Green algae on Glade Run Lake is not only nontoxic, it's beneficial, according to Dave Fowler, a Glade Run Lake Conservancy board member and geologist. It serves as sustenance for fish, crawfish, ducks, muskrats and other species, he said.

MIDDLESEX TWP — While the toxic blue-green algae that has killed dogs throughout the country might appear similar, the green stuff on Glade Run Lake is not only nontoxic, it's beneficial.

Dave Fowler, a Glade Run Lake Conservancy board member and geologist, said the green algae now living on the lake's surface appears every year in late summer and serves as sustenance for fish, crawfish, ducks, muskrats and other species.

“The algae in the lake is not blue-green algae,” Fowler said. “It's good stuff.”

Fowler, whose home is adjacent to the lake's property, said the lake is safe for dogs.

“I have a Chesapeake Bay retriever,” he said. “She swims up and down the lake almost every day.”

He said the 52-acre lake's water is tested regularly for chemical composition through a collaboration between the conservancy and the state Consortium for Scientific Assistance to Watersheds (C-SAW) program, which is funded by a Growing Greener Grant from the state's Department of Environmental Protection.

The testing ensures the lake is not too rich in phosphorus or nitrogen, Fowler said.

“That gives an indication for the presence of blue-green algae,” he said.

Since the dam was repaired in 2017 and the lake refilled, it has served as a successful habitat for many birds, Fowler said.

One recent resident has been the great egret, a large white bird that is on Pennsylvania's endangered list.

Fowler said at four feet tall, the birds are almost the size of the great blue herons that have become a commonplace sight in the county.

“(The great egrets) are pretty impressive birds,” Fowler said.

He said the smaller, mohawk-topped green herons, tundra swans, osprey, loons and a variety of ducks call Glade Run Lake home or visit at certain times of the year.

The endangered black-crowned night heron and yellow-crowned night heron have also been spotted at the lake.

“Glade Run Lake is one of the best places to observe birds in this whole area, according to a noted ornithologist,” Fowler said.

A stately bald eagle also has been seen casing the lake recently, Fowler said.

“An expert from the National Aviary said he might be looking for a place to nest next spring,” he said.

Many other small mammals, amphibians and reptiles thrive at the lake.

“I counted 21 frogs in 10 seconds the other day,” said Fowler, who kayaks in the early morning.

He said more than 150 fish structures have been installed in the lake. Some were associated with 20 Eagle Scout projects carried out there.

Completion of a walking trail, bat boxes, conservation benches and chimney swift towers are some of the other Eagle Scout projects that have enhanced the lake property, Fowler said.

He said the fingerling bass stocked in the lake in April 2017 by the state's Fish and Boat Commission have flourished, and are now 10 inches long.

Channel catfish, blue gill and other forage fish placed into the lake are also thriving.

“The fish population is just going like crazy,” Fowler said.

He said the conservancy invites residents to enjoy the refilled and improved lake off Overbrook Road.

“We've got kind of an environmental gem here,” Fowler said.