ON THE ROCKS"
The Green Invader
The Paper Boat
The Sea within the Sea
ALAN ALDA: Why does a Mediterranean fishing net come up filled
with Caribbean weed? On this edition of Scientific American
Frontiers, ancient and modern mysteries of the Mediterranean.
ALAN ALDA: (Narration) We're on the trail of an underwater green
ALEX MEINESZ: It's a kind of toxic.
ALAN ALDA: (Narration) We're working out how to build a Stone Age
BOAT CREW: Hey-oh-hup.
ALAN ALDA: (Narration) We're trying to produce copper in a three
thousand-year-old smelter… And we're tracking down new ideas
about the Sea's unique wildlife.
ALAN ALDA: I'm Alan Alda. Join me now for Mediterranean on the
ALAN ALDA: (Narration) Hold on. We're heading into the Mediterranean,
through the Strait of Gibraltar. Here comes the water. The
Mediterranean last filled up only 5 million years ago… until
it looked like this. Let's explore.
ALAN ALDA: We're beginning our Mediterranean journey in Nice on
the French Riviera. It's perhaps the most famous of the resort
areas in a part of the world that is apparently nothing but
resorts, stretching from the Spanish beaches in the west for
2,000 miles across to the Greek Islands in the east. This
is going to be a program not just about vacation land but
about the reality of the Mediterranean today -- and it's a
mixed picture at best. Today hundreds of millions of people
living around the Mediterranean use the sea for just about
everything -- as a vital source of food, as a major highway
and of course as a huge waste dump. And everywhere there are
signs of stress, as we'll see in stories about turtles, tuna
and whales. That's right, whales! The Mediterranean has lots
of whales. Of course it's not just the heritage of the wild
life in this sea that we have to worry about, it's our own
human heritage too. Ten thousand years ago, people first settled
down as farmers on the shores of the Mediterranean. And at
about that same time, people first ventured offshore on the
waters of the Mediterranean. Later in this program we'll be
meeting archaeologists working hard to secure that human heritage.
But first, an underwater horror story -- the invasion of the
green seaweed. Stay tuned.
ALAN ALDA: How long have you been studying this caulerpa?
ALEX MEINESZ: More than 10 years.
ALAN ALDA: 10 years.
ALEX MEINESZ: Yes, 10 years
ALAN ALDA: (Narration) We're in a small town just along the coast
from Nice. Alex Meinesz, a biology professor from Nice University,
is taking me out fishing.
ALAN ALDA: Do you think in those ten years, how much has it increased?
ALAN ALDA: (Narration) As with thousands of places like it around
the Mediterranean Sea, this town depends on a mix of fishing
and tourism for its livelihood.
ALAN ALDA: Is this the fishing boat we're going on?
Yes. On peut monter?
ALAN ALDA: Okay, thanks. Bonjour!
FISHERMAN: Bonjour! Patrick.
ALAN ALDA: Patrick, Alan.
ALEX MEINESZ: Alex. Bonjour!
ALAN ALDA: (Narration) We're on the Vergé family boat. The waters
around here have been fished for generations. Until now, that
is. They don't fish here any more. We had to persuade them
to set their net out last night, just so we could film the
result. And the result is this.
ALEX MEINESZ: Caulerpa
ALAN ALDA: Yeah.
ALEX MEINESZ: Caulerpa
ALEX MEINESZ: Look. Oui,
oui. On arrêt un peu, uh? Look. And this caulerpa clogs the
nets and the fish see the nets and there is no fishes.
ALAN ALDA: Oh, I see. So it hurts fishing just because…
They see the nets.
ALAN ALDA: …it calls attention to the nets.
ALEX MEINESZ: Yes.
ALAN ALDA: (Narration) The weed, called caulerpa taxifolia, doesn't
belong here. It's a tropical plant, common in the Caribbean
and other warm waters. The northern Mediterranean gets cold
in winter, but somehow the caulerpa is surviving, and thriving
- nothing can touch it.
ALEX MEINESZ: When you broke it, there
comes a kind of juice out of it, you see?
ALAN ALDA: Does that juice have anything in it that keeps away
ALEX MEINESZ: Yes, absolutely. That are terpanes,
caulerpanines. And this is a kind of toxic matter and a repellent
matter. So the fish don't eat it.
ALAN ALDA: So it repels fish. So in this area nothing is a natural
ALEX MEINESZ: No! You see all the leaves are entire.
ALAN ALDA: Nothing has been eating it!
ALEX MEINESZ: No, no biting
ALAN ALDA: Yeah.
ALEX MEINESZ: On y va?
ALAN ALDA: On y va. Holy moly! He really jumps in!
ALAN ALDA: (Narration) Alex took us into the shallow water near
the town's bathing beach. Everything below was covered by
the caulerpa - rocks, sand, mud. There's nothing else down
here, no other plants, barely a fish. It's a classic example
of an alien plant that just takes over - like kudzu. Nothing
eats it, and nothing competes with it.
