01x02 - Goat Island

[bunniefuu]

[mysterious music]

[water splashes]

[water splashes]

[peaceful music]

Narrator: Goat Island in the Hauraki Gulf

and the reefs are alive with fish,

like nowhere else around mainland New Zealand.

Tens of thousands of fish school just meters from the shore,

only 90 kilometers north of Auckland.

[dramatic music]

This is such a special piece of our big blue backyard

that in 1975,

Goat Island became New Zealand's first marine reserve.

[birds calling]

Snapper, crayfish, and many other species

may be fully protected from us

while they remain in the reserve,

but life here is full of jeopardy.

[water splashing]

Human laws don't prevent ocean-going marauders

like dolphins calling in for a feed.

The aerial assaults of shags,

and kingfishers,

[water splashing]

or the vanguard of predators that lie

and wait beyond the boundaries of the reserve.

Even those which never leave the safety of the reef

as adults face a massive hurdle at the beginning

of their lives.

[suspenseful music]

Scattered as tiny eggs on the ocean currents,

they must somehow find their way back,

guided by the unique sounds of their birthplace.

[water bubbling]

[waves crashing]
[gentle music]

The Goat Island Marine Reserve consists

of five kilometers of coastline,

from the mudstone platforms of Okakari Point,

to the rocky cliffs of Cape Rodney,

and extends 800 meters out to sea.

In the middle of the reserve lies Goat Island itself,

named for goats released as food for shipwrecked sailors

around the turn of last century.

On the seaward side,

spectacular caves are carved out by the waves.

[water rushing]

Below the surface, they provide shelter for numerous fish.

[gentle music]

The rocky platforms extend 300 meters out to sea

in a series of stepped reefs towards the sandy bottom.

Before the reserve was established,

this coastline was mostly barren rock decimated

by overfishing in the 1950s and '60s.

Today, the only word for it is lush.

Dense kelp forests now cover much of the reserve.

In turn, huge schools of silver drummer have returned

to feed on the kelp,

along with other algae eaters, like this parore.

Gray and blue maomao have also returned in massive numbers,

[gentle piano music]

but snapper are probably Goat Island's

most famous residents.

Outside the reserve, snapper are shy, retiring fish,

rarely seen by divers.

Inside the reserve, they are everywhere.

They're huge, and they appear to feel safe.

Some grow so big and distinctive, they have names.

This is the legendary Monkey Face.

[suspenseful music]

Only the oldest fish turned dark gray,

and develop this domed forehead.

No one knows if Monkey Face is male or female,

or how old he or she is.

Left alone, snapper can outlive most humans.

This magnificent fish was probably able

to outsmart the spear fishes of the 1960s,

and was already living here when Goat Island

became a marine reserve nearly 40 years ago.

On the reef, fish this big have few natural enemies,

but the same can't be said

for the schools of small bait fish.

[water splashing]

These bottlenose dolphins are some of a population of 450

that travel between Northland and Tolaga.

Pods frequently visit to raid the reserve's fish stocks.

[mysterious music]

Each adult dolphin needs to eat up

to 15 kilos of fish a day.

The sheltered reserve is also a perfect training ground,

where young dolphins learn the pods fishing techniques

by mimicking the adults.

Bottlenose dolphins are highly social

and intelligent creatures.

It's recently been discovered they even have names

for each other.

One dolphin will call to a specific individual

with a unique whistle,

[dolphins chittering]

and only that dolphin will respond

by echoing the signature call.

[dolphins chittering]

[water splashing]

For now, this pod seems content to play

in the safety of the marine reserve.

[gentle music]

[birds calling]

From above, nothing escapes the attention

of a colony of pied shags

that occupy prime real estate overlooking Goat Island Bay.

It's now March, the end of summer,

but the yellow patch beside the eyes shows this pair

is just getting ready to breed.

Pairs usually stay together for life,

and often rebuild nests from previous years.

[birds chirping]

Pohutukawa twigs are the building material of choice,

and this male seems to have found a good source.

His nest has a front door.

He always arrives by the same branch.

The female takes care of construction,

[birds chirping]

while her mate slips out the back door

to gather more material.

[birds chirping]

Pied shags breed all year round,

so some of the colony's residents

already have chicks,
[birds chirping]

while others are just getting started.

[water splashing]

[gentle music]

Below the waves, another cycle of life also starts afresh.

