HARVEYS LAKE — What’s green and floats and will help bolster Harveys Lake’s water quality?
On Tuesday, almost 30 folks gathered at Sandy Beach to set thousands of plants into five large floating islands that will soon lap lazily offshore, soaking up excess nutrients that feed the lake’s chronic algae problem.
The plants atop each 250-square-foot island can absorb about 10 pounds of phosphorus each year, Fred Lubnow, an aquatic expert from the New Jersey-based firm Princeton Hydro, said.
That may not sound like much, Lubnow said, but then he stepped to the water’s edge and scooped up a handful of soggy green slime.
“One pound of phosphorous can generate up to 1,100 pounds of that stuff, the green cotton candy,” Lubnow said.
Three of the islands will be anchored near Sandy Beach, a fourth will be anchored near Kunkle Alderson Road, and the fifth will sit near the southern point. They all are to be set up inside the no-wake zone. The islands will have reflectors, but swimmers and boaters are advised to stay vigilant while out on the water.
Two similar islands were anchored on the lake at Frances Slocum State Park in Kingston Township last year.
Native plants including sedge grass, bullrushes and ironweed are planted on the flat, matted pads, which are made from recycled plastic. Milkweed often has been added to attract butterflies, Lubnow said.
The islands won’t necessarily help increase fish populations, but fish often hang around them to munch on bugs that feed on the plants, Lubnow said.
Lubnow said he has been to working to balance algae growth in Harveys Lake for more than 20 years and he has made significant strides with the help of the lake’s Environmental Advisory Council.
About a decade ago, state Department of Environmental Protection determined phosphorus produced naturally in the lake exceeded optimal limits by about 23 percent each year, advisory council chair Sid Halsor said.
Since then, officials have been tweaking the rules at the lake to curb sedimentation and balance plant growth.
The borough enforced a don’t-feed-the-ducks ordinance that has trimmed the number of ducks on the water, advisory council member Michael Daley said. Duck and goose droppings create large amounts of phosphorous, and the ordinance has reduced it by as much as 10 percent each year, Daley said.
Over the years, about 250 catch basins were installed around the lake to filter out sediment from the inlets that feed the lake. Those basins are cleaned twice yearly to keep the sediment from reaching the lake, where eventually it would decompose and spur more algae growth.
The borough also has an ordinance forbidding phosphorus as grass fertilizer on lakeside properties. It’s hard to enforce, Daley said, and he turned his head nodding toward some emerald lawns.
But Daley said they’ve tried to make residents aware that things such as duck-feeding, phosphorus fertilizer and leaving dog waste set in the yard all boost nutrient levels in the lake. Oftentimes, it’s enough to make a difference.
The islands and the research behind them were paid for with a federal Environmental Protection Grant through the state DEP. Planning began around 2010 and, in all, the project has cost around $100,000, DEP spokeswoman Colleen Connolly said.
The islands are part of a long-term plan designed to preserve fish populations, balance plant growth and keep the water clean.
“If plant life and aquatic life can’t survive, how’s the lake going to survive?” Connolly said. “So this is an intricate, small part of preserving the life of the lake. The benefits will be seen 10 to 20 years from now.”