INFLUENCE OF A COMMON STREAM RESTORATION PRACTICE ON FISH COMMUNITY STRUCTURE AND DIETS

Transcription

1 INFLUENCE OF A COMMON STREAM RESTORATION PRACTICE ON FISH COMMUNITY STRUCTURE AND DIETS Sophia M. Bonjour, Heidi M. Rantala, Micah G. Bennett, and Matt R. Whiles Department of Zoology and Center for Ecology, Southern Illinois University

2 Degradation & Restortion Land use change Agriculture & urbanization Increased degradation of rivers (Gleick, 2003) Irrigation, energy, transportation, recreation Interest in ecological & environmental impacts of restoration (Palmer et al. 2005) O Donnell and Galat, 2007

3 Cache River Watershed Demissie et al. 2010

4 Upper Cache River Photo: Kelly Fritz

5 Construction of Rock Weirs stabilize stream channel Photo: Scot Peterson

6 Constructed Riffle dissolved oxygen & stable substrate

7 Previous Research Walther and Whiles, 2008 Macroinvertebrate Biomass EPT Biomass mg AFDM m mg AFDM m Old weir New weir Snags Streambed 0 Old weir New weir Snags Streambed Habitat: F [3,20] = 1.9, p = 0.17 Habitat date: F [9,20] = 4.0, p = Habitat: F [3,20] = 50.2, p < Habitat date: F [9,20] = 3.6, p = 0.008

8 In-stream restoration Increased habitat heterogeneity Enhanced aquatic insect diversity & production Difference in fish community structure Difference in diets between weir and non-weir fishes

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10 Methods June Weir, 4 Non-weir, ~100 meters Hand nets, seines, and backpack electrofishing Stomach lavage or dissection Biomass of invertebrates from guts was estimated (Benke et al. 1999) ANOVA, MDS, ANOSIM, SIMPER, student s t-test, Chesson selectivity, Wilcoxon Sign test, and Fisher s Exact test

11 Fish Diversity Number of fish species Weir Non-weir * Indicates significant difference

12 Fish Communities Weir Non-Weir p=0.05 2D Stress: 0.06 Cottus carolinae Cyprinella whipplei Fundulus olivaceus Percina sciera

13 Gut Biomass * Average Gut Biomass (mg AFDM) Weir Non-weir * Indicates significant difference

14 Relative Abundance of Prey- Habitat Relative Abundance * * * * * * EPT Chironomidae Oligochaeta Weir Non-weir Drift

15 Relative Abundance of Prey- Guts Relative Abundance * * Weir * Non-weir * * Terrestrial Zooplankton Other Non-insect Other Insect Chironomidae EPT * General Invertivore- EPT Chironomidae Benthic Invertivore- Malacostraca Benthic Invert General Invert Macrocarnivore Detritivore Benthic Invert General Invert Macrocarnivore Surface feeder Macrocarnivore- Other Insect

16 Selectivity- Weirs Chesson, 1978 Alpha by Guild Benthic Invertivore General Invertivore Macrocarnivore Detritivore Chironomidae EPT Other Insect Malacostraca Oligochaete Other Invertebrate Zooplankton Terrestrial

17 Selectivity- Non-weirs Alpha by Guild Baetidae Heptageniidae Chimarra Caenis Chesson, 1978 Benthic Invertivore General Invertivore Macrocarnivore Surface feeder Chironomidae EPT Other Insect Malacostraca Oligochaete Other Invertebrate Zooplankton Terrestrial

18 In-stream restoration Increased habitat heterogeneity Enhanced aquatic insect diversity & production Difference in fish community structure Difference in diets Between weir and non-weir fishes Weirs: higher fish diversity Different communities increase overall diversity at larger scale Weir: more diverse diets and higher prey biomass Selection for EPT taxa

19 Cache River Restoration Heinrich et al Weirs increase diversity and production of emergent insects Bird richness and diversity higher at weir sites Bird density increased at and near weirs Current work Bats EPT taxa emergence production F=9.4, P=0.006

20 Implications >$1 billion annually (Bernhardt et al. 2005) Most restoration projects not ecologically evaluated Link between geomorphological changes & ecosystem functions Step to better understand, justify, & modify restoration

21 Acknowledgements Illinois Department of Natural Resources; Jody Shimp Tracy Fidler Nature Conservancy of Illinois Big Creek Drainage District #2 Society for Freshwater Science s Student Resource Committee and Endowment Committee SIU Center for Undergraduate Research and Creative Activities Undergraduate Research Assistantship Program SIU Center for Ecology Freshwater Ecology Lab at SIU Karen Baumann, Alicia Beattie, Kelley Fritz, Jessica Fulgoni, Jon Meats, Ricky Nesslar