Notes on the Occurrence of Northern Snakehead in a Mid-Atlantic Lake System: 16 Years of Monitoring

Colin R. Rohrback^1,*, David H. Keller¹, Paul F. Overbeck¹, and Daniel P. Morrill¹

¹Patrick Center for Environmental Research, The Academy of Natural Sciences of Drexel University, 1900 Benjamin Franklin Parkway, Philadelphia, PA 19103. *Corresponding author.

Northeastern Naturalist, Volume 30, Issue 4 (2023): 429–439

First published early online: 24 November 2023

Abstract
Channa argus (Northern Snakehead) was first discovered in Pennsylvania and the Delaware River watershed in 2004 in Franklin Delano Roosevelt Park (FDRP), Philadelphia, PA. We monitored this population by boat and/or backpack electrofishing from 2005 to 2021. Our objective was to summarize common population characteristics and compare these with other non-native Northern Snakehead populations. Length-at-age data indicated the FDRP population was slower growing and lacked larger individuals relative to other populations. Data from stomach dissection documented feeding on Anguilla rostrata (American Eel), Lepomis macrochirus (Bluegill), Lepomis gibbosus (Pumpkinseed), Fundulus diaphanus (Banded Killifish), and Micropterus salmoides (Largemouth Bass), suggesting potential impacts to these species. Backpack electrofishing in 2005 and 2008 showed significant decreases in the densities of American Eel and Banded Killifish which may be due to predation by Northern Snakehead.

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