Quamichan Lake used to be seen as an "ecological jewel" in Vancouver Island's verdant Cowichan Valley, but since the dogs started dying people have begun to fear its beautiful waters are becoming toxic.
The lake, surrounded by a mix of farms and rural housing developments on the outskirts of Duncan, has long been troubled by summer algae blooms. But this fall, the problem – thought to be caused by an inflow of phosphorous and nitrogen from agriculture land and septic fields – took a sinister turn when dogs began vomiting and dying suddenly after swimming or wading in the lake.
City officials have taken note and a meeting is planned next week to discuss how the lake might be restored. In the meantime, signs have gone up on all roads leading to the water warning the public that blue-green algae is present and directing them to seek more information on a health website.
"I had no idea it could kill my dog," said Lyn Pascoe, a family physician whose six-year-old border collie cross, Austin, died suddenly Oct. 18 after wading through a scum of algae.
Ms. Pascoe, who has lived on the lake for 28 years, said her dog apparently ingested toxic bacteria after licking a yellow green stain left on his legs by algae. Hours later, he started to vomit. And by morning he was dead.
Ms. Pascoe talked to neighbours and soon found two others whose dogs died similarly. A three-year-old dog died Sept. 26 after wading in the lake and a 14-year-old dog died Oct. 12 after a daily swim.
Samples of the algae and water have gone in for testing, but Ms. Pascoe said she has little doubt the dogs were killed by cyanobacteria, which is commonly called blue-green algae.
"My dog wasn't swimming in it. He wasn't drinking the water. He merely walked around the edge of the fence [into the lake]… and he had the stuff on his legs … so it's incredibly toxic to dogs."
One lakeside resident, Christopher Jones, an adjunct professor of law at the University of Victoria, said he's become increasingly worried about water quality.
"Obviously when dogs start to die, it's a pretty big problem," said Mr. Jones, who in years past didn't worry much about the algae blooms.
"In the past I've been cavalier about swimming in the lake. I mean, who's afraid of a little green water? And now, maybe I am," he said. "I'm thinking maybe the lake is becoming a poison cesspool instead of the ecological gem of the Cowichan Valley that it should be."
Mr. Jones said the lake is beautiful most the year. Surrounded by groves of rare Garry oak and trimmed with lush reed beds, it is known as a great place to go bird watching or trout fishing.
But the blue-green algae blooms that routinely occur in the summer apparently intensified this fall when heavy rains or winds stirred up sediment on the lake bottom, adding to the inflow of nutrients. The result was a toxic bloom.
Mr. Jones said the government needs to pay attention to what is happening to the lake, especially with growing pressure for increased development in the area.
North Cowichan Mayor Jon Lefebure said it is clear something has to be done.
"It is definitely a wake-up call," he said of the deaths of the dogs. "It comes at a time when we are deciding how to improve water quality … and it really has brought a lot of focus to the question."
Roger Hart, chair of the Quamichan Watershed Stewardship Society, said in 2006, the B.C. Ministry of Environment did a study that documented the health of the watershed over the past 50 years.
"They found it had been going downhill steadily," he said. A management plan was drawn up and its title, The Jewel of North Cowichan, suggested the lake was seen as an ecological treasure worth saving.
But Mr. Hart said there was "a lack of political will" and not much happened to address the water quality issues.
He's hoping the death of the dogs will finally stir action.
Mr. Hart would like to see a task force struck to look at ways to treat the existing algae problem and to control the nutrient flow. Water treatment systems, he said, should be mandatory for new housing developments, such as one that proposes to add 900 residential units on nearby Mount Tzouhalem. He also wants regular water testing done so the public can be warned when blooms make the lake a health concern.
"I think all of us who live by the lake want to see it restored," he said. "The lake is fixable."