Volunteers Emily Nelson and Ray Carlson from the Audubon Community Nature Center (ACNC) remove invasive water chestnut plants from the Chautauqua Lake Outlet. Photo by Twan Leenders

As the trees are signaling the end of another growing season in quite a spectacular fashion, I reflect on the less obvious end-of-season changes to the submerged aquatic vegetation in Chautauqua Lake.

CWC’s Aquatic Invasive Species (AIS) Early Detection Network may appear similarly unassuming, yet it plays a critically important role in maintaining the health of the lake. When it comes to new invasive species, early detection and rapid action are the critical next steps in case prevention fails. And our staff, volunteers, and program partners have been very busy this summer keeping potentially harmful new invasives from getting a foothold here.

The old adage “an ounce of prevention is worth a pound of cure” very much holds true when it comes to invasive species. To avoid economic or ecological harm, it is always best to prevent them from establishing. During the high-traffic summer season on Chautauqua Lake, boat steward programs are in place at several boat launches to educate boat owners on the importance of cleaning watercraft and equipment so that no vegetation fragments are inadvertently transported in from elsewhere. At least half a dozen new aquatic invasive species are known to occur within an easy drive’s distance from Chautauqua County, and any could hitch a ride here and potentially spell bad news for the lake. Voluntary boat checks are not a perfect defense against new invasives, though, and some will eventually find their way in.

This is exactly where the AIS Early Detection Network shines. Through targeted education and outreach efforts, CWC staff trains volunteers in the identification of watchlist nuisance species through in-person and online training sessions. Next, instructors and students take to the water for “online classroom” experiences that are hosted in areas where new invasives have been reported in years past. Such on-water surveys allow volunteers to apply their newfound identification skills while simultaneously re-surveying areas where potentially harmful invasives may persist. If found, such target species are reported through the online reporting portal www.imapinvasives.org and the offending plants are carefully removed.

It is in exactly this manner that, under the guidance of CWC staff, lake stewards, volunteers, and community partners, hundreds of invasive water chestnut plants have been removed from the Chautauqua Lake outlet. This high-priority invasive species was detected shortly after it first arrived in the lake some years ago, and it has been effectively managed since. Water chestnut plants reproduce by dropping spiky nutlets by late summer. Every plant can produce 15-20 nutlets, each able to grow 10-15 new plants. Once dropped in the sediment, nutlets remain viable for up to 12 years. Clearly, these plants will spread exponentially if not properly managed, and their timely removal is critical. Even removal of a single water chestnut plant can prevent dozens from appearing the next year. And the longevity of their seeds indicates why annual re-surveys of previously treated areas is necessary.

Another example of the effectiveness of this program is the discovery this summer of two “meadows” of the plant-like algae starry stonewort. This invasive has been in Chautauqua Lake in low densities since 2009, but for reasons still unclear, it recently exploded to nuisance levels in these locations and now cover more than 7 acres. Fortunately, rapid re-surveys of other areas where starry stonewort had been found previously did not reveal such growth. The AIS Early Detection Program and its stewards will continue to keep a watchful eye on these areas while we figure out, in collaboration with aquatic invasive species experts and local partners, how to best keep starry stonewort from expanding farther into Chautauqua Lake.

While prevention may have failed in both of these cases, early detection and rapid action are stopping these newcomers from becoming a systemic threat to Chautauqua Lake. Please be a vigilant lake user and consider joining our programs next season. With more watchers on the water, you too can help keep Chautauqua Lake healthy!

The Chautauqua Watershed Conservancy is a not-for-profit organization with the mission to preserve and enhance the water quality, scenic beauty and ecological health of the lakes, streams, wetlands and watersheds of the Chautauqua region. For more information, call 716-664-2166, visit chautauquawatershed.org and follow CWC on Facebook and Instagram.