Caulerpa Taxifolia

Caulerpa Taxifolia is a seaweed that has been altered by man, to look pretty in aquariums. The problem? If even a small branch is put into the ocean it explodes into a massive growth that is almost impossible to kill. The only ways to kill it, that are known so far, are massive amounts of salt, copper sulfate (which kills EVERYTHING), chlorine, and some predators.

The problem first began in the Monaco, when a small amount of Caulerpa Taxifolia got into the water. It was brought to the Oceanographic Museum, run by Jaques Cousteau in 1982. In 1984, Alexandre Meinsez discovered a growth area under the windows of the museum, in the ocean, approximately 1 meter square. By 1995, it had reached the Adriatic, by 1997, it had reached France, and Tunesia. Also in 1997, new growth areas were identified in California off San Diego, Port Hacking, Lake Conjola, and Careel Bay in Australia.

Several predators of the plant have been discovered, but there have been problems with this method of control. They aren't able to eat the plant fast enough, and in large enough amounts to destroy established growth areas, but are able to slow the spread somewhat.

The other method of destroying the plant involves using chemicals. Rock salt seems to work, however, it is needed in such large amounts that growth areas that are established need more salt than can be found in most areas. Copper works well, but kills everything else as well. The US tried an experiment with chlorine, where a growth area was covered with a special tarp, with a valve to pump in chlorine. This worked well, however it also had the effect of killing everything else along with the taxifolia. The only other method is manual uprooting.

The spread of this plant is insidious, because it only needs a small part of a branch to begin to take over an area. Once it fully begins its growth, it simply takes over an entire area and soon looks like an underwater forest. Once it has fully taken over an area a new ecological balance is created, and the area is forced to adapt to the new growth.

Very little is currently being done to fight this problem. In fact not many people are even aware of the problem that is going on. Until, and unless more is done then this plant can soon take over huge portions of the oceans, and decimate currrent species. The plant has been found everywhere from deep cold regions, to shallow warm regions. Anywhere there is light, it will grow.

In the early 1980s, the curator of the tropical saltwater aquarium at the Wilhelmina Zoo in Stuttgart (FRG), noticed the exceptional properties of a bright green, beautiful green alga, C.taxifolia, used as tank decoration in the presentation of multicolored tropical fish. It was captively bred by the aquarium staff and exposed, for years, to chemicals and ultraviolet light. This exposure to abiotic stressors altered and switched on genes that have not been previously present, expressed or active in wild type strains found across the Pacific. The genetically altered seaweed, in contrast to other algae does not wither and grows with astounding vigor resisting cool water temperatures. Specialists quickly learned about these qualities, and public aquaria around the globe acquired cuttings.

Prolific growth of Caulerpa along the Cote d’Azur (France), where the introduction was first reported, has been associated with urban wastewater pollution (1.3Chisholm et al., 1997). It easily proliferates vegetatively via fragmentation aided by subsequent dispersal via anchors and fishing nets (1.4Meinesz, 1992), or dumping ballast water across the oceans; in particular at harbors, marinas and other places where boats anchor (1.6Boudouresque et al., 1995). Mid range spread of this species is easily achieved by currents, which transport fragments of it into new areas yet to be colonized (1.3Chisholm et a., 1997). Apart from shipping vectors, long range dispersal of this alga was facilitated by the aquarium trade (1.7Schaffelke et al., 2002). The fact that C.taxifolia possess a chemical defence mechanism (the alga produces repellent toxins) renders it unpalatable to generalist herbivores in the N-W Mediterranean (1.8Paul, 2002), which facilitated this biological invasion. Thus, C.taxifolia is upsetting the biocoenosis by invading and out-competing the indigenous flora while protecting itself against predation, thus threatening the biological stability of the marine environment (1.9Pesando et al., 1996). Apart from a few serious attempts to eradicate this species (mainly in AUS and USA), monitoring, mapping and public awareness programs are the only efforts made so far. It seems that control of the invasion was and still is never a priority for most of the affected EU-countries. A shameful attitude that aids in the dispersal of this invasive strain.

