LAKE ECOLOGY WITH PAUL Paul Garrison Bureau of Science Services
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LAKE ECOLOGY WITH PAUL Paul Garrison Bureau of Science Services WATERSHEDS, LANDUSE, AND SHALLOW LAKES • Why does the lake care what you do on the land? • Does the depth of my lake affect the water quality? HISTORY IN THE MUCKING • Have our lakes always been like this? LAND USE AND WATERSHED IMPACTS WHY DO WE CARE ABOUT PHOSPHORUS? AGRICULTURE IMPACTS S o i l T e s t P h o s p h o r u s (p p m ) Phosphorus Distribution Dane County - Farm 1 140 120 100 80 Median 60 40 20 0 Required 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 Number of Farm Fields University of Wisconsin Nutrient and Pest Management Program Dane Co. Soil Test P Data 1974-1994 60 Phosphorus (ug/g soil) 55 56 55 50 49 45 40 44 40 35 1974-1977 1978-1981 1982-1985 (after Combs et al. 1996 as reported in Bennett et al. 1999) 1986-1990 1991-1994 WATER BUDGET SURFACE WATER Photo by Paul Garrison WATER BUDGET Ground Water Lake Water Table Septic System Groundwater Observation Wells WATER BUDGET Ground water N ground water Basins Topographical Watershed WATER AND NUTRIENT BUDGETS NUTRIENT BUDGETS Silver Creek 67% WWTP 1% Direct 4% Internal 28% WATER AND NUTRIENT BUDGETS INTERNAL LOADING 0 2 Depth (m) 4 6 8 0 500 1000 1500 Total Phosphorus (µg L-1) 2000 BENTHIVOROUS FISH SHORELAND DEVELOPMENT Undeveloped – Apr.-Oct. phosphorus/sediment runoff model Source: Wisconsin Dept. of Natural Resources 1995 John Panuska 1940’s DEVELOPMENT 1940s development – Apr.-Oct. phosphorus/sediment runoff model Source: Wisconsin Dept. of Natural Resources 1995 John Panuska 1990’s DEVELOPMENT 1990s development – Apr.-Oct. phosphorus/sediment runoff model Water (m3) 150 100 Sediment (kg) 50 50 0 undeveloped 1940s 40 1990s 30 20 10 0 undeveloped Source: Wisconsin Dept. of Natural Resources 1995 John Panuska 1940s 1990s Effect of Compaction on Infiltration Rate 14 12 Infiltration 10 8 Rate 6 (In/Hour) 4 2 0 Native Compacted Sandy Clayey Soil Type Pitt, et. al., 1999 Restoration and Management of Shallow Lakes Paul Cunningham Bureau of Fisheries, Wisconsin DNR Clearwater state Clearwater state Turbid state, Beaver Dam Lake Shallow Lake Ecology Clear State Turbid State Abundant Rooted Plants Frequent Algal Blooms Lower Phosphorus Higher Phosphorus Clearer Water Suspended Sediment Gamefish Dominate Carp & Crappies Dominate Biomanipulation Rotenone HIGH WATER LEVELS DESTROY HABITAT NOW 1930 Seasonal Levels CONVEX or CONCAVE ? Water levels are Often Managed for Navigation Rather than Plants, Resulting in High Summer Levels, Opposite What Nature Intended. Boats Paleolimnology or History in the Mucking HOW DO YOU COLLECT SEDIMENT CORES? Gravity Corer Piston Corer 168 lakes Types of Cores Full core Top/Bottom Modern Sedimentation Rate 2000 1980 1960 1940 1920 1900 1880 1860 1840 1820 0 0.1 0.2 0.3 (g cm-2 yr-1) Reference Lead-210 Dating 222 Radon 210 Lead 222 Radon 226 Radium 238 Uranium HALF LIVES 226 Radium 222 Radon 1024 yr 3.8 days 210 Lead 22.26 yr FALLOUT FROM ATMOSPHERIC BOMB TESTING Cs (pCi/g) 0 5 10 0 Depth (cm) 2 4 6 8 10 12 1963 1954 DIATOMS BLUE-GREEN and GREEN ALGAE AGRICULTURE Green Lake Green Lake Titanium Uranium Soil Erosion Manganese Fertilizer Low Oxygen 2000 1990 1970 1950 1930 1980 1960 1940 1920 1900 1880 1860 1840 0.00 0.05 0.10 0.15 0.00 0.01 Western Basin 2000 0.02 0.03 0.04 10 15 20 25 Eastern Basin 1990 1970 1950 1930 1980 1960 1940 1920 1900 1880 1860 1840 Increasing Phosphorus Concentrations SHORELAND DEVELOPMENT circa 1940 2009 Shift in the ratio of isoetids to elodeids 1930s: 50/50 2000s: 30/70 Susan Borman and Ray Newman-U. of Minnesota Little Bearskin Lake Little Bearskin Lake FERNLEAF PONDWEED Present Day circa 1930s 1800s 0 500 1000 1500 2000 2500 COONTAIL Present Day circa 1930s 1800s 0 500 1000 1500 2000 LARGE LEAVED PONDWEED Present Day circa 1930s 1800s 0 50 100 Number 150 g-1 200 250 CHANGE IN PHOSPHORUS PHOSPHORUS 40 Modern Reference 30 n = 73 µg L-1 20 10 0 Northern Lakes CLIMATE CHANGE Max Lake 0 cm 120 270 410 11,300 BP 6100 BP 2600 BP 460 BP 50 340 200 13,100 BP 8500 BP 450 4200 BP 100 1600 BP 11,000 BP 270 410 pH 7.0 Drainage Seepage 6.5 6.0 5.5 5.0 0 2000 4000 6000 8000 Calibrated 14C BP 10000 12000 14000 5,000-12,000 yrs BP MAX Berry Lake CHANGING WATER LEVELS Berry Lake, Oconto County Wind Ancient Sand Dunes Berry Lake Dr. Samatha Kaplan— UW Stevens Point Berry Lake Floral foam 50 0 cm 100 11,521 BP 60 10 110 70 20 120 296 BP 80 30 391 BP 40 50 cm 934 BP 130 12,752 BP 90 2730 BP 97 cm 133 cm Floral foam LAKETIDES Winter 2007 Winter 2008
