over half of all animals in the open ocean drift in currents jellyfish cross entire oceans feeding on whatever happens to tangle with their tentacles some can grow to a meter even 2 m across and when by Lucky chance they encounter a patch of sea rich in Plankton their numbers explode [Music] [Music] it's such a successful strategy the jellies are one one of the most common life forms on the planet but among the jellies and looking somewhat like them is a rather more complex and Sinister creature the Portuguese man of war it floats with the help of a gas filled bladder topped by a vertical membrane with that serving as a sail it maintains a steady course through the waves [Music] [Music] long threads trail behind it some as much as 30 m [Music] long each is armed with many thousands of stinging cells a single tentacle could kill a fish or in rare cases a human but among its lethal tentacles lurs a Mana War fish that feeds by nibbling them once this fish has some resistance to the stings it must still be extremely careful most other fish are not so [Music] [Applause] [Music] lucky a tentacle has caught this one and reels it in it's already paralyzed specialized muscular tentacles transfer the victim to others that digest the catch liquefying it with powerful chemicals [Applause] eventually all that is left is a scaly husk this voracious man of war May collect over a 100 small fish in a day [Music] they're cover blown Escape seems impossible but these particular fish have a unique ability [Music] there are flying fish [Music] with an extra thrust from their tails the flying fish get airborne once [Music] more with a good wind they can glide for hundreds of meters [Music] [Music] but this is just what the frig birds have been waiting for when frigs join the hunt the flying fish are literally caught between the devil and the deep blue sea [Music] if the flying fish get too much lift they become easy prey for the frig [Music] [Applause] if they dive to evade attacks from above they could fall into the mouths of the Dorado [Music] [Music] [Music] holding my breath I free dive to the action [Music] one whale swims under a sh of Sprat which drives the fish up to the [Music] [Applause] surface common dolphins have also found this sh but the minkies are the dominant Force here [Music] [Music] I keep my distance so as not to interfere a [Music] [Music] the minkies sometimes blow a Shar line of bubbles near the sh of Sprat I've never seen this behavior before it seems the whales could be using the bubbles to partly H the Sprat [Music] [Music] after half an hour it's all over the birds take off perhaps searching for more shs oh my go you can actually smell the fertile areas in the ocean because phol Plankton give off a gas known as dimethyl sulfide DMS and seaboards have an incredible sense of smell and I wonder if they use that to find the vertile areas in the ocean and the shs of fish maybe even whales and other animals could follow concentrated flocks of seabirds feeding there's so much that we don't know still but when you think you know a shoulder face might be 20 M wide in an area of the ocean could be tens of thousands of square kilometers it's Quite a feat for these animals to find them so maybe the sense of smell is what's driving the whole thing but what a wonderful scene thousands of seabirds common dolphins and more than a dozen linky whels all feeding on shs of Sprat and sandil who themselves are here to feed on the Plankton during the dry season over half a million turns crowd onto this remote ATL in the Indian Ocean their chicks are still in their dark juvenile plumage they vary in age [Music] whilst the more advanced chicks take to the [Music] air others aren't quite ready yet [Music] those just starting to learn to fly use the shallow Lagoon that occupies the center of the atol as their training ground it's difficult for some of them to stay a loft for long [Applause] [Music] giant treales usually they are solitary Hunters but about 50 of them have come here from neighboring reefs attracted by this abundance of potential prey the fledglings stay out of the water if they can they even drink on the wing [Music] if the chalia to catch one now they have to up their [Music] game so there is a fish here that amazingly has a brain capable of calculating the air speed altitude and trajectory of a bird the time comes when every fledgling has to take to the air and collect food for itself [Music] their parents lead them to the training grounds [Music] he [Music] [Music] [Music] [Music] if they are to survive they must learn [Music] quickly after a month of practicing over the Lagoon the youngsters start to leave and take their chances out over the Open Sea the oceans around southern Asia are also feeling this pressure these Seas feed billions of people around the world for many fishermen here their catch is their only source of livelihood and there is one fish here that they prize above all others the way Shar it swims slowly gently harvesting the Plankton it's almost 20 M long the largest fish in the world they are also under threat like many shark species in Asia populations have declined by more