Ocean World

How big is the Blue Whale?

30 meters long and weighing over 200 tons. it's far bigger than even the biggest dinosaur. Tongue weighs as much as an elephant. Heart is the size of a car. Some of its blood vessels are so wide that you could swim down them. Tail alone is the width of a small aircraft's wings.

(%) of the planet is covered by the sea. The Pacific Ocean covers (fraction) of the globe. The ocean makes up (%) Of Earth's inhabitable space.

70% of it is covered by the sea. The Pacific Ocean alone covers 1/2 the globe. The ocean makes up 97% of the earth's inhabitable space

The Biggest Animal on Earth

A blue whale

Ridley's Turtles Nesting

A quarter of the world's population of Ridley's turtles come to this one beach on a few key nights each year. The rest of the time, they are widely distributed through the ocean. Forty million eggs are laid in just a few days.

Killing the Calf

At last the killers succeed, and now they've got the calf on its own. They leap right onto the calf, and try to push it under, trying to drown it. The calf snatches a desperate breath. But now it's so exhausted that it has to be supported by its mother's body. The killers won't give up. Soon, the sea is reddened with the calf's blood, and the killers close in for the final act. The calf is dead.

One of the Fastest Animals in the Sea

Blue Whale!

Common Dolphin and Sardines

Coming in from the open ocean to join the feast. When they catch up with the sardines, they drive the shoal towards the surface. it's easier for the dolphins to snatch fish up here. Now the sardines have no escape. The sardines have come within the diving range of the gannets.

Herring Spawning

Each female produces round, sticky eggs. The males release their sperm in clouds. After a few days, this gigantic spawning comes to an end, and the herring head back out to deeper waters, leaving behind them fertilized eggs. Two weeks later, when the eggs hatch, the annual plankton bloom will be at its height, and the fish fry will have plenty to eat.

Why do Sardines leave the Cape?

Each year the coastal currents reverse. The warm Agulhas current that flows down from the north has been displaced by cold water from the south, bringing up rich nutrients. They in turn have created a bloom of plankton, and the sardines are now feasting on it.

Why do R. Turtles synchronize nesting?

Ensure that 6 weeks later, their hatchlings will emerge in such enormous numbers that predators are overwhelmed

Moon Cycles

Gravitational pull creates the daily advances and retreats of the tide. Each month, it waxes and wanes as it travels round the earth, and this monthly cycle also triggers events in the ocean.

Grey Whales

Grey whales followed the sun north, and seeking the food generated by the phytoplankton bloom. Krill are feeding off it, and these whales are feeding on the krill.

What controls the distribution of nutrients and life in the seas?

Huge currents, such as the Gulf Stream

What is at the top of the Alaskan Food Chain?

Humpback whales. This herring bonanza provides the majority of their food for the year.

Costa Rica

Just after midnight and the tide is coming in. The moon is in its last quarter. At high tide, turtles start to emerge from the surf. Within an hour, they are appearing all along the beach. They are all female Ridley's turtles who will lay eggs.

Blue Whales eat...

Krill, a crustacean just a few centimetres long. Gathered in a shoal, krill stain the sea red, and a single blue whale in a day can consume 40 million of them.

Who Eats the Eggs?

Millions of birds arrive to collect a share of the herrings' bounty. Some of it is easily gathered, for millions of eggs have been washed up onto the shore. This encapsulated energy is particularly valuable to migrating birds.

Nutrients Brought up by Rough Weather

Near the poles, storms stir the depths and enrich the surface water. In the South Atlantic, the seas are the roughest and richest on Earth. The cold Falklands current from the south meets the warm Brazil current from the north.

Silky Sharks

Normally ocean-going species, but attracted to sea mounts in the eastern Pacific like Cocos, Mapelo and the Galapagos. Silkies seem to specialize in taking injured fish and constantly circle sea mounts on the look out for the chance to do so.

Opalescent Squid Mating

On their way to the shallows. As the males grab the females, their tentacles flush red. Part of these breeding schools for a few weeks. Wave after wave rise, and soon the seabed in the shallows is strewn with dense patches of egg capsules. As each female adds another capsule to the pile, the males fight to fertilize its contents. Dawn the next morning, and the squid have all gone.

Grey Whale Migration

One of the longest migrations of any marine mammal - a round trip from their breeding grounds off Mexico along the entire coast of North America up to the Arctic Ocean. Travel close to the coast. The males and non-breeding females leading the way, last to start are cows that have just given birth. They have to wait until their calves are sufficiently strong to tackle such an immense journey.