Sea urchins, or kina, spawn from November to March.

On the sea floor,

a female releases around 80 million eggs into the water,

while males broadcast their sperm from a high vantage point.

[gentle music]

The clouds of kina spawn meet in the current,

and the eggs are fertilized.

They then drift and develop for 10 weeks.

Most will be eaten by predators,

but enough settle to continue the species.

[suspenseful music]

Autumn is also the time for another

of the reserve's residents to begin its breeding cycle.

[gentle music]

Crayfish were once among the most over-fished species

in these waters,

but along with snapper, they recovered the quickest,

flourishing in the first 10 years.

There are now thousands

of these massive crays of breeding age.

They may be 10 years old,

and weigh more than six kilograms each.

For most of the year,

they pack tightly into crevices and caves

for mutual protection.

Venturing outside during daylight hours

could mean death by snapper.

This looks like a crayfish made a fatal mistake,

but the owner of this shell or carapace

is safe inside her cave.

In order to grow, crayfish must molt regularly.

While their new shells harden,

they stay well hidden.

The females always molt in autumn just before they breed.

Soon they'll carry their eggs under their tails,

and won't be able to shed their armor.

[suspenseful music]

Crayfish often share their caves

with these shy nocturnal fish called bigeyes.

For years, divers believed

that crayfish made noises when approached,

but scientists discovered that the noise

was produced by the bigeyes.

All fish respond to sound, and most have internal ears,

but only a few can vocalize.

bigeyes produce this distinctive sound

by vibrating their swim bladders,

the air-filled sacs that keep them afloat.

[bigeyes calling]

These sounds may be a way to help the school stay together.

[bigeyes calling]

[water splashing]

Communication in the dolphin pod is much more sophisticated.

They're not just keeping in touch with each other.

They're hatching plans.

The complexities of their highly developed language

are still a mystery,

[dolphins chittering]

but it's not hard to guess what they're discussing.

The hunt is on.

[suspenseful music]

The piece of an autumn afternoon

at the Goat Island Marine Reserve is shattered

by the arrival of a pod of bottlenose dolphins.

[water splashing]

Tail slapping is an effective way to attract attention.

It can be heard all over the bay,

and may very well mean, "I found fish."

[dolphins chittering]

Bottlenose dolphins feed mostly

on small school fish and squid.

This rich marine reserve is a perfect place

to teach youngsters the pod's various hunting strategies.

One technique is to corral the fish

before charging into the school.

[suspenseful music]

Some dolphins achieve this by swimming

around the fish in tight circles,

while others herd their quarry toward the beach,

trapping them in shallow water.

[water splashing]

As the dolphins feed,

scraps drift down to the snapper waiting below.

Snapper will eat almost anything,

whether it's dolphin leftovers,

or the supposedly inedible puffer fish.

Many species of puffer fish contain a deadly toxin

in their organs,

but it seems large snapper might be immune to it.

These big fish have formidable jaws lined

with teeth strong enough to crush muscles,

break limpets off rocks, and even pierce crayfish's armor.

[suspenseful music]

But luckily for this one,

it seems Monkey Face has already eaten.

[gentle guitar music]

It's mid-afternoon, yet all over the shallow reef,

the usually nocturnal crayfish cruise the sea floor,

risking attack from predators.

They are all males.

Most of the year, they jam into caves together,

but autumn signals the time to fight.

Big males go head to head to win the best cave,

which will attract the most females.

Some disputes can be settled with displays

of size and strength,

[suspenseful music]

but equally matched males have to fight it out.

When the victor courts a female like this,

they'll spend hours face to face,

gently stroking each other's antennae.

Eventually, the male transfers a package

of sperm to the underside of his mate,

which she'll use to fertilize up to half a million eggs.

This dedicated mother will carry her developing eggs

under her tail for the next five months,

constantly watched by hungry predators.

[suspenseful music]

The bottom-dwelling blue cod are also voracious consumers

of just about anything they can sink their teeth into.

[suspenseful music]

When a cod attacks,

the crayfish momentarily cease fighting,

and used their armored antennae to fend off the invader.

This cod is persistent, but it nets nothing more than a leg,

which the crayfish can regrow when it next molts.

[suspenseful music]

On the sea floor nearby,

another persistent predator is on the prowl.

An 11-armed starfish st*lks its relative, the kina.

