MACKEY, MATTHEW M., MS May 2017
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MACKEY, MATTHEW M., M.S. May 2017 ECOLOGY & EVOLUTIONARY BIOLOGY ANALYSIS OF THE ICHTHYOFAUNAL COMMUNITY AT OLD WOMAN CREEK, A LAKE ERIE COASTAL WETLAND (117 pp.) Thesis Advisor: Mark W. Kershner Great Lakes coastal wetlands are of significant ecological and economic importance. These wetlands collect runoff from surrounding land, mitigate natural disasters, and provide habitat for plants and animals at all life stages. There is a growing literature describing the factors effecting spatial and temporal patterns in fish diversity in brackish coastal wetlands that surround marine waters, but similar studies are lacking in freshwater estuaries and little is known about these patterns in larval fishes. Adult fishes were collected weekly between May and October 2015 using fyke nets set in monotypic stands of vegetation. Larval fishes were collected weekly between May and October 2015, and biweekly from April to August 2016. Water depth was measured at all fyke nets and all traps. A suite of abiotic variables was also measured during 2016. Patterns in fish distribution and diversity were assessed using univariate and multivariate statistics. Fish did not appear to choose specific types of vegetation, but preferred the presence of vegetation to open water areas. Patches of submerged aquatic vegetation and water lily/lotus had a significant effect on larval community structure, as did dissolved oxygen, pH, and secchi depth. Larvae peaked in abundance in mid-July in 2015, and early June in 2016, but the 2016 peak had over 1000 more individuals than the 2015 peak. Further, abundance values from 2015 were similar to those from the same dates in 2016. This suggests that spawning periods of Lake Erie fishes are predictable from year to year within the same estuary. These studies suggested that fish prefer macrophytic cover, and they improved understanding of the effects of water level on fish distributions. The studies also identified spawning patterns as constant from year-to-year. Future studies should examine whether larval fish actively choose habitats following spawning, as well as whether abiotic variables influence hatching and growth rates. Finally, the work on larval fish opens the door to studying the benefits of different spawning patterns (i.e. protracted and early spawning compared to single-burst spawning). ANALYSIS OF THE ICHTHYOFAUNAL COMMUNITY AT OLD WOMAN CREEK, A LAKE ERIE COASTAL WETLAND A thesis submitted To Kent State University in partial Fulfillment of the requirements for the Degree of Master of Sciences by Matthew M. Mackey May, 2017 Thesis written by Matthew M. Mackey B.S., Saint Vincent College, 2014 M.S., Kent State University, 2017 Approved by Mark W. Kershner______________________, Advisor Laura G. Leff__________________________, Chair, Department of Biological Sciences James L. Blank________________________, Dean, College of Arts and Sciences TABLE OF CONTENTS TABLE OF CONTENTS ............................................................................................................... iii LIST OF FIGURES ....................................................................................................................... iv LIST OF TABLES ......................................................................................................................... vi ACKNOWLEDGEMENTS .......................................................................................................... vii CHAPTER 1 - INTRODUCTION .................................................................................................. 1 General Benefits of Great Lakes Coastal Wetlands .................................................................... 1 How Great Lakes Coastal Wetlands Affect Fishes ..................................................................... 3 How Fish Impact Great Lakes Coastal Wetlands........................................................................ 5 Fish Aid Understanding of the Benefits of Great Lakes Coastal Wetlands ................................ 8 CHAPTER 2 - SPATIAL AND TEMPORAL VARIABILITY OF THE FISH ASSEMBLAGE IN A GREAT LAKES FRESHWATER ESTUARY ..................................................................... 2 Introduction ................................................................................................................................. 2 Methods ....................................................................................................................................... 3 Results ......................................................................................................................................... 6 Discussion ................................................................................................................................. 25 Conclusion ................................................................................................................................. 33 CHAPTER 3 - LARVAL FISH COMMUNITY RESPONSE TO VEGETATION AND WATER QUALITY IN A COASTAL WETLAND ................................................................................... 36 Introduction ............................................................................................................................... 36 Methods ..................................................................................................................................... 38 Results ....................................................................................................................................... 44 Discussion ................................................................................................................................. 76 CHAPTER 4 - CONCLUSIONS .................................................................................................. 84 General Importance of Spatial and Temporal Patterns in Fish Abundance, Diversity, and Spawning ................................................................................................................................... 84 Key Findings from these Studies .............................................................................................. 85 How these Findings Fit in the Bigger Picture ........................................................................... 87 REFERENCES ............................................................................................................................. 90 iii LIST OF FIGURES Figure 1: Map of Old Woman Creek National Estuary Research Reserve. .................................... 4 Figure 2: Average fish abundance and species richness during fyke net sampling. ....................... 9 Figure 3: Average fish abundance in each microhabitat, by date.. ............................................... 10 Figure 4: Fish abundance and species richness by OWC sampling site. ...................................... 12 Figure 5: Total Fish Abundance by water depth (cm). ................................................................. 14 Figure 6: Comparison of total and average fish abundance in OWC when the barrier beach at the estuary mouth was open or closed (24 June and 17 October 2015). ............................................. 15 Figure 7: Effect of Vegetation Type on Total and Average Fish Abundance and Species Richness. ....................................................................................................................................... 16 Figure 8: Fish Community RDA................................................................................................... 17 Figure 9: Percent Tolerant Species in Each Cover Type. ............................................................ 20 Figure 10: Species Growth During the Sampling Season ............................................................. 22 Figure 11: Frequency Distribution of Fish Total Lengths During Sampling Season. .................. 24 Figure 12: Map of Old Woman Creek. ......................................................................................... 40 Figure 13: 2015 Total Larval Abundance. .................................................................................... 46 Figure 14: 2015 Average Larval Fish Abundance over Time. ..................................................... 48 Figure 15: Abundance of Three Most Abundant Fishes of 2015. ................................................ 49 Figure 16: Abundance of Common Carp, White Crappie, Goldfish, and White Bass. ................ 50 Figure 17: Total Larval Abundance and Species Richness by Cover Type ................................. 51 Figure 18: Relative Abundance of Families in Each Cover Type in 2015 ................................... 52 Figure 19: Proportion Abundance by Vegetation Type of Three Most Abundant Species of 2015 ......................................................................................... 53 iv Figure 20: Lengths of Larval Fish by Vegetation Type over Time. ............................................. 55 Figure 21: 2015 Average Larval Fish Abundance Across Sampling Sites ................................... 56 Figure 22: 2016 Average Larval Fish Abundance in Each Sampling Site. .................................. 57 Figure 23: 2016 Total Abundance, Average Abundance, and Proportion of Catches with Zero- Yield .............................................................................................................................................. 58 Figure 24: Total and Average Larval Fish Abundances from 2015 and 2016.............................