87° 86° 85° 84° 83° 82° 81° 80°

87° 86° 85° 84° 83° 82° 81° 80°

25°

26°

27°

28°

29°

30°

25°

26°

27°

28°

29°

30°

87° 86° 85° 84° 83° 82° 81° 80°

87° 86° 85° 84° 83° 82° 81° 80°

25°

26°

27°

28°

29°

30°

25°

26°

27°

28°

29°

30°

75-10

65-02

75-02

65-01

65-06

65-04

75-03

75-01

65-03

75-01

65-05

75-01 75-08

75-04

75-05

75-09

75-06

75-07

75-14

75-11

75-12

75-16

75-15

75-13

75-11

75-11

75-21

75-18

75-19

75-17

75-20

75-26 75-27

75-22

75-35

75-32

75-25

75-36

75-24

75-31

75-34

75-28 75-30

75-23

75-34

75-31

75-34

75-29

75-33

76-01 76-03

75-37

76-02

76-04

75-04

75-10

65-02

75-02

65-01

65-06

65-04

75-03

75-01

65-03

75-01

65-05

75-01 75-08

75-04

75-05

75-09

75-06

75-07

75-14

75-11

75-12

75-16

75-15

75-13

75-11

75-11

75-21

75-18

75-19

75-17

75-20

75-26 75-27

75-22

75-35

75-32

75-25

75-36

75-24

75-31

75-34

75-28 75-30

75-23

75-34

75-31 75-34

75-33

75-29

75-33

76-01 76-03

75-37

76-02

76-04

75-04

< 5

5 - 9

10 - 14

15 - 19

20 - 29

30 - 49

50 - 79

> 80

insufficient data

Total Phosphorus (μg/l)

Regional median value

Total Alkalinity (mg/l)

Regional median value

< 1.0

1.0 - 1.9

2.0 - 3.9

4.0 - 9.9

10.0 - 19.9

20.0 - 40.0

> 40.0

insufficient data

Alabama

Georgia

Alabama

Georgia

< 5.0

5.0 - 5.4

5.5 - 5.9

6.0 - 6.4

6.5 - 6.9

7.0 - 7.5

> 7.5

insufficient data

pH

Regional median value

< 400

400 - 599

600 - 799

800 - 999

1000 - 1300

> 1300

insufficient data

Total Nitrogen (μg/l)

Regional median value

< 4

4 - 7

8 - 11

12 - 15

16 - 30

> 30

insufficient data

Chlorophyll a (μg/l)

Regional median value

< 1.0

1.0 - 1.4

1.5 - 1.9

2.0 - 2.4

2.5 - 3.0

> 3.0

insufficient data

Secchi (m)

Regional median value

< 10

10 - 19

20 - 29

30 - 49

50 - 99

100 - 200

> 200

insufficient data

Color (pcu)