ALEX MEINESZ: It's
ALAN ALDA: Yeah, there's a lot of it down there.
All the bottom is covered, eh?
ALAN ALDA: There's a lot there!
ALEX MEINESZ: All the bottom is
ALAN ALDA: (Narration) The caulerpa arrived here about nine years
ago. Advancing at an inch a day, it has ruined the fishing
and it'll soon clog the town beach. It's the same disastrous
story, spread out along 1,000 miles of Mediterranean coast.
Caulerpa is easily spread. It's carried along in fishing nets,
and there are millions of small boats in the Mediterranean
- all with anchors.
ALEX MEINESZ: A little piece like this,
I put this in the water, after 6 months you have 3 square
meters, with this little piece.
ALAN ALDA: Any part of this?
ALEX MEINESZ: Any part. Any part.
ALAN ALDA: (Narration) With its rapid spread from fragments, and
its cold water survival, caulerpa in the Mediterranean is
behaving in ways that shocked marine plant experts like Alex.
After years of investigation, Alex is pretty certain he knows
how this disaster happened. This is the aquarium at the famous
Monaco Oceanographic Museum, where Jacques Cousteau was once
director. In the early 1980s the Museum, along with several
other European aquaria, started using a decorative, and easy
to grow, plant in their tropical tanks. The plant was caulerpa
taxifolia. It's still used here today, as it is around the
world. Alex believes that somehow some fragments of caulerpa
were released from the tanks into the sea. A museum diver
first saw caulerpa right outside the building, on the bottom,
in 1984. It covered just one square yard. By 1989, when Alex
first saw it, it covered 2 acres. By 1990 it was at nearby
Cap Martin, next year Toulon, 100 miles away, and now it's
found from Spain to Croatia. With no natural enemies to hold
it back, the caulerpa has been steadily smothering normal
Mediterranean sea life. In the shallow areas, a complex community
of over a thousand different algae, shellfish, worms and fishes
has evolved around meadows of native sea grass. In the darker
depths there's a different balance, with the grass giving
way to red sea fans. This is the steep, 100 foot rock wall
off Cap Martin, once a favorite spot for scuba divers. The
film is from 1996, shot as the caulerpa was taking hold. Alex
has been diving here every year since the caulerpa arrived.
As the alien plant advances, it blocks light out -- from the
red sea fans, for example, which die off. Alex has seen the
same process repeated all over the rock wall. Did this all
originate with the Monaco aquarium? Genetic analysis has shown
the caulerpa is a mutant strain, unique to European aquariums
including Monaco, and not found in the wild. But we'll never
know for sure how it first got loose. In the summer of 1999,
our underwater cameraman swam down the rock wall at Cap Martin
to record the progress of the caulerpa. The wall is now completely
covered. The last sea fans are dying. The wall is essentially
a biological desert. Once again we're looking at caulerpa
growing in an aquarium. But there's something else - it's
a kind of slug, and it's eating the weed. The result - all
over the tank, ghostly white fronds of weed, with their toxic
juice sucked right out by the slugs. The slugs are being studied
in his lab at the University of Nice by
ALEX MEINESZ:. In his view, they represent the single best
hope for controlling caulerpa taxofolia in the Mediterranean.
We've jumped 2,000 miles across the Atlantic to the Indian
River in Florida. Alex's slugs came from here, collected by
Cecelia Miles, a marine biologist from Florida State University.
Here caulerpa is eaten -- and controlled -- by the highly
specialized slugs, as it is further south all over the Caribbean.
The hope is that slugs from Florida -- the northern extreme
of their range - might be hardy enough to survive the Mediterranean
winter. In the summer of '99, Cecilia collected and packed
a batch of Florida slugs for shipment to Alex in Nice. The
slugs had their own air supply for the flight, and were escorted
across the Atlantic by a French grad student.
GRADUATE STUDENT: And I see you when I get back. See you
Cecilia. Bye bye.
ALAN ALDA: Here you were a student of caulerpa and all of a sudden
it shows up on your doorstep…
ALAN ALDA: (Narration) Alex has been studying different slugs for
years. The Florida batch had been in residence at Nice University
for about 2 weeks when I visited. His work with slugs and
caulerpa is done on a shoestring budget, in a makeshift lab
behind the biology building. The Monaco Aquarium connection
makes this a very political subject, so research grants have
been hard to come by.
ALAN ALDA: …so you've got a chance to see who's working out.
ALEX MEINESZ: Yes. Come in, please. Come in.
ALAN ALDA: So they're in there, I don't see any slugs.
ALAN ALDA: Oh yeah. yeah, yeah! Now is he eating now?
Yes, I think so, yes.
ALAN ALDA: So these slugs really like that toxic stuff.
Yes. They need the toxic, because they take the toxins and
they stock it in them and then the fishes doesn't eat it.
ALAN ALDA: Oh, I see. So the slugs use the toxins to keep the fish
away from them!
ALEX MEINESZ: Exactly. Exactly. Exactly.
