Brigitte Nixdorf, Jacqueline Rücker, Ingo Henschke, Ronny

Hämmerling

BTUCottbus, 1IGB Berlin,

Water quality and biodiversity in Lake Scharmützelsee from 1993 to 2005

Lakepromo October 2005

1. Since 1990 a drastic reduction of the external P load was calculated and measured

2. The current external P load of lake Scharmützelsee with 0.8 t a-1 P, estimated by the MONERIS model, is very low compared with the internal P release with 6.75 t a-1 P.

3. L. Scharmützelsee shows the tendency to better ecological quality.

Is this observation confirmed by ecological water quality components (phytoplankton biomass and diversity, macrophytes, fish)?

Results from April 2005/ Question in Oct. 2005:

Biological components Present state (April 2005)

Composition and

abundance

(Biomass) of

water plants

Final report in Aug.2005( LAWA, Nixdorf et al.

BTUC/LBH) Final report (BLW Schaumburg et al.) January

2004 (BMBF, LAWA)

Composition and

abundance of

benthic

invertebrates

Final report 2/2005 (BÖHMER et al., December

2004, LAWA)

Composition,

abundance and

age structure of

fish

Phytoplankton,

Makrophytes,

Aufwuchs

Makrozoo-

benthos

Fish

Final report 2/2005 (Mehner et al., IGB, BMBF)

1.1 Quality elements for the evaluation of lakes and ecological status – present state in Germany – Practical tests in 2005/2006

Lake Scharmützelsee region :

Urban areas 15.8 %

Agricultural crop land 13.7 %

Grassland 3.8 %

Surface waters 10.6 %Wetlands 2.1 %

External phosphorus inputs into the lake Scharmützelsee by point sources (sewage effluent, military hospital) and diffuse sources 1969 and 2001

No further reduction of external loads!

0,00

0,10

0,20

0,30

0,40

0,50

0,60T

P [

t a-1

]

Erosio

n

Grund

wasse

r

Input of phosphorous (TP) from different sources into lake Scharmützelsee from 1996 to 2000 calculated by MONERIS-model

Groundwater TP-concentration

between 20...140 µg/L

Dynamics of phosphorus: Decreasing trend in TP, but high internal P-release

Precipitation of P?

94 95 96 97 98 99 00 01 02 03 040

20

40

60

80

100

120

140

160

0

20

40

60

80

100

120

140

160

P [

µg

l-1]

TP DIP

Phytoplankton

JOJA JOJ A JOJ A JOJ A JOJA JOJ A JOJ A JOJ A JOJA JOJ A JOJ A JOJ A0

2

4

6

8

10

12

14

16

0

2

4

6

8

10

12

14

16

HPLC

Bio

volu

me

[m

m-3 L

-1]

Cyano Bacill Crypto Dino others

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004HPLC

ICE

Phytoplankton dynamics in lake Scharmützelsee 1993-2005Data: Zippel, Hoehn – LBH)

Good ecological status for lake Scharmützelsees (Phytoplankton Report (/2005)

Biovolume [mm3 L-1] *: 0.5 – 2Chl a [µg L-1] *: 2.5 – 10

Considering the trophic state from good ecol. state means:

• Reduction of phytoplankton biomass by at least 50%• Increase in Secchi depth by more than 100% to more than 2 m during the vegetation period

Assessment of ecological state of lake Scharmützelsee acc. to LAWA (1999) and WFD (2000)

19941995 - 1999

2000 2001 2002 2003

LAWA (1999)

Reference state (morphometry)

mesotroph

Natural nutrient input

mesotroph

Present state e2 e1 m e1 e2 m*

Assessment 3 2 1 2 3 1#

WFD (2000) - Phytoplankton

Biovolume (BV) [mm3 L-1]*

3,4 5,3 – 8,6 1,1 6,3 9,9 1,4#

Assessment acc. to BV

3 4 - 5 2 4 5 2

0

10

20

30

40

50

60

70

Sep.

93

Feb.

94

Jul.

94

Apr.

95

Aug.

95

Jan.

96

Jul.

96

Jun.

98

Sep.

98

Feb.

99

Apr.

99Ju

l. 99

Sep.

99

Dez.

99

Feb.

00

Mai

. 00

Jul.

00Se

p. 0

0

Dez.

00

Apr.

