1. LIMNOLOGY 101 Courtesy of the WI Lakes Partnership Wisconsin Department of Natural Resources Wisconsin Association of LakesUniversity of Wisconsin Extension

2. Wisconsin Lakes

3. OVERVIEW • Unique Properties of Water • Lake Types • Physical, Chemical, Biological and Habitat Characteristics • Technical Aspects

4. UNIQUE PROPERTIES OF WATER • Universal Solvent • Chemical Molecular Structure H20 • Greatest Density at 4º C or 39º F

5. UNIQUE PROPERTIES OF WATER • Physical Properties • 71% Earth’s Surface Covered by Water • <1% Water on Earth is Freshwater • .009% water on Earth is Freshwater Lakes

6. HYDROLOGIC CYCLE

7. OVERVIEW • Unique Properties of Water • Lake Types • Physical, Chemical, Biological and Habitat Characteristics • Technical Aspects

8. LAKE TYPES • Seepage • Groundwater Drainage • Drainage • Impoundments • Oxbow

9. SEEPAGE LAKE • Natural Lake • Water Source • Groundwater • Precipitation • Runoff • No Stream Outlet/ Inlet

10. SEEPAGE LAKE • Round Lake, Chippewa County

11. GROUNDWATER DRAINAGE • Natural Lake • Water Source • Groundwater • Precipitation • Limited Runoff • Has Stream Outlet

12. GROUNDWATER DRAINAGE LAKE • Sand Lake, Chippewa County

13. DRAINAGE LAKE • Water Source • Streams • Groundwater • Precipitation • Runoff • Stream Drained

14. DRAINAGE LAKE • Long Lake, Chippewa County

15. IMPOUNDMENT • A manmade lake • Dammed riveror stream

16. IMPOUNDMENT • Lake Altoona, Eau Claire County

17. OXBOW • Half Moon Lake, Chippewa County • Lake Hallie, Chippewa County

18. OVERVIEW • Unique Properties of Water • Lake Types • Physical, Chemical, Biological and Habitat Characteristics • Technical Aspects

19. PHYSICAL CHARACTERISTICS • Mixing / Stratification • Lake Depth • Retention Time / Flushing Rate • Drainage Basin/ Lake Area Ratio • Influence of Watershed Runoff

20. MIXING/ STRATIFICATION

21. LAKE DEPTH MATTERS • Deep Lakes Stratify • Shallow Lakes Continuous Nutrient Recycling

22. RETENTION TIME/FLUSHING RATE • How long would it take to fill a drained lake? • Retention Time Matters • Long Lake & Altoona • Round Lake, 7 years • Lake Altoona, 22 days

23. DRAINAGE BASIN/LAKE AREA RATIO • Seepage Lake- small • Drainage Lake- large watershed • Seepage Lake w/ drainage area mapped Round Lake

24. LANDSCAPE POSITION

25. CHEMICAL CHARACTERISTICS • Nutrients • P • N • pH • Hardness/ Alkalinity • Dissolved Oxygen(optimum 5 ppm)

26. LIMITING NUTRIENT PRINCIPLE …That Nutrient in Least SupplyRelative to Plant Needs N:P Ratio in plant Tissue 10:1 - 15:1 If the Ratio of N:P in Water is <10:1 Nitrogen Limited >15:1 Phosphorus Limited

27. PHOSPHORUS LIMITATIONLAKE 227

28. BIOLOGICAL CHARACTERISTICS • Viruses/ Bacteria/ Fungi • Primary - Producers Algae/ Macrophyte • Zooplankton/ Inverts • Fish

29. ALGAE • Primary Energy Sourcefor Invertebrates • Can be Nuisance • Produce O2

30. AQUATIC PLANTS • Habitat • Energy Dissipation • O2 Producers

31. ZOOPLANKTON &AQUATIC INVERTEBRATES Zooplankton Dragonfly

32. FISH Planktivore Piscivore Benthivore

33. TROPHIC PYRIMID

34. OVERVIEW • Unique Properties of Water • Lake Types • Physical, Chemical, Biological and Habitat Characteristics • Technical Aspects

35. TROPHIC STATE

36. TROPHIC STATE

37. TROPHIC STATE

38. TROPHIC STATE • Nutrients & Productivity • Sediment & Accumulation • Species Shifts • Species Richness

39. LAKE LITTORAL ZONE • Functions • Intercepts Nutrients • Refuge from Predators • Nursery for Fish Oligotrophic Northern Lake Eutrophic Southern Lake

40. TOTAL PHOSPHORUS/ CHLOROPHYLL a RELATIONSHIP • Phosphoruscauses algaeto grow

41. LAKE HABITAT ZONES

42. LAKE LITTORAL ZONE • Functions • Intercepts Nutrients • Refuge from Predators • Nursery for Fish Oligotrophic Northern Lake Eutrophic Southern Lake

43. ENVIRONMENTAL SIGNS OF DEGRADATION

44. LOSS OF WATER CLARITY

45. HYPOLIMNETIC DO DEPLETION

46. NUISANCE ALGAE BLOOMS

47. FISHERIES DEGRADATION

48. PALEOLIMNOLGY

49. LEAVING A LEGACY Help Protect Wisconsin’s… WATER RESOURCES