ALAN ALDA: (Narration) The slugs have other highly specific adaptations
to caulerpa - they need caulerpa cells as part of their own
metabolism, and they have a special tooth which matches only
caulerpa cell structure. Alex argues that the slugs are so
exquisitely adapted to their one food that releasing them
into the Mediterranean to control the invasion biologically
would present a very low risk. I asked him about it.
ALAN ALDA: How do we know the slugs that you bring in won't adapt
and find some other way to live in addition to caulerpa?
ALEX MEINESZ: When the slug have no more caulerpa, they can not,
in one generation say, Ah, we shall change our tooth, our
mouth, our toxin, to eat other things. You understand? You
ALAN ALDA: That takes a lot of plastic surgery!
ALEX MEINESZ: You
ALAN ALDA: Sure, sure!
ALEX MEINESZ: When there is caulerpa, they
eats caulerpa. No problem, no problem. When they see there
is no more caulerpa, it is too late. It's too late.
ALAN ALDA: (Narration) Alex's slugs may be the only way to go.
All kinds of non-biological control methods have been tried
- like releasing poisonous copper from underwater electrodes…
Or simply scraping the weed off… Vacuuming it up… Freezing
it with dry ice… Scalding it with hot water… Or cutting off
its sunlight. But there's nothing that's practical on a large
scale, except the slugs. I asked Alex again, Is it really
smart to release the slugs into such a paradise of food?
ALAN ALDA: All of a sudden, they're dining out every night. They're
going to Maxim's every night. And they're doing pretty well.
Now, you're liable to have some pretty fat, happy, healthy
slugs around looking for trouble.
ALEX MEINESZ: No, no. You
have a prairie of caulerpa with many slugs in it and then
they control the caulerpa and it is finished, that we think.
But what you want? Do you want to have a Mediterranean Sea
full with caulerpa without any control method? We must have
a predator for this invader. Without predator, the caulerpa
-- that is a risk that we see now. We can see, you have see
it when we snorkeled. You see with the fisherman. It covered
all the bottom and it expands every year. So what do we do?
Do we do nothing? Or do we try this?
ALAN ALDA: If you can't get rid of it, if the slugs don't work, if
the slugs are too dangerous, if the slugs work but governments
won't let you use the slugs, what will the caulerpa do? What
will happen to the Mediterranean?
ALEX MEINESZ: What happens is exactly the same that happened
since ten years. It extends. It extends every year, in new
country, new regions. And we think that this algae is able
to colonize most of the region of all the Mediterranean Sea.
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ALAN ALDA: (Narration) The Mediterranean is a vacation paradise.
Waterfront real estate is at a premium. Almost every strip
of sand is occupied. For those reasons, the Sea's turtles
are having a tough time. All over the world turtles are being
crowded off nesting beaches, hit by boats and caught in nets,
but the process has gone furthest in the busy Mediterranean.
Now there's a network of biologists dedicated to saving the
animals that remain. Europe's oldest aquarium, here in Naples,
is at the forefront.
ALAN ALDA: So this is the turtle hospital?
DR. BENTIVEGNA: Yes.
ALAN ALDA: Now what did this turtle have wrong with him?
This turtle had problems eyes.
ALAN ALDA: Eyes! What was wrong with his eyes? Something contagious.
DR. BENTIVEGNA: Conjunctivitis.
ALAN ALDA: She has conjunctivitis?
DR. BENTIVEGNA: Yes, but very
ALAN ALDA: What's this problem?
DR. BENTIVEGNA: The problem is
ALAN ALDA: He got a hook in his throat? And it stayed in his throat.
DR. BENTIVEGNA: Yes.
ALAN ALDA: (Narration) The hook was successfully removed two years
earlier, at the Naples vet school. It may seem like an extraordinary
effort to devote to a single animal, but every individual
counts now. There are only 2400 nesting female turtles left
in the entire Mediterranean, down from hundreds of thousands
in the past.
DR. BENTIVEGNA: Now she's very, very good and
I release now this Logger, next September.
ALAN ALDA: What about this one over here?
DR. BENTIVEGNA: The shell
was broken by boat propeller.
ALAN ALDA: (Narration) This is an amazingly common accident in
the busy Mediterranean. Nearly 2 years ago,
repaired the loggerhead's shell with the same surgical cement
used for people. Now it's time for a checkup across town at
the vet school.
DR. BENTIVEGNA: [Italian]
ALAN ALDA: (Narration) By the way, our restless young patient is
ALAN ALDA: You name them. You take care of them. You feed them.
DR. BENTIVEGNA: Yes.
ALAN ALDA: Do you get emotionally attached to them?
Yes, yes. I love. I love these animals.
ALAN ALDA: You love them, yeah. Do you usually X-ray turtles?
A few times. Not usually.
ALAN ALDA: (Narration) The trick to X-raying turtles is to grab
DR. BENTIVEGNA: [Italian]
RADIOLOGIST: So here
we see an area of lower density fracture in the bone. The
interesting part is here, we see higher density and that means
that new bone is being formed and the fracture is being repaired.
