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[Boat motor humms]
(Narrator) The warm tropical waters of Northern Australia
provide an ideal habitat for scuba divers,
spear fisherman and underwater photographers.
But these two men have a different mission.
They are, in fact, marine biologists,
who are working to better our understanding
of one particular animal,
the ornate rock lobster.
[Splash]
[Music playing]
In the course of the work of marine biologists from both Australia
and Papua New Guinea
a remarkable story is unfolding.
A story of lobsters that walk hundreds of kilometres and then disappear.
A story of sailing canoes that have remained unchanged for centuries.
Of modern trawlers involved in a multimillion dollar industry.
A fisherman caught between progress and their past.
[Birds chirping]
Our story begins on the islands and coral reefs of the Torres Strait.
These islands are all that now remain of the land bridge
that once existed between Australia and New Guinea,
but became submerged with rising sea levels many thousands of years ago.
[Music playing]
The Torres Strait lies just South of the Equator,
and stretches from the tip of Cape York
to the Southern shores of Papua New Guinea.
From the North, the Strait receives a massive input
of nutrients from Papua New Guinea's Fly River,
the seventh largest river in the world.
[Music playing]
These shallow tropical waters, rich in organic material, are
ideal conditions for an incredible diversity of marine life.
And it's here that Australia's Great Barrier Reef
reaches its Northern most limit,
fanning out across hundreds of square kilometres.
This creates a vast network of coral outcrops and reefs,
and an ideal habitat for the tropical rock lobster.
There are five species of rock lobster found in tropical Australian waters,
but by far the most abundant
is the ornate lobster, Panulirus ornatus.
[Divers talking]
Since 1980 researchers from Australia's CSIRO
and Papua New Guinea's Department of Primary Industry
have been carrying out an extensive programme of research.
They've been catching lobsters throughout the Torres Strait
and tagging them in order to trace their movements.
(Male 2) Carapace length is eighty-seven point one.
(Male 1) Eighty-seven point one. L244.
They record their sex and size,
and number each lobster with harmless plastic tags.
They then release the animal alive.
(Male 1) What was the antennal tag on the last one?
(Male 2) L246, male.
(Male 1) Yeah. Carapace length?
(Male 2) Seventy-seven point three. Away we go!
More than 7,000 lobsters have been tagged,
and from the tags that have been returned by fishermen
a most remarkable picture of animal migration is emerging.
For example, a lobster that was tagged here
was caught here several months later.
One tagged here was later caught here.
And one tagged here was caught way over here.
For two or three years the young lobsters live amongst the reefs.
They spend the day in dens among the rocks and coral,
and move out at night to forage on shellfish and other small animals.
Although lobsters are abundant on the reefs of the Torres Strait
lobsters that are breeding are hardly ever found.
The three and four year old lobsters on the reefs are immature,
and the tagging studies have shown that before they breed
they undertake a journey that takes them hundreds of kilometres
across the Torres Strait into the Gulf of Papua.
The mass movements take place around August and September each year.
A number of large groups of lobsters
appear to leave the reefs at different times,
moving through the deeper waters of the great North East Channel
and around the Gulf of Papua to the area of Yule Island.
Each December breeding lobsters begin to appear
in this comparatively small region around Yule.
This, it appears, is the birthplace for future generations.
It may take the migrating lobsters
many months to reach their breeding grounds,
and by the time they do, their shells, which are normally quite clean,
are covered with dirt and barnacles, and are showing signs of wear.
(Male 1) Damage on the antenna.
These animals have been migrating for about six months.
Their skin is discoloured,
and they have tears and scratches around their mouth parts.
This one even has a broken antenna.
During their migration they do not moult,
and their shells become covered with fouling organisms.
This one has small barnacles all along its antennae.
The females carry an egg mass that may number over half a million.
When the lobsters mate, the male deposits a tar spot,
or spermataphore on the underside of the female.
(Male 3) This one's got tar spots, brown eggs.
Once she has laid the eggs
she fertilises them by scraping the tar spot with her feet.
Each brood is carried by the female for about
four weeks until the eggs are ready to hatch.
[Music playing]
The tiny larvae are released in to the ocean amongst the plankton,
where they drift and feed for up to nine months before settling.
[Music playing]
Once the eggs have been released at Yule Island
the journey of the larvae remains a mystery.
The researchers believe that prevailing winds and currents
must carry them back to the Torres Strait.
