Wildlife Instincts: Australia's Curious Port Jackson Sharks | Free Documentary Nature

every year extraordinary sharks descend on mass to a secluded bay on the coast of australia [Music] port jackson sharks share their tranquil waters with an array of strange and wonderful creatures finding a partner is the name of the game risking all in their quest for a mate [Music] not all are successful in their pursuit to add to their bloodline new life grows in mystifying eggs while storms batter the coast the new generation enter the world alone and must learn fast in order to survive amid the bay's many residents [Music] [Applause] to the south of australia's sprawling city of sydney lies the serene jervis bay the bay encompasses over a hundred square kilometers and is surrounded by the world's most pristine white sands part of a national park the tranquil waters are protected by the government and are teeming with life every winter mysterious objects are discovered on the bay's famed sands the 15 centimeter spiraled shaped objects are in fact shark eggs [Music] susan newson has been observing the bay's wild residence for years and has been captivated by the peculiar eggs [Music] diving into the tranquil waters she sets out to find the sharks that lay these mystery eggs it's winter and the waters are a cool 14 degrees celsius [Music] moving deeper into the bay the environment changes from white sands to hard rocks covered in seaweed [Music] there is in excess of 230 kinds of seaweed growing from the sea floor 200 species of fish live amongst the sprawling aquatic foliage old wife fish endemic to australia congregate in the tranquil waters [Music] the tiny fish schooled together seeking the shelter of the bay's many rocks [Music] multiple species gather in the shallows ensuring safety in numbers [Music] at a depth of five meters a shark appears from within the seaweed bed this is what susan has been searching for a port jackson shark black banding on the back and sides are the shark's distinguishing features [Music] it's a meter in length with a large bull-like head and slender body relaxed in the presence of humans susan is able to get within inches of the resting individual port jacksons belong to the bullhead order of sharks these distinctive fish have truly extraordinary mouths their powerful jaws are specialized in grinding up tough food sources using sharp teeth at the front and powerful crushing molars at the back [Music] with poor eyesight port jackson sharks rely on their excellent sense of smell to find their prey rather clumsily they search for mollusks and crustaceans as bottom feeders much of their time is spent on the sea floor [Music] more sharks can be found in shallower parts of the bay the abundance of seaweed provides the perfect hiding place multiple port jacksons rest in close proximity showing no signs of aggression [Music] two objects protrude from the resting shark's pelvic fins these are the males genitalia and are known as claspers [Music] in this patch of the bay all the sharks encountered bear the distinctive organs it is only males lurking in the shallower waters [Music] females can be found at deeper depths their domain is located towards the mouth of the bay some 10 kilometers from the shallows diving into the deeper waters susan sets out to find the jervis bay's female port jackson shark population [Music] the landscape is very much different to the shallower reefs of the males sea tulips sprout from the seabed's rocks swaying in the current they feed on drifting plankton at a depth of 20 meters sharks begin to appear hundreds of port jacksons litter the ocean's floor they are all missing the claspers of the [Music] males these are the bay's females [Music] they are much larger than the males of the shallow reefs and take between 11 and 14 years to reach sexual maturity [Music] it's not unusual for male and female port jackson sharks to be separated like this in fact this is their natural behavior [Music] port jackson sharks spend their summer in separate groups near tasmania as winter descends they travel over 800 kilometers to jervis bay the males swim to the shelter of the rocky reefs while the females linger in deeper waters as the spring tide hits the females become more active gradually swimming into the shallows during this period the difference between high and low water is at its greatest it can increase by as much as two meters as the motions of the bay's water change so do its residents behavior [Music] male port jackson sharks will be waiting for the female's arrival however it's not only the males lurking in the shallows a smooth stingray glides through the tranquil waters at four meters long and weighing a hefty 300 kilos it is australia's largest stingray [Music] the bay's inhabitants are becoming more active another enormous creature emerges a giant australian cuttlefish the world's largest [Music] its body can reach up to a meter in length and weigh over 10 kilos their specialized eyes can see aspects of light that are invisible to humans gracefully the highly evolved mollusk waves its lateral fins to propel itself through the bay this individual is a male effortlessly he swims into a crevice [Music] port jackson sharks rest within and are undisturbed by their unusual visitor from the depths of the crevice a female appears [Music] in a rare sight the pair gently lock tentacles and begin to mate [Music] with a specially modified arm the male transfers a capsule of sperm port jackson sharks will also soon get their chance to extend their bloodlines females are beginning to appear in the [Music] shallows [Music] swollen bellies indicate they are ready to mate more and more females arrive in the shallows they start to gather around crevices [Music] finding the most sheltered spot is the wandering shark's assignment once a suitable crevice is found they finally rest [Music] now they will wait for the males to come to them out in the open males begin their search for a mate using their heightened sense of smell they comb the shallows for the scent of a female one has picked up the aroma of a potential mate peering inside the crevice he finds what he's been searching for the egg laden female dwarfs the male but he is not overwhelmed by her imposing size [Music] in what looks like an act of aggression the male bites the female's pectoral fin she manages to shake off the aggressor the