The DNA fingerprints of C.taxifolia presented here support existing evidence for the descent of the Mediterranean C.taxifolia from an aquarium strain. The introduction of C.taxifolia via the Oceanographic aquarium in Monaco is strongly supported on the basis of having identical internal transcribed spacer (ITS) rDNA sequences (2.32Jousson et al., 1998). The phylogenetic analysis of these sequences show that the Mediterranean alga is genetically identical to the strain cultivated in aquaria (see figure 2.h - left image). Interestingly, the aquarium strain differs from all tropical populations of Caulerpa in lacking internal transcribed spacers (ITS) polymorphism, a fact that can be related to a prolonged confinement under aquarium conditions.

Wiedenmann et al., (2.302001) compared samples from 11 locations in the Mediterranean Sea with 3 representatives from public aquaria. The uniformity of hybridization patterns indicates that representative specimens from the Mediterranean and aquaria belong to the same clone. The slight differences in hybridization patterns in C.taxifolia from Manly Harbour (Australia) suggest that it carries very similar chloroplast and mitochondria traits. The Australian population of Manly Harbour/Moreton Bay is well suited for comparative studies of the role of C.taxifolia in a non-Mediterranean ecosystem because of the close relationship to the aquarium strain.

The comparative results of C.taxifolia strains from aquaria, the Mediterranean Sea and from Manly Harbour (Australia) are shown in fig. 2.j in which (CAC)5-hybridised Southern blots of total DNA after TaqI digestion (restriction patterns in ethidium-bromide stained agarose gels) have been performed. In contrast, the control sample (left lanes 1-2) clearly distinguishes them from the aquarium strain (C.prolifera, C.taxifolia from Martinique). The aquaria strains from Stuttgart and Enoshima reveal identical restriction patterns as samples from the Mediterranean Sea (Monaco, Krk, Sicily, Mallorca, Elba 1-3, St.Cyprien 1-3). Only slight differences in the position of a single band (indicated by the circle) were detected between the sample from Manly Harbour (lane 16) and the aquaria specimens.

www.sbg.ac.at...

aquat1.ifas.ufl.edu...
swr.nmfs.noaa.gov...
www.isima.fr...
www.ridnis.ucdavis.edu...

if it spreads that fast - cann it not be harvested as animal feed or feriliser stock ??

current sea weeds are used for this - so why not the new one ?

This new strain has been altered so much by exposure to the UV lights, and chemicals in aquariums that it's toxic to most creatures. One of the original strains, which grows here in Hawaii is kept in check by fish and crabs and other creatures, and can be harvested if necessary. This new strain actually emits toxins that keep it from being eaten.

What about as a biofuel? Can it be harvested, dried, ground and compacted into pellets to be burned as a fuel source? See the link in my sig about algae-based biofuels.

I'm not sure about that, I don't think they've investigated it. The biggest problem is the growth rate. It took less than 15 years for it go from Monaco to France, and less than 5 to have taken over around the aquarium in Monaco. If they don't get every single bit of it, then it won't go away, and will start growing again.

I couldn't find anything on the net. A Google search on "Caulerpa Taxifolia" +biofuels didn't yield any useful info.

But they should use it as a fuel source. If they can't get the lipids (if any) out of it for biodiesel, they could at least burn the dried and compacted remains. Since it grows so fast, and from that factsheet you supplied it apparantly thrives on wastewater discharge, why not?

Harvest it, dry it under the sun, compact it into pellets and burn it. If I'm not mistaken there are also machines out there that does all this and uses the pellets it produces to power itself.

Well now we run into our second major problem with this plant. No one is willing to get off their chairs and DO much about it. The EU has barely tried to contain it, the US is putting the minimum into it, and even Australia isn't devoting much to stopping it. Turning it into fuel would require people DOING something, which it appears that no one is willing to do at this time. If nothing is done soon it's going to be too late. It has a truly nasty effect on breeding habits of fish, and the survival rates of sea urchins. The earliest stages of sea urchin larva have a 25% survival rate to get to when they change to the next stage around caulerpa taxifolia.

If I have US$12,000 (for the machine I was talking about), several hectares of beachfront land, a boat and a contact in the government I'd be willing to start it up.

Unfortunately I don't have any of those except for an idea for a world powered by organic renewable energy sources.

The problem is that what you said appears to be more than what just about everyone else is willing to do to stop the problem. NO ONE seems to be taking it seriously.

Perhaps if they can be convinced of the profits to be made harvesting this pond scum for use as biofuels then maybe, just maybe, somebody would do it.