Sea Cucumber - Species of the Reef

Like the vaccum cleaners of the sea, the sea cucumber scavages it's food along the sea floor, where it eats decaying matter and plankton. It is has and endoskeleton which means it's bone structure is just below it's leather and tough skin. The sea cucmber shoots out a sticky goo that it uses as a self defence mechanism to entangle any would be predators out there.

The sea cucumber is able to strengthen and loosen the outside of their body at will allowing them to squeeze through tight crevaces and then harden the outside of it's body again when it is in more exposed areas. Because ten percent of the sea cucumbers blood is vanadium and not hemoglobin their blood is not red but yellow.
Some of the earliest form of trade between Asia and indigenous Australia was the trade of sea cucumbers, which are highly regarding in some forms of eastern medicine and as a food dish.

Damsel Fish - Species of the Reef

No one ever talks about the poor old damsel fish. But they are very important in the reef ecosystem, eating algae allowing for reef regrowth. Damselfish are one of the most abundant groups of coral reef fishes. They display remarkable diversity in habitat preferences, feeding habits, behaviour and colouration. Most species are highly territorial. Algal-eating species zealously defend their 'plot' against intruders, regardless of size. These algal feeders. These algal feeders generally have drab colour patterns whereas the plankton-feeding damsels are brightly coloured. Damselfish eggs are laid on coral rock and are guarded by the male until they hatch in 2-14 days. All damselfish, except the anemonefish (genus Amphiprion and Premnas), change sex from male to female. The anemonefish goes through a reverse sex change from male to female.

Minke Whales - Species of the Reef

This young Minke whale decided to cruise around one of our dive sites on the outer reef. The curious young fellow was very intrigued with these strange creatures wearing bottles and blowing bubbles constantly. Jonny our intrepid young dive instructor happily snapped these photos as Fred swam around the boat and divers.
The Minke whales migrate from southern waters off Victoria to the northern areas of the Great Barrier Reef from about June every year. They grow to about 8m (26') log and adults can weigh about 6 tonnes.
More on the Dwarf Minke Project can be found at the CRC Reef Research website.

Angelfish - Species of the Reef

This is another of the vibrant and colouful fish found commonly seen our our trips to the Great Barrier Reef. There are over 80 different species of Angelfish. Most of which are about 30 cm (12") long. Most of the different species exhibit a friendly and curious personality and often come over to investigate what the divers are doing on their turf. Smaller species such as the bi-coloured angel are very popular with home aquariums. Angel fish are found at all levels of the bommie fields, from the surface to swimming around the base of the reef formations and seabed.
The angel fish changes colours as it reaches maturity, and can also change sex if the male in the group disappears. If this happens the dominate female in the group will then become the male. The angel fish releases it's eggs to float with the plankton until hatched.

Cuttlefish - Species of the Reef

This is one of the coolest fish on the reef or one of my favourites anyway. He just hangs out relaxed taking everything in his stride. They can often be seen hanging on the back edges of the reef and the juveniles often hang out by our mooring lines. The cuttlefish is related the squid, octopus and nautilus. The cuttle fish can also change colour (as the photo below demonstrates) and uses ink to defend itself.
The bone inside the cuttlefish is used for birds in the home and is often washed up on the beach or seen drifting on the ocean.
A couple of interesting facts about the cuttlefish are that they have amongst the best eyesight in the world although they do not differentiate colour the same as we do. The other fact is they have three hearts and green-blue blood instead of the usual red. Maybe this is why they act so cool, they have similar characteristics to the Vulcans from Star Trek.

Turtle Weed Algae - Species of the Reef

The unsung hero of the reef are the algaes. They provide food for the many herbivores on the reef providing the foundation of most marine food chains. In todays' world one of their most important roles is turning carbon dioxide into oxygen and food. As you can see, protecting the reef helps protect our oxygen supplies.
Large algae may also provide homes for a wide variety of small organisms. The algae above is known as turtle weed and is found on the Great Barrier Reef. It can be found from 5 m to about 20 metres deep. Turtle weed is popular in home aquariums also, playing its' part in the removal of nitrates and converting CO2 to oxygen.

The Parrot Fish - Species of the Reef

One of the most colourful fish on the Great Barrier Reef in the Parrot Fish. So named because of the parrot like beak which it uses to eat algae off coral and other organisms off corals. They are essential to the ecology of the reef and their gardening plays a pivotal part in the survival of the reef. The parrot fish feeding on the reef ensures that algae does not suffocate the reef. The coral they eat is ground up and excreted as sand.
Most of the Parrot Fish family grow to about 30-40 cm (12-16"). They release their eggs into the ocean where the eggs float until settling in the reef until they hatch.

