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It travels over 8,000 kilometers 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. After days of travel, the smell of food gets stronger. This could be a real feast, but the blue shark must be cautious. are highly possessive around a whale carcass. Great whites are eager to feed on energy richch whale blubber, which we now know forms a major part of their 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. Within days, the carcass will be stripped of its blubber. 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 2 months without eating. Even when more sea lions arrive, they can't seem to break down the sardines coordinated defenses. With a shaw this big, the sea lions need to isolate a smaller, more manageable group of fish. But with so few predators, the fish still have the advantage. All the sea lions can do is keep the sardines at the surface and wait for others to join them.
Tuna, their arrival changes everything. Tuna attack from below, cutting off the sardines escape route down to deep water. 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. As the fish pack ever tighter, their shing strategy now makes it easier for the hunters. Copper sharks. They've scented blood in the water. Surprisingly, perhaps, the predators never attack one another. They work together to corral the ball of fish, taking turns to grab a mouthful,
As the shell gets ever smaller, each sardine scrambles desperately to hide in the middle. But now there's no escape. A brood's whale finishes off the feast. Tons of sardines devoured in less than an hour. In Bengal Lagoon in Fiji, the local people are proving that sharks can be more valuable alive than dead. Tourists will pay good money for an encounter with real live sharks. This is a community-owned reef and some of the money goes to the local villages.
A big incentive not to kill the main attraction. Fian have long had an affinity with sharks. Their ancestors worshiped a shark god who they believed kept them safe from harm. They would feed sharks, not hunt them. And these divers continue the tradition. First to the feast are Tory nurse sharks. But these sharks are scavengers. It's the big predators the tourists want to see. Bull sharks. [snorts] Growing up to 3 and 1/2 m long. These sharks are one of the ocean's top predators with an aggressive reputation.
The chief shark feeder is from a village where the shark god is still worshiped. So he has no fear. A bowl of shark fin soup can sell for over $100. But here, each tourist pays that to see these sharks alive. And dives take place several times each week. To protect the sharks, this reef has now been declared a marine reserve with the added bonus that other fish are protected too. Before the reserve was established, this reef had been fished out. Even a single giant travali of this size was a rarity. Today the divers are in for a special treat. The dive leaders have named her Scarface.
She turns up once a month or so. She's inquisitive but not aggressive. Blacktip reef sharks. They are bigger and more powerful than Tvali, but not as fast or as agile. The hardyheads are well aware of them, but so long as they stay just out of reach, they have little to fear. But now the sharks and the tribal join forces. Together they enter the shadows, each looking for a chance to attack. The Trabelli make the first move and the hardyheads take refuge again in the waves. And this is what the sharks have been waiting for.
Surging forwards, they chase the hardy heads out of the water, beating 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 trapali. Now the receding waves help to pull the sharks back into deeper water. Heat. In the chaos, the seabirds get their chance. It's a feeding frenzy in only 10 cm of water. These 7-month-old blackfooted albatross chicks have recently been abandoned by their parents. And now, driven by hunger, it's their time to get airborne.
Unfortunately, with space at a premium, there is little room for maneuver, and they must make their maiden flights over water. But this is no place for a paddle. A dozen sharks, each over 3 m long, have crossed hundreds of kilometers of open ocean to attend this annual feast. Uncannily, these fearsome predators often arrive on the same day as the first chicks take to the air. Nothing could have prepared these chicks for such an encounter. Yet, despite looking like sitting ducks, inexperienced sharks find them hard to sink their teeth into. In an ocean where food is so hard to come by, the sharks can't afford to keep
missing. They must quickly perfect their technique. Heat. For these albatross chicks, running the gauntlet of sharks may seem an impossible challenge, but the vast majority make it to a life in the open ocean. In the shallow waters around an island's base, coral reefs rise towards the surface. Of all the formations in the Pacific, these reefs are by far the richest in life. There are hundreds of different kinds of coral and all are made up of millions of tiny creatures called polyp, each covered in a hard skeleton.
Reefs are home to thousands of specialists like these razor fish that blend into the stagghorn coral around them. But not all animals here need to blend in. The reef's top predators. These sharks patrol the waters on strong currents. But without all the life on the reef here, they could never exist in such numbers. They may be idle right now, but they won't remain this way for long. As night falls, it's feeding time. Needlefish stalk the coral shallows in search of food. Predators by day, at night they become the prey.
Speeding away at 30 km an hour, the needlefish give the chasing sharks a run for their money. But it's hard to escape from so many. Heat. 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. It swims slowly, gently harvesting the plankton. It's almost 20 m long, the largest fish in the world. Like many shark species in Asia, populations have declined by more than half in recent years. But here there is a respect for the seas and their inhabitants.
Whale shark hunting has now been banned across Indonesia'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 too.
The people here have made a simple but extraordinary choice. Fishing in a way that is sustainable for themselves and the 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.