01

Aug.

01

Jan.

02

Jun.

02

Okt

. 02

Apr.

03

Aug.

03

Jan.

04

Apr.

04

Sep.

04

Feb.

05

Num

ber o

f tax

a &

Chl

a [µ

g/L]

AnzahlvonTaxon 9 11 Chla (µg/l) Polynomisch (AnzahlvonTaxon 9 11)

Number of phytoplankton taxa in L. Scharmützelsee and trendline from 1993 to 2005 (between 30...60 per sample)

Person APerson C/D

Person B

Person B

Macrophytes

Distribution of species groups (macrophytes) within one lake type across a degradation

gradient

Index/MelzerIndex/TKg1994 2005Ceratophyllum demersum 5 B x xMyriophyllum spicatum 3 B x xPotamogeton perfoliatus 3 B x xPotamogeton pectinatus 4 B x xPotamogeton lucens 3,5 B x xNittellopsis obtusa 2,5 A xUtricularia vulgaris 3 A xElodea canadensis 4,5 C xFontinalis antipyretica xStratiotes aloides 1,5 A xRanunculus trichophyllus 4,5 C xNajas marina B x

Species number 5 12

Dominant species of macrophytes in L. Scharmützelsee 1994 and 2005

Increase in dominant species number from 5 to 12, „good“ species (Nittellopsis, Stratiotes, Najas) as well as „bad“ species (Elodea, Ranunculus)

Fish (z.B. Gründling, Steinbeißer im Litoral des Müggelsees)

Scharmützelsee Periode

Art wissenschaftlicher Name Refe-renz

histo-risch

1945-1990

aktuell

Aal

Anguilla anguilla

H + + + Aland

Leuciscus idus

E Barsch

Perca fluviatilis

H + + + Bitterling

Rhodeus amarus

E Blei

Abramis brama

H + + + Döbel

Leuciscus cephalus

A + Dreistachliger Stichling

Gasterosteus aculeatus

H + + Giebel

Carassius gibelio

+ Graskarpfen

Ctenopharyngodon idella

+ + Gründling

Gobio gobio

A + Güster

Abramis bjoerkna

H + + Hecht

Esox lucius

H + + + Karausche

Carassius carassius

H + + + Karpfen

Cyprinus carpio

+ + + Kaulbarsch

Gymnocephalus cernuus

H + + Kleine Maräne

Coregonus albula

H + + Marmorkarpfen

Hypophthalmichthys nobilis

+ nein Moderlieschen

Leucaspius delineatus

E Plötze

Rutilus rutilus

H + + + Quappe

Lota Iota

E Rapfen

Aspius aspius

A + Regenbogenforelle

Oncorhynchus mykiss

+ + Rotfeder

Scardinius erythrophthalmus

H + + Schlammpeitzger

Misgurnus fossilis

A + Schleie

Tinca tinca

H + + + Silberkarpfen

Hypophthalmichthys molitrix

+ + nein Steinbeißer

Cobitis taenia

A + Stint

Osmerus eperlanus

A + Störhybriden

Acipenser spec.

+ Ukelei

Alburnus alburnus

H + + Wels

Silurus glanis

H + + + Zander

Sander lucioperca

H + + + Zwergwels

Ameiurus nebulosus

+ Gesamt 25 16 14 28

Number of fish taxa in L. Scharmützelsee (historical reports and before 1990 and now):

Increase from about 15 to 28 (acc. to the reference state)

External nutrient inputs (TP) have been reduced during the last 15 years by more than 90 %

Main nutrient pathways are internal P-release from the sediments and input from the groundwater as well as atmospheric deposition.

Species numbers for macrophytes and fish increased, diversity for phytoplankton depends on taxonomic knowledge

L. Scharmützelsee reached a threshold for TP – reduction in phytoplankton biomass and composition – but shows annual fluctuations mainly due to:

Climatic influences, Biological food web interaction, Low silica concentrations favouring cyanobacteria

Summary

Kenngrößen Phytoplankton

nach trophiebasierter Voreinstufung und typspezifischen ReferenzzuständenBiomassesindex

Indikatortaxa

Chlorophyll a

Gesamt-biovolumen

„Algenklassen“Einzelmetrics gelten für ausgewählte Seen-Typen und Bewertungszeiträume

