Advancing Volunteer Lake Monitoring on Lake Vermilion – St. Louis County
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Citizen Lake Monitoring Program: Advancing Volunteer Lake Monitoring on Lake Vermilion – St. Louis County 2008 Assessment Report March, 2009 Minnesota Pollution Control Agency 520 Lafayette Road North Saint Paul, MN 55155-4194 http://www.pca.state.mn.us 651-296-6300 or 800-657-3864 toll free TTY 651-282-5332 or 800-657-3864 toll free Available in alternative formats Report Prepared By: Jesse Anderson – MPCA Duluth Office Steve Heiskary – MPCA St. Paul Office Report Review: Dana Vanderbosch- MPCA St. Paul Office Johanna Schussler- MPCA St. Paul Office With Cooperation From: • The Sportsmen’s Club of Lake Vermilion • Minnesota Department of Natural Resources, Tower Area Fisheries Lake Vermilion CLMP+ Water Quality Report • March 2009 2 Minnesota Pollution Control Agency Table of Contents List of Tables ........................................................................................................................................................ 4 List of Figures....................................................................................................................................................... 4 Executive Summary.............................................................................................................................................. 5 Introduction........................................................................................................................................................... 7 Background........................................................................................................................................................... 8 Lake Assessment Overview .................................................................................................................... 8 a. Lake Trophic Status....................................................................................................................... 8 b. Lake Morphometry and Mixing .................................................................................................. 11 Study Area Overview............................................................................................................................ 12 c. Watershed, and Land Use Characteristics .................................................................................... 14 d. Precipitation and Lake Levels...................................................................................................... 18 e. Fisheries Summary ..................................................................................................................... 20 Methods.... .......................................................................................................................................................... 22 Results and Discussion.... ................................................................................................................................... 24 2008 Water Quality Summary ............................................................................................................................ 32 Trophic Status and Water Quality Trends........................................................................................................... 37 Modeling............................................................................................................................................................. 41 303(d) Assessment and Goal Setting .................................................................................................................. 47 References .......................................................................................................................................................... 49 Appendices A Glossary ................................................................................................................................................ 50 B Water Quality Data Abbreviations and Units........................................................................................ 52 C Water Quality Data ............................................................................................................................. 53 Lake Vermilion CLMP+ Water Quality Report • March 2009 3 Minnesota Pollution Control Agency LIST OF TABLES 1. 2008 Lake Vermilion Water Quality Monitoring Stations............................................................................. 7 2. Lake Vermilion Morphology ...................................................................................................................... 14 3. Lake Vermilion Watershed Areas................................................................................................................ 14 4. Lake Vermilion Land Use Data ................................................................................................................... 16 5. MDH Laboratory Methods and Precision Estimates.................................................................................... 23 6. 2008 Summer-mean Water Quality Data and NLF Ecoregion Typical Range ............................................ 33 7. Comparison of Observed and Model Predicted Values ............................................................................... 42 8. 2008 and 2000 Estimated Lake Vermillion Total Phosphorus Budget from BATHTUB Model………….45 9. Minnesota Lake Eutrophication Standards…………………………………………………………………48 10. Lake Vermilion 303d Assessment Summary……………………………………………………………...48 LIST OF FIGURES 1. Map of 2008 Lake Vermilion monitoring sites.............................................................................................. 7 2. Carlson’s Trophic State Index ......................................................................................................................... 9 3. Minnesota’s Ecoregions............................................................................................................................... 10 4. Mixing Types and Lake Layers for Shallow and Deep Lakes ..................................................................... 11 5. Monthly Mean Total Phosphorus, Chlorophyll-a and Secchi. Based on 30 shallow lakes sampled from West-Central MN in 2003............................................................................................................................ 12 6. Lake Vermilion Watershed .......................................................................................................................... 15 7. Lake Vermilion Watershed Land Cover ...................................................................................................... 17 8. Spring 2008 and 2008 Water Year Precipitation Totals .............................................................................. 18 9. 2008 Lake Vermilion Lake Levels…………………………………………………………………………19 10. 1994 to 2008 Lake Vermilion Water Levels……………………………………………………………….19 11. Pike Bay Temperature and DO Profile…………………………………………………………………….24 12. Big Bay Temperature and DO Profile……………………………………………………………………..25 13. Armstrong Bay Temperature and DO Profile……………………………………………………………...26 14. Frazer Bay Temperature and DO Profile…………………………………………………………………..27 15. Trout Lake Portage Temperature and DO Profile………………………………………………………….28 16. Niles Bay Temperature and DO Profile……………………………………………………………………29 17. Wakemup Bay Temperature and Oxygen Profile………………………………………………………….30 18. Head of the Lakes Bay Temperature and DO Profile……………………………………………………...31 19. TSI Values for Pike Bay and Entire Lake Vermilion Basin……………………………………………….34 20. 2008 Total Phosphorus, Chlorophyll-a and Secchi Transparency Data for east end sites…………………35 21. 2008 Total Phosphorus, Chlorophyll-a and Secchi Transparency Data for west end sites……………….36 22. Summer-mean total phosphorus, chlorophyll-a, and Secchi for 2000 and 2008…………………………..38 23. Trends in August chlorophyll-a concentrations at DNR’s Wakemup Bay site……………………………39 24. Trends in Lake Vermilion Secchi Transparency Data for: site 203, 218, and lake-wide average…………40 25. 2000 and 2008 estimated relative phosphorus contributions from external sources………………………46 Lake Vermilion CLMP+ Water Quality Report • March 2009 4 Minnesota Pollution Control Agency Executive Summary In 2008, the Minnesota Pollution Control Agency (MPCA) and the Sportsmen’s Club of Lake Vermilion (SCLV) partnered to conduct a water quality assessment on Lake Vermilion. This Advanced Citizen Lake Monitoring Program effort monitored 8 sites spread out across the lake’s numerous bays. The MPCA last conducted a water quality assessment on Lake Vermilion in 2000. Lake Vermilion is located between the towns of Tower and Cook in northeastern Minnesota. It is the seventh largest lake in Minnesota, with an area of about 39,000 acres on the southern edge of the Canadian Shield. The Lake Vermilion watershed covers approximately 488 square miles (312,000 acres) spread out over several basins. The Pike River is the dominant tributary, contributing about 40 percent of the watershed area. Lake Vermilion was sampled from May – September, primarily by Club volunteers. Samples were sent to the Minnesota Department of Health laboratory for analysis. Distinct thermal and dissolved oxygen (DO) stratification was evident at the deeper sites; whereas the shallower sites exhibited variable or well-mixed conditions. Epilimnetic DO concentrations consistently exceeded 5 milligrams per liter (mg/L) throughout the monitoring season, a level necessary to maintain healthy cool water fisheries. Carlson’s overall Trophic