|THE GREEN INVADER Video Transcripts
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?
ALEX MEINESZ: 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…
ALEX MEINESZ: 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 predators?
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 predator.
ALEX MEINESZ: No! You see all the leaves are entire. Nothing…
ALAN ALDA: Nothing has been eating it!
ALEX MEINESZ: No, no biting crease.
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 full, uh?
ALAN ALDA: Yeah, there's a lot of it down there.
ALEX MEINESZ: All the bottom is covered, eh?
ALAN ALDA: There's a lot there!
ALEX MEINESZ: All the bottom is covered.
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.
ALEX MEINESZ: Yes, here.
ALAN ALDA: Oh yeah. yeah, yeah! Now is he eating now?
ALEX MEINESZ: Yes, I think so, yes.
ALAN ALDA: So these slugs really like that toxic stuff.
ALEX MEINESZ: 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 understand?
ALAN ALDA: That takes a lot of plastic surgery!
ALEX MEINESZ: You understand?
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.