Regional median value

75-10

65-02

75-02

65-01

65-06

65-04

75-03

75-04

75-01

65-03

75-01

65-05

75-01

75-08

75-04

75-05

75-11

75-09

75-06

75-07

75-11 75-14

75-12

7516

75-15

75-16

75-13

75-11

75-21

75-18

75-19 75-11

75-17

75-20

75-26

75-22 75-27

75-35

75-32

75-25

75-36

75-24

75-31

75-34

75-28 75-30

75-23

75-34

75-31

75-34

75-33

75-10

75-29

75-33

76-03

76-01

75-37

76-02

76-04

76-03

75-10

65-02

75-02

65-01

65-06

65-04

75-03

75-04

75-01

65-03

75-01

65-05

75-01

75-08

75-04

75-05

75-11

75-09

75-06

75-07

75-11 75-14

75-12

7516

75-15

75-16

75-13

75-11

75-21

75-18

75-19 75-11

75-17

75-20

75-26

75-22 75-27

75-35

75-32

75-25

75-36

75-24

75-31

75-34

75-28 75-30

75-23

75-34

75-31

75-34

75-33

75-10

75-29

75-33

76-03

76-01

75-37

76-02

76-04

76-03

75-10

65-02

75-02

65-01

65-06

65-04

75-03

75-04

75-01

65-03

75-01

65-05

75-01

75-08

75-04

75-05

75-11

75-09

75-06

75-07

75-11 75-14

75-12

7516

75-15

75-16

75-13

75-11

75-21

75-18

75-19 75-11

75-17

75-20

75-26

75-22 75-27

75-35

75-32

75-25

75-36

75-24

75-31

75-34

75-28 75-30

75-23

75-34

75-31

75-34

75-33

75-10

75-29

75-33

76-03

76-01

75-37

76-02

76-04

76-03

75-10

65-02

75-02

65-01

65-06

65-04

75-03

75-04

75-01

65-03

75-01

65-05

75-01

75-08

75-04

75-05

75-11

75-09

75-06

75-07

75-11 75-14

75-12

7516

75-15

75-16

75-13

75-11

75-21

75-18

75-19 75-11

75-17

75-20

75-26

75-22 75-27

75-35

75-32

75-25

75-36

75-24

75-31

75-34

75-28 75-30

75-23

75-34 75-31

75-34

75-33

75-10

75-29

75-33

76-03

76-01

75-37

76-02

76-04

76-03

75-10

65-02

75-02

65-01

65-06

65-04

75-03

75-04

75-01

65-03

75-01

65-05

75-01

75-08

75-04

75-05

75-11

75-09

75-06

75-07

75-11 75-14

75-12

75-16

75-15

75-16

75-13

75-11

75-21

75-18

75-19 75-11

75-17

75-20

75-26

75-22 75-27

75-35

75-32

75-25

75-36

75-31

75-34

75-28 75-30

75-23

75-34

75-31

75-34

75-10

75-29

75-33

76-03

76-01

75-37

76-02

76-04

76-03

Total phosphorus is a measure of one of the primary nutrients that regulates algal and macrophyte growth in lakes. Phosphates can enter the aquatic system through atmospheric deposition, groundwater percolation, and terrestrial runoff. Phosphate loadings can be increased

with inputs from sewage treatment plants, industrial sources, agricultural and residential runoff, or from phosphate mining and fertilizer processing activities. High phosphorus concentrations can accelerate the process of eutrophication. The highest regional phosphorus

values are found in southwest Florida where phosphates are often naturally high (e.g., 75-30, 75-36), and the lowest regional values are found in some of the upland sandy ridges (65-03, 65-05, 75-04, and 75-33).

Total alkalinity measures the components in water, such as carbonates, bicarbonates, and hydroxyl bases that tend to elevate pH and buffer against increases in acidity. Although much of Florida is underlain by limestone, many lakes in the state are situated in overlying sands

and are soft-water, acidic lakes with low alkalinity. Low alkalinity is found in many clear lakes of some of the sandy upland ridge regions (e.g., 65-03, 65-05, 75-04, and 75-09), as well as in some darkwater lakes in lowland regions (75-01, 75-02, 75-10). Higher alkalinity is

generally found in central and southern Florida or in lakes with groundwater contacts. High alkalinity occurs in lake regions where limestone is near the surface (e.g., 75-06, 75-12), where lakes are limed for fish production (65-01), or in urbanized regions with a combination

of groundwater influence and human disturbance (75-21, 75-28).

Total nitrogen is the combined measure of nitrate, nitrite, ammonia, and organic nitrogen found in a lake. Nitrogen is

an important nutrient to many aquatic organisms, serving with phosphorus as the nutrient base for primary productivity.

Nitrogen-to-phosphorus ratios are generally low for Florida lakes. Nitrogen levels of lakes are increased by inputs from

sewage treatment plants, citrus and agricultural runoff, or other urban and residential sources. This can lead to algal

blooms and subsequent reductions in dissolved oxygen.

Chlorophyll a is the predominant form of photosynthetic green pigment found in plants. As an indicator of

phytoplankton biomass, it is used to approximate algae levels in a lake. It is correlated with total phosphorus and secchi

depth, and helps indicate the trophic condition of lakes. While many of Florida's shallow lakes have low chlorophyll a

levels, a large part of the nutrient pool may be used by the larger aquatic plants called macropyhytes.

Color or true color of a lake is a measure of the dissolved and colloidal substances in water that reduce light

transmission. It is measured in comparison to a scaled series of platinum-cobalt unit (pcu) color standards. The

decreased light penetration in high color or humic-stained darkwater lakes can reduce primary productivity and the

extent of the littoral zone. The sandy upland ridges generally contain the lakes of lowest color, while most of the dark

water lakes are found in lowland flatwoods regions or swampy areas that have peat and organic soils.