than half in recent [Music] years they are an easy and valuable catch But Here There is a respect for the Seas and their inhabitants whale shark hunting has now been banned across inter's Waters this whale shark plays a different part in the lives of these fishermen they feed him and the relationship seems to bring joy to both parties and with this new protection has come something truly remarkable whale sharks from far away are seeking out these fishermen and in these safe Waters there is a chance for their numbers to increase and maybe one day other shark species will be protected [Music] too the people here have made a simple but extraordinary choice fishing in a way that is sustainable for themselves and the [Music] Animals caring for wildlife is surely our shared responsibility across this vast continent and across the world it is decisions like these that are key to protecting the planet's most precious diversity for thousands of years shs of Herring had gathered in the small Bays of our North Atlantic Coast for several Winters now I've been trying unsuccessfully to find shaes of herring in our inore Waters December is the key month when shs would aggregate in these protected Bays before spawning and also when they were fished the cold water at this time of year helps with spawning the further north we go the colder and darker it gets but this can lead to more fertile Waters in the fishing port of kils County dyal I go to Sea like many a man before in search of these Herring shs I'm using Scuba as Herring usually stay deeper and these are cold dark [Music] [Applause] [Music] Waters at 20 M depth it's more or less dark looking down after a few days effort I sense movement and look towards the sun Haring thousands of them they scatter from my dive Bubbles and seem to move in syn they never allow me to get close [Music] it's wonderful to find some Herring after several winters of trying but what a fabulous fish they are the old folk called them the king of fishes but they were also hugely important for the ocean ecosystem because hering feed on Plankton and fish lar and effectively convert that energy into the rich fatty fish that they become but uh I have to wonder what these Bays looked like maybe 100 years ago and the Herring shs were reputed to be you know 2 km long and what the wider ocean looked like at that time compared to [Music] know a kilometer from the surface beyond the reach of the Sun a giant black void larger than all the rest of the world's habitats combined there's life here but not as we know it alien likee creatures produce dazzling displays of light nearly all animals need to attract mates and repel Predators this language of light is so widespread here that these signals are probably the commonest form of Comm communication on the entire planet and yet we still know little about them [Music] [Music] Hunters illuminate themselves and by doing so attract inquisitive [Music] prey this is fang tooth it has the largest teeth for its size of any fish there are precious sensors all over its head and body which can detect anything moving in the surrounding [Music] water it's the midnight Zone's most fous fish but prey used light as a distraction a decoy of luminous ink down here in this Blackness creatures live beyond the normal rules of time siphonophores are virtually Eternal they repeatedly clone themselves some eventually growing longer than a blue whale down here it snows continuous clouds of organic debris drift slowly down from [Music] above this is food and a whole variety of filter feeders depend on it [Music] jellyfish and delicate sea cucumbers [Music] the 1% of marine snow they miss eventually settles on the sea floor [Music] over millions of years it forms a layer of mud up to a kilometer thick it's an empty plane that covers half the surface of our planet [Music] the Deep seabed May at first appear lifeless but it's home to a unique cast of mud dwellers [Music] the sea toad it is an ambush Predator with an enormous mouth and infinite [Music] patience this fish has been living for so long here that its fins have changed into something more more [Music] useful feet they help it shuffle about on the seaf Flor [Music] [Music] the flapjack octopus it hovers just above the surface of the mud as it delicately sifts through it searching for worms but it can jet away at the first sign of danger even when more sea lions arrive they can't seem to break down the sardines coordinated [Music] [Applause] [Music] defenses with a sh this big the sea lions need to isolate a smaller more manageable group [Music] fish but with so few Predators the fish still have the [Music] [Applause] advantage all the sea lions can do is keep the sardines at the surface and wait for others to join them [Music] tuna their arrival changes [Music] [Applause] [Music] everything tuna attack from below cutting off the sardines Escape Route down to deeper water [Applause] [Music] next to appear sheer Waters excellent Flyers but also surprisingly agile underwater with so many predators attacking from all sides the advantage starts to shift away from the sardines [Music] [Applause] [Music] as the fish pack