The Underwater Wonderland of Australia | Free Documentary Nature

[Music] [Music] the ocean its waters cover over 70 percent of the earth's surface many thousands of living creatures make their home in this underwater world and only a small number of them have been studied [Music] that is true of the ocean surrounding australia as well anyone getting their head underwater off the coast of the fifth continent begins a journey into a still largely unknown wonderland [Music] the most popular diving areas are the ningaloo reef in west australia and the great barrier reef off the continent's eastern coast [Music] our journey through the wet wonderland starts in west australia the small town of xmith is located on the westernmost tip of the country the town offers nothing more than an american marine base and a small town of 2000 souls the only historical attraction is the abandoned lighthouse on one of the hills on the cape range point but more emus visit the old lighthouse than tourists they are more drawn to the turquoise-colored ocean the descriptions of pristine dream beaches in the travel brochures completely devoid of humanity are in no way exaggerated [Music] it is a different story on the water over the coral reefs just off the coast particularly between april and june during those months a very special event draws thousands of tourists from all over the world it is the season of the whale shark every year just after the coral has spawned these largest sharks on earth come here to fill their bellies in the plankton-rich waters the national park administration allows people to swim with the whale sharks under strictly defined conditions and the tour guides pay very exact attention to see that the gentle giants are not harmed in any way the boats are guided to where the whale sharks are by observation aircraft at different times of the year many other marine animals visit the waters of the ningaloo reef as well the reason for that is the natural food chain which is still intact it offers each species what it needs to survive the gulf of xsmith is even a regular stop for whales on their seasonal migrations from the south pole to tropical waters and back [Music] whale sharks are not mammals like dolphins or whales they are strictly gill breathers when fully grown they are the size of a tour bus and weigh up to 19 tons people like to swim next to these giant fish because they are so gentle they feed only on plankton and small fish so people are free to romp about in the water like seals without fear of being attacked by the enormous creature [Music] that wouldn't be the case around other kinds of shark [Music] in the 1990s scientists successfully tagged whale sharks with transmitters for the first time now it is known that during the course of a year they cover nearly half the globe in their travels [Music] marine biologist brad norman from perth has been in exmouth studying whale sharks for many years [Music] using this kind of system he collects plankton and analyzes its nutritional value among other things how the whale shark manages to grow to such a stature on this diet is still not completely understood where the animals mate and how they bring their young to birth is still not known a pregnant whale shark caught by malaysian fishermen did reveal however that the young of these gentle giants hatch out of their breeding sacks while still inside the mother's body and are then born completely formed the mortality rate must be enormous a female whale shark gives birth to many young the majority of them must fall prey to predatory fish otherwise the world's oceans would be saturated by whale sharks and according to brad that would have a dramatic effect on the ocean's food chain the reason is that when a whale shark opens its mouth to filter the nutrient-rich water through its gills several tanker truck loads of water at a time are purified through this natural cleaning system only very little of the floating nutrients and minuscule life forms are left over for all the other living creatures that are dependent on the plankton for food [Music] [Applause] [Music] many thousands of years ago whale sharks also swam where now only mangroves grow and red cliffs rise above the ocean surface that which we currently fear today has happened before in earth's ancient past ocean levels were once many meters higher than they are today the cape range heights consist of sedimentary material forced upward by tectonic activity coral fossils found in the rock however prove that the red cliffs which tower above the surface today were once covered by an underwater coral reef over the millennia constant winds strong rainfall and violent storms have ground away at the sandstone canyon walls of this small mountain range [Music] um [Music] the vegetation is sparse but it is enough to provide a good habitat for the typical outback animals such as the emu or kangaroo [Music] with a little bit of luck visitors to the beaches at the ningaloo reef between october and february may be witnesses to a spectacle scene at only few beaches on earth [Music] here close to exmouth as one of three turtle species the green sea turtle lays its eggs