Like their cousins,

kina have hydraulically operated tube feet

between their rows of spines.

They pump water into these tubes,

which makes them expand and able to move.

[suspenseful music]

They may be relatives,

but starfish are voracious predators of kina.

When the starfish gets close enough to attack,

this kina activates its novel escape tactic.

[kina chewing]

Kina feed mainly on kelp.

Each one chews through about two grams a day.

They catch drifting fragments with their suckers,

and move them foot over foot towards their mouths.

[kina chewing]

This is the sound of their munching teeth,

amplified by their shells,

which are natural underwater loudspeakers.

[gentle music]

Kina have five razor sharp teeth buried in their underside

that make short work of the tough kelp.

As the teeth grow continually,

chips flake off the cutting edges,

which makes them self-sharpening.

A herd of munching kina can be a thousand times louder

than the ambient sounds of the reef,

and may be heard kilometers out at sea.

[suspenseful music]

The lush fish life of the reef attracts many predators.

[water splashing]

Fast hunters like kingfish

and bronze whaler sharks often make forays into the reserve,

or close to its boundaries.

[water splashing]

[birds calling]

There's also danger from above.

[birds calling]

Kookaburras are large kingfishers that were introduced

to nearby Koro Island in the 1860s.

They're now frequently seen

on the mainland around Goat Island.

[birds chirping]

[gentle music]

Our own native kingfish fisher is not as big

and brash as its Australian cousin,

but it's quite partial to a fish meal.

At Goat Island,

they're often perched in trees above the tidal platforms.

Small fish are frequently left stranded in rock pools

by the receding tide,

sitting ducks for the kingfisher.

[water splashing]
[dramatic music]

[gentle music]

[bird chirps]

[water splashing]

In the bay, the bottlenose dolphins have also enjoyed

a great day's fishing.

Now it's time to do what dolphins do every day:

strengthen the bonds of their pod through play.

[suspenseful music]

As the sun sets over the Goat Island Marine Reserve,

the dolphin invaders finally head back out to sea.

Life on the reef returns to normal.

For many fish,

dawn and dusk are the busiest feeding times of the day.

As a stingray lazes on the sea floor,

goat fish forage for prey in the sand,

recently disturbed by the ray.

Goat fish have two barbles on their chin,

which are sensitive whiskers tipped with taste buds.

They taste the sea floor,

looking for small worms and crustaceans.

Like goats, they'll eat anything.

[gentle music]

As night takes hold, the reef life changes.

Many of the familiar fishes from the day seek shelter

in caves or crevices,

as the night predators begin to patrol.

The goat fish puts on red pajamas.

This color makes it harder to see in the darkness.

Some predatory fish, like this snapper, sleep by night,

but new dangers lurk on the reef.

A hungry conga eel has spent the day in a cave.

By night, it roams the reef,

looking for any vulnerable creatures to pick off.

Finally, the bigeyes,

named for their massive light-sensitive eyes,

leave their caves to hunt small creatures floating

in the plankton.

As they hunt, they call to each other,

possibly to keep the school together.

[suspenseful music]

Nighttime is also when their neighbors venture out to feed.

Crayfish leave their caves on the rocky reef,

and make long foraging trips, up to a hundred meters,

to seek shellfish which live on the sandy sea floor.

[gentle guitar music]

They gather up this prey to take back to their caves to eat.

c*ck shells around cave entrances are a dead giveaway

that crayfish have been feeding.

[claws crunching]

Crayfish arms are powerful enough

to pry open their victims to devour their flesh.

[suspenseful music]

As the sun rises over the Goat Island Marine Reserve,

red moki leave their caves to graze

amongst the hard pink algae that encrusts the rocks.

These moki are hunting

for small creatures living in the algae.

They suck them in, and expel the waste out

through their gill slits.

[gentle music]
[birds chirping]

In the branches overlooking the bay,

the shag families

are also waking up.
[birds calling]

On average, they have three chicks,

not all of which will survive to adulthood.

One parent always stays with the chicks,

while the other goes off to fish.

They swap shifts at least three times a day.

[water splashing]

Shags don't plunge dive from a height.

Instead, they duck dive.

[mysterious music]

Once underwater, they're remarkable swimmers,

methodically checking the reef for small fish.

They can hold their breath for three and a half minutes,

feeding to depths of around 10 meters.

Unlike other seabirds,

they have very little waterproofing oil in their feathers.