DR. BENTIVEGNA: To see this that our turtle is good, in good
condition, it's very important. I am happy.
ALAN ALDA: (Narration) It's Fall, and the team from the Naples
Aquarium is taking 14 of their best patients for a boat ride.
They're heading 100 miles south to the relatively isolated
volcanic island of Stromboli. The Aquarium is now releasing
about 25 rescued turtles a year. It's a small number, but
significant. A young female may go on to breed for 50 years
or more, laying her eggs on one of the nesting beaches now
protected in 7 Mediterranean countries. With luck, hard work,
and dedication, turtles can still have a future in the Mediterranean.
back to top
Athens 2500 hundred years ago, the classical Greeks were inventing
Western art, architecture, democracy and so on. But we're
heading out of town, into the Greek countryside, to a much
earlier time. We're looking for a cave by the sea, once occupied
not by classical Greeks, but by people from the Stone Age.
It's likely that these people invented one of the most basic
human tools - boats. This is the cave, called Franchthi. We're
here with a Boston University archeologist, Curtis Runnels,
and Harry Tzalas, an expert on Greek maritime history.
CURTIS RUNNELS: So here's the first trench, Harry, that was excavated.
So then you see this deep trench and what we did here was
dig straight down through a whole series of Neolithic layers.
See those dark layers of charcoal and the lighter gray or
even whitish layers that are ash? There have been fires in
that region continuously during the Neolithic period.
ALAN ALDA: (Narration) The Neolithic goes back about 7,000 years,
and then deep layers of debris in the third trench showed
occasional human occupation back another 20,000 years.
CURTIS RUNNELS: All that charcoal, the ash, the potsherds, the stone
tools just slowly created a pile of earth here until this
is, as you see, a mound, sloping away from us.
It's a time capsule.
ALAN ALDA: (Narration) Around 5,000 years ago a section of roof
collapsed, the cave became an uncomfortable wind tunnel, and
the people left. But they left behind a trail of clues that
Curtis and Harry believe leads back to the world's first boats.
The trail starts with stone tools uncovered in the cave. Curtis
excavated thousands of tools and stone fragments from toolmaking.
There are probably millions still buried. The tools are made
of obsidian, a volcanic glass.
CURTIS RUNNELS: There we go.
Perfect. Now when we turn that up you'll notice how the edge
is continued around here and you can actually begin to see
some shape here.
ALAN ALDA: (Narration) You can imagine toolmaking skills being
taught just like this, in Franchthi cave.
Excellent. You just made a perfectly good hand axe, that would
be, let's put it this way, you could have used this to introduce
yourself to early hominid society. You can just do this…
ALAN ALDA: I could just hold that up…
CURTIS RUNNELS: Hold that
up and say, oh yeah you know what you're doing.
ALAN ALDA: It's like my Visa card.
CURTIS RUNNELS: That's right,
sure. It's your introduction to prehistoric society.
ALAN ALDA: Do you accept these?
CURTIS RUNNELS: I bet they would
because if they didn't, right…
ALAN ALDA: (Narration) About 13,000 year ago, not just occasional
but continuous human occupation started at Franchthi. A little
later, the toolmaking improved. It was my turn to try making
one of these more sophisticated tools.
CURTIS RUNNELS: Yes,
excellent. Yes. There you go. I think you can stop there for
a moment because look how nicely that's coming out.
ALAN ALDA: (Narration) Here's my rather crude effort… and here's
the beautiful blade Curtis made in the cave. 30 years of toolmaking
have given him an insight into the thinking of our stone age
CURTIS RUNNELS: The edge had to be in their mind.
ALAN ALDA: There's a kind of strategic thinking going on.
CURTIS RUNNELS: Strategic thinking. Forward thinking -- that they
knew what the final product was going to be and they had to
go through these stages to do it. That shows human intelligence
in its clearest form.
ALAN ALDA: It's like what Michelangelo said how…
Just take everything away except what looks like David.
ALAN ALDA: And they were beginning to do that.
Yes, yes. And they were doing that probably a million years
ago. They were able to sculpt these rocks. They were not just
breaking them in some random way. And this to me is the drive
behind all of our technological productions even today.
ALAN ALDA: In what way?
CURTIS RUNNELS: It's first in the mind.
It's first in the mind and then we project it on the raw material.
ALAN ALDA: (Narration) Now here's where the trail heads out to
sea. All the tools found in Franchthi cave were made of obsidian
from one place. That place is Milos, an island in the Cyclades
chain, 100 miles from Franchthi. It's an open water journey,
even if you do hop around the islands. So what kind of Stone
Age boats were used? Probably something like this. It's a
reed boat on Lake Titicaca in the Andes. Or like this, on
Lake Chad in central Africa. Or like this, on the Italian
island of Sardinia. They're disappearing now - this film was
shot in the 50s - but reed boats, once used all over the world,
have a very long history. At least 6,000 years ago the Egyptians
used papyrus reed boats on the Nile. They were perfect for
gathering papyrus from the marshes, for hunting and for fishing.
