Original subtitles

Vancouver Island is home to

one of the world's most diverse ecosystems.

Glacier capped mountains,

ancient forests,

nutrient rich oceans,

and a network of rivers and creeks

that support a wilderness like no other.

But one creature stands out above all the rest,

the pacific salmon.

Virtually all life here relies on its existence.

As summer draws to an end,

the island prepares for an invasion of salmon,

a spectacle that fuels the region's rivers of life.

Hugging the west coast of Canada,

Vancouver Island stretches

approximately 450 kilometers long by 100 wide.

It's the largest island of the west coast of North America.

While glaciers fuel the flow

of some of Canada's tallest waterfalls,

an endless network of rivers and creeks

provides the ideal habitat for one pf the world's

most important fish.

Each year, half a billion salmon leave the sea

to return their spawning grounds

in the rivers of North America.

Vancouver Island is the destination for millions

of these determined fish.

On their remarkable journey, the salmon face

an endless array of challenges and obstacles.

Not all manage to make it home to spawn the next generation.

It's thought the salmon in these streams

feed more forms of life

than any other creature on the planet.

It's late summer on Vancouver Island shores.

And the temperature is beginning to drop.

Black bears needs to stock up for the forthcoming winter.

Over 10,000 roam the island and they anticipate the arrival

of a calorie rich food source any time now.

But they'll have to remain patient,

for a little longer at least.

At the northern tip of the island,

in the Johnstone Strait, millions of salmon converge

after having spent up to five years at sea

in the Pacific Ocean.

This is the first stage of their testing journey.

And although the black bears lie further inland,

another predator is eager to eat them.

Named after the naturalist George Wilhelm Stellar,

who first described them in 1742,

Stellar sea lions are the largest of all sea lions.

They can reach over three meters in length

and weigh more than a ton.

Unlike most true or crawling seals,

they can walk on all four flippers.

Sea lions also have visible ears

and are often much more vocal than their counterparts.

Sounding like a group of grumpy old men,

the males constantly bicker for a better position

in coastal waters.

Stellar sea lions need to eat

around 6% of their body weight each day.

Soon hunger kicks in.

And it's time for a spot of fishing.

Sea lions may seem cumbersome on land,

but underwater they become streamlined and sleek.

Hitting speeds of over 30 kilometers an hour,

they make tight turns to outmaneuver their prey.

Victims are captured, shaken

and torn into more manageable chunks.

Although many salmon fall at this first hurdle

on their journey home, there's one gentle giant

they need never fear.

Humpback whales can reach 16 meters in length

and weigh more than 36 tons,

making them the fifth largest animal on the planet.

Fortunately salmon aren't on their menu.

The humpback's enormous frames are fueled

by small schooling fish of herring

and swarms of tiny shrimp like crustaceans, known as krill.

These toothless whales use a mass of bristles

called baleen plates to filter food from the water.

Like the salmon, the humpbacks are also about to embark

on a mammoth journey.

They spend each winter in the warmer, southern waters

of Mexico and Hawaii, around 5,000 kilometers away.

This is where they'll breed before returning

to Vancouver Island's food rich waters

with their calves in tow.

But one whale never leaves the region

and this predator can have a taste for salmon.

Killer whales weigh up to nine tons

and roam the island's coast in pods of up to 30 individuals.

Unlike humpbacks, they have over 20 pairs

of conical interlocking teeth.

Also known as orcas,

named after the roman guard of the underworld,

they hunt in packs and are often referred to

as the wolves of the sea.

But this particular pod poses no threat to the salmon.

These killer whales hunt mammals.

While the resident pods of orcas eat only fish,

this visiting group goes for much larger prey,

such a sea lions.

As shoals of salmon

commence their return to Vancouver Island,

another creature prepares to leave.

In East Sooke Park on the southern tip of the island,

thousands of turkey vultures gather,

creating a unique spectacle.

They are the masters of soaring flight.

Turkey vultures breed along the entire length of the island.