ever tighter their showning strategy now makes it easier for the hunters [Music] [Applause] [Music] [Applause] [Music] copper sharks they've scented blood in the [Music] water surprisingly perhaps the Predators never attack one another they work together to Corral the ball of fish taking turns to grab a [Applause] [Music] mouthful common Dolphins as the show gets ever smaller each sardine scrambles desperately to hide in the middle but now there's no Escape [Music] [Applause] a budda's whale finishes off the feast tons of sardines devoured in less than an hour the whales can sense the presence of the Herring and dive in Pursuit holding my breath I dive to film The Action they're not easy to find in the [Music] darkness Tiny Bubbles rise from the deep like a gas then I see a cloud of them and goost like a massive sh of fish emerge from the deep thousands and thousands of Herring killer whales have found them and driven them up from the deep with their Sudden Change of pressure gas has burst from their swimbladders which control their buoyancy the whales work together to squeeze the fish into an even tighter ball gos have spotted the signs [Music] [Music] the killer whales push the Herring up but the humpa will be there to profit from this the whales flick their tails into the Herring sha to stun the [Music] fish the animals briefly surface only to catch breath birds have learned to be in the right place but then hums with their enormous mouths and cooperation take the Lion's chair [Music] [Music] and after less than 30 minutes it's all over and the Animals leave to search for more Herring [Music] shones but most of the creatures come together for a very different reason to breed the giant cuttlefish the largest of all [Music] cuttlefish they live for just one or two years now as the Australian summer draws to an end they have one last act to complete to find a mate but there are over 100,000 males competing for the arriving females in this one Bay among them a giant a true Goliath he probably weighs about 10 kilos B of color sweep across his skin that's how cuttlefish communicate this smaller male couldn't possibly take him on [Music] beside Goliath and under his protection a female who has just mated with him but other Rivals are still interested it seems a small male wouldn't stand a chance the female female is now displaying a white stripe along her side nearest Goliath it's a clear signal that she no longer wants to mate with him it's all the encouragement that the little male needs [Music] [Music] he's going to have to use trickery [Music] he tones down his colors and Tucks in his arms he's just the right size to mimic a [Music] female Goliath is deceived the small male now displays is a white stripe just like the real female to deter his advances he slips beside her and they [Music] meet by mating with multiple partners the female ensures the greatest genetic diversity for her young the sneaky male leaves his final Act [Music] complete so even among giant cuttlefish it seems it's not all about size he's a Marine iguana the only lizard in the world that gets its food from the [Music] sea the seaweed on which he totally relies only grows in abundance here because of the nutrients brought by The Cromwell current Once In The Water he has just 30 minutes to find [Music] food any longer than that and his muscles will seize up and he'll drown for like most reptiles he can't handle the cold chil water isn't a problem for a warm blooded corant she can swim in it all day but can only hold her breath for a few minutes [Music] he on the other hand completes his whole half hour trip on one single breath his flat face and sharp teeth make him an efficient seaweed cropping machine but with the clock ticking he must eat [Music] fast the corant having caught its fish goes back to the surface one last mouthful and it's also time for the Iguana to head for home but to stop his muscles from seizing up in the cold water he must get back [Music] quickly so he could do without the attentions of an inquisitive seaon [Music] [Music] dry land is now just 30 m away but the biggest hurtle is still to come [Music] the surging water now fights against him he's out but he stayed in the coal so long that he's lost his strength [Music] and he's made it it's my chance to document these animals it would be my first time in years of trying to film a fin whale underwater [Music] being in the water with whales this size is something I've learned to do safely over many years now but it's still scary I think about my ancestors and wonder what they would have made of [Music] this the fin whale swallows an enormous mouthful of Sprat and Dives coming within a few two Shar meters of me an awesome animal water visibility is just a few meters [Music] [Music] what an incredible moment to my knowledge it's the first time anyone has filmed a fin whale underwater in [Music] [Music] Ireland and then a h back wave but this is no ordinary humb back whale I can recognize from the tail and Dorsal fins that this is boomerang a whale that has been coming to our South Coast for 20 years now and for some reason always Associates with fin Wheels