EUTROPHICATION Nutrients primarily phosphorus EUTROPHICATION Nutrients primarily phosphorus

EUTROPHICATION Nutrients - primarily phosphorus

EUTROPHICATION Nutrients - primarily phosphorus Aquatic plant response - algae

EUTROPHICATION Nutrients - primarily phosphorus Aquatic plant response - algae Decreased water clarity

Water Temperature - Density Relationship Density difference between the temp. shown and 1 degree lower. From: Limnology by Wetzel 2 nd Ed.

Lake Mixing From: Understanding Lake Data by Shaw, Mechenich and Klessig

Summer Stratification From: Understanding Lake Data by Shaw, Mechenich and Klessig

Phosphorus and Trophic Response Lake 226, September 1973

Deep Lakes Versus Shallow Lakes

Internal versus External Loading

Phosphorus Concentration and Water Quality Wisconsin Lakes and Reservoirs

Lake Trophic State

Trophic State Index (TSI) A water quality index used to compare the trophic state between lakes and parameters. TSI uses TP, Chl a and Secchi depth data; was developed using Secchi depth. Trophic State Index numbers are normalized to range from 0 to 100.

Trophic State Index (TSI) Scale 0 = Secchi Depth of 64 m 10 20 Oligotrophic 30 35 --------------40 Mesotrophic 50 --------------60 70 80 Eutrophic 90 100

Wisconsin TSI Equations Total Phosphorus TSI = 28. 2 + (7. 73 Ln (TP)) TP in ug/l Chlorophyll a TSI = 34. 8 + (7. 56 Ln (Chl a)) Chl a in ug/l Secchi Depth TSI = 60 - (14. 4 Ln (SD)) Secchi in meters Source: Lillie, R. A. , S. Graham and P. Rasmussen, WDNR Research Findings Report 35.

A lake is a product of its watershed

WHERE DO MODELS FIT ? Linkage between WQ targets and sources