Bloom d'algues dans le Lac Champlain

Photo: Jessica Ackerman

La vague de chaleur qui frappe la côte est de l'Amérique du Nord provoque un bloom d'algues bleu-vertes dans la partie sud du Lac Champlain cette semaine. Les conditions sont idéales: la chaleur, le soleil et peu de vent sont favorables aux blooms. Les algues de cette semaine dans le Lac Champlain sont de deux sortes capables, mais pas toujours, de produire des toxines qui attaquent le système nerveux et le foie.

La chaleur rend les plages très attirantes, mais si l'eau semble avoir reçu un déversement de peinture ou a l'apparence laiteuse, il est plus prudent de ne pas s'y tremper.

L'Université UVM va connaître les résultats de toxicité le 8 juillet. On peut aller vérifier sur le site Web du département de la santé du Vermont pour les dernières alertes: http://www.healthvermont.gov/

Les éclosions des dernières années dans le lac n'ont pas produit de toxines, mais cela peut changer d'année en année. En 1999, plusieurs chiens en sont morts.

La pollution dans mes endroits préférés pour me baigner d'il y a 50 ans m'empêche de jouir du plaisir de me rafraîchir dans un lac ou une rivière comme quand j'étais petite. Çà me révolte au plus haut point!
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"Heat triggers Lake Champlain algae growth

A blue-green algae bloom, shown Tuesday, has emerged off Thompson’s Point in Charlotte on Lake Champlain. Hot, sunny and calm weather has contributed to blooms in the southern portion of the lake. Just when Vermonters want to escape the heat with a plunge in Lake Champlain, the water in some places may not be safe for swimming.

This week’s hot, sunny and almost windless days created perfect growing conditions for potentially toxic blue-green algae. Widespread blooms were reported Wednesday from Burlington Bay south to Ferrisburgh and Port Henry, N.Y. Blooms also were reported at Shelburne Pond and could appear in any inland pond, said Angela Shambaugh, an aquatic biologist at the Vermont Agency of Natural Resources.

“Basically, if you are looking at the water and you are seeing lots of algae — if the water is milky, or it looks like a chemical or paint has been spilled on the water — just stay out,” Shambaugh said Wednesday. Watzin said water samples collected around the lake Monday and Tuesday contain dense concentrations of two kinds of blue-green algae capable of, but not certain to, produce toxins. One toxin attacks the nervous system, the other the liver.

Tests to be completed today at UVM will answer the toxicity question. (Updates on the status of algae blooms are available on the state Health Department website, www.healthvermont.gov. Click on Contents A-Z, then on “algae, blue-green.”)

“This weather is horrible for people, but it is absolutely perfect for blue-green algae — hot, sunny and still,” Watzin said. While she cautioned people to use care, she said in past years many dense algae blooms on the lake failed to produce toxins. “For some reason we seem to have a lake where our algae haven’t always made the toxins,” she said, “but things can change from year to year.”

Toxic algae blooms in the lake were blamed for the deaths of several dogs in 1999.

To the naked eye, dense blooms of the algae look like paint spilled on the water. Shambaugh said some of the calls she fielded Wednesday came from people who thought there had been a toxic spill. In one cove at Thompson’s Point in Charlotte, the algae had turned the water an intense, milky blue — a color most people would not associate with an algae bloom. “I thought someone had thrown dye in the water,” said Jessica Ackerman, a Burlington resident and Thompson’s Point camp owner who photographed the bloom."

Excerpts of article written by Candace Page of the Free Press, published here: http://www.burlingtonfreepress.com/article/20100708/NEWS02/100707024/Heat-triggers-Lake-Champlain-algae-growth

Pollution in my favorite swimming holes of 50 years ago is preventing me from enjoying what I took for granted when I was a child: the joy of cooling down in a river or a lake! It absolutely infuriates me that these simple pleasures where taken away from me!