he blows a single line of bubbles perhaps to her the Sprat and lunges from below the wall [Music] [Applause] [Music] [Applause] [Music] Pac whales usually blow Circles of bubbles to ENT trap fish but this animal is just blowing a line perhaps he's competing with the fin [Music] wheeles again and again they rise one giant mouth after another [Music] four fin whales feeding oh my God they're 20 M and up to 80 tons of weight that's two fully loaded articulated trucks for 16 elephants in the underwater forests of Northern Japan the residents of this sunken wreck are waiting for the summer temperature to reach 16° [Music] C that for some is the time for mating [Music] a kind of giant Rass called a cobod die this is a [Music] male and in female terms he's particularly handsome [Music] he's a meter long and weighs 15 [Music] kilos much larger than the diminutive [Music] female and he is ready to breed he attempts to mate with her and with any of the other dozen or so females that live in his territory whenever he gets the [Music] chance but females from around 10 years old take little notice of his advances [Music] [Music] this is because when any large female reaches a critical body size she can begin a dramatic transformation over just a few months particular enzymes inside her body cease to work and male hormones start to circulate as time passes her head expands and her chin gets longer a she has changed into a he and with this comes a change in temperament the old male who ruled all the females here is challenged to a face off the more bulbous the head the more it intimidates an opponent [Music] [Music] the territory has a new ruler only the largest females transform themselves in this way but the change enables them to have more mates so they will have many more offspring carrying their [Music] jeans but a new male can't afford to be complacent inside the body of every cobod ey female there is a new mail in Waiting Northern Australia has the highest tides in the tropics which expose vast areas of Shoreline and here lives a truly extraordinary species of [Music] octopus octopuses are marine animals they live and breathe underwater at low tide most octopuses would be imprisoned in their Rocky [Applause] [Music] pools but this is no ordinary octopus [Applause] [Music] [Music] it's the only one specially adapted to walk on land it pulls itself along using the hundreds of tiny suckers that line its arms [Music] hunting for crabs it walks from pool to [Music] pool apart for a rather startled fish this one is empty so the octopus moves on a rock pool may seem like a safe Refuge but the octopus's suckers enable it to move just as stealthily in water as out of it [Music] [Music] nowhere is safe when this octopus is around on St Brendan's Voyage the monks wrote of having arrived at a coagulated sea a place where the water appeared oily and absolutely no wind all they could do was [Music] wait I go for a swim in C C Blue [Music] Water salps are a chain of creatures living together they suck seawat through their bodies to filter Plankton and this also propels them forwards [Music] a mother in very small calf this doesn't feel like [Music] Ireland we're here finally in the edge of the continental shelf 250 km Southwest of Ireland this place is called the porcupine seab bite what's incredible about here is that the seab bed as you come West of Ireland it's about 200 M deep and then suddenly it just drops down to 1,000 M then 2,000 M and then eventually to 5,000 m the Abyssal plane that's more than half the height of Mount Everest and you can see the conditions are just I mean it's surreal it's absolutely beautiful here and the water it's blue crystal clear and blue not like the coastal Waters we get in Ireland which are green because there's so much organic matter and plon in there here it's blue and we can see for maybe 15 M what we're hoping to find here is the fin whale we've managed to fil them in the inshore waters close to Ireland and other parts of the North Atlantic and if we can find them here and maybe film or photograph that the back of their heads the Chevron and the blaze pattern that's unique to every individual fin wheel a bit like our fingerprints are to us then maybe maybe we can confirm some migration roots of these animals are at the very least show the different areas where they're feeding and they're moving around and try to protect them in all those areas and the areas in between right here on the edge of the continental shelf to the west of Ireland it's one of the most fertile places in all of the North Atlantic and this is where they're likely to [Music] be the struggle to survive in our green Seas can can have far-reaching consequences once a year one particular Meadow in Australia is transformed around the first full moon of winter an army materializes spider crabs for the past year they've been feeding in deeper waters now they march across the seagrass plains [Music] hundreds of thousands of [Music] them they clamber over one another [Music] creating great [Music] Mounds nearly 100 m long they're not seeking mates neither are they laying eggs they have come here in order to grow