But during winter, they head further south,

to mainland America.

On reaching the cooler coastal air,

they form large flocks or kettles,

waiting for the right conditions to cross the sea.

Turkey vultures aren't strong fliers, so rely on winds

and thermal currents to keep them aloft.

This efficient way of traveling

uses just a fraction more energy

than when they're standing still.

Like all vultures, they have excellent eye sight,

but this particular species

also has an extraordinary sense of smell.

The part of their brain controlling this sense

is three times larger than some other vultures.

Turkey vultures also lack a nasal septum,

the wall that separates their nostrils.

This allows more air to pass through,

helping them to detect a decaying carcass.

Carrion makes up the majority of their diet.

They lack the sharp beak and talons

used by other birds of prey to make a kill.

Their feet more resemble those of a chicken.

Acids inside their stomachs are thought to play

a part in helping curb the spread of disease.

Even anthrax bacteria is killed off after being consumed.

Despite their decaying diet,

turkey vultures are one of the cleanest animals around.

Constant preening and a featherless head

keeps germs and microbes to a minimum.

Along with drying and warming their bodies,

this spread wing stance in the sun also bakes off bacteria.

With stomach refueled and wings warmed up,

it's time to rejoin the flock ahead of the journey south.

100 kilometers further north,

along the Englishman River, one creature

is busy stockpiling food for the winter ahead.

Beavers are North America's largest rodents

and can reach a meter in length.

Most of their time is spent building dams

along the region's fast flowing streams.

The rivers eventually flood, creating enormous ponds.

This way the beavers can remain in water

and reach their favorite trees

without having to travel on land.

Beavers only eat the inner bark of trees and shrubs.

But will gnaw through huge trunks to create a dam.

Their front teeth never stop growing,

and this constant chewing prevents them becoming too long.

Beaver ponds play a key role in the life of pacific salmon.

These vast, calm stretches of water

trap nutrients flowing downstream.

This creates a perfect habitat for aquatic invertebrates,

which in turn provides fish with foraging opportunities

not found in fast flowing streams.

These juvenile salmon hatched six months ago,

following last year's spawning.

They'll spend the next year or so

in these freshwater nurseries before they're large enough

to head out sea.

At around three years of age,

they'll return to this exact stretch of water to breed.

Further downstream towards the ocean,

many rivers flow far too fast down.

A stretch of mountains

running the entire length of the island

gives rise to some of Canada's most spectacular waterfalls.

Shoals of salmon have worked their way inland.

Using an extraordinary sense of smell,

they've honed in on the fresh water river

in which they hatched.

They can sniff out a single drop from their nursery stream

in almost 10 million liters of sea water.

But the salmon aren't home and dry yet.

They pause and prepare themselves

for the obstacle that lies ahead.

These salmon were born to return to their spawning ground.

And nothing short of death can stop them.

Racing towards the fall,

they launch themselves into the air.

Beneath the white froth, water is squeezed

back up to the surface, the salmon use this hydraulic uplift

to boost their jumps.

Initial leaps are rarely successful,

but giving up isn't an option.

Eventually perseverance pays off.

These athletic efforts are fueled by just stored energy.

The salmons cease eating or drinking

as soon as they entered the freshwater rivers

several days ago.

For some, the journey home has already taken its toll.

Taking time out to catch a breath can be a costly mistake.

Especially in black bear territory.

Vancouver Island has the densest population

of black bears in the world.

They're darker than mainland bears and slightly larger,

weighing up to 275 kilograms.

Although largely vegetarian,

feeding on grasses and berries for most of the year,

they are the island's largest predator.

The annual salmon run provides a major food source

for many bears.

The brain, eggs, skin and back muscles

contain high levels of fat.

And it's these areas the bears focus on.

They can each eat up to 15 salmon a day.

Four centimeter curved claws

and a set of flesh tearing teeth

aren't the only qualities keeping black bears

at the top of the food chain.

They can also scale trees with ease,

run at over 55 kilometers an hour, and swim long distances.

