Large RiversLess physical stability

Difficult to sampleHighly modified Commercial fishing

on large rivers

The Wabash RiverLongest free flowing river

east of the Mississippi RiverSubstantial commercial

fishery for catfish 300 licenses 34 tons of harvest

Southeastern border of IllinoisDifferent management

strategiesIL=15 inches (381 mm),

IN=10 inches (254 mm)

Catfish FisheriesImportant to fishers of

the Midwestern and southern United states.

One in four anglers in the United States target catfish

Issues with management

Flathead CatfishPylodictis olivaris

Popular sportfish and commercial speciesBig, mean, taste good Oklahoma

They are thought to be sedentary

Typically have self-sustaining populationsIllinois ?

Demographics of a Commercially Exploited Population of Flathead Catfish, Pylodictis olivaris, 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

OverviewWhy??

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

Why?Wabash River

Biological sampling (10%) vs. commercial fishing harvest (27%)

Information on population scarceSampling protocols inefficient

Indiana’s harvest limits may change Must be 15 inches (381mm) and only one fish over

35 inches (889 mm)Trophy?

Objectives of StudyEstablish 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

Where?Lower 200 miles 10-1 mile sites

Upstream Darwin Downstream New

Haven

How?Active

ElectrofishingDC and AC1 hour at each site

PassiveTrotline

2 lines per site25 hooks per lineCut bait

How?Passive

Hoopnets15 nets each siteBar mesh 1,1.5,2 inches Commercial fisherman

harvestJohn FarmerSaving fish ≥30 lbs

How?Movement and habitat

assessment25 fish with ultra

sonic tagsStationary VR2

receiversManual tracking with

VR60

How?Age, growth, and mortality

Pectoral spines from fish >200 mm TL, floy tagSectioning the articulating process Pictures of “best” section and counting annuli

Results

*trotlines had very low catch rates

DC Electrofishing (N=240)

120

160

200

240

280

320

360

400

440

480

520

560

600

640

680

720

760

800

840

880

920

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

Total Length (mm)

Pro

port

ion

mean=264.9median=237.5

AC Electrofishing (N=39)

120

160

200

240

280

320

360

400

440

480

520

560

600

640

680

720

760

800

840

880

920

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

Total Length (mm)

Pro

port

ion

mean=296.8median=278

Hoopnetting (N=163)

120

160

200

240

280

320

360

400

440

480

520

560

600

640

680

720

760

800

840

880

920

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

Total Length (mm)

Pro

port

ion

mean=509.9median=505

Age Structure of Flathead Catfish (2010)

1 2 3 4 5 6 7 8 9 10 11 12 130

5

10

15

20

25

30

Age (years)

Fre

quen

cy (#

)

Mean=2.9 yearsMedian=3 years

What Now?Aging fish from 2011, growth and mortality estimatesFall hoopnetting runLive bait trotlines???Continue to use a multi-gear approachMovement assessment

Acknowledgements

Eastern Illinois University graduate students and undergraduates

Illinois Department of Natural ResourcesIllinois Natural History Survey

Questions?

Guess Who???