[Researchers talking]
As the larvae grow they pass through a series of stages
gradually becoming more mobile.
Exactly how long they remain in the plankton is uncertain,
but it is thought to be between six and nine months.
By this time they are at the so called puerulus stage
and have begun settling on the coral reefs.
The ornate lobster differs in many ways from the more familiar
rock lobsters found in the Southern waters of Australia.
It grows extremely rapidly,
reaching a commercial size at about two and a half years of age,
almost two years earlier than some of the Southern species.
It's also more colourful,
with striking patterns on its legs and carifice.
[Splash]
However, the most important difference is that
the ornate lobster does not enter traps or pots.
This makes the lobster fishing industry in the Torres Strait
unique in Australia,
for it is a dive fishery,
one of the few dive fisheries in the world in which
skin divers use spears or nets to catch the lobsters.
As the lobsters move between Australia and
Papua New Guinea during the course of their lifecycle,
the same lobsters are the target of many different fishermen.
Fishermen who come from different cultures and different histories.
And the story of the lobster fishery in the Torres Strait today
is a story of the merging of Western values with traditional ways.
[Man talking]
In the Torres Strait the sea has always been an integral part of life.
The treacherous tides and reef strewn waters of the Strait
kept early European settlers at bay,
and resulted in disaster for many vessels
that were tempted by the short cut to Europe.
(Arthur Kebisu) Well, this club here,
this was great, great grandfathers,
King Kebisu.
(Narrator) It was a little more than a hundred years ago that
Arthur Kebisu's great grandfather,
the legendary King Kebisu
wielded his stone club, or gabagaba,
over an empire that spanned much of the Torres Strait,
and was feared by sailors.
(Arthur Kebisu) He used to fight with this one.
He used this one very close,
and, you know, when they're coming along people, like he see
people coming and rush up, he come and get the bow and arrow.
He shoot with the bow and arrow, kill the people with the bow and arrow,
so all the people, rush, coming very close so he can't do nothing.
If people come, you know, close to him on the side of him, he grabbed the gabagaba
and then he used this one.
He's a big man.
Everyone coming lay down straight away; hit their head, fall down.
[Organ music playing]
(Narrator) But the Torres Strait Islanders
have long since laid down their weapons,
and with the coming of Western ways
their traditional fishing activities have also undergone many changes.
In the early 1900's the Torres Strait was the centre
of the lucrative Australian pearling industry.
Pearling luggers packed the harbour at Thursday Island,
and they relied on the Torres Strait Islanders,
as well as the Japanese, to act as divers and crews.
But pearl oysters are no longer abundant,
and it's left to a few remaining pearlers,
like Shigeru Yamashita,
to carry on the tradition.
It's no longer economic to dive for pearls,
so they must now be cultured on pearl rafts such as these.
But the decline of the pearl fishery has coincided
with an increase in demand for lobsters.
And for the fishermen of the Torres Strait,
the old wooden boats, with their hand driven air pumps
have been replaced by fast aluminium dinghies.
There are lobster fishermen on
all the inhabited islands of the Torres Strait.
Most of them, like Samson,
work in a small team using only a bare minimum of equipment.
They rely on an intimate knowledge of the sea,
it's creatures, and the changing seasons.
Knowledge handed down from generation to generation
by islanders like Uncle Elder.
(Uncle Elder) So they go in,
you can feel they're soft,
and when that... June, July, after that southeast blow
you'll find the shell wash up on the beach here.
They've been shedding their skin
and that's how you find they're soft enough.
And they stay there for two or three weeks
while their shell gets harder
before they move
(Narrator) Most Torres Strait divers work close to their home island.
They catch the young lobsters which have not yet left
the reefs on their migration to their breeding grounds.
[Water splashes]
Back on land, the tail is skilfully removed, cleaned and then snap frozen.
Other island fishermen operate from freezer boats,
which allow them to work the remote reefs more easily.
Some of the freezer boats, like this one,
are converted pearling luggers.
For several weeks at a time
it is a base for six or more dinghies, and their crew,
and it only returns to Thursday Island to unload the catch and re-fuel.
The dinghies leave the freezer boat with a crew of two.
[Boat motor humms]
The diver stands on the bow directing it to likely fishing spots.
[Splash]
The lobsters shelter under lumps of coral called bommies
and it is these bommies the diver is looking for
as the boat moves across the shallow reef top.
