top of page

Summer Event Challenges Participants to Hunt for Water Chestnut


Story written by Amy Jewitt, Pennsylvania iMapInvasives Coordinator

September 2017

Water chestnut (Trapa natans) is considered a high priority invasive species in Pennsylvania because it causes significant harm to the environment and is not (yet) widespread within the state. Given this status, findings of water chestnut should be documented in a database such as iMapInvasives and managed quickly to ensure spread does not occur into new waterbodies or continue to invade waterbodies where infestations currently exist. 

Earlier this summer, the Pennsylvania iMapInvasives program issued a challenge to anyone willing to accept it: In the month of July, visit your local lake, pond, stream, or river and search for water chestnut. Report your findings, both presence and absence, to iMapInvasives using your desktop computer or mobile device. At the end of the month, all findings recorded in iMapInvasives will be tallied and a grand prize awarded to the person with the most records documented in iMapInvasives.

Reservoir in Bucks County, PA, completely infested with invasive water chestnut. Credit: Nicholas Macelko, PSU Eco Action

and efforts related to the management of invasive species.  

Eleven people accepted the "Water Chestnut Chasers Challenge", representing a group of both natural resource professionals and citizen scientists.

Findings from the challenge indicated a handful of new waterbodies in Bucks County (southeastern Pennsylvania) that were heavily infested with water chestnut. These new infestations were not previously known about (according to data in PA iMapInvasives) and represent important "early detection" findings.

In total, waterbodies located in 19 counties in Pennsylvania were searched by challenge participants, and thankfully, many did not contain water chestnut infestations.

One unexpected outcome from the challenge was the opportunity to shine a spotlight on the importance of data from citizen scientists, a group of people often overlooked for their contributions to science

Close-up of dense water chestnut infestation in Bucks County reservoir. Credit: Nicholas Macelko, PSU Eco Action

In the case of the 2017 water chestnut challenge, many of the new (positive) findings came from a citizen scientist.


Data resulting from the challenge are intended for use by natural resource professionals all across Pennsylvania who have an interest in managing this high priority aquatic invader. 

Learn more about the results of the 2017 Water Chestnut Chasers Challenge by clicking the "data analysis" button below.

Water chestnut (Trapa natans) 

Credit: Ron Keeney, Conewango Creek Watershed Association

bottom of page