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Planet Earth Shallow Seas online movie

Eight percent of the world's oceans but they contain the vast majority of its marine life. Our planet's continents are fringed by shallow seas. Rarely more than two hundred meters deep they lie on the continental shelves which may stretch sometimes for hundreds of miles before the sea floor drops into deeper darker waters. The whales have just returned to their breeding grounds in the shallow seas of the tropics. The calf is no more than a few weeks old. Despite being three meters long and weighing nearly a ton. These shallows around the equator are excellent nurseries. The playful calf is now drinking five hundred liters of milk a day but his mother must starve. Like many tropical shallow seas these crystal clear waters are virtually lifeless. They receive year round sunlight but they lack the nutrients essential for the growth of plankton. The mother will be trapped here for the next five months until her calf is strong enough to make the journey to the feeding grounds, near the poles.





 
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Coral reefs are oases in a watery desert. Most tropical shallows are barren but these coral havens contain one quarter of all the marine life on our planet. Reefs are the work of polyps tiny colonial animals like minute sea anemones yet the Great Barrier Reef is so big it can be seen from the Moon. It's actually two thousand separate reefs that together form a barrier stretching for over a thousand miles along Australia's northeastern coast. Despite its vast size this reef does not contain the greatest variety of marine life on the planet. To film that one must travel north to Indonesia. There are individual reefs in Indonesia that contain almost as many kinds of fish as live in the whole of the Caribbean. There is also ten times the number of coral species. Corals thrive in these waters with the help of microscopic plants, algae that grow within the tissues of the polyps and the polyps feed by snaring passing morsels with their tentacles. This well balanced alliance brings benefits to both polyps and algae and between them; they turn the barren seas into rich gardens. The Indonesian reefs contain such a variety of life because they lie at a giant crossroads. This is the meeting place for different seas the Indian Ocean and the Pacific. Here everything demands a closer look. On the surface of this sea fan, there are two polyps that are not polyps. They're pygmy sea horses, the worlds smallest, less than two centimeters high. They are males, settling a territorial dispute, by head butting. An electric flash? No, the display of a file clam. These are banded sea crates. They lay their eggs on land but they hunt here in the water. And on this reef the snakes do not hunt alone. Shoals of yellow goatfish and trivali are seeking similar prey and they attract the snakes' attention. In fact it's an octopus. A gurnard. Its huge pectoral fins disguise its shape and they can also help in clearing away sand when searching for food. The jaw fish hides underground. Plants manage to take root and they're cropped by green turtles. Sea grasses are the only flowering plants that have managed to grow in the sea although they put out a few ribbon like leaves they produce much extended networks of fleshy stems, rhizomes that are buried in the sand. At their lushes they can transform the sea bed into an underwater meadow.
The whales have just returned to their breeding grounds - Shallow Seas online
The whales have just returned to their breeding grounds in the shallow seas
  The Great Barrier reef along Australia's northeastern coast - Planet Earth movie series
The Great Barrier reef along Australia's northeastern coast is so big it can be seen from the Moon
 
