Why was this project funded?

2. Why was this project funded? -Novel approach -Not business as usual -Uncomfortable -Confusing -May not be possible in 5 years -Potentially very exciting $ $ $ $ $$ $$ $$ $$ $ $

3. Adaptive Integrated Framework (AIF): a new methodology for managing impacts of multiple stressors in coastal ecosystems End-point #2: Fish production TEAM: Tomas Hook, Tammy Newcomb, Craig Stow, Scott Peacor, Steve Pothoven, Steve Brandt, Hank Vanderploeg, and Tom Nalepa NOAA Great Lakes Environmental Research Laboratories: Craig Stow (lead), Stephen Brandt, Thomas Croley II, Julianne Dyble, Gary Fahnenstiel, Thomas Nalepa, Steven Pothoven, Henry Vanderploeg Michigan State University: Scott D. Peacor (lead), Michael D. Kaplowitz, Frank Lupi University of Michigan: Tomas Höök (lead), Dmitry Beletsky, Carlo De Marchi, Thomas Johengen, Donna Kashian University of Akron: Peter J. Lavrentyev Limno-Tech, Inc.: Joseph V. Depinto Western Michigan University: Chansheng He Michigan Department of Natural Resources: Tammy J. Newcomb Michigan Department of Environmental Quality: James H. Bredin

4. Overview • Background • Potential effects of stressors on fish production • Potential research approaches • Modeling • Ecosystem survey and empirical research • Issues to consider

5. Percids in Saginaw Bay Walleye Historically second largest commercial fishery in Great Lakes. Walleye collapse ~1950 due to eutrophication, over-fishing, invasive species, etc. Recent collapse of L. Huron alewives has led to improved reproductive success, but very poor growth and long-term survival. Yellow perch Fielder and Thomas 2006 MI-DNR; Fielder et al. 2007 JGLR

6. Percid Production Requires a Balance Within the Ecosystem Moderate temperatures Mesotrophic conditions Balance between sufficient pelagic and benthic prey Yellow perch Benthic invertebrates Zooplankton Invasive Species

7. Overview • Background • Potential effects of stressors on fish production • Potential research approaches • Modeling • Ecosystem survey and empirical research • Issues to consider

8. Loading effects on percid production Recruitment linked to river discharge. Mechanisms unclear. Too much loading probably bad. Ludsin et al, unpub. data

9. Invasive species effects on percid production Ecosystem engineering and the disrupted food web of Saginaw Bay. The substrate provided by the shells provides substrate for benthic plant and invertebrates, and increased light increases benthic plant production as well as potentially increasing predation intensity of visual (invertebrate and vertebrate) predators. The red shaded species are non-indigenous species.

10. Location of sites sampled for benthos in 1987-1996. Black dot: Ponar samples for total benthos (1987 and 1988) Circled black dot: Ponar samples for total benthos (1987-1996) X: diver samples for zebra mussels (1991-1996)

11. Mean density and biomass of zebra mussels at sites with hard substrate in inner Saginaw Bay in 1991-1996. Density Biomass

12. Mean biomass of non-dreissenids at deep, silty sites in inner Saginaw Bay (1991-1996) Total Chironomids

13. Non-dreissenid biomass; Shallow, sandy sites Total Gammarus

14. Climate change effects on percid production • Temperature is the “master variable” for fish • May also affect: • Watershed loading • Water levels • Community composition

15. Respiratory cost(g g-1 d-1) 0.0053 0.003 0.002 Yellow perch bioenergetics • Respiratory cost (g g-1 d-1) activity (x2) • 0.011 • 0.006 24oC 15oC 11oC *Model run for a 20 g adult yellow perch (5942 J/g); Chironomid (3138 J/g); Zoop. (2510 J/g)

16. Maintenance consumption(g/d) 0.934 0.517 0.301 Yellow perch bioenergetics • Maintenanceconsumption (g/d) activity (x2) • 1.89 • 1.05 24oC 15oC 11oC *Model run for a 20 g adult yellow perch (5942 J/g); Chironomid (3138 J/g); Zoop. (2510 J/g)

17. Overview • Background • Potential effects of stressors on fish production • Potential research approaches • Modeling • Ecosystem survey and empirical research • Issues to consider

18. Fish Models

19. MI-DNR Saginaw Bay Surveys • Spring sampling of river spawning walleye (1981-present) • Fall bay-wide surveys of fish populations • Gillnet (1989-present) • Bottom trawls (1971- or 1986-present) • Abundance, size, condition, age, diets • Smattering of additional data from 1926-present

20. Empirical models • Regression models -(e.g., Fielder et al. 2007 JGLR) • Neural networks -(trained on meta-data and then applied) • Bayesian probability networks -(hocus-pocus vodoo)

21. Coupled 3-D process –based models • Saginaw Bay Ecosystem Model (SAGEM) • Deterministic, process-based model • Phytoplankton model first developed in 1970’s • Updated to include: • Multi-class phytoplankton • Zebra mussel bioenergetics • PCB fate, transport and lower food web bioaccumulation • Benthic algae productivity • Latest version: Bierman et al. 2005 JGLR 2005 • Will be coupled to fish individual-based model

22. Add new individuals Loop through individuals Forage ƒ(fish size, temperature, prey densities, water clarity) Respire (bioenergetics) ƒ(fish size, temperature, food consumed) Predation Mortality ƒ(fish size, current location) Starvation Mortality ƒ(fish size, % storage tissue) Move? ƒ(fish size, current location) Next Individual Next Day

23. Foraging: Swimming distance Reactive distance and encounter rate Stochastic capture success Optimal foraging Consumption

24. Overview • Background • Potential effects of stressors on fish production • Potential research approaches • Modeling • Ecosystem survey and empirical research • Issues to consider

25. Fish-related ecosystem chracterization

26. Fish sampling Collect (monthly spring-fall) 1) Young percids 2) Potential interacting biota prey competitors predators

27. Fish sampling Quantify: fish size age diets growth (incl. short-term) mortality Relate to: available prey physical conditions predation pressure

28. Proposed Effort for Benthic Community Dreissenid Abundance and Biomass: Needed for estimates of nutrient excretion, filtering capacity, and materials cycling (carbon, energy). Key question: has the population remained stable since 1994-1996? Macroinvertebrate Abundance and Biomass: Needed for estimates of food available to fish. Emphasis on the dominant taxa: (Chironomidae at deep sites and Gammarus sp. at shallow sites.)

29. New Links—emphasizing the microbial food web (conceptual) and invaders (real)

30. Zooplankton sampling Vertical tows of 64µm net Collect small zooplankters Oblique tows of 153µm net Collect large zooplankters

31. Experimental Research Examples: • Effects of water clarity on fish foraging • Effects of dreissenid shells on fish foraging efficiency • Effects of dreissenids on P-availability

32. Overview • Background • Potential effects of stressors on fish production • Potential research approaches • Modeling • Ecosystem survey and empirical research • Issues to consider

33. Nearshore sampling • Nearshore areas potentially important nursery grounds • Nearshore sampling not described in proposal • How will we consider these habitats?

34. Invasive species • Proposal refers to invasive species, but really focuses on dreissenids • Is the invasive species stressor really just a dreissenid stressor? • Or, will we explicitly consider effects of other stressors? • Bythotrephes • Round gobies • Phragmites