9/30/2004
Blue-green algae bloom causes at least one dog death at Lake Benton
Mark Fode



At least one dog is believed to have died after going into Lake Benton in the past week and possibly ingesting algae that had formed on the lake.

Lincoln County Environmental Officer Robert Olsen said Thursday that he believes a dog owned by Mark McCallum, who lives on Marshfield Cove on Lake Benton, may have died as a result of the algae bloom on the lake. Olsen said the dog was seen in the algae and cleaned itself off after being in the algae last Saturday. Olsen said another dog in that cove has also died in the past two weeks, but it is unclear whether that death can be attributed to the algae bloom.

Olsen said water samples have been taken by the Minnesota Pollution Control Agency to determine the toxicity level of the water. But Olsen said officials believe they know what happened: that the circumstances of blue-green algae in the lake — as it has in other lakes around Minnesota lately — has caused the danger.

“I’m not saying it’s not serious, because (the algae) could do serious damage,” Olsen said. “It’s not just Lake Benton however. It’s a combination of things, like nutrient levels and a warmer than usual September. The setup was perfect for blue-green algae.”

The Minnesota Pollution Control Agency is warning residents on several lakes, including Lake Benton, that this type of algae can be harmful to people or animals. There are at least two others lakes that have been identified by the MPCA, Lake Crystal and Fish Lake.

The Department is advising people not to swim or wade in water and to keep pets or farm animals out of the water until the algae clears up.

Olsen believes that the water in Lake Benton probably has already cleared up. He said the most concentrated bloom was likely in the lake last week.

“This type of thing typically happens in lakes every year,” Olsen said. He also said residents should be concerned when they see a “latex-like sheen” on the water.

Although this blue-green algae occurs in most lakes, the type and concentration can vary considerably from lake to lake. This bloom, Olsen said, is not tied to the invasive curlyleaf pondweed. Blue-green algae can thrive in wrm, nutrient-rich lakes which are located in rural Minnesota. Sometimes, the MPCA says, the nutrients can become so abundant that they dominate the lake, turning parts of it bright green or bluish green, with the water taking on a “pea soup” consistency. And occasionally, these blooms turn toxic. Although such algae is relatively common in late summer, most blue-green algae does not become toxic. And they can also go from harmless to toxic, back to harmless again, without necessarily changing appearance. Sometimes wind will dissipate the toxic bloom in just a short time, and at other times, wind can blow mats of the floating algae to the shoreline. Most problems then occur when algae clumps near the shoreline and pets, wild animals or farm animals — or humans — get into the water.

Steve Heiskary, a lake expert with the MPCA, said this year’s bloom seems to have had more than the usual number of toxic blooms. “Heavy rains this spring and early summer probably carried more than the usual amount of nutrients into surface water,” he said. “And this could be why we’ve had more problems this season.”

Tom Conroy, a DNR information officer in New Ulm, said the combination of abnormally warm temperatures and the opening of Minnesota’s hunting seasons can be “a potentially dangerous situation for hunting dogs.” Not only are there concerns about dogs ingesting toxic blue-green algae but there is also the danger that dogs can “quickly become overheated in warm temperatures,” he said. “Dogs don’t know when to quit so it’s up to the owner to make sure it doesn’t overdo it. Keep a close eye on your dog. Don’t let it drink or lick algae off itself, rest it often and have plenty of cool water on hand.”