Secchi depth is a simple measure of water clarity or transparency. It is determined by the average of the depths at

which a black and white disk disappears and reappears when viewed from the water's surface. The secchi depth is

dependent upon the turbidity, color, and total suspended solids in the water, among other factors. The low-color lakes

of the upland ridges (65-03, 75-04, 75-09, 75-15, 75-20, and 75-33) generally have the greatest secchi depths.

The pH of a lake is a measure of its hydrogen ion concentration or whether it is acidic or basic (alkaline). Many of

Florida's lakes are acidic and have been acidic throughout their history, with the biological communities adapting to

these conditions. Regions of high pH are mostly found in central and southern Florida, or in the north where limestone

is near the surface (75-06) or the lakes are limed (65-01).

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 4

65-01

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 17

65-02

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 28

65-03

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 37 

65-04

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 7 

65-05

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 28

65-06

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 32

75-01

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 4

75-02

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 11

75-03

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 72 

75-04

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 5 

75-05

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 9

75-06

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 2

75-07

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 46

75-08

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 61

75-09

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 85 

75-10

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 51 

75-11

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 17

75-12

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 18

75-13

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 17

75-14

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 18

75-15

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 66 

75-16

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 8 

75-17

% of lakes

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 3

75-18

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 39

75-19

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 15

75-20

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 89

75-21

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 8

75-22

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 32 

75-23

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 39 

75-24

% of lakes

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 3

75-25

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 1

75-26

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 18

75-27

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 6

75-28

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 44

75-31

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 20 

75-32

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 42 

75-33

% of lakes

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 27

75-34

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 13

75-35

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 44

75-36

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 1

75-37

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 18

75-30

100

90

80

70

60

50

40

30

20

10

Total phosphorus (μg/l)

n = 2

76-03

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 4

65-01

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 17

65-02

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 28

65-03

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 25 

65-04

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 6 

65-05

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 21

65-06

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 26

75-01

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 4

75-02

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 9

75-03

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 50 

75-04

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 5 

75-05

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 6

75-06

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 1

75-07

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 44

75-08

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 57

75-09

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 39 

75-10

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 29 

75-11

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 16

75-12

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 18

75-13

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 13

75-14

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 14

75-15

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 47 

75-16

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 6 

75-17

% of lakes

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 3

75-18

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 33

75-19

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 9

75-20

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 40

75-21

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 6

75-22

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 19 

75-23

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 20 

75-24

% of lakes

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 2

75-25

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 17

75-27

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 2

75-28

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 17

75-30

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 15 

75-32

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 35 

75-33

% of lakes

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 28

75-34

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 13

75-35

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 17

75-36

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 1

75-37

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 25

75-31

100

90

80

70

60

50

40

30

20

10

Total alkalinity (mg/l)

n = 2

76-03

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<5

5-9

10-1415-1920-2930-4950-79

>80

% of lakes

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

<1.0

1.0-1.92.0-3.94.0-9.9

10.0-19.9

20-40

>40

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes% of lakes

% of lakes

% of lakes

% of lakes

% of lakes

% of lakes% of lakes

LAKE REGION CHARACTERISTICS

The maps below illustrate some of the regional differences in the characteristics of Florida lakes. An understanding of regional differences in the current status of lakes, as well as of

potential or attainable conditions, is important for effective lake management. The maps are derived from mean lake data from 1133 lakes, sampled between 1979 and 1996. Most of the

data (82%) are from lakes sampled between 1990 and 1996. The data are from the University of Florida (54%), the Lakewatch program (34%), the U.S. EPA's Eastern Lake Survey (8%),

and from the U.S. Forest Service (4%). Lake data from the Florida Department of Environmental Protection, the Florida water management districts, and other sources were also assessed

for the delineation of the lake region boundaries, but are not included in these chemistry maps or histograms due to differences in detection limits, sampling methods, duplication of lakes,

or other quality control and comparison efforts. The maps are color-coded by the median value for each lake region. A median, or middle value, is used as a measure of the central

tendency of a region's data because it is less skewed by extreme values than is the mean or average value. In regions where there were insufficient data (generally less than three lakes

sampled), the regions were not color-coded unless there was confidence that the one or two lakes represented the region's total population of lakes or ponds. In some regions, the

extrapolation of the median value to the entire region can give a misleading view of the spatial distribution of the actual lake values. However, the maps do help portray some of the

statewide patterns and regional tendencies. The histograms on the phosphorus and alkalinity maps illustrate the frequency distribution, or range of variation, of the lake values in each

region.