Trends in Abundance of Northern Snakeheads in Virginia Tributaries of the Potomac River

Abstract

AbstractA population of nonnative Northern Snakeheads Channa argus was documented in the Potomac River system during 2004. We estimated relative abundance (fish/h of boat electrofishing) for up to 12 years in four Virginia creeks within and downstream of the original area of colonization. Population estimates were also calculated for adult Northern Snakeheads in Little Hunting Creek (one of the four study creeks). Relative abundance increased dramatically after colonization, but trends suggest that increases in abundance may have slowed. Population estimates for Little Hunting Creek (12–22 fish/ha) declined each year from 2013 to 2015, supporting the assertion that Northern Snakehead density increases have slowed or that density has stabilized in some creeks.Received October 6, 2015; accepted January 26, 2016 Published online June 15, 2016