For the past 11 years, DEP staff have volunteered with the Bucks County Conservation District to remove invasive water chestnuts (Trapa natans) from Lake Towhee for the annual "Paddle With a Purpose" event. Located in Haycock Township in Upper Bucks, this 50+ acre lake needs help fighting this intrusive invader.
From July 1 through August 16, DEP employees volunteered their time to kayak and canoe around Lake Towhee and manually pull and remove these invasive plants, which have taken over much of the lake's surface. These water chestnuts are damaging to native biodiversity and make large portions of the lake virtually unusable for recreation. Until recently, manual removal was the only strategy available to fight the invasion in Towhee. The plant material is then dumped inland in the woods to compost. For the past two seasons, thanks to funding from the PA DEP Growing Greener program, volunteer mechanical removal efforts have been aided by targeted herbicide application to further knock back this aggressive invader.
The dense growth of water chestnuts stops light from penetrating the surface of the lake and prevents other aquatic plant life from growing. Water chestnuts also outcompete most other plants for nutrients and space. Both the reduction of other plant growth and the decomposition that occurs when chestnut plants die decrease dissolved oxygen levels, which is damaging to fish and other aquatic life.
Not only are they bad news while they're growing in the lake, each water chestnut plant can drop up to 20 seeds, and each seed remains viable for up to 12 years. In addition to the detrimental environmental impacts, mature seeds have spikes sharp enough to penetrate tires, shoes, and skin, making them a major nuisance to recreation in regions where the chestnut is present. It's obvious why this annual event is so important.
Of course, we can't talk about a 2020 event without talking about COVID-19 and how the organizers had to adapt to ensure that all participants were able to adhere to CDC and Commonwealth recommendations pertaining to social distancing. Meghan Rogalus, the event's organizer, laid out these changes in an email to volunteers. Instead of everyone gathering for a few days, the event was expanded to a month and half to allow for smaller groups to spend a few hours at a time. Unlike years past, volunteers were asked to bring their own boats instead of sharing kayaks and canoes. Volunteers were also strongly encouraged to wear masks if volunteering with others from outside of their household.
"Despite the extra precautions, this year's event remained wildly successful," said Rogalus. "While we were saddened to not be able to connect directly with our volunteers and celebrate our conservation efforts, we are encouraged by how many still dedicated their time to help keep Lake Towhee from being overrun by these invasive plants. We're hopeful that by next summer, we can reconvene on the banks of the Lake and pull the chestnuts together."
These efforts were not in vain. Rogalus reported that this year, just over 50 people have removed over 10 cubic yards, or approximately 3 tons, of plant material. Since 2009, when the pull first began, the amounts of plant material removed and volunteer hours have steadily risen.
Ed Filip, Stream Assessment Biologist in DEP's Southeast Region, has participated in the chestnut pull for the past ten years, and organizes the volunteer effort for the DEP Southeast Regional Office through email signups and carpools. He feels that the project is well worth the time, physical labor, and taking all COVID precautions.
"I've been involved in all but one of the cleanups, so I've seen the difference we've been making," said Filip. "We've cleaned up most of the lower half of the lake slowed the rate of reemergence and even made some inroads to the choked-out upper portion; not just holding the line, but pushing back. If it were not for our efforts, most of the lake would be overrun with water chestnuts. Native plant populations, fishing, boating, recreation: all of these things have improved. And we are helping to keep this invasive species from spreading to the much larger Lake Nockamixon downstream, where it could become an even bigger problem than it is now."
Like with all things, COVID has forced us to assess and reassess how we do things. So, whether you're in line at the grocery store or pulling invasive water chestnuts with your colleagues, remember to wear your mask and practice social distancing.