Paddle with a Purpose: Remove Water Chestnut

Photo of water chestnut

Water Chestnut

Water chestnut (Trapa natans) is an aquatic invasive plant that impacts lakes by quickly covering the water’s surface, forming dense mats that block sunlight and compete with native vegetation for space and nutrients, disrupting the aquatic foodweband habitat structure. The plant also dramatically impedes recreation: dense plant mats clog boat motors and make paddling extremely difficult and spiny seedpods pose hazards to swimmers’ feet and even boat trailer tires. Because water chestnut is not native to North America (its native range is parts of eastern Europe, western Asia, and portions of Africa), our native wildlife and pest species cannot keep the population in check. In addition to being released from predators and diseases here, the plant also spreads rapidly because it has multiple means of reproduction – it is an annual plant that primarily spreads by seed, but it can also reproduce from small plant fragments. Once a population is established, water chestnut management requires a long-term effort because after plants flower annually in late June, they produce about 10-20 seedpods, which can remain viable on a lake bottom for up to 12 years!

 

Staff show volunteers plant

Meghan shows participants how to identify water chestnut.

Water chestnut was first documented on Lake Towhee in July 2009; however, at that time over half of the lake was already impacted by this plant. Since August 2009, Bucks County Conservation District (BCCD) has coordinated an annual event branded ‘Paddle with a Purpose’ (PWAP) with partners from the Bucks County Parks and Recreation Department, Pennsylvania Department of Environmental Protection (PADEP), Nockamixon State Park and Delaware Canal State Park. From 2010 on, the event has been timed between mid-June and mid-July to remove plants before the seeds mature. During the event, volunteers are educated on plant identification and impacts and then paddle (in canoes or kayaks) or slowly motor to different sections of the lake to pull as much of each plant from the lake as possible. Some volunteers work with BCCD staff on shore to assist boaters with unloading their quarry. BCCD staff then haul the plant material to a pre-approved composting site. Lake Nockamixon, the largest reservoir in Bucks County. is only 2 miles downstream of Lake Towhee and has had small populations of water chestnut. By managing the water chestnut population at Lake Towhee, our ultimate goal is protecting large portions of Lake Nockamixon from being overrun by this invasive plant.

In addition and thanks in large part to the documented long-term and ongoing commitment of volunteers, partners, BCCD management and staff, BCCD was awarded a Growing Greener grant in Spring

photo of paddlers with bags of trash

Volunteers paddle back with bags full of water chestnut.

2018 to build upon existing efforts and fund additional invasive control and monitoring in the watershed. This funding has supported targeted herbicide applications were initiated on the lake in 2019 and more will be completed in the 2020 season. This multi-pronged approach is critical to make a lasting impact on water chestnut in Lake Towhee and downstream Lake Nockamixon.This event started small but has steadily grown over the past 12 years. One key factor to the success and growth of the event was primarily the strength of the partnership between the county-level organizations and the state agencies: all were committed to preventing a continued, unchecked spread of the plant to Lake Nockamixon. Another major component was a loyal and consistent contribution of local volunteers who return year after year to assist with this event and help spread the word.

 

Due to health and safety concerns surrounding COVID-19, our 12th annual volunteer event is structured a bit differently. BCCD will provide kits of supplies to volunteers to collect water chestnut and deposit it in bags on the shoreline for BCCD staff to pick up and bring to the composting location. After receiving their supplies via mail or contactless delivery volunteers can conduct safe, socially distanced water chestnut pull(s) anytime in the window of July 1 through August 16. Volunteers who participate must complete a waiver and provide their own boat, PFD, and paddle. We ask that volunteers leave full bags of water chestnut at a designated location in the park and BCCD will follow-up with responsible disposal of the collected plant material.

Your support, even for just a few hours of your time, is more important than ever to keep up the momentum! Please contact Meghan Rogalus, BCCD’s Watershed Specialist, to get involved.