But these were small river boats, not suited to open sea.
They may have looked something like this. It's a reproduction
papyrus boat at Phaoronic Village, a living history exhibit
in the middle of Cairo. Laid out along canals cruised by tourist
boats are colorful scenes from daily life in ancient Egypt.
The heart of the place is papyrus, the all purpose Egyptian
raw material used for rope, sandals, mats and of course, paper.
Hassan Ragab, who started Phaoronic Village, was dismayed
that papyrus reeds were extinct in Egypt. So he re-introduced
them, using plants from Sudan, 1,000 miles to the south. Here's
our souvenir sheet of paper. Recently there was some extra
activity in the thick stands of papyrus now established nearby.
We've asked Phaoronic Village to build us a reed boat, but
unlike any they've ever built before. Our boat begins the
way reed boats have always begun, with the first tight bundle.
Just like the stone toolmaker, the ancient reed boatbuilder
must have had in mind a final shape for his creation. Here's
a vital step - swept up bundles for the ends, so the boat
rides the waves. They're working to a design first created
11 years ago by Harry Tzalas, the Greek maritime expert, and
based on the traditional Greek reed boat, the papyrella. He
had to use the thin papyrus reeds - actually the last in Europe
- available from the Greek island of Corfu. Harry, an experienced
sailor, concluded the boat was too small to handle long open
water journeys. For our Frontiers boat we're using the large
reeds available in Egypt. The vessel's to be 20 feet long,
containing half a ton of dried papyrus. It should be able
to accommodate a crew of 8. As our boat took shape, Harry
came down from Greece, making the last leg of his journey
in a Phaoronic Village tour boat.
HARRY TZALAS: Hello.
ALAN ALDA: (Narration) When shown the boat by Abdelsalam, son of
the Phaoronic Village founder, Harry was enthusiastic about
the size of the reeds, and the virtues of papyrus - known
no doubt to Stone Age people, as well.
HARRY TZALAS: You cannot
sink a papyrus boat. It is impossible to sink it. You can
destroy it but it will not sink. Inside you have millions
of tiny miniscule air chambers and that's what gives the buoyancy.
ALAN ALDA: (Narration) We sailed our maiden voyage on the Nile,
with an inexperienced and good natured crew of tour guides
from the exhibits, using makeshift paddles.
ALAN ALDA: (Narration) Harry couldn't resist trying to impose proper
HARRY TZALAS: They never learn how to paddle
and the paddles are so bad that it's a miracle that they are
moving it. But the craft is very, very good. It has a very
good buoyancy and it will go very fast, faster than the papyrella.
ALAN ALDA: (Narration): So far so good. Our boat is stable, heavy,
controllable, and maybe fast. Ours is not the first attempt
to build a seagoing reed boat. In the 60s the Norwegian explorer,
Thor Heyerdahl, built a huge boat intended to cross oceans.
The papyrus boat moves in the shadows of the pyramids, first
pulled by chanting Egyptians then carried on a truck the to
Egyptian port of Alexandria and at last born by ship to the
ancient Phoenecian port of Saffi, on the Atlantic coast of
ALAN ALDA: (Narration) Heyerdahl's romantic ambition was to prove
that ancient Egyptians could have sailed to the Americas.
But it soon became clear that, while papyrus may be unsinkable,
it's not really practical for long voyages. The reeds gradually
became waterlogged. After 2 months at sea the boat was virtually
underwater, and had to be abandoned. For its first sea trials,
we've moved our boat to Alexandria, Egypt's ancient Mediterranean
port. Harry believes this is the only kind of boat that could
have been made with stone tools, that's big and stable enough
to ride waves.
HARRY TZALAS: [Arabic]
ALAN ALDA: (Narration) The boat holds 8. The only problem is half
are Greek, half are Egyptian, and they're all archeologists,
anyway, so they can't agree on anything - until Harry's naval
instincts take over. BOAT CREW: Hey-la-hup. Hey-la-hup. Hey-la-hup.
ALAN ALDA: (Narration) Was he happy so far?
HARRY TZALAS: Well
it's good. It comes naturally you see they have not tried
before and it goes so quickly. It's good.
ALAN ALDA: (Narration) Harry follows the reed boat to observe its
behavior further out in the harbor.
HARRY TZALAS: They're doing well and although there is a
strong wind, the boat has no problem at all. It can take any
BOAT CREW: Hey-la-hup. Hey-la-hup.
ALAN ALDA: (Narration) After only an hour of work, our crew is
moving at a respectable 2 miles an hour - enough to hop between
Greek islands in a day, and then pull the boat up to dry out
overnight. It's a safe and stable boat, easily capable of
transporting obsidian from Milos, and even going further afield.
It's better than the original papyrella Harry built.
HARRY TZALAS: With the papyrella you could go up to Milos and you
can circumnavigate in the Cyclades. With that boat which we
are using now in Alexandria, which is a little larger, a stronger
craft, more perfections, I would not hesitate in saying that
you can reach going coastal-coastal, you can reach Cyprus
without a problem.