To top it off, their sense of smell

is seven times sharper than the bloodhound's.

Despite these impressive attributes,

catching live salmon in these deeper waters

is easier said than done.

Further upstream, the water levels are too low

for the salmon to continue their journey home.

Until the heavy autumn rains arrive,

they'll just have to sit tight

as will the island's many bears.

Black bears play a vital role

in Vancouver Island's ecosystem.

Not all salmon are completely consumed

after being carried into the forests.

And this has a significant effect on the surrounding land.

When these carcasses break down, nitrogen, phosphorus

and other nutrients are absorbed

by the surrounding vegetation.

Up to 70% of the nitrogen in some areas

comes directly from the fish.

Trees taking root close to salmon rivers

grow three times faster

than those next to fish free streams.

Here, Sitka spruce take just 86 years to rich a thickness

of 50 centimenters, rather than the usual 300 years.

Vancouver Island is home to the tallest

Sikta spruce trees in Canada, possibly the world.

Some reach heights of over 95 meters,

taller than a 30 story building.

Sitka seedlings, however,

have a difficult time starting out.

Dense mosses and smaller plants carpet the forest floor,

making it difficult for them to take root.

But many are given a helping hand.

Fallen trees repay hundreds of years worth of benefits

by acting as nurse logs.

Seeds landing on these downed giants

already have a height head start

as well as an open area to germinate and develop.

Over 90% of the Sitka seedlings here start out this way.

Fungi also feed on decaying trees

and play their part in recycling nutrients.

This Pacific Banana Slug

is the 2nd largest land slug in the world

and can grow up to 25 centimeters long.

They're fond of mushrooms

and spread seeds and spores when they eat.

After which, they excrete a nitrogen rich fertilizer.

Possibly the most important tree on the entire island

is the western red cedar.

This particular giant is over 18 meters in circumference

and almost 60 meters tall.

It's the largest tree in Canada

and the largest red cedar in the world.

At an estimated two and a half thousand years old,

it's one of the oldest living organisms on the planet.

Red cedar has a high natural resistance

to rot and insect damage.

For thousands of years it's been the wood of choice

for the island's only settlers.

This half finished warrior canoe still bears carving marks

made before it was abandoned several centuries ago.

Back then, people lived off the land

and had a deep spiritual connection with all living things.

Especially the island salmon and huge cedar trees.

Cedar carved totem poles preserve stories of encounters,

adventures and accomplishments by the various clans.

The Namgis people have lived off

the northeast coast of the island for millennium.

Ancient culture is kept alive

through oral history and ceremonies.

Their ancestors relied on the island's salmon for survival.

Even today, the fish are revered,

as are the rivers around them.

It's said that long ago when the world was young,

a man was approached by a spirit being.

The spirit asked him if he wanted to become a mountain.

The man refused because mountains eventually crumble away.

He was then asked if he'd like to become a cedar tree.

The man also refused, as trees can split, fall and rot.

On being asked if he'd like to become a bolder,

the reply was also negative.

Bolders crack and crumble.

Finally, when asked if he'd like to become a river,

then man answered yes.

The spirit then pushed the man down,

saying "There you'll be a river

"for as long as the days dawn in the world.

"And you will be full of salmon

"so that your descendants may never starve."

The river became the largest on Vancouver Island

and eventually bore the name, the Namgis.

It's now known by its modern name, the Nimkis River.

Before reaching the sea, the island's network of rivers

feeds over 2,000 separate lakes.

Nitinat Lake lies so close to the coast,

it contains mostly saltwater.

Haley Lake sits further inland

and is filled by freshwater streams

from the surrounding mountains.

On these inclines, one creature makes the most

of the autumn sun before bedding down for winter.

Marmots are the largest members of the squirrel family.

They're about the size of a domestic cat

and weigh around five kilograms.

Vancouver Island marmots

are the rarest marmots in the world.

At one point their numbers dropped to just 25,

but are now slowly recovering.

