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The Green Tide of Brittany

By Staff | Oct 8, 2009

The “canicule,” or heat wave, alert was sounded for a large part of the south of France this summer. Even in northerly Brittany, in the Ctes-Armor, the heat was one of the compounding factors in a large bloom of green algae that was so bad it emitted poisonous gas enough to kill a horse, literally, on the beach in July. The man who was riding the horse lost consciousness but was saved by passersby who responded rapidly.

The algae bloom (a macro-algae) is caused by agriculture in the region. While this is a problem in South Florida, too, there have been no horses or other land-based creatures killed yet by poisonous gas emitted by the algae on Florida beaches.

First of all, with the plethora of types of algae, let’s be specific: the Latin name of the type of macro-algae that is plaguing Brittany’s beaches is Ulva armoricana. The part of Brittany most affected is the Ctes-Armor. “Ar mor” means “the sea” in Breton. So this particular macro-algae is named for the Ctes-Armor, and may be unique to this area.

Ulva amoricana is not too dangerous when it is fresh and in the bay water. But when it washes up on the beach and is in contact with the air, it forms an almost impenetrable white top layer, beneath which the rest of the algae rots and builds up hydrogen sulfide gas that can be lethal.

It is this white, tough layer that makes the decaying Ulva amoricana a bit different from the heaps and masses of red drift algae that the Sanibel and Fort Myers beaches have experienced. If there is anything good that can be said of red drift algae, it is that it doesn’t rot on the beach in the quite same manner that Ulva amoricana does.

The French prime minister’s recent visit to the Ctes-Armor to make a show of concern about the rotting algae brought snide criticism from some, who immediately and correctly pointed out that this problem has been going on for the past 25 to 30 years. “Where has the government been all that time?” the critics asked.

Brittany has been allowed to practice agriculture in a very intensive way. While the region represents less than 5 percent of the agricultural land surface in France, it raises 60 percent of the pigs, 45 percent of the chickens and 30 percent of the veal.

Compounding the problem is Brittany’s surface hydrology. Its surface water network is extremely dense and permits the rapid transport of pollutants.

Compounding that problem is the fact that many of the hedgerows and embankments that formerly slowed down the surface water flow have been eliminated.

When the polluted surface water reaches certain bays where the conditions are just right for this algae (lots of sun, the right kind of sand, the perfect tidal conditions), it grows monstrously. This year, weather conditions have favored the algae growth.

The horse that died on the beach this summer was not the first animal victim of the poisonous gas emitted by rotting Ulva amoricana. Evidently, a couple dogs died earlier. It took a horse dying to attract the attention of the nation, however. And 10 years ago, one of the employees of the company charged with cleaning up the algae lost consciousness while operating his small tractor. This man, Maurice Brifault, fell 1.3 meters off his tractor onto the green slime. Fortunately, two nurses who happened to be jogging nearby came to his aid, saving his life.

Brifault was in a coma for four days. Nobody alerted the public authorities or the media because, as the president of the Federation of the Ctes-Armor division of France Nature Environnement explained, in those days “one did not talk about it; it was well hidden.”

Maybe someone did die. Pierre Philippe, an emergency room doctor, recalls a jogger who was found dead in the algae in 1989 on the beach at Saint-Michel-en-Grve in Brittany.

After the horse died in late July, people started asking questions about a 48-year-old truck driver who died on July 22 after unloading three truckloads of green algae at a compost factory. The paramedics first concluded that he’d had a heart attack because of his weight. But the president of the compost factory (where the decaying algae is taken and treated), Thierry Burlot, made his doubts about that diagnosis known in a letter that he wrote on Aug. 25 to the prefect of the Ctes-Armor, Jean-Louis Fargeas.

Burlot’s doubts arose after he heard the prime minister, Franois Fillon, speak about the extreme toxicity of the decaying algae during his visit to the Ctes-Armor on August 20. Local groups also denounced the algae as dangerous.

The victim’s body has recently been exhumed and autopsied. Analysis of his lung tissue is being conducted this month.

Local people will no longer swim in the affected bays. The clean-up of the algae is an economic catastrophe for local communities. One small village, Saint-Michel-en-Grve, spent 100,000 euros this year to remove 13,000 tons of algae. The decline in tourism has caused one local campground to close, and a hotel to be placed on the real estate market.

Several sections of beach in Brittany were closed to the public for part of the summer because of the dangers posed by the decomposing algae. The ban applied not only to swimmers; it was for pedestrians, too. Everyone had to stay at least 20 meters away from the closed beaches.

In the bay of Saint-Michel-en-Grve, samples have been taken which reveal a concentration of hydrogen sulfide of about 1,000 parts per million (ppm). At concentrations higher than 500 ppm, the hydrogen sulfide gas can cause a rapid loss of consciousness followed by a coma, sometimes with convulsions, accompanied by respiratory difficulty and cardiac rhythm problems. Above 1,000 ppm, death can come rapidly, within several minutes.

The personnel charged with cleaning up the algae on the beaches and treating it may soon be given portable devices for measuring the risk of poisonous gas emissions, if the experts’ recommendations are followed.

Those who raise pigs are pointing the finger at those who use fertilizer, and vice versa. But Prime Minister Fillon will have none of this blame game; he says the cause is a “conjugation of several factors.”

Although “actions for modifying agricultural practices accompanied by the enforcement inspections have permitted some advances in certain areas, the results are not in rapport with the level of efforts made,” according to Fillon.

Time for improvement. What will Prime Minister Fillon do? According to him:

1. The French government commissioned a study that has demonstrated the toxicity of the algae, in which the level of hydrogen sulfide can be lethal in several minutes.

2. The French government will take charge of the clean-up of the beaches most affected by the bloom.

3. An inter-ministerial mission will be started which, in three months, will come up with a plan of action. “We are going to experiment with the clean-up of the algae out in the ocean in winter, to avoid the proliferations [on the beaches],” promised the Prime Minister. Nevertheless, scientists have pointed out that this will not be a workable solution.

4. Finally, the Prime Minister promised “the experimentation of new politics” in the region. That one is probably the biggest challenge. The local groups remain dubious because they think it will take an “agricultural revolution” to resolve the problem.

The programs in place for fighting against the green algae pollution for 15 years have cost 700 million euros. Gerard Mevel, the vice president of the Brittany region in charge of water said that the results obtained are limited, and are not enough for the level of the investment that has been made. The average concentration of nitrates in Brittany’s rivers was 5 milligrams per liter in 1971; it attained a level of 38 milligrams per liter in 1998. In at least 15 places where potable water is collected, the level is more than 50 milligrams per liter now.

More than 450 stations for treating the collected animal excrement have been constructed. The farms have been equipped with tanks for collecting the excrement for use as fertilizer “at the right time.” Numerous programs of “good agricultural practices” have been instituted.

But everyone seems to know that the problem is too many animals on too little surface. And the levels allowed when spreading treated manure as fertilizer are too high.

When the farmers’ groups bring up their economic heavyweight status, the environmental associations point out the hidden costs of agriculture, including the cost for cleaning up the green algae, treating it, and extra work for making water potable (thus augmenting the cost of water), and loss in tourism revenue as well as real estate values. These costs have never been evaluated.

Meanwhile, the demonstrations by people angry about the algae are growing. On Sept. 27, more than 2,500 people demonstrated on the beach near Hillion. The owner and rider of the horse who died has also filed a complaint with the courts, making a charge of “involuntary violence by neglecting an obligation of security, involuntary injury to the life of an animal, and neglecting to fight a natural disaster creating a danger to people.”