ALAN ALDA: (Narration) Harry believes it was islands beckoning
on the horizon, and calm seas between, that made Greek strength
in shipping inevitable. Today the ships are 1,000-foot steel
giants, but in the Stone Age they were 20-foot papyrus reed
HARRY TZALAS: Greece is a shipping nation because it
has always been a shipping nation.
ALAN ALDA: (Narration) By 13,000 years ago, the valuable Milos obsidian
had been discovered and brought back to the mainland - some
of it to Franchthi cave.
HARRY TZALAS: There is a chain of seamanship that goes back
to Franchthi. If you live around the Aegean with all these
islands, that you can see these islands, then you become curious,
then you become seamen, then you get a civilization and you
export this civilization. Civilizations were not exported
by road with horses and carts. All civilizations were put
around the Mediterranean with ships.
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The interior of the island of Cyprus. It would have been
a vista of forests, a few thousand years ago. But the forests
went up in smoke, burned in smelters to produce copper. The
mines and smelters of Cyprus became the eastern Mediterranean's
major source of copper soon after the beginning of the Bronze
Age, 4,000 years ago. Bronze is 90% copper, so in some ways
Cyprus was the foundation of the Bronze Age. Metal tools made
sophisticated woodworking possible, so sturdy, seaworthy traders
like this were a common sight. She was built by Harry Tzalas
in the 70s, based on a wreck from 300 BC discovered here at
the port of Kyrenia on the Cyprus coast. A local sponge diver's
chance discovery and the subsequent excavation had yielded
enough information to make an exact replica. Harry found she
sailed beautifully. So, no secret about how Cyprus copper
had reached the farthest corners of the Mediterranean. But
back on shore things aren't quite so easy.
ALAN ALDA: What went wrong here?
WALTER FASNACHT: Something went
wrong that the tube was plugged and now I have to exchange
it because I broke it.
ALAN ALDA: One of these pipes down there?
WALTER FASNACHT: So we
have these two pipes. They put the air into the furnace via
ALAN ALDA: (Narration) Swiss archeologist,
WALTER FASNACHT:, and
his students have an emergency on their hands. They're trying
to smelt copper in a replica ancient furnace, and they've
just broken a tuyere - the clay nozzles that squirt air into
the furnace. Here's one part of the broken tuyere. The other
has to be fished out. The end melted after it was blocked
by slag and overheated - Walter should have been keeping it
ALAN ALDA: The fact that the other nozzle melted means that you're
already above 1200 degrees?
WALTER FASNACHT: Yes. Right.
ALAN ALDA: So what does that tell you? When you're above 1200 degrees,
WALTER FASNACHT: Well, it is forming slag. So
the process should be going on and it looks good for the process.
We just had this little accident.
ALAN ALDA: (Narration) Once the new tuyere's installed, it's time
to check the other one - without breaking the end off this
WALTER FASNACHT: I have to punch it and - watch out
- very carefully. So. And this is the slag that forms.
ALAN ALDA: Tell me Walter, you think they had emergencies just
like this all the time in antiquity?
WALTER FASNACHT: This
accident probably wouldn't have happened to them because they
wouldn't have been talking to TV crews for an hour.
ALAN ALDA: Well, you haven't found any remains of TV crews. You
really don't know.
ALAN ALDA: (Narration) In 1989, Walter, an expert on ancient metals,
uncovered the only complete copper-working site ever found
in Cyprus. There were two broken smelters, made of clay. There
were sections of furnace wall, burned on the inside. This
is a solidified puddle of slag, the waste product from smelting.
He found charcoal fuel. And sections of round clay pipe, like
the one Walter broke. There was also a large, clay-lined pit,
and nearby, a source of copper ore. Walter decided the only
way to fully understand the discoveries was to try reproducing
how they worked, on the hill beside the ancient site. First
the ore is crushed. It's chalcopyrite, a mixture of copper,
iron and sulfur - the most common copper ore. Next, fire up
the open clay pit. It's a half-scale model of the clay pit
excavated on the site. Analysis of the ancient residues showed
that the pit was used for low-temperature roasting, which
drives off some of the sulfur in the ore. Walter has to bring
in charcoal, that would normally end up in vacation barbecues.
The finely crushed ore, held together with a little clay,
is roasted for several hours. This step will remove the sulfur
attached to the iron. The red color shows that has been accomplished.
But there's still sulfur attached to the copper. Burning that
off is the next step. We're going to need high temperatures,
and that means a forced draft, from leather bellows. Bellows
were common throughout the ancient world. Walter found pieces
of the clay bases and tubes, so he's pretty certain this is
how they were made here. The goal is to both burn the sulfur
off the copper, and at the same time melt sand with the iron
to make slag. That'll take temperatures inside the furnace
of over 1200 degrees Celsius, sustained for at least 6 hours.
There's a lot of pumping to be done.
ALAN ALDA: Can I try it if I'm really careful?