Family colonies are made up of around six members

and at this time of year,

they're grabbing the last of the food.

Tail flipping is a visual way of keeping in contact

with the rest of the group while on the move.

Nose greeting is the marmot's way of saying hello.

Smelling a visitor's cheek

helps identify who's who among the neighbors.

Most marmots live above 1,000 meters,

where open alpine meadows provide a variety

of grasses and herbs.

Lupines are a particular favorite.

In the next few days,

the marmots will hibernate in their burrows

to avoid the winter cold.

They'll have lost a third of their weight

by the time they reemerge in April.

But not all family members are hungry.

Sun bathing on bolders helps to cool and regulate

the marmots body temperature.

These elevated vantage points also provide a lookout tower

for small predators.

A high pitched whistle

alerts the whole family to the danger.

Other colonies relay the warning,

creating an echo across the entire valley.

A circling bird could be a golden eagle and pose a threat.

But this particular predator has a different meat in mind.

The bald eagle is the most iconic bird in North America.

It has a wind span of over two meters

and can weigh up to five kilograms.

Despite its name, it isn't bald and unlike the golden eagle,

it isn't classed as a true eagle,

because it's legs aren't completely feathered.

However, it's the only eagle exclusive to North America

and the only member of the sea eagle family

living throughout this range.

Bald eagles are expert at fishing.

Fish make up around 90% of their diet

and salmon is of key importance.

This particular eagle isn't searching for food

in the rivers and lakes.

Hunting fish requires lots of energy,

and it's thought that only one in 18 missions is successful.

Panting helps to regulate body temperature.

After catching its breath, the eagle moves in.

It shields the find from other predators,

an act called mantling.

Dead or discarded salmon make up a major part

of the bald eagle's diet.

This bird is no fussy eater.

And the black bear's leftovers are a welcome meal.

The nutrients that the salmon bring to the island

on their journey home

originate almost entirely from the sea.

Vancouver Island has some of the most

food rich shores on the planet,

which are home to an abundance of marine creatures.

This intertidal zone is a colorful cold water paradise

that puts many tropical reefs to shame.

In summer, super rich plankton blooms,

giving aquatic creatures a huge steroid boost.

During winter, the water temperature drops

to just five degrees Celsius.

This allows deeper ocean oxygen and nutrients

to rise to the surface and be washed closer to shore.

Barnacles sweep for plankton with their fan like feet.

Feather duster worms wave their sticky tentacles,

trapping edible debris much like a spider's web.

Starfish here grow to enormous sizes.

Some, like the sunflower star reach up to a meter across.

These giants can have up to 26 arms

and 15,000 tubed feet.

They can move at over one meter a minute.

Many tidal creatures prefer to keep a low profile.

Camouflage is often key to survival.

For a crab, breaking cover is a dangerous decision.

The intertidal zone is patrolled by a monster.

And crustaceans are always on the menu.

The giant Pacific octopus is the largest in the world.

It can have an arm span over over nine meters

and weigh more than 250 kilograms.

Fish, sharks, even birds are sometimes eaten.

Predators aside, the intertidal zone can be

one of the most violent habitats.

High tides bring crashing waters,

capable of crushing anything untethered

or not glued to the rocks.

Low tides can expose plants and animals to hot sun,

fresh water and dehydrating air.

In one location, boiling sulfur saturated water

is even thrown into the mix.

On the western side of the island,

on the shores of Maquenna Provincial Park

lies evidence of the island's volcanic past.

Boiling spring water bubbles up from deep in the Earth.

It cascades along a series of rock pools

before finally entering the sea.

This part of the coast lies on a fault in the Earth's crust,

an enormous crack traveling deep beneath the surface.

This water hasn't seen daylight for hundreds of years.

It's traveled over five kilometers

towards the center of the Earth and back.

On its slow journey through the rock layers,

the water is geothermically heated

to over 100 degrees Celsius,

before pressure forces it back to the surface.

The water reemerges at around 50 degrees,

having absorbed high concentrations of minerals.

