Midwest Fish & Wildlife Conference 2016

AUTHORS: Jeremiah J. Davis*, USFWS Carterville FWCO- Wilmington Sub-station; Samuel T. Finney, USFWS Carterville FWCO; Rebecca N. Neeley, USFWS Carterville FWCO- Wilmington Sub-station; Robert L. Simmonds USFWS Carterville FWCO

ABSTRACT: A series of large electric fish barriers exists in the Chicago Sanitary and Ship Canal to prevent the dispersal of bigheaded carps between the Mississippi and Great Lakes basins while simultaneously allowing the passage of commercial barge traffic. Recent studies by the USFWS utilizing caged and tethered fish showed that tethered fish could become entrained within junction spaces between barges and transported upstream. Caged fish that were placed within rake to box junctions between barges were carried across the Electric Dispersal Barrier without becoming incapacitated. Here, we investigate the potential for entrainment, retention, and transport of freely swimming fish that were not caged or tethered within the rake-to-box junctions between barges traveling on the Illinois River. A modified mark-recapture approach was employed to provide direct evidence of fish transport by barge tows. This approach was supplemented with a multi-beam sonar fish observation system that was deployed into the rake-to-box barge junction. This system made direct observations that allowed quantification of entrainment and retention rates. Trials took place in the Upper Illinois River at the Electric Dispersal Barrier, in Lockport Pool, at Lockport Lock, in Brandon Road Pool, at Brandon Road Lock, and in Starved Rock Pool. The results presented here provide insights into the potential for entrainment, retention, and transport of freely swimming fish by barge tows, as they traverse substantial barriers to fish dispersal in the Illinois River.