‘Lake Mess Monster’ sucks up scum in Prospect Park

Invasive species coats Prospect Park lake in green sheen
Photo by Bryan Bruchman

You can call him a “scum sucker” — and mean it as a compliment.

Prospect Park-goers can thank nature technician Martin Woess — and the lake-cleaning boat he operates — for decreasing the amount of green slime that harms aquatic life in the watercourse, park officials say.

The city-sanctioned machine, dubbed the “Lake Mess Monster,” sucks up an invasive fern from the lake’s surface and stores it in the base of the boat, preventing the rapidly growing gunk from suffocating other organisms.

Prospect Park Alliance spokesman Paul Nelson credits the procedure with reducing the so-called Azolla Caroliniana bloom on park waterways.

“It’s one of the reasons why the lake is not choked with azolla, which is pretty much gone,” Nelson said.

Woess, who works for Prospect Park Alliance, steers and positions the machine’s vacuum-like apparatus over the slime once every week in the fall.

Prospect Park’s lake-cleaning machine — the “Lake Mess Monster” — helps get the gunk out of the lake.
Photo by Elizabeth Graham

And proving that there really is a circle of life in Prospect Park, workers then compost the scum and use it as fertilizer in the park — killing one plant to help others grow.

The visibly less-green lake comes after park-goers complained over the summer that the thick slime scares away waterfowl, blinds turtles, and sickens mammals.

Some park watchdogs say the growth is still a problem, especially near the dog beach.

“Large mats of azolla are decomposing, causing widespread de-oxygenation of the water — affecting organisms such as fish and other aquatic life negatively,” said greenspace activist Anne-Katrin Titze said.

Nelson said the amount of scum has decreased in the past two months, but noted the agency has not officially tested levels of the azolla because one can simply eyeball it — unlike some forms of lake bacteria.

Reach reporter Natalie O'Neill at [email protected] or by calling her at (718) 260-4505.

Prospect Park's lake was covered with tons of scum this summer.
Photo by Bryan Bruchman