like all crabs their bodies are enclosed in a hard unexpandable shell so to grow they have to break out of it and that allows the soft one that has developed beneath to expand it will take days for the new shell to harden its legs are so limp that they won't work properly the crab is unprotected and in great great danger a smooth Stingray it's huge about 4 M long it wants a soft freshly moled crab that will be easier to eat the crabs try to stick together but now disturbed by the Ray they're scattering a newly moled crab is too weak to keep up with the crowd the safest place is right in in the middle of the pile that is why they have all assembled here there is safety in numbers but the vast majority of the crabs escape and within the next few days they will be ready to return to the depths and resume their lonely wanderings in search of food this is no graveyard but the Triumph of 100,000 crabs successfully molded black tip reef sharks they are bigger and more powerful than true Valley but not as fast or as [Music] agile the Hardy heads are well aware of them but so long as they stay just Out Of Reach they have little to [Music] fear but now the Sharks and the triell join [Music] forces together they enter the shallows each looking for a chance to attack the trian make the first move and the hardheads take refuge again in the waves and this is what the sharks been waiting for surging forwards they chase the Hardy heads out of the water beaching themselves in a daring bid to Hoover up their prey the Hardy heads that escape the sharks swim back out to deeper water but into the mouths of the chipal now the receding waves help to pull the Sharks back into deeper water in the chaos the seabirds get their [Music] chance it's a Feeding Frenzy in only 10 cm of water I fure here to the Mid-Atlantic Ridge in search of fin whales I believe they may come here to [Music] feed these underwater mountains are known as sea mounts and they can be hugely fertile areas because of their shape in the middle of the ocean they cause nutrient-rich water to well up from the deep creating a wases of life in the open ocean [Music] in places they rise within a few meters of the surface in other areas they may Peak at 40 or 50 m deep I dive in a sea mount almost 100 km man land [Music] shs of Barracuda gather here to feed on smaller fish as do these trigger fish they even try a bite of me [Music] shes of small snip fish Gather in numbers and squeeze together to form bait balls the larger trigger fish Barracuda and other smaller fish arrive to feed on this open ocean bounty [Music] blue sharks migrate here annually because they know there'll be [Music] fish in the relative barrenness of the open ocean the sea mounts of the Mid-Atlantic Ridge are an oasis of Life per sea creatures [Music] it's funny the sea can be so much more stable at depth than it is at the [Music] surface the blue shark it travels over 8,000 km a year riding on the currents supported by its broad wing-shaped fins this one may not have eaten for 2 months but the currents can carry promising traces of fatty oils from many kilometers away and will lead it to its next meal [Music] after days of travel the smell of food gets stronger [Music] a dead whale recently struck by a ship this could be a real Feast but the blue shark must be cautious great white sharks 10 time s heavier than a [Music] blue a highly possessive around a whale carcass great whites are eager to feed on energy rich whale blubber which we now know forms a major part of their [Music] diet once the great white has had its fill smaller sharks like the blue shark tackle what's left of a carcass as the oils from this dead whale spread more widely more and more blue sharks appear [Music] within days the carcass will be stripped of its blobber then no longer kept buoyant by its oil it will sink Into the Depths below the blue with its reserves of fat replenished can now survive for another two months without eating Eden's whales have lived here for Generations but the world around them is changing today agricultural pollution flowing from the land is beginning to suffocate this [Music] sea many fish now stay closer to the surface where the waters still contain enough oxygen to survive Eden's whales depend on these fish they swallow huge quantities of water before filtering out their prey it takes a lot of energy to drive their 15 T bulk through the water and with so few fish the rewards from feeding like this are barely worth it so to survive here the whales have developed a new hunting [Music] technique one that requires almost no [Music] effort they simply open their mouths and [Music] wait the panicked fish Jump Right [Music] In swimming alongside another whale scares even more into the open Jaws [Music] with this ingenious new technique Eden whales have found a way to survive the pressures they now face all across the planet animals are having to adapt to a changing world but the speed of these changes will be too fast for many [Music] if we could only halt our unrestrained plunder of the ocean its habitats and species would recover and at a time when our overexploited lands are already failing