Phytoplankton-Taxa-Seen-Index

- 1 -

- 2a - - 2b - - 2c -

- 3 -

Taxonomische Zusammensetzung - Bewertung

Summe Indices 1-3(4)/(Summe Fx) = Trophischer

Index

Indices GFBiomasse- Bewertung

planktische Diatomeen

Profundal

nur für Tieflandseen, wennDiatomeenanalyse Plankton fehlt und/oderweniger als 4 Indikatortaxa

( 4 )

x F1

x F2

x F4

Mittelwert aus Einzelmetrics 2

x F3

Klassengrenzen für Gesamtbiovolumen

Tabelle 1: Klassengrenzen des Phytoplanktonbiovolumens [in mm³/l] für die Seetypen (Spalte 3 -6) Hartwasserseen der Alpen & Voralpen (Typ 1 – 4 in Kopfzeile) sowie der Tieflandseen (Typ 10 – 14, Kopfzeile) mit den dazugehörenden Bewertungsstufen mit dem Bewertungswert (B-Wert, Spalte 2).

B-Wert 1 2+3 und 4 13 14

Very good 1 <1,5 <0,6 <0,8 <1,3

good 2 1,5-<2,5 0,6-<1,2 0,8-<2,5 1,3-<5,5

moderate 3 2,5-<7,0 1,2-<3,0 2,5-<5,0 5,5-<9,0

unbefried. 4 7,0-<11,0 3,0-<8,0 5,0-<10,0 9,0-<17,0

bad 5 >11 >8,0 >10 >17

B-Wert 10 11.1 11.2 12

sehr gut 1 <3,0 <5,0 <10,0 <5,0

gut 2 3,0-<7,0 5,0-<10,0 10,0-<18 5,0-<10,0

mäßig 3 7,0-<12,0 10,0-<14,0 18,0-<28,0 10,0-<15,0

unbefried. 4 12,0-<20,0 14,0-<30,0 28,0-<40,0 15,0-<25,0

schlecht 5 >20 >30 >40 >25

Lake types in the German lowlands and phytoplankton biomass

LAWA-See-Typ-Nr:

Einzugsgebiet zu Seefläche

VQ VQ >1,5 VQ >1,5 Flussseen

VQ >1,5 VQ <1,5 VQ <1,5Schichtung geschichtet polymiktisch polymiktisch polymiktisch geschichtet polymiktisch

Degradations- stufe

Biovolu- men= BV Chl a BV Chl a BV Chl a BV Chl a BV Chl a BV Chl a

sehr gut <4,0 5,0 <5,0 ,0 <5,0 ,0 <5,0 ,0 <0,6 <1,3 gut 4,0-<8,5 >5-15 5,0-<10,0 >15-30 5,0-<13 >15-45 5,0-<10,0 >15-30 0,6-<3,5 >3-10 1,3-<5,5 >5-20

moderat 8,5-<13,0 >15-30 10,0-<14,0 >30-38 13-<18,0 >45-60 10,0-<15,0 >30-40 3,5-<5,0 >10-20 5,5-<12,0 >20-40unbefried. 13,0-<20,0 >30-50 14,0-<30,0 >38-80 18,0-<35,0 >60-100 15,0-<25,0 >40-60 5,0-<15,0 20-45 12,0-<20,0 40-60

schlecht >20 >50 >30 >80 >35 >100 >25 >60 >15 >45 >20 >60Anzahl

Saisonmittel85 80 28 37 102 45

10sehr flache Seen (<3m mittl. Tiefe)

VQ >1,5

Tieflandseen

1411.1 11.2 12 13

Degradation of lakes in Germany acc. to the lake types (phytoplankton biomass)

51 0 1 0 0 2

103 0

72 0

11

17 4

0 01

10

5

21

50

4

4

4 5

1 10

18

18

4

14

5

1

1

0

1 0

0 1 0

10

19

13

6

5

0

0

0

00

0 0 0

5

12

2

2

1

1

21

0

10

20

30

40

50

60

70

Typ

1

Typ

2

Typ

3

Typ

4

Typ

6

Typ

7

Typ

9

Typ

10

Typ

11

Typ

12

Typ

13

Typ

14

Str

an

dse

e

schlecht

unbefried.

moderat

gut

sehr gut

Nu

mb

er o

f la

kes