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Early Detection of Invasive Species in the Lake Erie Watershed

Updated: Feb 5, 2021

The following article was written by Mary Walsh, Aquatic Ecologist with the Pennsylvania Natural Heritage Program and was originally included in the Spring 2020 edition of the "Tracking Invasive Species with Pennsylvania iMapInvasives" newsletter.

Pictured above: Lake Erie Watershed. Credit: Kierstin Carlson, WPC/PNHP

Transplanted outside their native ranges, invasive species can have population explosions, outcompete native organisms, and be destructive to ecosystems. Large and widespread infestations of invasive species are costly and time-consuming to manage. Early detection of a newly established invasive species with rapid control of the infestation can minimize adverse impacts, as well as greatly reduce the costs of removal or remediation.

Natural resource professionals, land owners, and others should be on the lookout for newly arrived invasive species so that timely and efficient responses can occur. To this end, the Pennsylvania Natural Heritage Program and the Lake Erie Watershed Cooperative Weed Management Area developed educational information about 13 early detection invasive species in the Lake Erie watershed in Pennsylvania and presented it during a March 31, 2020 webinar titled “Be on the Lookout! Report Findings of High Priority Invaders in Northwest Pennsylvania”.

Invasive species determined to be priorities for early detection for the watershed include plants that invade uplands, riparian areas, and waterways. A selection of them are discussed here in this newsletter article.

One early detection plant, porcelainberry (Ampelopsis brevipedunculata), is a vine which grows densely over native vegetation. Seeds from its berries may be spread to distant locations by birds. Another aggressive invader, lesser celandine (Ficaria verna), becomes abundant and outcompetes native spring ephemerals in forested floodplains. To date, porcelainberry and lesser celandine are each recorded from only a few locations in the Lake Erie watershed in Pennsylvania.

Pictured above: Porcelainberry (top left), Lesser celandine (top right), European frog-bit (bottom left), Yellow floatingheart (bottom right). Photo credits (in same order): James Miller, Leslie J. Mehrhoff, Leslie J. Mehrhoff, Shaun Winteroton

In aquatic ecosystems, early detection plants in the Lake Erie watershed in Pennsylvania include two floating plants: European frog-bit (Hydrocharis morsus-ranae) and yellow floatingheart (Nymphoides peltata). Both species crowd out native plants and clog waterways. Considered highly invasive, European frog-bit is recorded from only a few counties in Pennsylvania. European frog-bit is not yet known from the Pennsylvania portion of the Lake Erie watershed; however, yellow floatingheart has been documented in sparse locations in the watershed. The plants both have rounded floating leaves and are spread easily by fragmentation.

Additional information about porcelainberry, lesser celandine, European frog-bit, yellow floatingheart, and other early detection invasive species is available from the March 31st webinar recording and associated presentation. Information includes photos, distinguishing characteristics of early detection species, and look-alike species.

Any findings of early detection invasive plants can be documented in the iMapInvasives database, which is available online or through the iMapInvasives mobile app. In addition, the Pennsylvania iMapInvasives Program may be contacted for more information about early detection plants and can provide assistance with plant identification. You can email the program at


Additional Resources:

The purpose of this guide is to help people slow the spread of invasive species in Pennsylvania. Therefore, in addition to identification, it includes sections on prevention, reporting, and collecting specimens.

For identification of invasive plants, treatment, and protection for your property, explore the fact sheets provided on the DCNR website. DCNR has deemed the trees, shrubs, vines, herbs, and aquatic plants highlighted in these fact sheets to be invasive on state lands and are managed by DCNR staff.


About the Author

Mary Walsh coordinates the aquatic zoology program at the Pennsylvania Natural Heritage Program. She works on inventories of aquatic invertebrates and communities, assesses conservation statuses, models species distributions, and tracks invasive species with the iMapInvasives database.

When she’s not managing projects with the PNHP, Mary watches thriller series, devours novels, and hikes with her family. You can contact Mary by email at


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