and buries them in the sand to protect them from predators [Music] they lay up to 100 eggs in the nest it takes about two to three months for the babies to hatch the gender of the hatchlings depends on the prevailing temperature in the nest at about 28 degrees celsius they develop into males at about 32 degrees celsius they become females after laying the eggs the turtle returns to the ocean the young are left to fend for themselves [Applause] things have to happen very quickly when the baby turtles hatch their race to the water is a matter of life and death the hatchling shell has not yet hardened and they are easy prey for airborne enemies such as seagulls or sea eagles [Music] but even in the ocean there are many hunters waiting for the tasty prey only a small number of these sweet little turtles will survive to grow to be over a meter long and weigh up to 185 kilograms [Music] [Applause] [Music] turtles are loners and only enter into short relationships to meet on their long journeys through the oceans often from continent to continent they feed on crustaceans and mollusks they also enjoy the occasional jellyfish [Music] in contrast to small fish and humans they are immune to the stinging venom of the animal's tentacles [Music] the lifespan of the green sea turtle is between 40 and 50 years they do not reach sexual maturity until the ages of between 10 and 15 years [Music] corals are life forms as well they are made up of colony building polyps depending on how they grow they are categorized as either soft corals or stony or hard corals the hard corals develop calcified skeletons through their excretements when they die new living tissue grows over the remains that is how huge coral reefs have developed over the ages these life forms with their plant-like appearance provide an ideal habitat as well as important nutrients for fish and other creatures that is particularly true during the coral spawning season the polyps expel their egg and sperm cells to launch their external propagation process the billions of gametes in the water during that time make the ocean look like it is snowing this process clearly portrays the progression of the ocean's food chain the corals feed on bacteria and single-celled algae [Music] the minuscule life forms which make up plankton multiply by feeding on the gametes expelled by the coral and that happens explosively fish and other animals then feed on the plankton krill and larger fish then feed on the smaller ones as majestic as the colors of the coral banks might look they are not a paradise here too the cruel rule of nature applies eat and be eaten [Music] the many cave-like niches in the coral colonies provide many marine life forms with refuge and protection from predators but of course they are also wonderful hiding places for lurking hunters in order to protect themselves from such as these many types of fish form swarms living in swarms increases the chances of surviving attacks from hunters the predators can only catch and eat a certain number of prey the disadvantage is that swarms attract more hunters nonetheless pulling together is the best survival tactic for most fish it saves them from having to be on high alert all the time and give some time to forage for their own nourishment [Music] there is a difference between real swarming fish and so-called obligating shoulders and conditional swarming or facultative shoulders the real ones spend their entire lives in the group they hardly react as individuals at all often one observes that even the distance between the fish is almost the same as a rule these fish are of the same species and of the same age fish that swarm only under certain conditions do so when threatened or to form a communal hunting group such swarms are often made up of various types of fish of various ages [Music] [Applause] [Music] [Applause] [Music] [Applause] [Music] another type of self-defense is camouflage and that can take on several forms some animals can change their color to fit their surroundings or develop bizarre shapes trumpet fish sea dragons or pipefish and seahorses are particularly creative when it comes to concealment [Music] mom [Music] [Applause] [Music] fish form swarms not only for protection but also as a successful hunting strategy one that the barracuda have mastered to perfection for example large fish like rays for example often search for their nourishment alone [Music] most of the time they stir up the ocean floor in search of crustaceans other fish also find food in the disturbed sediment [Music] so everything fits together one either takes advantage of another's efforts or provides an advantage for others [Music] but the larger the fish the less good it does for the smaller ones that is the case with most types of shark scientists have isolated about 500 types of this cartilaginous fish in the world's oceans with their fine sensory organs from hearing to electrical sensors they react to low frequencies among other things the thrashing of fish or the grunting of seals produces just such frequencies in addition they are sensitive to pulsating oscillations and electrical fields with their lateral line organs sharks