Mercury in Fish of the American and Bear River
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MERCURY IN FISH OF THE AMERICAN AND BEAR RIVER WATERSHED RESERVOIRS: TISSUE ANALYSIS AND STRATEGIES FOR MINIMIZING EXPOSURE AT LAKE CLEMENTINE AND ROLLINS RESERVOIR, CALIFORNIA ____________ A Thesis Presented to the Faculty of California State University, Chico ____________ In Partial Fulfillment of the Requirements for the Degree Master of Science in Environmental Science ____________ by Alexandria Kathleen Keeble-Toll Summer 2016 MERCURY IN FISH OF THE AMERICAN AND BEAR RIVER WATERSHED RESERVOIRS: TISSUE ANALYSIS AND STRATEGIES FOR MINIMIZING EXPOSURE AT LAKE CLEMENTINE AND ROLLINS RESERVOIR, CALIFORNIA A Thesis by Alexandria Kathleen Keeble-Toll Summer 2016 APPROVED BY THE INTERIM DEAN OF GRADUATE STUDIES: _________________________________ Sharon Barrios, Ph.D. APPROVED BY THE GRADUATE ADVISORY COMMITTEE: ______________________________ _________________________________ Guy Q. King, Ph.D. Carrie Monohan, Ph.D., Chair Graduate Coordinator _________________________________ David Brown, Ph.D. _________________________________ Glen Pearson ACKNOWLEDGMENTS For my Mom and Dad who pushed me to pursue graduate work in a third discipline, even if it was only through casual questions. And for my family for understanding that I needed to be more than just “Momma,” for not complaining about my late nights and early mornings on the road to Chico, and for sharing a year and a half of cold burrito dinner leftovers. Jackson and Astella – may you fish lots and only eat trout. For the staff of The Sierra Fund, for inviting me to join the “smart girls club,” and especially for Dr. Monohan – a mentor, and a friend. For Bill Templin of DWR, who taught me how to fish, and Tiffany Stillwater of BAL for being there when I thought I lost the fish. Finally, to the many experts who offered their feedback on this project at various points along the way: Charlie Alpers of USGS; Susan Klasing, Margy Gassel, and Bob Brodberg of OEHHA; Alyce Ujihara of CDPH; Michelle Wood of CVRWQCB; Fraser Shilling of UC Davis; and David Brown and Glen Pearson of CSU Chico. iii TABLE OF CONTENTS PAGE Acknowledgments ...................................................................................................... iii List of Tables.............................................................................................................. vi List of Figures............................................................................................................. viii List of Acronyms........................................................................................................ x Abstract....................................................................................................................... xiii CHAPTER I. Introduction.............................................................................................. 1 Background Literature.................................................................. 2 Statement of the Problem ............................................................. 16 Purpose of the Study..................................................................... 19 Research Questions ...................................................................... 19 Fish Tissue Research in the Sierra Nevada .................................. 20 Site Information............................................................................ 21 II. Methods.................................................................................................... 28 Fish Tissue Data ........................................................................... 28 Field Sampling Methods............................................................... 45 Laboratory Analysis ..................................................................... 48 Statistical Analysis ....................................................................... 53 Angler Survey Data ...................................................................... 57 Data Analysis................................................................................ 60 III. Results...................................................................................................... 63 Initial Screening............................................................................ 63 Fish Tissue Data ........................................................................... 63 Data Acceptance Criteria.............................................................. 64 iv CHAPTER PAGE Statistical Analysis ....................................................................... 64 Descriptive Statistics .................................................................... 65 Addressing Research Questions: Fish Tissue Data ...................... 78 Addressing Research Questions: Angler Survey Data ................. 94 IV. Discussion................................................................................................. 103 (A) Mercury Exposure Risk at Target Water Bodies ................... 103 (B) Impact of Size and Trophic Position on Fish Tissue Mercury Concentration........................................................ 107 (C) Strategies for Minimizing Exposure ...................................... 110 Study Limitations ......................................................................... 112 V. Conclusions and Recommendations......................................................... 114 Recommendations for Future Research........................................ 115 References Cited......................................................................................................... 119 Appendix A. Angler Survey Protocol and Survey Form ............................................... 127 v LIST OF TABLES TABLE PAGE 1. Reservoirs Selected For Analysis............................................................. 30 2. Fish Species Selected for Analysis........................................................... 34 3. Legal And/Or Edible Size Criteria by Fish Species................................. 36 4. Number of Fish Recommended for Harvest Based on Water Body Type .......................................................................................... 38 5. Existing Fish Tissue Data for Rollins Reservoir...................................... 39 6. Existing Fish Tissue Data for North Fork of the American River ........... 42 7. Number of Fish, By Species and Water Body, Proposed for Collection ........................................................................................... 43 8. OEHHA Advisory Tissue Levels for Mercury......................................... 56 9. OEHHA 90th Percentile Value Means...................................................... 57 10. Sampling Plan for Angler Survey Data Collection .................................. 58 11. Black Bass at Rollins Reservoir ............................................................... 66 12. Sunfish at Rollins Reservoir..................................................................... 68 13. Trout at Rollins Reservoir ........................................................................ 71 14. Black Bass at Lake Clementine................................................................ 72 15. Sunfish at Lake Clementine...................................................................... 75 16. Sacramento Pikeminnow at Lake Clementine.......................................... 77 17. Rainbow Trout at Lake Clementine ......................................................... 78 vi TABLE PAGE 18. Comparison of Statewide Advice to Site-Specific Mean Mercury Concentrations ..................................................................... 84 19. Angler Survey Data for Rollins Reservoir and Lake Clementine ............ 95 vii LIST OF FIGURES FIGURE PAGE 1. Map of Water Bodies Selected For Analysis ........................................... 31 2. Fish Consumption by Species, Gold Country Angler Survey................... 33 3. Black Bass at Rollins Reservoir ............................................................... 67 4. Boxplot of Black Bass at Rollins Reservoir............................................. 68 5. Sunfish at Rollins Reservoir..................................................................... 69 6. Boxplot of Sunfish at Rollins Reservoir................................................... 70 7. Trout at Rollins Reservoir ........................................................................ 71 8. Black Bass at Lake Clementine................................................................ 73 9. Boxplot of Black Bass at Lake Clementine.............................................. 74 10. Sunfish at Lake Clementine...................................................................... 75 11. Boxplot of Sunfish at Lake Clementine ................................................... 76 12. Sacramento Pikeminnow.......................................................................... 77 13. Comparison of THg to OEHHA ATLs, Rollins Reservoir ...................... 81 14. Comparison of THg to OEHHA ATLs, Lake Clementine ....................... 82 15. Relationship between TL and THg, Black Bass Species, Rollins Reservoir, California.............................................................. 85 16. Relationship between TL and THg, Black Bass Group, Rollins Reservoir, California.............................................................. 86 viii FIGURE PAGE 17. Relationship between TL and THg, Sunfish Species, Rollins Reservoir, California .............................................................