Spinner Dolphins - Species of the Reef

Another favourite of all our guests and crew, the spinner dolphin. These playful and friendly creatures love to swim along the bow wave of the boat as we sail both to and from the reef. The most common sight is a group of half a dozen or so, however occasionally the come to join us in the dozens.
They grow to just over 2 metres long (7') and weigh up to about 75 kg (175lbs). It is one of the most athletic of the dolphins jumping out of and skimming across the water.

Anemone Fish or Clown fish - Species of the Reef

OK, I was holding off including these little fellas, as they are superstars in their own right already and we were respecting their privacy as celebrities. It is tough for these guys to just blend in with the crowds anymore and the simplest of tasks such as taking the kids out often ends in a frenzy of paparazzi. But due to popular demand I have to include them.
There are 28 different types of clown fish, the largest being about 18cm (7"). The clown fish forms a symbiotic relationship with its host anemone and will defend its home with vigour. Spawning season lasts all year. The female lays their eggs next to the host anemone, which they then are guarded by both parents. The eggs take 7 days to hatch and hatch about an hour after sunset to avoid predators.
Now how does the clown find find his way home? Research at JCU suggests that the anemone fish smells the scent of the host anemone. When the baby clown fish are ready to move out and find a place of their own they use this scent to locate a suitable anemone.

Humpback Whale - Species of the Reef

An annual favourite with crew and guests alike, the annual whale migration (June-November), as whales swim north to escape the cold of winter. Whales were the earliest tourists to Cairns and for centuries have known what humans are now just discovering.
The humpback whale's common name is derived from the humping motion they make when diving below the surface (as seen in the above photo). They have a social networking where they hang out together for a few hours and then move on. They eat a variety of fish and they hunt fish by direct attack or by stunning them by hitting the water with its pectoral fins or flukes.
The humpback whale population has continued to grow at an average of 11% and is steadily returning to pre-hunting days, although these threats still exist even today. Their playful antics and curiosity amuse everyone and have to been seen in real life to get the true appreciation of this species.

The Green Turtle - Species of the Reef

The green turtle is a common sight around the reefs of Cairns, lazily eating and swimming around the dive sites they make a peaceful presence to the fantastic underwater landscape.

Quick Facts
Breeding Season - Late October to February
Years between breeding - Two to Eight Years
Nesting female carapace length - 107 cm (42 inches) (range from 91-124 cm)
Nesting weight - 130 kg (286lbs) (range from 98-184 kg)
Clutch size - 115 eggs (range from 62-153 eggs)
Hatchling emergence season - December to May
Hatching success - 84%
Hatchling size - 4.97cm (2 inches) (range from 4.02-5.19 cm)
Hatchling weight - 24.83g (0.87 oz) (range from 19.8-28.4 g)
Predators of hatchlings - Crabs, herons, dingoes and fish such as trevally and sharks

Conservation Status - Internationally Endangered — World Conservation Union
Description - Adult green turtles have a smooth, high-domed carapace, are olive green in colour, with occasional brown, reddish-brown or black highlights. Hatchlings have a black carapace with white margins around the carapace, flippers and on the plastron. Green turtles have one pair of prefrontal scales between their eyes.
Threats to Survival - Threats to survival include incidental capture in fishing and shark control program gear, ingestion of synthetic materials, boat strike, predation of eggs or hatchlings at rookeries, incidental capture in dredges, Indigenous harvest of adults and eggs within Australia and overseas and increased incidence of disease (high incidence of fibropapillomas).
Distribution and Habitat - Green turtles are found in tropical, subtropical and temperate waters around the world and appear to be the most abundant of the six species of marine turtle found in the Great Barrier Reef World Heritage Area. They are found in subtidal and intertidal coral and rocky reefs and seagrass meadows of the continental shelf. Green turtles are principally herbivorous as adults, eating mostly algae, seagrass, mangrove fruit and jellyfish.
The proportion of a green turtle population that nests each year is highly variable (up to an order of magnitude difference) and is influenced by variations in the El Nino Southern Oscillation (ENSO) Index. Green turtles are the species of marine turtle for which this correlation has been shown and it may be based upon nutrition.
For green turtles nesting and foraging in the Great Barrier Reef World Heritage Area, tag returns indicate migration to Indonesia, Gulf of Carpentaria, Arnhem Land, Torres Strait, Papua New Guinea, the Solomon Islands, Vanuatu and New Caledonia.
Breeding Areas
There is low density nesting on many islands and along the Queensland coastline. Although genetically distinct nesting aggregations are known, the stocks often occur in the same foraging habitat.

