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Large Rivers

Large Rivers. Less physical stability Difficult to sample Highly modified Commercial fishing on large rivers. The Wabash River. Longest free flowing river east of the Mississippi River Substantial commercial fishery for catfish 300 licenses 34 tons of harvest

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Large Rivers

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  1. Large Rivers • Less physical stability • Difficult to sample • Highly modified • Commercial fishing on large rivers

  2. The Wabash River • Longest free flowing river east of the Mississippi River • Substantial commercial fishery for catfish • 300 licenses • 34 tons of harvest • Southeastern border of Illinois • Different management strategies • IL=15 inches (381 mm), IN=10 inches (254 mm)

  3. Catfish Fisheries • Important to fishers of the Midwestern and southern United states. • One in four anglers in the United States target catfish • Issues with management

  4. Flathead CatfishPylodictisolivaris • Popular sportfish and commercial species • Big, mean, taste good • Oklahoma • They are thought to be sedentary • Typically have self-sustaining populations • Illinois ?

  5. Demographics of a Commercially Exploited Population of Flathead Catfish, Pylodictisolivaris, in the Wabash River Cassi J. Moody1, Leslie D Frankland2, Greg G. Sass3 and Robert E. Colombo1 1Biological Sciences Department, Eastern Illinois University, Charleston, Illinois 61920, USA 2Illinois Department of Natural Resources, Division of Fish and Wildlife, 3Illinois Natural History Survey, Illinois River Biological Station, 704 North Schrader Avenue, Havana, Illinois 62644, USA

  6. Overview • Why?? • Information scarce, changing regulations • Where? • Boundary water of the Wabash River • How? • Proposed sampling protocol • What Now? • Use of preliminary results and future of study

  7. Why? • Wabash River • Biological sampling (10%) vs. commercial fishing harvest (27%) • Information on population scarce • Sampling protocols inefficient • Indiana’s harvest limits may change • Must be 15 inches (381mm) and only one fish over 35 inches (889 mm) • Trophy?

  8. Objectives of Study • Establish a long term monitoring program for catfish • Determine the most effective sampling methods • Assess habitat use and movement • Estimate current state of population before and after shift in management

  9. Where? • Lower 200 miles • 10-1 mile sites • Upstream Darwin • Downstream New Haven

  10. How? • Active • Electrofishing • DC and AC • 1 hour at each site • Passive • Trotline • 2 lines per site • 25 hooks per line • Cut bait

  11. How? • Passive • Hoopnets • 15 nets each site • Bar mesh 1,1.5,2 inches • Commercial fisherman harvest • John Farmer • Saving fish ≥30 lbs

  12. How? • Movement and habitat assessment • 25 fish with ultra sonic tags • Stationary VR2 receivers • Manual tracking with VR60

  13. How? • Age, growth, and mortality • Pectoral spines from fish >200 mm TL, floy tag • Sectioning the articulating process • Pictures of “best” section and counting annuli

  14. Results *trotlines had very low catch rates

  15. DC Electrofishing (N=240)

  16. AC Electrofishing (N=39)

  17. Hoopnetting (N=163)

  18. Age Structure of Flathead Catfish (2010)

  19. What Now? • Aging fish from 2011, growth and mortality estimates • Fall hoopnetting run • Live bait trotlines??? • Continue to use a multi-gear approach • Movement assessment

  20. Acknowledgements • Eastern Illinois University graduate students and undergraduates • Illinois Department of Natural Resources • Illinois Natural History Survey

  21. Guess Who??? Questions?

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