While the diver searches for lobsters
the dinghy circles, waiting to take the catch.
[Boat Motor humms]
Fishing in this way, moving from bommie to bommie across the reef,
the divers can cover a large area.
[Boat motor humms]
After fishing the divers return to the freezer boat
for their catch to be cleaned, weighed and frozen.
[Boat motor humms]
Depending on conditions,
experienced divers can spear over 150 lobsters in a single day.
Each team is paid according to the weight of their catch.
The Torres Strait divers catch about 200 tonnes of lobsters each year,
with a total value of about $3 million.
The bulk of the catch is processed and packed at Thursday Island.
Most of these tails are destined for the tables of
restaurants in mainland Australia and the United States.
For the people of the Torres Strait
the lobster industry has had obvious economic benefits,
as the Chairman of Yam Island, Getano Lui Junior, explains.
(Getano Lui) Well the lobster fishery to the Torres Strait Islanders
has made a substantial
contribution to the economy of not only Yam Islanders
but for most of the islands in the Torres Strait.
Certainly a turnaround in creating job opportunities for islanders
and to participate in their own private enterprise.
(Narrator) By the time they are four years old
those lobsters that have managed to avoid being caught
are ready for their migration.
Around August they move out in to the great North East Channel
and around to their breeding grounds in the Gulf of Papua.
After leaving the shallow reefs
they're safe from the divers of Torres Strait,
but the deeper waters of the channel hold a
threat of a quite different kind.
During their long journey to Yule Island
they must thread their way past a gauntlet of fishing boats
which are capable of catching more lobsters in a single night
than the best divers can catch in a month.
These are the large modern prawn trawlers which work the
Torres Strait all the way from Thursday Island to Yule Island.
Boats which can be worth well over half a million dollars,
and are equipped with radar and satellite navigation.
They scoop up everything from the sea bottom,
prawns, fish and lobsters.
Small numbers of lobsters are caught by prawn trawlers throughout the year.
But it is during the migration season,
when the lobsters are moving in large groups,
that they are especially vulnerable to the nets of the trawlers.
Because of this, both Australia and Papua New Guinea have,
since 1984, imposed a ban on trawling for lobsters during their migration.
[Birds chirping]
Birds, dolphins and sharks often follow the trawlers,
scavenging on the unsaleable items that are thrown overboard.
[Music playing]
The lobsters that survive their 500 kilometre walk
to their breeding grounds
arrive at Yule Island to be met by the local fishermen.
The lobster fishery at Yule Island
is a traditional fishery which has been operating in the same way
for hundreds of years.
[Splash]
Each lobster is caught by hand,
and the day's catch is carried alive to the markets.
A good fishermen at Yule Island might catch 12 lobsters in a day.
Here, the village people make use of the whole lobster.
While the tails are sold to provide much needed income,
the main part of the body is stuffed with leaves
and cooked to provide food for the whole family.
During the height of the lobster season
the people of the villages fish the reefs by night,
as well as by day.
But the season only lasts a few months.
By the end of April the reefs are empty.
Why the lobsters disappear and where they go to is a mystery.
It has been suggested that the combined stress of emigrating and breeding
is enough to result in the death of most of the lobsters.
The lobsters at Yule Island
certainly appear to be in poorer condition than lobsters elsewhere.
But whether there are mass mortalities,
or whether the lobsters simply move away in to deeper water
has yet to be established.
And so the research continues.
Understanding the biology and behaviour of the lobster is vital
so that a sound foundation of knowledge is established,
on which better management of the industry can be based.
It's an industry that spans two nations
and involves fishermen who have different cultures and beliefs.
(Male 1) You been catching much, Joe? (Male 4) No, not much today.
(Male 1) Where you been finding them mostly?
(Male 4) Just around the edge here.
(Male 1) Yeah, yeah. What size?
(Male 4) Just only, you know...
(Male 1) Not real big, hey? (Male 4) No.
(Male 1) You know, you got a couple of tags the other day didn't you?
(Male 4) Oh yeah, I've got a few tags at home.
(Male 1) Can we come around and pick them up? (Male 4) Oh yeah, yeah.
In the various stages of their complex migration,
right up to their mysterious disappearance,
the lobsters run the risk of being caught.
Over fishing at any stage of their lifecycle
could result in the collapse of the whole industry.
[Music playing]