apparent act of aggression is actually a display of courtship males will bite the female's fins to assess their willingness to mate wriggling free is a clear sign of rejection more and more males begin to inspect the bay's crevices in search for mating partners one contains a nasty surprise a banded wobbagong springs from the darkness it is a superbly camouflaged carnivorous carpet shark at three meters in length it is more than twice the size of the port jackson shark it is the perfect ambush predator easily able to blend into the bay's seabed a careless port jackson male swims right into the predatory wobbegong's path but he's lucky this time not all have been so fortunate this individual bears the scars of a recent shark attack males are willing to risk all in their quest for a mate all around the bay romance's blossoming one male makes his move and latches on to a potential mate persistence is key this female does not wriggle free from the male's grip with a firm grasp he pulls his mate closer the claspers are inserted and mating begins [Music] another male tries to take advantage rudely cutting in on the couple he is rapidly shrugged off failing in his bid to cut in on the mating female the impatient male will have to wait for another chance of romance the whole saga does not last long but the female bears the marks of the rough courtship fortunately she has thick skin these wounds should heal given time a freshly fertilized egg will now begin to develop inside the female's body [Music] of the 500 species of shark around 70 of them give birth to live pumps it's only the minority that lay eggs some of the bay's port jackson sharks are near to lane and begin to search for suitable spawning sites with such a precious cargo finding the perfect location is paramount an egg is already protruding it will not be long until she lays a suitable spot must be found soon but she seems reluctant to commit finding the right spot is crucial for the egg's chances of success and decisions cannot be rushed as night draws in the shark has yet to lay susan does not want to miss the rare occasion and believes there is a higher chance of discovering a laying shark at night diving into the pitch black depths she sets out to find a spawning port jackson shark the search is focused around the crevice the females were examining during the day [Music] sure enough a female on the verge of laying is found restlessly she swims around the crevice an egg protrudes from her body she is ready to lay port jackson shark eggs take between 10 to 12 months to hatch finding a safe nesting spot is crucial a long deep crack in the rock looks like the perfect location it would supply the eggs with plenty of shelter from the ocean's currents happy with the crevice as a spawning ground the female moves into position frantically she shakes her tail into the gap this is the moment susan has been waiting for [Music] a single spiraled egg drops into the crevice [Music] exhausted the female swims away her job here is done the egg rests deep within the rocks newly laid it is about 15 centimeters long there is an ingenious purpose to the exquisite shape [Music] currents push the egg into the back of the crevice wedging it into a small gap acting like a corkscrew it screws itself into the perfect position the longer it is in the water the harder it will become rocky reefs provide perfect nooks and crannies for the spiraled eggs but not all make it to hatching [Music] many are dislodged from unsecured spawning sites the displaced eggs wash up on the bay's sandy beaches other than their unique shape they also have an astonishing tough outer shell susan takes the opportunity to dissect one of the stranded eggs even a sharp pair of scissors struggles to penetrate the protective case the thick shell is made up of the same protein keratin found in human hair and nails jelly-like albumin surrounds the yolk it takes around 10 months for the shark to fully develop and hatch the first stage of development can already be seen a well-placed port jackson shark will safely develop over time tightly packed into crevices another species of bull head shark employs a different tactic their eggs are similar in appearance but use tendrils to anchor themselves to the bay's seaweed the tiny developing sharks only have their tough keratin shell as protection it is a crested bullhead shark that lays these eggs they look almost identical to paul jackson's but lack the port jackson's telltale lateral banding [Music] breeding is at its peak for the bay sharks in mid-august port jacksons will lay up to 16 times during the mating season [Music] eggs litter the seabed drifting in the current as if they were somehow dislodged many of the ruined eggs bear distinct puncture wounds they have been predated the bay contains many likely suspects some carnivorous fish are of a monstrous size like the eastern blue grouper reaching over a metre in length it has a powerful set of teeth adapted to ripping barnacles off rocks swimming near a port jackson shark egg it appears the grouper could be one of the egg eaters however it shows little interest many fish swim past the eggs but only show a slight curiosity the egg's tough outer shell and large size prevents most fish from being able to feed on them a culprit is yet to be found one female begins to lay what will be one of the last eggs of the breeding season twisting her body into the crevice she begins to lay unfortunately it is a failed attempt dislodged from the crevice the egg falls to the sea floor [Music] drifting in the current it is dangerously exposed [Music] an opportunistic male spots the wayward egg [Music] swimming over he clasps it in his powerful jaws [Music] it is not unknown for port jackson sharks to transport their precious eggs but this male has something else on his mind [Music] he takes the egg away from the safety of the rocks carrying it to a secluded sand bed [Music] astonishingly the male begins to bite down repeatedly it attempts to pierce the tough keratin shell once penetrated it sucks out the eggs contents [Music] utilizing its specialized jaws this male makes short work of the spiraled food it's not just a single wayward male some will go to great lengths in their pursuit of the eggs they will even squeeze into the tightest of gaps to get to the spiraled snacks this cannibalistic behavior is not limited to the males alone [Music] female port jackson sharks will also resort to eating their own species eggs [Music] it may seem brutal but the sharks expend a lot of energy during the mating season eggs provide a valuable food source during this testing time [Music] however not all are devoured some are left untouched and become brilliantly camouflaged among the bay's rocks marine life has started to grow on the keratin shell susan believes the egg has survived here for almost a year inside the shell a shark pup must be near to hatching a narrow gap in the shell allows a specialized camera to enter inside is a tiny port jackson shark pup [Music] breathing steadily it is almost ready to hatch [Music] a few days later susan searches for the same egg a tiny head pokes out of the spiraled shell the pup is on the verge of fully hatching [Music] wriggling with all its might it is finally freed into its underwater world its first swim is a little unsteady the newly hatched pup is only 20 centimeters in size it soon becomes a more established swimmer and heads up to the surface to explore its new world [Music] the pup's umbilical cord that was once connected to the yoke can still be seen [Music] this energetic young shark seems to have a destination in mind [Music] susan heads to the area of the bay she believes the pup is heading to the waters here are particularly calm with only a gentle current seagrass stretches in all directions many different species surround the area including eelgrass and paddleweed curious creatures live within the aquatic garden a tiny pygmy leather jacket appears the miniature fish is only three centimeters in size a wide body piper fish sways in the current looking remarkably like the seagrass it lives in [Music] a year old port jackson pub rests on the seafloor there is a reason why it has chosen this location the sandy seagrass garden is teeming with micro life [Music] a pup scans the floor for food [Music] it has sensed something in the sand [Music] on this occasion the tiny shark has bitten off more than it can chew but the sands and seagrass are bristling with life [Music] more opportunities will arise it is the perfect place for the sharks to develop for a few years the pups will remain in their serene nursery deeper in the bay an airplane wreckage has been enveloped by the ocean and has become an artificial reef eastern fortescue endemic to australia swarm around the wreckage [Music] the small 15 centimeter long fish have poisonous spines on their back and are more commonly known as wasp fish [Music] a juvenile port jackson shark rests among the school similar in colour to the wasp fish the pup blends in there is safety in numbers but they must not let their guard down something disturbs the fish [Music] a meter long eastern fiddler ray plows into the school [Music] the wasp fish part way but confidently the shark pup stands its ground it appears as if the ray is sizing up the young shark defiantly the youngster does not budge it has something up its sleeve a defensive weapon that is enough to deter the ray [Music] joined to the joint of the dorsal fin protrudes a protective spine at its sharpest during the juvenile stage of the shark's life it is enough to deter the would-be predator poor jackson sharks enter the world on their own with only their dorsal fin spine as defense with a life span of 40 years they spend their first few years in the bay before heading out to the open ocean as august comes to an end low air pressure consumes the bay a storm surges across the coast raging waves smash against the bay's beaches the fierce storm has persisted for three days susan walks along the coastline examining the damage where there was once a white sandy beach there is now a thick covering of seaweed the powerful storm surge shifted the aquatic foliage onto the land [Music] port jackson eggs are strewn across the beach a mere 10 of the sharks will make it to hatching [Music] only the most well-placed of eggs will survive it is the first time susan has been able to head out into the bay since the fearsome storm she is keen to see how the bay's shark population has fared the torn seaweed of the storm obscures visibility finding anything amid the carnage is difficult port jackson sharks begin to appear in the murky water they have weathered the storm but the fate of their eggs is unknown the sharks begin to venture out into the open to feed [Music] they sift through the sand looking for stray crustaceans heading further out into the bay more begin to appear sheltering under rocks the sharks avoided the storm's harsh conditions susan is keen to find their eggs with so many washed up on the beach have any remained in the bay [Music] tightly corkscrewed into the crevices the best-placed eggs have survived the monstrous storm it's thanks to the unique spiral shape that they have remained intact [Music] the port jackson shark pups have also withstood the storm in their seagrass nursery [Music] one in five of the shark pups will make it to adulthood [Music] as winter comes to an end the adult port jackson sharks will leave the tranquil jervis bay and head out once again into the open ocean they leave behind their spiraled eggs safely squeezed into rock crevices [Music] next winter they will once again return and give birth to a new generation [Music] these extraordinary sharks have made jervis bay a home away from home their time in the tranquil waters is crucial for both the old and the young timing is everything in carving out a successful future sometimes a ruthless edge is required to survive in the competitive bay with their specialized eggs and unique adaptations port jackson sharks will continue to thrive in their aquatic [Music] realm [Music] [Music] [Music] you

Channel: Free Documentary - Nature

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Rating: 4.8526645 out of 5

Keywords: Free Documentary, Documentaries, Full documentary, HD documentary, documentary - topic, documentary (tv genre), nature documentary, Free Documentary Nature, Port Jackson Shark, Port Jackson Sharks, Sharks, Shark, Shark Documentary, Wildlife, Wildlife Documentary, Wildlife Documentary 2021, Wildlife Instinct, Australia, Bullhead Shark, Southern Australia, Wildlife Australia, Fish, Fish Documentary, Ocean, Ocean Life, Marine Life, Sea Animals, Sea, Sea Documentary

Id: 9pxWMzI-dV0

Length: 49min 15sec (2955 seconds)

Published: Fri Apr 16 2021