Hagfish

Scavengers, over half a meter long only found in the deep sea. Breathe through gill openings along their sides. They're very primitive creatures - not even true fish for they lack jaws. They feed by rasping off flesh with two rows of horny teeth. in just a few hours, a hagfish can eat several times its own weight of rotting flesh.

Sharks, Dolphins, and Sardines

Sharks can feed well once the dolphins have driven the sardines into more compact groups near the surface. Walls of bubbles drift upwards, released by the dolphins working together in teams to corral the sardines into ever tighter groups. The sardines seldom cross the wall of bubbles, enabling the dolphins to grab every last trapped sardine.

Grey Whales getting Cornered

She can inflict real damage with her tail. The killers are after her calf. As long as the mother can keep it on the move, it will be safe, and she does her best to hurry it along. At first, the killers avoid getting too close but just stay alongside. After three hours of being harried, the calf becomes too exhausted to swim any further. The mother has to stop. This is the moment the killers have been waiting for. They start to try and force themselves between mother and calf. A calf separated from its mother will not be able to defend itself.

Where is the largest Albatross Colony in the world?

Steeple Jason, a remote island in the far west of the Falklands. Nutrients and also the heat and light from the sun is also essential for the growth of the microscopic floating plants - the phytoplankton.

Surfbirds, Bonaparte Gulls, and Ducks

Surfbirds are on their way to their breeding grounds in the Arctic and come down to refuel with eggs. Bonaparte gulls collect the eggs just below the surface of the water. Flocks of ducks have gathered. They're mostly surf scoters - diving ducks that can feed off the bottom several meters down.

How does the Sun affect Alaska?

The coastal waters turn green with a sudden bloom of phytoplankton. Herring that have spent the winter far out to sea return in vast numbers and initiate one of the most productive food chains in all the oceans.

Why are the herrings in Alaska?

The herring are about to breed. Nothing deters them as they head for even shallower waters. In spite of these attacks from glaucous-winged gulls, the herring swim until they reach the vegetation that the females need to lay.

The Disappearance of the Sun triggers...

The largest migration of life on Earth. 1000 million tons of sea creatures ascend from the deep ocean to search for food near the surface. They graze on the phytoplankton. At dawn, the whole procession returns to the dark depths.

Why do the squid go to the shallows?

Their eggs will develop faster in the warmer water here, and when the young emerge, they will find more food more easily than they would in the ocean depths.

Things we don't know about Blue Whales

Their migration routes are still a mystery, and we have absolutely no idea where they go to breed.

Migration of Cows and Calfs

Their progress is necessarily slow. The mothers stay with their young, and even a strong calf only travels at a couple of knots. They stick even closer to the shore, often within just meters.

Why do Hammerheads come to Sea mounts?

These sharks are not here for food. Some of the locals provide a cleaning service. Following the last El Nino year, when a rise in water temperatures gave many sharks fungal infections, the number visiting the sea mounts reached record levels.

Bronze Whaler Sharks and Sardines

These three-meter sharks cut such great swathes through the sardine shoals that their tracks are visible from the air.

Killer Whales Targeting Grey Whales

They have learnt that grey whales follow traditional routes. The killers have no trouble in overtaking the calf and its devoted mother. Normally, they continually call to one another, but now they have fallen silent.

Sardines on South Africa's Eastern Seaboard

They look like immense oil slicks up to a mile long.

Arribada

This mass nesting of Ridley's Turtles. Start when the moon is either in its first or last quarter.

Cape Gannets

Thousands of Cape gannets track the sardines. They nested off the Cape and timed their breeding so that their newly-fledged chicks can join them in pursuing the shoals.

Why do R. Turtles use the moon?

Vultures have learnt that the returning tide can wash freshly laid eggs out of the sand. The risk of eggs being exposed by the surf may be why arribadas tend to occur around the last or first quarter. When the moon is neither full nor new, the tides are weakest so it's harder for eggs to be washed out of the sand.

Sleeper Shark

moves slowly to conserve energy - an important strategy for so large an animal surviving in such a poor habitat. Sleeper sharks live over a mile down, and grow to over 7 meters long. Can go for months without food, slowly cruising along, waiting for rare bonanzas.

What is the basis of all life in the ocean?

phytoplankton

Most animals at Sea Mounts eat...

plankton - tiny floating plants and animals nourished by the richness brought up from the depths

Water Vapor rising from the ocean form...

the clouds and generates storms

What causes animals to come to sea mounts?

the deep ocean currents

Black-Browed Albatross

wanderers across the face of the open ocean and eat krill. Most of the time, the birds are widely dispersed