacles corals also derive nourishment from simple
single celled algae called zooxanthellae (pronounced zoo-zan-thelly). living
within their tissues. Like all plants, zooxanthellae photosynthesize, producing
nutrients from the suns energy which are used by the polyp for its own nutrition.
Corals with zooxanthellae are able to lay down limestone skeletons up to three
times faster than those corals without. |
WHAT TYPE OF CORAL IS THAT ?
Trying to identify particular species of coral is very difficult. What makes
it so difficult is that one type of coral may appear as a branching form in
calm water and look like a plate coral in another area. In many cases it is
the environmental conditions, such as wave action, light levels and the amount
of sediment in the water, that influence coral colony shape. The easiest way
to identify corals is by their appearance * boulder * branching * plate * table
* vase * bushy * solitary
WHAT ABOUT CORAL SPAWNING ?
Every year over one third of the reef's 350 species of coral reproduce sexually
during a mass spawning event. The majority of inner reefs spawn around November
with the outer reefs spawning later in December. Spawning always takes place
at night, and follows any time up to six days after the full moon. Eggs and sperm
are released into the water where they eventually combine to form a free swimming
planktonic larval stage.
WHY IS THE REEF SO FAR OFFSHORE ?
Most of the Great Barrier Reef is located off the mainland of Queensland. Corals
need clear waters which are low in nutrients. They cannot tolerate freshwater
or nutrients carried in the water run-off from the mainland. That is why the
most diverse and abundant corals grow offshore where the environmental conditions
are more suitable.
WHAT IS THE WATER CLARITY GOING TO BE
LIKE ?
The clarity of water on the reef is determined by a combination of the amount
of sediment and the amount of phytoplankton in the water. Sediment becomes suspended
due to increased water motion caused by tide changes, high winds and storms.
Phytoplankton are the microscopic plants that drift around in the water. They
are more numerous in areas where the nutrient levels of the water are higher
particularly around coastal reefs which receive nutrient rich runoff from the
land. |
ARE WE GOING TO SEE
ANY WHALES ?
Whales are normally encountered during the winter months when they migrate up
to the reef from Antarctic waters to mate and give birth. One of the most spectacular
visitors during this period is the Humpback. They are seen in the shallow coastal
waters of the Great Barrier Reef ranging from Hervey Bay to
Port Douglas. Whale watching is conducted by a number of tourist operators through
these areas. The Minke is another species of whale seen during winter, particularly
around the Ribbon Reef area. The smallest whales, the dolphins can be seen all
year round in most parts of the reef. * What about Crown-of-Thorns Starfish?
The cause of Crown of Thorn Starfish outbreaks is still the focus of a lot of
research and debate. Increased nutrients from the mainland and effects due to
El Nino are all being investigated as is the possibility that it is a naturally
occurring event. Crown of Thorns starfish may actually serve to maintain coral
diversity on the reef by feeding on the fast growing species, that if left unchecked,
could dominate the reef.
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Humback Whale |
WHERE CAN WE GO FISHING ON THE REEF
?
Fishing is not allowed in green national park zones or pink preservation and
orange scientific zones. In other zones fishing is allowed subject to Queensland
fisheries restrictions. Legal sizes, closed seasons and catch quotas also apply
to a variety of fish and shellfish. The following animals are totally protected:
whales, porpoises, dolphins, dugong and turtles, clam, trumpet and helmet shells,
female crabs all grouper and cod over 1.2 metres. What about the weather? In
general the average passenger is not so much concerned with the weather as they
are with how it will influence their day at the reef. Therefore an answer should
be given in reference to their concerns eg.sea sickness, water clarity, and the
colour of the reef. Whats that slick? When good growth conditions exist, blooms
of a simple floating algae called Trichodesmium are often confused with oil and
coral spawn slicks. Blooms can be easily identified by their rusty brown colour
as they occur in wind rows along the surface of the water. Slicks of coral spawn
generally do not last more than two days after coral spawning. Any oil spill
should be immeditely reported to the local maritime authority. |
Whitsunday Islands - Airlie Beach - Queensland
- Australia |
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