can detect water movements in their immediate area all in all they are perfectly suited to the hunt the best defense against them is either camouflage deception being poisonous or just not tasting good jellyfish obviously try it with a combination of stinging venom and alluring beauty [Music] you wouldn't eat such a breathtaking beauty would you [Music] keemstar foreign [Music] [Applause] [Music] the clownfish is especially clever it maintains a mutually beneficial business relationship with the sea anemone the fish defends the coral from smaller attackers in return with its venomous tentacles the anemone provides the clownfish with a great hiding place from its enemies [Music] [Music] the colorful nudibranchs are also classified as mollusks the cute little bushes on their outer jacket are their gills used to filter oxygen out of the water their bright coloration is a defensive trick what looks beautiful to us humans is often a warning signal in the underwater world that says watch out i am poisonous but in this case it is mostly bluff [Music] even the large manta rays feed mainly on plankton that they filter out of the water the wingspan of the largest animals can extend up to six meters [Music] here [Music] [Music] [Music] as we can see the unesco world heritage ningaloo reef is not just a playground for whale sharks the biodiversity of the coral reef is particularly rich it provides habitat for over 500 types of fish a good 200 species of coral and countless crustaceans echinoderms and other mollusks such as the octopus for example anyone visiting only to swim with the gentle giants will miss the true beauty of this natural wonder but there are several operators in eczema who offer their guests expeditions into the underwater coral world along the 250 kilometer length of the reef [Music] the race with the largest shark on earth makes one hungry the excitement is obvious in everyone for the scientist brad norman these excursions are routine of course unless he is called upon to report on the results of his research in front of an international television camera team but he is happy to do so because he is aware that every time in front of the camera is another opportunity to share his conviction regarding the importance of preserving these amazing creatures with the broader public our journey takes us from the ningaloo reef right across to the east coast of the continent up here in the north of queensland the over 2 300 kilometer long great barrier reef comes relatively close to shore that also brings it into the so-called typhoon zone and is thus subject to violent tropical storms between the months of october and march while it is relatively easy to get to small coral islands like low isles excursions to the extremely interesting reefs at the edge of the continental shelf only makes sense if one takes a couple of days time and overnights on board ship for the effort the ancient reef rewards experienced divers with some very special and lasting impressions the ship in the harbor of cairns is a relatively simple affair but it is the beginning of an unforgettable adventure in a world of coral the size of a small continent right [Music] by the way the great barrier reef can't be considered to be a single massive closed system it is rather a conglomerate of many smaller individual reefs each with its own development history and it's certainly not like being in a little goldfish pond even dolphins or whales like the southern or antarctic mink whale still find plenty of water under the keel they are drawn by the plankton rich water with its abundance of crab type animals and swarms of small fish as a rule mink whales are loners and grow to be up to seven meters long if they do occasionally form a swarm it consists of about a hundred animals the northern part of the great barrier reef reaches beyond the northern tip of australia the water temperature in this region has always been between 18 and 30 degrees celsius except perhaps during ice ages those conditions particularly favor the growth of the reef building stony or hard corals in essence they form the landscape that the soft corals can settle into [Music] today's brightly colored wonderland did not enjoy continuous growth however during times when the sea level dropped exposed areas of the reef dried out and the corals died sedimentation then created rises where new corals settled this process is still going on today [Music] so continuous changes to their habitat are nothing special for this huge potato cod or the more than 1 500 types of other fish at home in the reef [Music] [Music] besides the fish many other marine animals live in the reef there are also about 80 different types of soft coral over 1 500 kinds of sponge 5 000 types of mollusk and over 800 different species of echinoderms there's no way to count how many individual animals that makes there must be billions of creatures enjoying the good life among the acropora coral or the fine branches of the gorgonian fan coil [Music] [Music] [Music] until the end of the 20th century it was believed that corals could only survive in warm tropical waters but then science discovered corals living in cold