us this has never been more important for [Music] Humanity west of the clear Coast some ocean Giants have arriv d [Music] [Music] [Music] I wonder what s Brendan and the early seaf fars in their open boats would have made of these creatures basking [Music] sharks I can only imagine how many sharks they would have encountered in the Atlantic Waters a thousand years ago did the Sharks terrify them or did they perhaps spend time getting a sense of the animals and their quiet [Music] nature we see basking sharks for maybe a week or two every year in sunlet spring waters when they arrive to feed on Plankton and then just sporadically over the summer they then disappear in Early Autumn for another eight months where do they go we're really not sure there are almost no winter sightings of basking sharks in our inore Waters they appear to be gentle Giants but we really only see them when they're feeding on Plankton at the water surface gliding ly to catch as much Plankton as they can filtering it from the seawater with their Gil rers but I'm not convinced they're just docile creatures at up to 10 m and 5 tons these are intimidating animals to meet in the open [Music] ocean and wave power creates towering fortresses like these cliffs in the Arctic home to tens of thousands of breeding seabirds the faces of the cliffs are accessible only from the air and have plenty of nooks and crannies for those that can get there but to feed seabirds must still Master the ocean World Beyond a puffin he's a fisherman and a father he has a mate for [Music] [Applause] life both share the burden of raising their weak old chick there puffling who needs five square meals a day the parents alternate fishing [Music] trips it's Dad's turn [Music] when fish stocks are low puffins must fly as much as 50 kilm out to sea to reach the good fishing grounds [Music] once there they plunge into another world good fishing spots are hard to come by and they have company gilot like the Puffin their wings are short and good for diving puffins can hold their breath for over a minute and dive as deep as 40 m a catch but it's a long way home after an exhausting round trip of almost 100 kilm this puffins nearly made it but there are pirates on this Coast Arctic skewers [Music] all around returning parents are being robbed [Music] the skewers long rback Wings make them faster and more maneuverable [Music] [Music] puffins must choose their moment wisely [Music] a near miss the last desperate burst of speed and it's made it [Music] [Music] safely home after a 3-hour round [Music] trip where his patient partner is waiting [Music] [Music] [Applause] today their puffling will [Music] eat but where fish numbers are in Decline many puffins Now find it hard to get enough food for their chicks in the changing seeds of today it can be even harder to be a successful Puffin parent [Music] hunting is only possible for 3 hours around low tide when the mud banks are exposed razor sharp oysters cover much of the shore beaching here could be lethal [Music] the hunters need to find a stretch of Shoreline with just the right slope to level and the Dolphins risk stranding too Steep and they can't force their prey from the water working as a team the Dolphins surround the fish driving them towards the shore [Music] [Music] attacking in perfect synchrony the Dolphins create a bow [Music] wave it carries their prey onto the Muddy Banks [Music] [Applause] [Music] [Applause] other Fish Eaters profit from their daring herons and gulls follow every [Applause] hunt to get to the fish first the Dolphins drive themselves high up the bank but if they go too far they risk the [Music] stranding to prevent fish escaping between them the dolphins all beat themselves on the same side always the right but this has a cost each time they grab a fish they also take in a mouthful of mud the grit gradually wears down their teeth but on one side only in time these teeth get so worn down that older Dolphins can no no longer hunt like this and must find other ways to catch [Music] fish in Sunny Atlantic Waters 30 km south of Ireland I'm searching for open ocean [Music] sharks sadly most all of the 40 species of sharks in our waters are now in [Music] trouble unlike basking sharks most others are predatory sharks that is they have teeth and strong Jaws to eat fish they're curious animals blue sharks are the most common predatory shark in Irish Waters they're highly evolved hunters in their own ocean environment the pores around their heads are sensors filled with gel that can sense the tiniest movement of fish or other prey and humans are of no interest to these [Music] animals they migrate all around the North Atlantic visiting Ireland in the summer months to feed then traveling to theor and America in the last decade however their numbers have dramatically Fallen because of chronic over [Music] [Music] fishing these blue sharks have more than likely circumnavigate the North Atlantic they migrate with the seasons I guess you could say they live by the seasons and they come into ourish Waters in mid to late summer when the water warms up a bit to feed I guess you know sharks have been