Waterchestnut Removal
in Tonawanda Creek
The Lower Great Lakes Fishery Resources Office (LGLFRO) discovered waterchestnut (Trapa natans) in the Tonawanda Creek portion of the New York State Canal System (NYSCS) while conducting an electrofishing survey. Biological Science Technician, Denise Clay, first spotted a small, partially submerged, single rosette along the edge of the adjacent canal channel. This discovery led to further surveillance (via canoe) of adjacent backwater areas behind Ellicott Creek Island. In this 6-acre backwater, Fish Biologist, Mike Goehle and Biological Science Technician Eric Snyder, identified numerous plants and hand pulled approximately 33 lbs of waterchestnut. However, when monotypic colonies of waterchestnut measuring up to 30 feet in diameter were found, it was decided that additional support would be needed to effectively address the infestation.
On August 10, 2008 the LGLFRO led the first removal effort for the waterchestnut recently discovered in Tonawanda Creek. Partners from Buffalo Niagara Riverkeeper, New York State Office of Parks, Recreation, and Historic Preservation, the Western New York Partnership for Regional Invasive Species Management, the Army Corps of Engineers - Buffalo District, and the public all assisted in the removal effort. The Erie County Parks and Recreation Department provided logistical support and disposal for the harvested plants.
Despite periods of heavy rain, 17 volunteers and staff pulled 1,881 pounds of waterchestnut in about 3 hours of work. This tremendous effort made a sizeable impact on the north side of the park pedestrian bridge (see map), but plants to the south of the bridge could not be pulled due to weather cancellation. We estimate another 2,000-4,000 pounds of plant material remains on the south side of the bridge. We are currently investigating the possibility of conducting another pulling event to be held before the end of the season to harvest the remaining plants and eliminate as much seed bank as possible.
Map showing area where waterchestnut was pulled on 8/10/08 and where remianing plants are located. 
It is unclear as to how these plants were introduced since the previous closest reported waterchestnut sighting in the NYSCS is approximately 100 miles to the east. Waterchestnut is very abundant in the NYSCS in central NY. Ironically, since 1998, the LGLFRO has routinely sampled for fish and aquatic plants near where this infestation was found but had not identified waterchestnut until now. This is likely because the backwater area is shallow and not easily navigable by motorized boats and therefore was not previously explored. Also, survey sites for plants (2003-2005) were randomly selected and did not happen to include this area. Finally, the infestation may only recently have reached a “detectable” level.
Waterchestnut Factsheets
Below are some pictures taken during the pulling event: |
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