water regions in the ocean depths they have no specialized cells to convert nutrients from the ocean waters into sugars and fats but are dependent on plankton to do that for them this kind of life form has been found in the north atlantic at depths of more than 3 000 meters but all types of coral are endangered by environmental influences for example the world's oceans are becoming more acidic due to the many pollutants washed into them that hinders the formation of the coral skeleton in hard corals on top of all that the mechanical destruction caused by dragnet fishing offshore drilling and laying pipelines and trans-oceanic cables does irreparable damage [Music] [Music] [Music] this is a puffer fish when threatened it blows itself up like a balloon to predators its face then looks threatening and it is nearly impossible for its typical hunters to swallow a ball of that size we humans find it rather cute for the fish the trick is an indispensable survival tactic but what must animals think about us humans when we encounter them with our unusual diving gear in photo and film equipment they probably think we are some sort of monsters [Music] this frogfish would certainly fit in the monster category it makes the feeler dangling in front of its mouth to look like a small floundering fish to lure its prey a close relative frogfish simply sucks its prey right in by the way many of these unusual fish are not indigenous to the great barrier reef but to the limbus straits on the north side of sulawesi [Music] sepia wonderpus a type of small octopus and many other fascinating and unique creatures make their home here on the volcanic ocean floor they have names like flying gernard seamoth napoleon fish etc [Music] [Music] [Music] [Music] in the great barrier reef on the other hand one tends to find more of the real beauties of the ocean like the trusting maori race for example [Music] this is a leopard trigger fish and this is a barramundi cod the extremely venomous sea snake is very shy around humans by the way thank god it is not aware of how dangerous it could be to the creature in the dark neoprene suit if it wanted to be the parrotfish could easily take the tip of a diver's finger off with its strong beak [Applause] and it is best not to give a hand to the moray eel [Music] but in reality all of these ocean dwellers are mostly as peaceable as these grunts [Music] [Music] a few representatives of the underwater ocean world have a particularly bad reputation with humans that has come not only as a result of their natural behavior but they have also been stigmatized by hollywood action films they are the sharks the secret rulers of the oceans these are not very aggressive they are reef sharks they prefer the cooler regions around the steep underwater cliffs at the edge of the continental shelf from this point it drops off two thousand meters into the depths it is also a particularly appealing zone for the experienced divers they conquer rugged steep cliffs but don't have to worry about falling so [Music] a few diving operators offer tourists an adrenaline rush of a very special kind it is the feeding of the predators [Music] operators like take a dive for example offer this type of event in cooperation with the environmental protection agency the goal is to demonstrate that although sharks are predatory fish they do not attack humans under normal circumstances at least as long as they don't try to feed them by hand when a favorable source of food is detected the predators form a hunting school the swarm attracts several types of predatory fish from bass to the sharks which then compete for a piece of the prey [Music] the demonstration shows that fish are able to learn the creatures with the rising bubbles are doing something good for them in this case all of the thrashing activity is concentrated on the food if one of the divers were to be bitten at this point it would be nothing more than an unfortunate accident in the confusion sort of like what might happen when playing with a group of dogs on land the feeding takes place at irregular intervals so that the fish don't grow accustomed to the convenient free meal the location was chosen because it had already been damaged by other circumstances [Music] so observing the symphony of life in the underwater world of the australian oceans is like looking into a mirror for us humans there is good and evil brilliant color and dull gray common and uniquely fascinating creatures everything is possible and nothing is abnormal you

Channel: Free Documentary - Nature

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Keywords: Free, Documentary, Documentaries, adventure, nature, nature documentary, documentary - topic, documentary (tv genre), ocean documentary, sea life, australia sealife, australia documentary, underwater world, underwater world australia, coral reefs, fish documentary, coral reef documentary, Free Documentary, Free Documentary Nature, Underwater Wonderland, Great Barrier Reef, Australia, Down Under, Sharks, Portuguese man o' war, Marine Life, Ocean Life, underwater documentary

Id: d8d-wOBqy_0

Length: 44min 23sec (2663 seconds)

Published: Fri Dec 06 2019