Giant Clams - Species of the Reef

One of our guests' favourite sights on our Great Barrier Reef Tours are the Giant Clams. They come in various brilliant colours and impressive sizes, colours include bright purples, reds and blues. Divers get to experience the larger specimens up close, but if you are not a certified diver don't worry you can probably take an introductory dive (FAQ#5).
The giant clam, Tridacna gigas, is the largest living bivalve mollusk. They can weigh more than 200 kilograms (440 pounds), measure as much as 1.2 metres (4 feet) across, and have an average lifespan in the wild of 100 years or more.
By day, the clam opens its shell and extends its mantle tissue so that the algae receive the sunlight they need to photosynthesize.

History and Legend
As is often the case with uncharacteristically large species, the giant clam has been historically misunderstood. It was known in times past as the killer clam or man-eating clam, and reputable scientific and technical manuals once claimed that the great mollusk had caused deaths; versions of the U.S. Navy Diving Manual even gave detailed instructions for releasing oneself from its grasp by severing the adductor muscles used to close its shell.
Today the giant clam is considered neither aggressive nor particularly dangerous. The process of closing the shell valves is slow enough not to pose serious threat. Furthermore, many large individuals are unable to close their shells completely.

Conservation Status
The IUCN lists the giant clams as vulnerable. There is concern among conservationists for the sustainability of practices among those who use the animal as a source of livelihood. The numbers in the wild have been greatly reduced by extensive overharvesting for food and the aquarium trade. On the black market, giant clam shells are sold as decorative accoutrements, and the meat, called Himejako in Japan, is prized as an honor.

Giant clams are found in abundance on our dive sites, and make brilliant photos that you are sure to treasure for years. If you don't have a underwater digital camera, you can hire them through us as well. Just let us know at time of booking or the day before the trip.

Birds of the Great Barrier Reef - Red-footed Booby

A common sight on the reef are the Booby Birds scanning the oceans in search of food. The Booby, a type of seabird, is part of the family Sulidae and the genus Sula. It is closely related to the gannets (Morus), which were often included in Sula in former times.
Boobies are large birds, with long pointed wings and long bills. They hunt fish, by diving from a height into the sea and pursuing their prey underwater. Facial air sacs, under their skin, cushion the impact with the water. Boobies are colonial breeders on islands and coasts. They normally lay one or more chalky-blue eggs, on the ground or sometimes in a tree nest.
Their name is possibly based on the Spanish slang term bobo, meaning "dunce", as these tame birds had a habit of landing on-board sailing ships, where they were easily captured and eaten. Owing to this, Boobies are often mentioned as having been caught and eaten by shipwrecked sailors, notably Captain Bligh of the Bounty and his loyalists, during their famous voyage after being set adrift by Fletcher Christian and his mutineers.

Birds of the Great Barrier Reef - The Nightjar

Not only do you get to see some great reefs, dolphins, and fish on our trips you also get to experience the birds that inhabit the Great Barrier Reef. One of these seen in the reef is the Night Jar.
Nightjars are medium-sized nocturnal or crepuscular birds with long wings, short legs and very short bills. They are sometimes referred to as goatsuckers from the mistaken belief that they suck milk from goats (the Latin for goatsucker is Caprimulgus). Some North American species are named as nighthawks. Nightjars usually nest on the ground.
Nightjars are found around the world. They are mostly active in the late evening and early morning or at night, and feed predominantly on moths and other large flying insects.
Most have small feet, of little use for walking, and long pointed wings. Their soft plumage is cryptically coloured to resemble bark or leaves. Some species, unusual for birds, perch along a branch, rather than across it. This helps to conceal them during the day. Bracken is their preferred habitat.
Nightjars lay one or two patterned eggs directly onto bare ground. It has been suggested that nightjars will move their eggs and chicks from the nesting site in the event of danger by carrying them in their mouths. This suggestion has been repeated many times in ornithology books, but while this may accidentally happen, surveys of nightjar research have found very little evidence to support this idea.

Lion Fish - Species of the Reef

The lionfish blends very well into it's environment. The photo above was taken by one of our guests, Hans Knudsen, trying to capture the ravine and beautiful fans. He was surprised to see a lion fish in the front right of the picture when he got home and looked at his photos from the trip.

