Thursday, February 25, 2010
C'est pas l'azote, stupide!
Le Dr David Schindler fait une autre sortie: les millions de dollars dépensés pour enlever l'azote du Lac Winnipeg sont une dépense inutile. Il devrait le savoir. Çà fait 40 ans que son travail de scientifique lui fait étudier ce lac qui est l'un des plus grands lacs d'eau douce de la planète.
Selon lui, le monde entier se concentre à réduire le phosphore, le vrai coupable qui nourrit les algues bleues-vertes. L'argent que la province oblige Winnipeg à dépenser devrait être utilisé pour s'attaquer au phosphore, parce que les gens boivent l'eau du lac Winnipeg qui a une concentration élevée de toxines à bien des endroits. Selon Schindler, on doit dépenser cet argent, mais pas sur l'azote.
Le Manitoba s'était engagé il y a 6 ans à ramener les niveaux de phosphore et d'azote dans le lac Winnipeg aux niveaux d'avant 1970. Pour y arriver, le gouvernement a mis en place des contrôles aux éleveurs de porcs en obligeant la réduction d'utilisation de pesticides près des cours d'eau et en limitant l'épandage de purin, mesures critiquées par certains.
Les municipalités s'objectent aussi à leur obligation de modifier leurs usines de traitement d'eaux usées pour en retirer l'azote, les forçant à augmenter les taxes des contribuables. Schindler compare les proposants à la réduction de l'azote à ceux qui nient l'existence des changements climatiques: "Il y en a 1,000 d'un côté et 2 ou 3 personnes très arrogantes et vocales qui parlent bien de l'autre côté."dit Schindler, "On a eu 50 ans pour saloper le lac et çà va prendre au moins quelques décennies d'efforts concertés pour réparer les dommages".
"Removing nitrogen from Lake Winnipeg a waste of millions: water expert
WINNIPEG - One of Canada's leading scientists says Manitoba is squandering millions on a plan to reduce nitrogen to clean up Lake Winnipeg, one of the world's largest bodies of fresh water. David Schindler, who started studying the lake 40 years ago, says other lakes around the world are being rehabilitated by targeting phosphorus, the real culprit in feeding damaging blue-green algae blooms.
The province is forcing Winnipeg to spend $350 million to reduce nitrogen, but Schindler says that's not the right substance to focus on. "Removing the nitrogen is wrong," says Schindler, a University of Alberta professor who has won international awards for his fresh water research. "We need that money. I would be the last person to say let's cut corners on pollution or let's cut corners and have poor water quality. People drink the water from that lake and, in the summer, it's high in toxins in a lot of places. "That money is needed, but not to remove nitrogen."
Satellite images have shown massive blooms of algae taking over large swaths of Lake Winnipeg's north end. The algae can suck oxygen from the water and produce a number of toxins that are harmful to fish, humans and other living things.
Manitoba committed six years ago to bring nitrogen and phosphorus amounts in Lake Winnipeg back down to pre-1970 levels. To that end, the NDP government has placed controversial restrictions on hog farmers, seriously curbing the use of pesticides near waterways and limited the spreading of manure.
A ban is expected to come into effect this year on dishwasher detergents that contain phosphorus. But the province has raised the ire of Winnipeg municipal officials by forcing taxpayers to spend $350 million to upgrade the city's wastewater treatment facilities in the name of nitrogen reduction.
Schindler likened those advocating nitrogen removal to climate change deniers. "There are 1,000 people on one side and two or three obnoxious, vociferous people on the other who are very smooth," says Schindler, adding the province has been misled. "No matter how good you are, you blow one once and a while and I think they've blown this one." Manitoba Conservation Minister Bill Blaikie was not available for comment.
Schindler says any rehabilitation of the 10th largest body of freshwater in the world, covering 24,000 square kilometres, is going to take time. He says it took 50 years to "screw it up" and will likely take at least a few decades of concerted effort to undo that damage.
But Terry Sargeant, chairman of Manitoba's Clean Environment Commission, says Schindler's arguments haven't changed his mind. High levels of nitrogen are harmful to the lake and reducing them isn't a waste of money, he says. "Nitrogen is a serious nutrient that has a lot of negative effects," Sargeant says. "It does affect other plants and animals in the environment. It can potentially affect amphibians, other plankton in the water column. It can affect the growth of plants in the water column which is all part of the food chain in the lake." The commission took arguments like Schindler's into account before it made recommendations to the government, advocating the reduction of nitrogen, he says. "There was nothing new presented here today," Sargeant says.
Winnipeg Mayor Sam Katz is still hoping Schindler's science will sway those at the commission and the Manitoba legislature. They are ignoring "hard science," he says. "I think most citizens would agree that $350 million, plus another $9 million annually in operating costs, is a huge expenditure that should be receiving far more scrutiny," Katz says. "
Excerpts from article written by Chinta Puxley of the Canadian Press here: http://www.cftktv.com/news/14/1081277