around for 400 million years there was a shark fossil found in the burn dated to 300 million years ago but what I find incredible is that about a 100 million years ago most shark species actually stopped evolving because more than likely they had reached the perfect form to hunt and to live and survive in the ocean they've likely come into our bays and our shallow waters for hundreds if not thousands of years and I can find no credible record of a shark attacking anybody in Ireland or any place close but they're really curious they come right up to the camera what a privilege to share the water with these creatures look at this one absolutely beautiful animals [Music] in the Gulf of Mexico these eruptions also release a super salty liquid Brian [Music] it's heavier than seawater and it accumulates in great pools on the seaf floor it's difficult to make sense of the site a lake of con concentrated salt water 15 M deep at the bottom of the [Applause] sea around its margin perhaps even more strangely there is a profusion of life giant muscles that can live and grow for a Century or more pack tightly together dwarfing the shrimps and squat lobsters that feed around them Cutthroat eels scavengers come to the shores of the Brian Lake in search of something edible some even Venture into the brine [Music] spending too long in it can send an eel into toxic [Music] shock his only hope is to rise above it [Music] [Applause] it manages to escape others are not so lucky the rine embalms their bodies and the casualties of decades accumulate around the margins off the coast of South Africa more adolescents have reached that difficult age at 2 years old male bottl noos Dolphins leave their mother's pod to form boisterous gangs looking for excitement they like nothing better than surfing spy turtle is here to see what they get up [Applause] to he in turn is joined by another spy creature this is spy puffer based on a fish that blows itself into a defensive puff ball the Spy creatures are here to film these teenage terway spy puffer faces a bumpy ride bus stops are [Music] common it's easy to get caught in the [Music] middle young males are so unru the females kicked them out of the family [Music] [Music] pod this isn't spy puffer it's a real puffer fish the poor creature gets the same rough treatment perfect for a game of [Applause] catch but the Dolphins are dicing with death puffer fish are one of the most poisonous fish in the ocean they exude a powerful Nar of poison called tetrodotoxin it only takes a small amount to kill a human even so the Dolphins often look for puffer fish and love to chew on them taken in small doses the secretions seem to have a narcotic effect [Music] the Dolphins are careful not to swallow them instead they hold them gently in their mouths despite the risks passing the puffer has become a popular dolphin pastime [Music] [Music] luckily the little fishes usually survive the strange [Music] experience ocean creatur Crees migrate some to wherever the winds and currents bring them others quite deliberately to where there is food and they can breed and sometimes feed on other animals [Music] I'm drawn to the elemental beauty of [Music] jellyfish we're seeing increasing numbers of them in recent years possibly due to a decline in Predators who hunt them like turtles they abound in our summer Waters drawn to the light giving energy of the [Music] sun barl jellyfish are the largest in our [Music] Waters they can provide shelter for juvenile fish and because because of this scientists now believe that the increase in the number of jellyfish may actually help fish [Music] stocks jellyfish are inescapably drawn to the sun living for just a few months they strive to reach maturity chasing the Bounty of the early summer Plankton [Music] Bloom like most creatures they appear to have two life goals to reach maturity and reproduce I dive with this beautiful Sho of compass jellyfish in our warm summer [Music] Waters they' have come together to [Music] breed in a far corner of southeast Asia lies the coral triangle the custa of the richest coral reefs in the [Music] world undersea cities crammed full of life as in any crowded Metropolis there is fierce rivalry for space for food and for a partner but the reef is also a Place full of opportunity [Music] a cuttlefish it specializes in hunting crabs [Music] but a large crab is a dangerous Quarry it has powerful claws the Cuttlefish however has a remarkable Talent its skin contains millions of pigment cells with which it can create everchanging colors and [Music] patterns and that apparently hypnotizes the crab [Music] a cuttlefish may be clever but a shark is bigger and it eats cuttlefish time to disappear [Music] [Music] back to the hunt a new Target but the same mesmerizing technique [Music] for those that manage to establish themselves in these bustling undersea cities there can be great rewards sea snakes at one time these snakes ancestors lived on dry land they must still visit the surface to breathe but they are beautifully adapted to life at sea hunting for fish around the island reefs they have some of the most toxic venom of any animal so they