Wild Ocean

For centuries we have considered the ocean a vast limitless resource.

Why shouldn't we?

There were shoals of fish too big to imagine.

And we didn't just need to eat the fish and the whales we took...

...we needed their oil for fuel, for power and light.

Yet one by one, fisheries were depleted around the world.

In the Mediterranean, the north Atlantic, and the pacific.

The fish we took were at the centre of a delicate food chain

that connected the tiniest micro-organisms

to the largest animals on the Earth.

Break the food chain by taking too much from the sea,

and one by one, the other predators disappear.

But there is a place where man still shares the ocean,

where the food chain is still unbroken.

This is where Africa meets the Sea.

We are in the Transkei...

...on the Eastern coast of South Africa.

Each winter, the coastline becomes a battleground

where tropical predators meet cold water prey

in one of the greatest natural events on the planet.

Gigantic shoals of fish,

pursued by the highest concentration of ocean predators in the world,

will head here, to a place called...

the Wild Coast.

With no safe harbor for hundreds of miles,

it is a remote ocean wilderness.

Here we can have a glimpse

of what the oceans of the world

might have looked like hundreds of years ago.

Here, beneath the waves,

we will witness the circle of life.

These are the Sardines.

They are a valuable source of protein

for every predator at the top of the food chain.

They are central to the oceanic ecosystem.

For just a few weeks each winter,

millions of sardines find themselves drawn into the shallow water

creating shoals up to ten miles long.

From the air, they could be mistaken for an oil slick.

The sardines follow the cold water currents

sweeping northwards from the Southern Cape of Africa,

pursuing the plankton and nutrients they crave.

This can bring them as far as the Wild Coast,

and perhaps even further north to the beaches of KwaZulu Natal,

where another predator awaits them.

Passing northwards from the Wild Coast into KwaZulu Natal

is like entering a different world,

a different South Africa.

This is where Zulu and Western culture come together,

sharing a common link.

A connection with the sea.

Industry came to this region

from the land and the sugar cane fields,

but there is another kind of wealth in the ocean.

When the sardine shoals pass north of the wild coast,

opposing warm water currents can force the cold water,

closer to the shore.

If this happens, thousands and thousands of fish

can be literally swept up on the beaches

in a potential bonanza for the local fisherman.

Fishermen look for dolphins and gannets arriving from the south.

tell tale signs that sardines are on their way.

But for now they prepare their nets, and wait.

Not so far away, just beneath the waves,

another resident of this coastline is waiting for the shoals.

These Bottlenose Dolphins will work together in groups

using their sonar to track down the sardines.

The sardines begin their journey

hundreds of miles south of the Wild Coast

near the fishing ports Mossel Bay and Port Elizabeth.

It is also home to some of the predators

that will pursue them.

This is a colony of over 60.000 gannets,

many of whom will make the journey north.

They will be joined by Cape Fur Seals.

These seals have traveled only a short distance

from the Eastern Cape and have found a shoal,

not of sardines, but of a baitfish called Massbunker.

The school of fish has formed what is known as a baitball

in an effort to confuse the predators and protect itself.

The shoal moves and changes shape

allmost as if it is a single entity.

By swimming close together,

and only reacting to the movement of their neighbor,

every single fish contributes to this "shoal intelligence".

Another predator attacks the baitball:

the streamlining and speed of the African Penguin

is too much for the massbunker.

Nevertheless, this shoal is actually going to escape,

returning to the depths.

Many factors can affect the progress of the sardine shoals.

As global warming raises sea temperatures,

the fish may be forced further away from the coast

into deeper and colder water.

This far south, they face another hazard...

Fishing boats take thousands of tons of sardines each year.

The quantity of sardines taken

is strictly regulated by the South African government

in an effort to ensure the fishery is sustainable.

But there is allways the possibility that whatever is taken here,

may reduce the number of sardines heading north.

Back on the Wild Coast,

Common Dolphins begin to arrive from the colder waters

of western and southern South Africa.

They are not native to this warmer, subtropical waters.

In June and July, joining the sardine hunt,

they forget the territorial differrences

and gather in pods of up to 4 or 5000.

There can be as many as 20.000 of them here,

off the Transkei.

Their presence is a sure sign