Being waterlogged helps them stay under,

but there is a downside.

When the water gets cold in winter,

shags are susceptible to hypothermia,

and waterlogged wings don't fly well.

[birds calling]

At the end of a dive,

the birds often spread their wings to dry,

and perhaps absorb some warmth from the sun.

[gentle music]

[water splashing]

Then it's home to feed the waiting chicks.

Each adult needs to catch 500 grams of fish for itself,

[birds chirping]

but their fast-growing chicks

will each gobble up to 800 grams

of the marine reserve's inhabitants every day.

[mysterious music]

Small fish are constantly under attack.

To survive, they need some sort of protection.

Very young trevally often keep company with big snapper.

This smart one rides the bow wave by the snapper's head,

out of reach from any potential predator,

but always keeping on the safe side

of the snapper's powerful jaws.

As they grow a little bigger,

groups of trevally set up mobile cleaner stations

on the reef.

Fish with parasites come to have them removed,

and the trevally get an easy meal.

[suspenseful music]

This large parore is a gentle vegetarian,

so the little fish are in no danger.

A giant blue moki is a more dangerous proposition.

Only the biggest of these fish come to Goat Island.

They spawn a long way south from here.

To swim north against the prevailing currents,

moki have to grow very big and strong.

[suspenseful music]

This fish, with its worn and tattered fins,

may be more than 30 years old,

and it knows there's a strict etiquette

to these cleaning stations.

Even if you accidentally suck one in,

never swallow the mouth that cleans you.

[water splashing]

In the shallow water, the wave action noticeably picks up.

With the female crayfish carrying precious eggs

beneath her tails, just weeks away from spawning,

a major storm surge could threaten this critical stage

of their reproductive cycle.

[gentle music]

[waves crashing]

The Goat Island Marine Reserve bears the full brunt

of a storm rolling in from the Pacific Ocean.

The pied shags have no choice

but to ride out the storm in their nests,

while massive swells pound the beach and the shallow reef.

[waves crashing]

When the storm abates, the damage is obvious.

[water splashing]

[birds calling]

Huge piles of kelp have washed up.

It's a feast for many birds that come to feed

on small crustaceans caught in the kelp,

and on insects attracted to it.

[bird chirping]

[gentle music]

Below the surface,

extensive patches of rock have been stripped,

but the storm may not be the only culprit here.

The innocent-looking kina can be a force of destruction.

They usually feed on small fragments of kelp,

but if their numbers aren't kept in check,

they will attack the holdfasts,

the root-like structures that anchor the kelp.

An out-of-control colony of kina

can destroy a whole kelp forest.

The relationship between kelp,

the kina, and their predators is complex,

[gentle music]

but scientists studying this reserve for more than 30 years

have measured a big decline in kina numbers

as their predators reestablish themselves.

[gentle music]

Kina have no brain, and yet, they display cunning,

in attempts to camouflage themselves

by arranging small pebbles and shells on their backs.

However, crayfish see through the disguise,

and are responsible for nearly half of all kina predation.

Despite their defenses, Goat Island kina have many foes,

so their population is kept in balance,

which means the kelp forest

and all their numerous inhabitants

can flourish here in the reserve.

[gentle music]
[birds chirping]

It's now spring,

and the countdown begins for a significant annual event

for some of the residents of Goat Island Marine Reserve.

[water bubbling]

[creature moans]

After five months of carrying their developing eggs

under their tails, surviving storm surges and predators,

female crayfish are ready to spawn.

But first, they must make a journey.

Each female leaves her cave in the shallows

to walk several kilometers to deeper parts of the reef.

They need to time their arrival

to the hours just before dawn.

Not all will make it.

[gentle music]

A large blue cod is eager for a crayfish meal,

or at least her eggs,

but the cod hesitates,

because it sees something the crayfish doesn't,

as she backs away from the cod.

[suspenseful music]

[octopus whooshes]

The octopus doesn't even leave a scrap of leg for the cod.

[gentle music]

[waves crashing]

A marine reserve has no fences.

So many of Goat Island's inhabitants venture

beyond its borders.

At just five square kilometers,

the reserve doesn't match the range

of big fish like snapper and boarfish,

which make their own decisions on where they'll forage,

but they seem to return here time and time again.

Monkey Face once disappeared for three years

before showing up back in the reserve.

