Dr. Fred Lubnow of Princeton Hydro, the Lake Hopatcong Commission’s environmental consultant, explained why blue-green algae appeared in two shallow areas of the lake at the commission’s Monday, Sept. 15, meeting.
River Styx and Crescent Cove saw a bloom of blue-green algae which can cause rashes on swimmers.
Lubnow explained that type of algae contains cyanotoxins. He said the very shallow areas cause a concentration of oxygen which in turn feeds the bloom. The water was particularly clear in these areas especially in May and June and the sunlight penetrating the water caused plant growth.
Other algaes appear in the lake but are not harmful, he said.
Phosphorous also feeds the algae and phosphorous enters the lake through runoff from overtaxed septic systems, pet waste and goose guano. The severe winter resulted in excessive snow melt into the lake.
The lake had low phosphorous for 15 years, Lubnow said, but this year, the numbers went up again.
He said the fact the summer was relatively dry without being extremely hot also had an effect on the algae.
The four lake communities need to keep storm drains clean as well, he said.
Commission Chairman Russell Felter noted the municipalities ran out of salt and had to use grits for melting ice on the roads last winter. Salt is worse for the environment, but grits clog the storm drains, he said.
Lubnow said four of five seasonal water quality tests were run. The fifth was scheduled for this week, but the testing boat was stranded in Greenwood Lake by a problem with the towing vehicle.
Dan Bello of the state park reported to the commission on the progress of the weed harvesting. He said so far 2,600 cubic yards of weeds have been pulled out of the lake. This compares to a total of 2,300 cubic yards last year. There are three weeks of harvesting left, primarily in the southern part of the lake.
Bello said the small weed harvester has been on Lake Musconetcong since Aug. 20 and is making progress.
View original article at: Algae bloom, water tests, weed harvesting reviewed at Lake Hopatcong Commission meeting