Phosphorus and Nitrogen in Three Lakes

A study of the nutrient status in Lake Erken, Lake Limmaren and Lake Largen

Nitrogen Phosphorus

N P

Internal and external loading of nutrinets

Internal loading of nutrients from the sediment

External loading of nutrients from inlets

Sampling

Ekman grabber Ruttner sampler

Lake Erken

Location of sediment, surface and bottom water samplingLocation of inlet water sampling

Lake Limmaren

Location of sediment, surface and bottom water samplingLocation of inlet water sampling

Lake Largen

Location of sediment, surface and bottom water samplingLocation of inlet water sampling

Analyse of the samples

Spectrophotometer

Total phosphorus and phosphate

The total phosphorus and phosphate concentration in the lake water in the three lakes

Total phosphorus concentration

0

10

20

30

40

50

60

70

80

90Co

ncen

tratio

n [μ

g P/

l]

Lake Erken

Lake Limmaren

Lake Largen

Phosphate concentration

0

2

4

6

8

10

12

Conc

entra

tion

[μg

P/l]

Lake Erken

Lake Limmaren

Lake Largen

Total nitrogen and nitrate and nitrite

The total nitrogen and nitrate and nitrite concentration in the lake water in the three lakes

Total nitrogen concentration

0

200

400

600

800

1000

1200

1400Co

ncen

tratio

n [μ

g N/

l]

Lake Erken

Lake Limmaren

Lake Largen

Nitrate and nitrite concentration

0

0,5

1

1,5

2

2,5

3

3,5

4

4,5

Conc

entra

tion

[μg

N/l]

Lake Erken

Lake Limmaren

Lake Largen

• Lake Erken is a mesotrophic lake• Lake Limmaren is an eutropic lake• Lake Largen is an oligotrophic lake

Conclution

Thanks for your attention!