the history of eutrophication and restoration of lake geneva jean-luc loizeau and janusz dominik...

The history of eutrophication and restoration of Lake Geneva

Jean-Luc Loizeau and Janusz Dominik

CESNE and Institut F.-A. Forel, University of Geneva, Switzerland

curriculum in natural environmental science, 2005

Satellite image of Southern France

phot

o : C

laud

e Jo

min

i

Rhone river mouth

Lake Geneva

Rhone river mouth


10 km

Lausanne

Evian

N

Dranse River

Nyon

Morges

Thonon

Vevey

Montreux

St-Gingolph

Lutry

Versoix

Rolle

Yvoire

Geneva

Lake Geneva

100 - 200

200 - 300

300 - 309

0 - 100 m

Bathymetry

Rhone River

Rhone

Rive

r

Marse ille

Me diterranean Sea

40 km

Lyon Geneva

SwitzerlandFrance

Italy

Rho

ne R

iver

Petit-lac

Grand-lac

France

Italy

Germ any

CH

Spain


Lake GenevaAlt itude : 372 m aslSurface 580.1 km2Volume : 89 km3Mean discharge : 250 m3/ s

Theoret ical residence t ime of water : 11.4 yearsMax depth : 309.7 mMean depth : 152.7 mShore ligne length : 200.2 kmLake/ wat ershed ratio : 0.078

Watershed : 7975 km2Watershed without lake : 7393km2Max. alt itude : 4634 mMean altitude : 1670 mGlaciated area : 9.4%Population: 933’750

Switzerland : 807’850France : 125’900

Tourism : 624’240Switzerland : 443’620

France : 180’620

Land use:uncultivated : 35%forests : 22%

pasture : 23%cult ivated : 20%

meadows : 63%open land : 27%vineyard : 6.6%orchard : 2.6market gardening: 1 %


Lake GenevaWatershed : 7975 km2

Rhone River : 5220 km2

Dranse : 535 km2

Venoge : 231 km2

Aubonne : 91 km2

Promenthouse :100 km2

Geneva

50 km


Years

1960 1970 1980 1990 2000

P to

tal (

µg/

L)

0

20

40

60

80

100

Mean Ptot concentration

Management objective

Start of phosphateremoval in STP

Ban of P in textilewashing products(CH)

Data source: CIPELcurriculum in natural environmental science, 2005

Evolution of mean N concentration in lake water

Years

1960 1970 1980 1990 2000

NO

3- an

d N

tot (

µg

N*L

-1)

200

300

400

500

600

700

800

NO3-

Ntot


Evolution of N/P ratio in lake water

Years

1960 1970 1980 1990 2000

Pto

t (µ

g L-1

)

0

20

40

60

80

100N

- N

O3 /

P-P

O4 r

atio

4

6

8

10

12

14

16

18

20

22

Ptot

N-NO3/P-PO4 ratio


Dissolved oxygen in bottom water (309m)

Years

1955 1960 1965 1970 1975 1980 1985 1990 1995 2000

Dis

solv

ed o

xyg

en (

mg

L-1

)

0

2

4

6

8

10

12


Net yearly primary production

Years

1975 1980 1985 1990 1995 2000

Prim

ary

prod

uctio

n (g

C /

m2 *

y)

0

100

200

300

400

500


Yearly average biomass (Center of the lake)

Years

1960 1970 1980 1990 2000

Phy

to.

biom

ass

(mg

L-1)

0

500

1000

1500

2000

2500

3000

Pto

t (µ

g L-1

)

0

20

40

60

80

1004980


Evolution of the Secchi depth

Period of measurement

1874/75 1889/91 1957-60 1961-80 1981-2002

Dep

th (

m)

0

2

4

6

8

10

12

Summer meanAnnual mean

Data source: Forel 1892 and CIPELcurriculum in natural environmental science, 2005

Lake water transparency

Years

1960 1970 1980 1990 2000

Sec

chi

dep

th (

m)

0

2

4

6

8

10

12

summer meanannual mean


Seasonal variation of Secchi depth

Month

Mar May Jun Jul Aug Sep Nov

Sec

chi d

epth

(m

)0

2

4

6

8

10

12

14

~1900 1931-1932 1954-1955 1957-1959


Years

1960 1970 1980 1990 2000

Zo

op

lan

kto

n (

mL

/m2 )

0

50

100

150

200

250

300

Pto

t (µ

g L

-1)

0

20

40

60

80

100

Zooplankton

Ptot


Arctic char catches

Years1950 1960 1970 1980 1990

Fis

h c

atch

es (

ton

s)

0

5

10

15

20

25

30

35

Pto

t (µ

g L

-1)

0

20

40

60

80

100

Ptot

Data source: Rapin et al. 1995curriculum in natural environmental science, 2005

Algal summer biomass in lake water

Years1970 1975 1980 1985 1990 1995 2000S

um

mer

bio

mas

s (o

lig

o.

spec

ies)

(µ

g L

-1)

0

5

10

15

20

25

30

35

To

tal

sum

mer

bio

mas

s (µ

g L

-1)

0

1000

2000

3000

4000

5000

6000

7000

8000

9000All species

Oligotrophic species

Data source: Anneville et al. 2002curriculum in natural environmental science, 2005

Waste water treatment plant capacity inLake Geneva watershed

Years1960 1970 1980 1990 2000

WW

TP

cap

acit

y (m

io in

hab

.-eq

uiv

.)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Total capacity

with dephosphatation step

Data source: Rapin et al. 1995curriculum in natural environmental science, 2005

Primary stage basins of the Lausanne WWTP


Tabellaria fenestrata

http://www.epa.gov/glnpo/monitoring/plankton/images/diatoms01.html

http://www.marbot.gu.se/sss/diatoms/diatom_frame.htm

Cyclotella spp.

Oligotrophic phytoplankton species


http://www.science.uottawa.ca/bio/eng/prof/pick/lab/pages/images.htm

Ceratium hirundinella

5mm

Planktothrix rubescens

Eutrophic phytoplankton species

Anabaena flos-aquae

http://www-cyanosite.bio.purdue.edu/images/images.html


Larvee of Chironomus riparius

Some benthic fauna species

Lymnaea

Pisidium


Potamogeton pectinatus

Some macrophyte species

Cara major


Cyprinus carpio

Fish

Lota lota

Coregonus sp.

Salmo truttaSalvelinus alpinus

Esox lucius


« Lothar » storm at Vevey, December 26, 1999Lake Geneva and Mont Blanc during a windy day

Views from Lake Geneva


the history of eutrophication and restoration of lake geneva jean-luc loizeau and janusz dominik...

Documents

natural environmental

data source

lake geneva curriculum

switzerland curriculum

lausanne wwtp curriculum

university of geneva

tabellaria fenestrata

potamogeton pectinatus