1. Long-term variation in the Wabash River ecosystem The Wabash River Workshop IUPUI Dec 13, 2013 Mark Pyron Center of Aquatic Biology and Fisheries Environmental Science

2. Background –Side scan sonar Long term fish assemblage –Size spectral analysis –Isotope analyses

3. Wabash River 2nd largest trib of Ohio River 85,000 km 2 watershed 764 km long

4. Upstream Wabash River: medium-sized river with gravel substrates

5. Inner bends have sandy beaches

6. Downstream: large river; some vegetated riparian buffer

7. and flat meanders

8. 230 km 1. Fish data James Gammon 1974-98 Mark Pyron 2000-8

9. Jim Gammon began project 1974-98 500-m sites Boat electrofishing

10. Electrofish 500 m Collect all fishes Measure, release Sampling Protocol:

11. Fish assemblage patterns Major gradient = river distance: substrate and habitat variation Species separate along gradients

12. Upstream: riffles, pools, gravel- cobble Blue sucker River redhorse

13. Shovelnose sturgeon Everywhere = Freshwater drum

14. Downstream: runs, sand-silt Flathead catfish Bigmouth buffalo

15. Grass carp

16. Asian carp

17. Sauger Longnose gar

18. GIS Approach to Analysis of Fish Assemblages Using Bathymetry, Water Velocity, Sediment and Woody Debris Mark Pyron, Reuben Goforth, Jayson Beugly, Scott Morlock, Moon Kim

19. Sample 1: June 2009 Acoustic Doppler Current Profiler Interfaced with Differential Global Positioning System receiver 10-km reach at Lafayette, Indiana

20. Three boats collect fishes: Ball State, Purdue, IDNR Left, Center, Right bank Individual fish assigned lat-long GPS coordinate

21. Majority of fishes along banks Blue sucker Carpsucker Freshwater drum

22. CCA 4 x 4 m

23. CCA 10 x 10 m

24. CCA 30 x 30 m

25. Summer 2012 Sidescan sonar map; most of Wabash River Collect fishes at four locations Predict assemblages for entire river

26. Highest abundances? Rank abundanceSpecies 21.2 %Silver Carp 16.1 %Gizzard Shad 12.1 %Freshwater Drum

27. CCA: species and environmental variables MEAN DEPTH Gravel

28. Long term fish assemblage –Size spectral analysis –Time lag ordination –Isotope analyses

29. Size spectral analysis: examine organisms by size Convert size-abundance matrix into size bins Regress abundances against size bins

30. Examine organisms by size Convert size-abundance matrix into size bins Regress abundances against size bins Steeper with exploitation Steep regression = inefficient ecological transfer

31. Spectral analysis Use only individuals > 162 mm SL (susceptible to boat electrofisher) Regime shift in 1990s?

32. 1974-94 1994-1999 1999-2008 steep regression = inefficient ecological transfer

34. 1974-2008 Trophic Groups

35. Diet of fishes change? Pilot analysis Isotope analyses: 13C and 15N ratios Museum archives 1960-2008 Detritivore = gizzard shad Omnivore = spotfin shiner Piscivore = spotted bass

36. One trophic level ~ 3 ppt d15N http://sofia.usgs.gov AlgaeMacrophytes

37. INHS archival fishes: Wabash River

38. Gizzard shad consume additional sources NANFA.ORG

39. Gizzard shad consume additional sources Shiner consume lower trophic sources NANFA.ORG

40. Individuals consume lower trophic levels in upstream locations

41. ISOTOPE RESULTS Diet of consumer fishes (planktivore / omnivore) in 1990s Different algae? Different nutrients? Impact of Asian carp?

42. Summary Switch in functional group dominanceSwitch in functional group dominance Omnivores + planktivores to benthivoresOmnivores + planktivores to benthivores Asian carp cause change in food web?Asian carp cause change in food web?