An Acre of Algae

It’s not quite as serious as the toxic algae bloom in Lake Erie that cut off Toledo’s water supply a few years back, but it’s pretty dramatic nonetheless: A pond in Maine has an acre-sized blob of algae beneath its surface, and some local officials are calling the situation an emergency.

The 53-acre Hosmer Pond is used for swimming and boating—not as a drinking water supply. The Maine Department of Environmental Protection has given residents a permit to try to remove the algae but is warning locals in the town of Camden that removing it manually will likely not be successful, as it can regrow very quickly.

At least one local resident—the volunteer pond monitor—blames the problem on construction of a ski resort uphill from the pond. Inadequate erosion control measures and resulting sediment and associated nutrients in the pond have caused or exacerbated the algae growth, she maintains, although the DEP says the construction site is now stabilized.

The volunteer monitor, who herself runs a landscaping business, notes that there are two types of algae growing in the pond, which is about 16 feet deep at most. “One forms stringy, dry masses and is relatively easily scooped; the other is more diffuse, and disturbing it in any way may actually cause more damage,” she says.

Given the problems of algae blooms, and in some cases eutrophication from nutrients and other pollutants, what options do local groups have in cases like these—besides, of course, removing the source of the pollutants? Have you dealt with algae removal—physical or chemical—in an enclosed pond system like this one?