As the young trevally traval grow up,

they join schools of fish of similar size and age,

and leave home to feed in deeper water.

In the reverse, jack mackerel are visitors to the reserve,

feeding above the kelp forest

before heading back out to sea.

[dramatic music]

When the schools leave the safety of the shallows,

they run a gauntlet of predators in the deep Hauracki Gulf.

As spring turns to summer, beyond the Goat Island Reserve,

predatory ocean wanderers move in.

Marlins swim thousands of kilometers

to feed around Northern New Zealand.

[water splashing]

This one rounds up a school of jack mackerel

in a technique similar to the bottlenose dolphin,

swimming around them to herd the fish

into a tight bait ball.

Then it charges, knifing the school with its pointed bill

to stun and injure the fish,

which it will eat at its leisure.

[gentle music]

This female crayfish has survived her dangerous journey

with half a million eggs tucked safely under her tail,

and her timing is just right.

On the edge of the reef,

she discovers dozens of her sisters,

all ready to spawn before the day shift predators wake up.

[gentle music]

Just before dawn,

female crayfish release their eggs in unison,

entrusting them to the ocean currents.

After five long months of maternal protection,

millions of crayfish hatchlings float off

toward the rising sun, to an uncertain fate far out at sea.

[birds chirping]

[gentle music]

It's midsummer now in the Goat Island Marine Reserve.

[birds chirping]

Up above, the warm weather is welcomed

by all the resident birds,

and numerous sharks that venture into the Hauraki Gulf,

often coming close to shore.

[suspenseful music]

The bronze whalers are now joined by thresher sharks.

Hammerhead sharks call in, with eyes so far apart,

they have almost 360-degree vision.

Short fin makos can move at deadly speeds.

[water splashing]

Mako sharks are warm-blooded with a body temperature

up to seven degrees warmer than the surrounding water.

[suspenseful music]

Muscles work more efficiently when warm,

which enables them to swim in bursts

of up to 100 kilometers per hour.

[water splashing]

Few cold-blooded fish can match it,

and these teeth

[shark growls]

are designed to make sure nothing

a mako catches ever escapes.

[dramatic music]

In the weeks following the crayfish spawning,

the invisible cloud of larvae drifts hundreds

of kilometers out to sea, at the mercy of wind and currents.

It's a mystery where it goes, but as it floats,

the billions of eggs evolve

through a number of larval stages.

[gentle music]

Magnified, it's possible to see the crayfish eggs hatch

into larvae before they're released by the female.

Just a few minutes after spawning,

each hatchling shape shifts into this next stage,

where the eye st*lks are visible.

Then foreshadowing the molting process,

which will occur throughout its life,

it wriggles free of its tiny exoskeleton,

and heads for the surface with its siblings.

The young crayfish continue to morph into weird forms

for the next two years,

the longest larval stage of any marine creature.

[water splashing]

Many fall prey to plankton-eating fish,

like this school of adult trevally,

picking them off at the surface.

[water splashing]

Finally, the survivors take on a form

that's recognizably a miniature crayfish,

and swim back toward the coast.

They're not alone in the plankton soup.

They meet up with the larvae of many fish,

including snapper and bigeye,

and even kilometers out at sea,

they have the ability to orient themselves

towards the shore,

[waves crashing]

but much of our wild coastline is no place

for tiny fish and cray to settle down.

To find a nice, safe reef

like those around Goat Island, they listen.

[kina chewing]

It's faint but distinct.

[gentle music]

[kina chewing]

A noisy population of kelp-munching kina

is a sign of a healthy reef,

exactly the kind of home the young animals are looking for.

No longer content to drift wherever the ocean takes them,

these tiny survivors actively swim towards the kina chorus.

[kina chewing]

As they draw closer to the reef,

the baby bigeye may be reassured

to also hear their own kind.

[kina munching]

After life in the barren ocean,

this marine reserve reef is an oasis of life and color,

a welcome home for thousands of little fish and crustaceans.

It's the perfect place to put down roots,

[cheerful music]

with numerous rocky crevices

where growing crayfish can hide,

lush kelp forests for food and protection from predators,

and no interference from humans.

Since this first marine reserve was established,


but still, only a tiny fraction

of our coast enjoys this protection.

These Goat Island residents don't know how lucky they are

to have settled in these five square kilometers

of our spectacular big blue backyard.

[dramatic music]

[water splashing]