don't have many predators but as they forage off the coast of one small island their greatest Nemesis is approaching Yoko and setco are hunters and they have a fearsome reputation these two 70-year-olds are on a shopping trip like no other Yoko and cesco live on the tiny island of kudaka it's only 4 km across and with limited space on land the locals look to the sea to provide as the sun sets the lady's prey is [Music] approaching on certain summer nights venomous sea snakes move towards the island and gather in coastal caves looking for shelter and fresh water to drink but coming ashore on this island is extremely risky yeah it takes some nerve to Wade in with no protective clothing Seas snake venom can be 10 times more powerful than a rattlesnakes [Applause] Yoko has been hunting snakes for 40 years it's a skill that's been passed down the generations here for at least 5 centuries woo [Music] [Laughter] [Music] the snakes will be dried in this smok housee using a secret process known only by the hunters [Music] then they go into a special [Music] soup the catching and eating of sea snakes is a very old tradition on the island of kudaka where the sea provides more than the land oh a Sally Lightfoot crab one of thousands of shore crabs just waiting for their moment every day they gather on the tropical shores of [Music] Brazil waiting for the tide to go [Music] out which exposes their feeding grounds seaweed covered rocks 100 m from the shore getting there is a race against the tide they leap from rock to rock [Music] [Music] these crabs seem to be afraid of the water and for good reason the Moray eel the chain Moray is a specialist crab Hunter its blunt teeth can easily grip and crush a crab's shell [Music] it's the crab's deadliest [Music] enemy but the crabs feeding grounds are still a long way off they must Press On [Music] halfway but the enime has other [Music] ideas crossing the land to reset the Ambush to feed the crabs must keep going [Music] but nowhere is safe an octopus also a crab killer the crabs make a dash for it made [Music] it risking life and limb to graze on these seaweed [Music] pastures but in 2 hours time when the tide starts to turn they will have to run the gauntlet it all over again it's only the warmth of the kishio current that allows Coral to grow this far north in the Pacific Ocean [Music] the current also brings nutrients from the [Music] deep there's one very small resident who never Strays far from The Reef he's a Blue Streak cleaner us and he leads a very busy life he eats parasites and dead skin from other fish but he has to wait for them to come his [Music] way and right now no one is stopping long enough to give him as much as a nibble [Music] but then he spots something worth [Music] chasing a [Music] batfish like a customer at a spa the batfish lies back and waits for attention [Music] it opens its gills and the cleaner Rass bustles in to begin the [Music] treatment the batfish even changes color probably to make parasites more [Music] visible someone else has arrived at The Reef the batfish is abandoned there's a visitor from the open ocean that's worth dropping everything for a manta ray 2 m long has come back to a favorite stretch of reef [Music] [Music] he signals to the Manta by flicking his tail and the giant responds by unfurling itself for cleaning the Manta keeps its feeding loes rolled up while it swims but a thorough clean keeps them parasite [Music] free this enormous fish would never visit Japan if it wasn't for the warmth that bathes the the island chain and the helpful Services of this resourceful little Rass out here on the sand Flats there is safe accommodation for some a family of Saddle black clown fish have found an excellent home the tentacles of this Carpet Anemone can kill but the clown fish are immune to the [Music] poison so they can shelter from danger [Music] in return the fish keep the anemon clean of [Music] debris as with all clownfish the family is ruled by a big female her white face marks her out as the boss the dommin of male has to prove his worth so he works tirelessly removing debris and generally keeping on top of the [Music] housework his greatest challenge is to find a safe place where the boss can lay her eggs but there's nothing solid here for the female to lay them [Music] on a nearby shell could be the solution if only he can move it to the protection of the anemon too heavy besides it has a mind of its own hermit crab [Music] but out here twice a day the anony is swept by tidal currents and they bring in new opportunities an old plastic bottle perhaps this will do not heavy [Music] enough a coconut [Music] shell it looks just right but it's a long way from home [Music] and he can't move it by [Music] himself so prare now work together [Music] [Music] [Music] a little adjustment to the nemon's tentacles in order to clear a space for it and the shell is tucked [Music] in the Fe lays a safe Nursery at [Music] last he has proved himself worthy to Father her young and he fertilizes them [Music] now he will meticulously tend the [Music] eggs keeping them clean and healthy until they hatch in 10 days [Music] time for