While boiling water bubbles at sea level,

2,000 meters higher up, ice is a year round fixture

on many of the island's peaks.

Along with volcanism and the collision of tectonic plates,

glaciation also played a major part

in the region's formation.

Around 10,000 years ago,

the Comox Valley was buried beneath a sheet of ice

more than a kilometer thick.

As it moved, the glacier gouged valleys

out of the land below.

The climate eventually warmed and the ice sheets melted,

most of it at least.

The Comox glacier still looms over the valley.

It's the largest glacier on Vancouver Island

and is another reminder of the region's dramatic past.

One volcanic byproduct

had a magnetic effect on the human population.

It attracted people from Australia, California

and virtually all parts of the world.

In 1864, gold was discovered in the island's rivers

and prospectors stampeded to get here.

Some streams yielded up to 120 kilograms of gold a year,

around five millions pounds worth by recent values.

When animal trapper Joe Drinkwater

came across the precious metal in one particular creek

he set up a vast gold panning operation.

The dried up river bed yielded a huge amount

of the precious metal.

Joe soon became rich.

Further along the valley, Joe also discovered

Canada's tallest waterfall.

At 440 meters,

Della Falls is eight times taller than Niagara.

Joe eventually sold all his prospecting claims.

But even today his name lives on in Drinkwater Creek.

As does that of his wife, Della.

It's only October and many of Vancouver Island's

upper streams have dried to just a trickle.

The autumn rains are long overdue.

And the recent drought has prevented salmon

from moving up river to reach their spawning grounds.

But it appears change is in the air.

Even the island's black bears

who have been waiting patiently for weeks, sense it.

Soon, the rivers are full flow.

The salmon make their move.

And so do the bears.

Black bears can kill

up to half the salmon in these smaller streams.

They can each consume up to 20,000 calories a day

when stocking up for winter.

Despite the deluge of rain,

the rivers remain relatively clear and free of debris.

Tree roots in the surrounding forests

hold the soil, which filters water

before it enters the streams.

These rivers contain some of the purest water in the world.

For those salmon that manage to avoid the bears

and make it further up stream,

a final challenge lies ahead.

Males of this stage are often gaunt with hooked jaws,

humped backs and battle torn fins.

Many females display large white patches

of bruised and diseased skin.

Fortunately, their mission is nearly over.

Females jostle for position

above the best places to lay their eggs.

Males line up behind, fighting off competitors.

Finally, the female chooses her moment

and lays a batch of eggs.

The male instantly moves in to fertilize them.

Female salmon lay around 3,000 eggs in a series of nests.

Each one is covered by gravel to protect against predators

and to prevent the eggs from drifting away.

But even before they've hatched,

the salmon's battle for survival begins.

Glaucous-winged gulls paddle their feet

along the freshly visited spawning grounds.

Those large eggs are a protein rich delicacy.

Dippers usually eat aquatic insect larvae,

which they dive to collect from the river bottom.

At this time of year they capitalize on the salmon spawn.

However, certain pickings are often too big to swallow.

Only 10% of salmon eggs will successfully hatch.

For every 1,000 laid, only four

will make the journey to the ocean and back again.

These adult salmon are ultimate survivors.

Their job is done.

They've passed the baton to the next generation

and this final act marks the end of their life.

Pacific salmon always die after they've spawned.

Through a combination of exhaustion

and the effects of moving from salt to freshwater,

they breathe their last

in the same streams they started out in.

Their decomposing bodies release nutrients

that feed the aquatic food web.

This in turn will nurture the next generation of salmon

throughout Vancouver Island's rivers of life.

Vancouver Island is a diverse wilderness.

Shorelines, forests and mountainous peaks

are home to a whole host of creatures.

And a unique network of rivers and creeks

carries the fuel for many forms of life.

One fish plays a pivotal role

in sustaining the region's ecosystem.

Vancouver Island relies on its salmon.

And this remarkable creature depends on the island too,

throughout its life.