The largest expanse grows in the shallow waters of Shark Bay, in Western Australia. These vast aquatic grasslands stretch for fifteen hundred square miles and, like terrestrial prairies, they support herds of grazers. Dugongs are the largest herbivores in the sea. They can be three meters long and weigh half a ton and they eat nothing but sea grass, mostly the fleshy rhizomes, which they excavate with their mobile lips. A herd can clear a patch of sea grass the size of a football pitch in a single day. Food is not evenly distributed in the tropical shallow seas and it can take a lot of finding but bottlenose dolphins are inquisitive, energetic and very intelligent and they have discovered a shoal of baitfish. Together, they ride a wave, using it to carry them into the shallows and there, it will be easier to make the catch. In Western Australia these dolphins have taken on an ever tougher challenge. The fish are tantalizingly close but they're still out of reach, so the dolphins try another technique. Vigorously pumping their tails, they work up some speed and then, they hydroplane. Their momentum carries them right through the shallowest waters, and onto the fish. The desert of Bahrain seems a very unlikely place to find a crowded bustling colony of seabirds but every year, a hundred thousand Socotra cormorants gather here to breed. There's only bare sand and the warm shallow sea beyond. Neither seems likely to produce enough nourishment to support bird life on this scale. The answer is blowing in the wind. Sand whipped up by Shamals offshore winds blows into the seas of the Arabian Gulf. With the grains come nutrients, which act as fertilizer and they transform the shallow sea into a rich fishing ground. So, paradoxically, it's the roasted sands of Arabia that prevent the gulf from being another desert in the sea. All across the tropics, humpbacks are heading away from the Equator towards the rich temperate seas of both the southern and the northern hemispheres. Blooms the size of the Amazon Rainforest turn the seas green. Individually the algae are tiny but together, they produce three quarters of all the oxygen in our planet atmosphere. They're eaten by an array of bewildering creatures. Salps appear in the plankton soup. Individual's link together to form chains which can stretch for fifteen meters. Pumping water through their bodies they strain out algae and other edible particles. Comb jellies cruise through the water. They too flourish in this seasonal soup and for short periods, they appear in astounding numbers. By weight, Krill are the most abundant animals on Earth. A single swarm can contain two million tons of them and that is a lot of fish food. The shallow temperate seas support the greatest concentrations of fish on our planet. Huge shoals migrate from their overwintering grounds in the depths to feed in these rich waters. It's these shoals that support most of the world's sea mammals. Sea lions have all the agility and speed needed to collect what they want. Dusky dolphin, often in pods two hundred strong work together to reap the harvest. They break up the shoals into smaller, more manageable balls, and all the hunters benefit. By midsummer, the surface nutrients have all been absorbed. In a few special places, however the temperate seas sustain these levels of life throughout the summer. Along the coast of California, ocean currents carry a constant supply of nutrients up from the depths to the surface layers. These upwelling are fertilizing forests of giant kelp that thrive in the summer sunshine. The algal towers are as high as a three story house and they can grow by half a meter a day. Life in the kelp is as full of drama, as in any other forest but the cast is less familiar. An army of sea urchins is mounting an attack. The urchin plague strikes at the kelp's holdfasts their crucial attachments to the rock. Holdfasts are extremely tough, but each urchin has five teeth, which are self sharpening and are replaced every few months. Urchins fell vast areas of kelp forest creating clearings know as urchin barrens yet barrens are a poor description. Millions of invertebrates invade the seabed. The most fearsome predator here is a giant. The sunflower starfish is a meter across, with an appetite for brittle stars. It uses its feet to taste for prey. Sand dollars flat sea urchins cluster together as a defense but it doesn't seem to work against the sunflower starfish. The Californian upwellings are seasonal and relatively small but in Southern Africa they're so big they create seas rich enough to support colonies of over a million seals. The Beguile Current sweeps along the western coastline of Southern Africa driving nutrient rich waters up to the surface and then, at the southern tip of Africa it meets the Agulhas Current, arriving from the east. The result: even richer waters. The seals here thrive on a diet of fish and squid. In temperate seas there may actually be more squid than fish. There are choker squid, and they lay their egg capsules in sandy shallows bathed by the warmer Agulhas Current. Each capsule contains a hundred tiny squid. Short tailed stingray can be up to two meters across. They're the largest of all the stingrays, and they have appetites to match. Another predator is on the prowl. The aptly named ragged tooth shark. Raggies grow to three meters long, but they share these waters with a shark twice their size. Each dawn cape fur seals leave their colony to go fishing. To reach the open sea, they must cross a narrow strip of water and that is patrolled by great whites. Each seal is indeed swimming for its life. The shark relies on surprise. The great white's turn of speed is powered by a high metabolism. They only thrive in cold temperate seas for only these waters contain sufficient food necessary to fuel such a ravenous predator. As you travel towards the poles north or south the colder, stormier seas can become even richer. Midway between South Africa and the South Pole lies the isolated island of Marion.

Pictures

Sand whipped up by Shamals offshore winds blows into the seas of the Arabian Gulf
Sand whipped up by Shamals offshore winds blows into the seas of the Arabian Gulf
  The great white is the largest predatory fish on Earth
The great white is the largest predatory fish on Earth
 
The island sits in the infamous roaring forties where incessant gale force winds draw nutrients up from the depths ensuring plenty of food for king penguins. The humpbacks are nearing the end of their epic journeys. After two months and thousands of miles, they're entering the polar seas both in the north and the south. In the far north, winter is over at last and the ice is starting to melt. The Aleutian Island chain running west from Alaska is the gateway to the Bearing Sea. With the retreating ice, rough weather and ferocious currents stir up these shallow seas. Add sunshine and the mix is spectacularly productive. Five million shearwaters have flown almost ten thousand miles from Australia to get here. In all eighty million seabirds come here for the summer the greatest concentration to be found anywhere on Earth. A large humpback eats three tons of krill a day. The polar seas in summer are the most productive on the planet and the whales gorge themselves round the clock. With luck, the calf will make the epic journey across the oceans from equator to pole another seventy times cruising back and forth between the shallow seas where life proliferates so abundantly on our planet.
Planet Earth Shallow Seas
Planet Earth Shallow Seas
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