Yeah. Sure, sure. Oh, that's very good.
ALAN ALDA: You've got to open and close in rhythm.
ALAN ALDA: (Narration) In goes the first charge of roasted ore,
now crushed with a little sand. We'll be steadily adding charcoal
and ore throughout the day. It's a pretty elaborate recipe,
so I had a question for Walter.
ALAN ALDA: How did all these things come together? How did early
people arrive at this complicated process? How did they know
they were going to get copper out of this process?
WALTER FASNACHT: To begin with, they had blue or green copper mineral,
10,000 years ago. They found this nice colored stone and they
fiddled around with it-made nice jewelry and then it fell
into the fire and melted and gave them copper.
ALAN ALDA: (Narration) Well that's OK for the simple copper ores
that smelt easily. But for the stuff we're using, people must
just have found it so attractive that they believed it was
worth experimenting a lot until they got results. It's now
the end of the day. Time to see how we did.
I will have to take this whole lump out as an entire unit.
I hopefully succeed. I'll just try it with this shovel. Watch
ALAN ALDA: If this is the way you want it, what do you do with
WALTER FASNACHT: If it's the way I want it, we have
to separate the slag from the matte.
ALAN ALDA: (Narration) Here's the lump cut in half. At the bottom
is the matte - about 60% copper, double what we started with.
Next, the slag at the top would be removed and the matte re-smelted,
a step Walter has not yet tried. In fact this was only the
third smelting trial he's done here. So skipping ahead, Walter
set out to actually make something out of bronze, which is
copper with a little tin added as a hardener. In antiquity
the tin would have come from the mainland. We cheated - our
bronze was factory made, but the melting technique is authentic.
The aim is a rapid, high-temperature melt, then an immediate
pour before the tin burns off. Charcoal keeps the heat in,
but it mustn't contaminate the metal.
WALTER FASNACHT: It's
a crucial moment now. If I miss it, we burn the metal and
then you're in trouble. Yep, it's liquid.
ALAN ALDA: (Narration) There's still a lot of charcoal in the crucible.
We're making astragali, dice shaped like the heel bone of
sheep or goats.
WALTER FASNACHT: So. This one is quite okay.
And this one has a lot of charcoal in it. This one they would
consider as a failure. They would re-melt this.
ALAN ALDA: I thought these would have numbers on them or are there
numbers? I can't tell.
WALTER FASNACHT: You have to know the
numbers in your head.
ALAN ALDA: Oh, I like dice like that. You throw a couple of blank
dice, you say, I remember where the numbers were and I got
WALTER FASNACHT: Whenever you see these two horns, that's
the number 4.
ALAN ALDA: I see.
WALTER FASNACHT: And this round part is the number
ALAN ALDA: I see.
ALAN ALDA: (Narration) You need 5 astragali for an ancient Greek
fortune, so we threw real sheep bones.
ALAN ALDA: I can't tell what these numbers are.
Four, four, three, four, three. Twelve and six-eighteen.
ALAN ALDA: So now the high priest would look it up on his Xeroxed
WALTER FASNACHT: It was hammered into stone.
They would write the text into stone.
ALAN ALDA: So, that's how we come to know what the meaning is.
WALTER FASNACHT: Yes, yes. When 3 fours as well as 2 threes
fall-wait! You will have success but only later. For now stay
quiet. Obey the gods and be awaiting.
ALAN ALDA: I think I need to throw again. I need a little more
WALTER FASNACHT: But watch out! There are
also less comfortable ones.
ALAN ALDA: Less good ones? Here, thanks very much.
ALAN ALDA: (Narration) The next day, fortune smiled on us. Walter
made a perfect set of bronze astragali on his Cyprus hillside.
SEA WITHIN THE SEA
ALAN ALDA: (Narration) We're in Sardinia, the Mediterranean's largest
island. It's the village of Stintino's annual "sagra". The
sagra, or celebration, is for the arrival of the tuna. Celebrations
like this have been held around the Mediterranean for as long
as people can remember. In June, when the giant bluefin arrive
off the coast to spawn, celebrating the bounty of the sea
brings the whole village together. But like fisheries all
over the world in recent years, tuna catches have been dropping
alarmingly. So now there's an urgent need to understand and
protect the region's marine life - not least because in so
many places it's not just marine life that's threatened, it's
community life. The focus is on an area just north of Sardinia,
the Ligurian Sea. As of 1999, it has contained the world's
first international marine reserve. The waters are the most
productive in the Mediterranean, attracting in summer large
numbers of dolphin, tuna and whales, coming in to feed. It's
August in the Ligurian Sea, and we've joined an Italian government
research team looking for some of the area's most elusive
inhabitants - fin whales. The Mediterranean has a lot of fin
whales, about 4,000 it's believed. We know they concentrate
here in summer, but not much else.
CHRIS CLARK: Two… We got
them three at three o'clock.
ALAN ALDA: (Narration) Two American whale sound experts are visiting
CHRIS CLARK: It's like when you see whales you go,
Did I actually see something? Are they really there? Wow,
yeah. Boy, they're moving. Rapido!
