Toxic Seaweed

This NOVA special was first aired in April 2003, but was repeated recently. It documents a disturbing case of an invasive algae discovered along the French Riviera in the 1980s. French marine biologist, Alexandre Meinesz, tried to sound the alarm when he first observed large patches of this “seaweed” taking over in sensitive Mediterranean habitats beneath the Oceanographic Museum of Monaco, once headed by the legendary Jacque Cousteau. The “authorities” ignored him, and the infestation, which divers could easily have hand-pulled when it was first discovered, has now propagated throughout the Mediterranean. In fact, this weed has been discovered in San Diego (where it was killed with chlorine) and in Australia, where experts are still deliberating about how to get rid of it.

It turns out the toxic algae, Caulerpa taxifolia, was a “man-made” product, bred for aquarium use in Germany. Because of its bright color, fast growth, and resistance to cold, it was distributed to other aquariums, such as the Monaco museum, and eventually the whole world. It has become another example of an ecological disaster wrought by humans tampering with the natural order. Now, they’re talking about bringing in a marine slug to eat the algae, which is essentially toxic or at least unpalatable to other marine life. Who knows where that will lead?

DadConnections08/05/05 4 comments


David • 08/08/05 1:07 AM:

Nice tie-in with the finishing song lyrics. Applause.

Where will all this lead? Nobody knows. But there’s good money to be had in trying to figure it all out. Kinda like E.O. Wilson’s book, Consilience, where he calls for the unification of knowledge, in hopes of maybe being able to solve such difficult questions. Questions that have to do not only with biology, but conservation, extermination, jobs, coastal beauty and function, and tons of other things.

Check out the program made by PBS and National Geographic, Strange Days on Planet Earth, hosted by my man, Edward Norton. It has lots about invasive species, like this killer algae.

Patrick • 08/12/05 3:18 PM:

Another thought that comes to mind is that “evolution” may be helped along by human beings. Before we cared much about the environment, native flora and fauna, etc. animals and plants did find their way out of their native areas, invading and sometimes subduing what they found there. Maybe not as often or as much as once man started building ships and airplanes and purposely meddling with Nature, but it did happen, no? Don’t we think that certain plants actually need to be eaten and then pooped out by birds to spread? And albatrosses might have carried parasites or seeds long distances from their origins. So maybe this is not necessarily something to worry too much about. Maybe. It has happened before. I don’t like it, but we may be just tools in the big plan of Nature…

Dad • 08/12/05 5:51 PM:

Some people tend to treat humans as somehow outside of nature, but I’ve never bought that. We have always been a part of nature, albeit a big worldwide player. A case could be made that man has the biggest impact on nature, but I’m not sure that’s the case. What about all those insects? Bacteria? If man has a special place, it’s because we are aware of what we are doing and we strive to control nature in big ways through technology. All creatures are basically trying to control their environment, but most only impact their immediate surroundings.

In the case of the toxic seaweed, one of the scientists Meinesz was trying to convince to take action thought this was merely a “natural” event that would be taken care of by nature rebalancing. That always happens, but what if you don’t like the new balance?

David • 08/15/05 10:49 AM:

Here is a cool link to a pdf file from the PBS series Evolution (by the way, one of my top three science shows/series of all time). The first link details some of Darwin’s famous Seed Germination experiment.

Darwin saw great similarities between the plants on the Galapagos and the plants on the mainland in South America. He reasoned that there was common ancestry and that the island plants descended from the ones on the mainland. This was a major part of his theory, as explained in On the Origins of Species But before Charlie was going to publish such ideas, he had to test whether or not seeds could make it that far across the ocean. So he did an experiment, simple, yet elegant, to figure out the effect of salt water on germination. Although top botanists at the time though he was nuts, Darwin’s experiments showed clearly that seed dispersal via the ocean currents was totally legit. So, yes, species have in many ways, been invading new spots for a long time. The main difference now is the time it takes. We are accelerating these changes. And quick changes = little time for other/native organisms to adapt. And that = trouble, because the species do not have time to co-evolve.

And what about insects and bacteria? Those are gigantic groups of organisms. Accounting for possibly half of the world’s biodiversity (or something like that). Humans are just one species. So although we are a part of nature, our role is far more severe than it should/could be.

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