Background Report TABLE OF CONTENTS ACKNOWLEDGEMENTS ..............................................................................................................................................5 Our Supporters .......................................................................................................................................................5 EXECUTIVE SUMMARY ................................................................................................................................................6 INTRODUCTION ..........................................................................................................................................................9 Past Indicators ........................................................................................................................................................9 Muskoka’s Watersheds ....................................................................................................................................... 11 Subwatershed Evaluation .................................................................................................................................... 14 Benchmarks ......................................................................................................................................................... 16 Value of Ecosystems ............................................................................................................................................ 17 LAND ........................................................................................................................................................................ 20 Natural Cover....................................................................................................................................................... 20 Large Patch Size ................................................................................................................................................... 21 Interior Forest ...................................................................................................................................................... 23 Protected and Managed Areas ............................................................................................................................ 25 Riparian Areas...................................................................................................................................................... 27 Summary .............................................................................................................................................................. 31 WATER ..................................................................................................................................................................... 32 Background .......................................................................................................................................................... 32 Total Phosphorus ................................................................................................................................................. 33 Fish Habitat .......................................................................................................................................................... 37 Fish Contaminants ............................................................................................................................................... 38 Summary .............................................................................................................................................................. 41 WETLANDS ............................................................................................................................................................... 42 Wetland Values ................................................................................................................................................... 42 Wetland Area ....................................................................................................................................................... 43 Wetland Grades ................................................................................................................................................... 43 SUMMARY ............................................................................................................................................................... 45 CLIMATE CHANGE .................................................................................................................................................... 46 Surface Water ...................................................................................................................................................... 46 Forests and Wetland ........................................................................................................................................... 47 Biodiversity .......................................................................................................................................................... 47 Community Infrastructure ................................................................................................................................... 47 Human Health ...................................................................................................................................................... 48 3 Tourism ................................................................................................................................................................ 48 Agriculture ........................................................................................................................................................... 48 BIBLIOGRAPHY ......................................................................................................................................................... 49 List of Figures Figure 1: The Subwatersheds (Quaternary Watersheds) Included in the 2010 Muskoka Watershed Report Card. ................................................................................................................................................................................. 12 Figure 2: Muskoka River Watershed Elevations (From the Muskoka River Water Management Plan). ................ 13 Figure 3: Distribution of Lakes by Size in Muskoka's Watersheds. ......................................................................... 32 Figure 4: Long-Term Total Phosphorus Concentrations. ......................................................................................... 33 Figure 5: A Comparison of Total Phosphorus Concentrations (Predevelopment Estimates and Monitored Data).34 Figure 6: Example of Long-Term Monitoring Data. ................................................................................................. 36 List of Tables Table 1: Subwatersheds (Quaternary Watersheds) Included in the 2010 Muskoka Watershed Report Card. ...... 14 Table 2: Watershed Characteristics ......................................................................................................................... 14 Table 3: Benchmarks Used in the 2010 Muskoka Watershed Report Card. ........................................................... 17 Table 4: Natural Area Requirements ....................................................................................................................... 18 Table 5: Subwatershed Grades for Percent Natural Cover. .................................................................................... 21 Table 6: Subwatershed Grades for Percent Large Patch Size. ................................................................................. 23 Table 7: Subwatershed Grades for Percent Interior Forest (100 m Buffer). ........................................................... 25 Table 8: Subwatershed Grades for Percent Actively Managed Areas. .................................................................... 27 Table 9: Shoreline Alteration Data for Specific Lakes. ............................................................................................. 28 Table 10: Subwatershed Grades for Percent Unaltered Riparian Area. .................................................................. 30 Table 11: Overall Subwatershed Grades for the Land Component of the 2010 Report Card. ................................ 31 Table 12: Subwatershed Grades for Percent Surface Area Considered Over Threshold for Phosphorus. ............. 36 Table 13: Subwatershed Grades for Fish Habitat. ................................................................................................... 38 Table 14: Subwatershed Grades for Mercury Contamination of Fish. .................................................................... 40 Table 15: Overall Subwatershed Grades for the Water Component of the 2010 Report Card. ............................. 41 Table 16: Wetland Coverage for Each Subwatershed. ............................................................................................ 44 Table 17: Overall Subwatershed Grades for the 2010 Report Card. ....................................................................... 45 4 ACKNOWLEDGEMENTS The background report for the 2010 Muskoka Watershed Report Card is a combined effort of many people and organizations across the watersheds. Without their expertise and volunteer efforts this report could