FABRIZIO BORSANI: The problem
is that the whales are too fast for us. When they speed up
they go faster than ten knots.
ALAN ALDA: (Narration) Just ahead of the boat, the whales dive.
FABRIZIO BORSANI: They usually stay down for about 10 minutes.
So it's 7 minutes they have been down now.
CHRIS CLARK: Look
at that. Fantastic. Holy cow.
ALAN ALDA: (Narration) These 100-foot giants are found worldwide,
but they were never hunted in the Mediterranean so the population
should be healthy. Our whale swims under the boat at 18 meters
- 50 feet - depth.
CHRIS CLARK: Beautiful. Look at him. 18
FABRIZIO BORSANI: Yep. She passed underneath
us. And now the second one is here, to the right side of the
boat, about 10 meters.
ALAN ALDA: (Narration) It's a rare and lucky encounter, so Chris
and Fabrizio try listening for sounds. Fin whales have never
been recorded in the Mediterranean.
CHRIS CLARK: If you listen
every now and then you hear that - just a little bit of modulation
in the tone.
FABRIZIO BORSANI: It's too short.
ALAN ALDA: (Narration) They weren't quite sure what they were hearing,
and within 45 minutes the whales had vanished.
In the life of a whale, or in the day of a whale, 45 minutes
is nothing. You really need to listen over much, much longer
ALAN ALDA: (Narration) Chris Clark and
CALUPCA: have brought on board underwater sound recorders
they designed to be left behind, to run continuously for weeks.
The night before deploying the recorders, Fabrizio had to
coordinate things with the local fishermen.
FABRIZIO BORSANI: This
fisherman just told us where they trawl on the bottom at 500
meters so that we can choose a location that we're going to
tell them where we are going to place to pop-ups.
ALAN ALDA: (Narration) They're called pop-ups because the recorders
will float up from the sea floor on command. The team is putting
out 2 pop-ups - and it's the first time they've tried.
CHRIS CLARK: We've got a problem. Let it go!
ALAN ALDA: (Narration) The pop-up drops abruptly into the water,
but nothing seems to break and a few minutes later a solid
acoustic communications link is established with it.
TOM CALUPCA: The three long beeps, that means the pop-up recognized,
understood the message OK.
ALAN ALDA: (Narration) Finally the pop-up is released to sink gently
to the bottom, 1500 feet below. We're with another Italian
team, that recently made a surprising discovery about Mediterranean
fin whales. Tiny skin samples were collected and analyzed.
They showed that Mediterranean fins are genetically isolated
- they're on their own.
FABRIZIO BORSANI: No genes of the
Mediterranean whales have been found in the Atlantic and vice
versa, which speaks loudly for a resident population.
ALAN ALDA: (Narration) If fin whales are resident here, that means
they're especially vulnerable to the Sea's crowding and pollution.
It's essential we learn more about these whales, so we can
safeguard their future. It's Fall, and the team is heading
out to collect the pop-ups. With winter coming, it's thought
the whales will already have left. Tom will dial up the pop-up
on the sea floor, telling it to release its ballast weights.
TOM CALUPCA: There it is! The buoy's at the surface. It's
right over here - just off the boat, about 50 meters away.
We're in a good spot.
ALAN ALDA: (Narration) It's a little like a spacecraft splashdown,
and in truth the pop-up has just returned from a largely unexplored
TOM CALUPCA: Nine oh nine and thirty seconds - now.
ALAN ALDA: (Narration) The pop-ups brought another surprise result
- clear recordings of lots of whales in the Ligurian Sea,
right into winter. We never knew they stayed, and in fact
all other fin whales in the world migrate. ACTOR: (sub-titled)
They're coming. The tunas are coming.
ALAN ALDA: (Narration) These are scenes of a real bluefin tuna
"mattanza", or "killing", shot in Sicily in the 1940s. There's
no better evidence of the tremendous abundance the Mediterranean
yielded. But catches like this haven't been seen in decades.
We're back in Sardinia, for the 1999 mattanza near the village
of Carloforte. We're not here to catch tuna, but to tag and
release them. The tags are satellite transmitters that will
drop off in a few weeks and signal their positions. The question
is the same as with the whales - Are the tuna Mediterranean
fish, or Atlantic fish, or both? It's pretty rough above,
but tranquil below. There are enough fish in the net for a
few tags. In 2 years so far, 10 tags have been successfully
tracked. They seem to show there are distinct groups of Mediterranean
and Atlantic tuna. We have to understand these populations
soon, to work out how to regulate the catch before relentless
fishing pressure overtakes the species. The wonderful Mediterranean
fin whales are not yet in trouble, so far as we know. But
with the Sea's tuna and turtles under stress, and with the
looming caulerpa invasion, the Mediterranean offers one of
the world's clearest challenges to our ability to live alongside
nature. And meanwhile, don't forget about preserving our human
heritage around here, too. That's all for this edition. See
you next time.