A Lionfish is any of several species of venomous but not aggressive marine fish in the genera Pterois, Parapterois, Brachypterois, Ebosia or Dendrochirus, of the family Scorpaenidae. The lionfish is also known as the Turkey Fish, Dragon Fish, Scorpion or Fire Fish. They are notable for their extremely long and separated spines, and have a generally striped appearance, red, green, navy green, brown, orange, yellow, black, maroon, or white.
The lionfish is native to the tropical Indo-Pacific region of the world, but various species can be found worldwide. Due to a recent introduction, the lionfish has recently been spotted in the warmer coral regions of the Eastern Atlantic Ocean and Caribbean Sea. Lionfish are an invasive species in the Atlantic Ocean and the Caribbean Sea regions. Successful breeding of the lionfish in captivity has not been reported. In early 2009, the Lionfish was spotted in the Florida Keys, seemingly increasing its range.
There are many types of lionfish that vary in size. The common lionfish generally reaches a size of 30-35cm, while smaller lionfish, like the Fuzzy Dwarf, are typically the size of a tennis ball, not including fins.
We encourage everyone (divers and fishermen) to be extremely cautious and avoid contact with the venomous spines of the lionfish. Although they are not deadly, they are very painful. Lionfish are not aggressive toward humans and will almost always keep their distance when given the opportunity, so they pose a relatively low risk.
The lionfish is one of the most venomous fish on the ocean bottom floor. Lionfish have venomous dorsal spines that are used purely for defense. When threatened, the fish often faces its attacker in a head-down posture which brings its spines to bear. However, a lionfish's sting is usually not fatal to humans.
Lionfish are voracious predators. When hunting, they corner prey using their large fins and then use their quick reflexes to swallow the prey whole. In captivity, lionfish can be trained to eat frozen brine shrimp, mysis, and krill.
However the lionfish have very few natural predators, but the grouper and other lionfish have been found with lionfish remains in their stomachs.

Tawny Nurse Shark - Species of the Reef

The tawny nurse shark or giant sleepy shark is found in the tropical Indo-Pacific oceans between latitudes 31° N and 24° S, and reaches a length of 3.2 m.

The tawny nurse shark is a large, bulky species with a small mouth and small comb-like teeth, and with angular fins. The caudal fin is short, much less than half the length of body, and there are no ridges on the side of the body. The pectoral fins are sickle-shaped, and the spiracles are much smaller than the eye.

It is found on continental and insular shelves, from the intertidal zone down to a depth of at least 70 m. It occurs on or near the bottom in lagoons or along the outer edges of coral and rocky reefs, sandy areas near reefs and off sandy beaches. Primarily nocturnal, but may be active during the day. It prefers crevices and caves on reefs but may be found hiding in more exposed areas, forming resting aggregations, and often seen piled across or on top of one another.

It feeds on a wide variety of bottom invertebrates, small fish, crustaceans and sea urchins. It has a docile nature and has been known to allow itself to be touched, but as always it is best not to touch creatures in the wild.

Reproduction is ovoviviparous (producing eggs that are hatched within the body, so that the young are born alive but without placental attachment.) with 4 or more pups being born per litter. It survives in captivity.

The flesh is marketed fresh and dried-salted, the fins dried for the oriental sharkfin trade, and the liver is processed for vitamins and oil. The offal is processed for fishmeal, and the hide is potentially valuable for leather.

Colouration is brown dorsally, paler ventrally, with the fins slightly dusky. Nebrius ferrugineus, is a nurse shark in the family Ginglymostomatidae, the only member of the genus Nebrius.

The Maori Wrasse - Species of the Reef

The Humphead, Maori or Napoleon wrasse, is widely distributed across the reefs of the Indo-Pacific and a favourite of our guests. A big fish with a bigger personality, the Maori Wrasse as it is more commonly know here is Australia is an endangered species and is now protected. It has two complimentary traits that do not combine well for survival, it is a very friendly and personable fish and it is a good tasting fish. This species is a very important part of the ecology of the reef as it is one of the few fish that eats sea hares, boxfish or the crown of thorns starfish.
With the current protection offered on the Great Barrier Reef we are starting to see the numbers of this fish increase. They are regulars at our dive sites at almost every reef now.
This first photo is taken at Thetford Reef by myself and the second was taken by one of our honeymooning guests Olga at the Pinnacles at Milln Reef.