New summer, same problem.
The weeds in Lake Hopatcong in New Jersey are back and, according to at least one aquatic and watershed management expert, are “some of the worst” in recent memory.
Fred Lubnow, director of aquatics programs at Princeton Hydro, has been studying the lake for more than 20 years. He said in the last two years the weed problem in Lake Hopatcong has been as bad as it was in the early 1990s.
The recent mild winter contributed to the weed growth this year, he said. But two factors are really contributing to the weed growth in Lake Hopatcong: nutrients that come into the lake and settle down in the sediments and sunlight reaping the sediments, which stimulates plant growth.
There are a number of ways to manage aquatic plant growth, he said, but the most common is mechanical weed harvesting.
“Even though it’s expensive and there’s a lot of cost associated with the machinery, you can more selectively remove vegetation,” Lubnow said. “And more importantly, as you remove that vegetation, you’re removing nutrients out of the lake and sediments as well. So there’s an ecological value to mechanical weed harvesting.”
Lubnow said that when the weed harvesting in Lake Hopatcong was operating at full capacity, there was a, “major reduction in the amount of weeds.”
“We’ve seen that when we have sustained harvesting over a number of years it does help reduce that seed bank and the amount of vegetation in there,” he said.