Predicting impacts of climate change on survival and growth …...Predicting impacts of climate change on survival and growth of freshwater pearl mussels in Vogtland (Germany) Jointly

Predicting impacts of climate change on survival and growth of freshwater pearl mussels in Vogtland (Germany)

Jointly funded by BMBF and BMU/BFN(Funding Code: 01LC1313A-Dand 3514685E13-I13)

Fakultät Umweltwissenschaften Fachrichtung Hydrowissenschaften Institut für Hydrobiologie

© T

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© J

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© F

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© T

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Annekatrin Wagner,

J. Schneider, T. Schiller, F. Grunicke, D. Jähnichen, D. Linke, T. Berendonk

For further information see www.flussmuschel.de

Status quo of Pearl mussels in Vogtland rivers

• The entire river system was settled with pearl mussels

• up to 1000 FPM/m2

• Stong decline ofpopulations

• lack of natural recruitment despite 30% of adults are gravid

• only three relict populations

• since 2002 successful captive breeding (Hruška-method),

First release to the wilderness 2009

What are best habitats for future reintroduction?

1920 1960 2000

Foto: T, Schiller TUD

Otto Baer 1995

T, Schiller TUD

Questions

1. Effects of change in temperature and precipitation on survival and

growth of juvenile mussels (Margaritifera margaritifera)

2. Probability for the occurence of critical condition in low mountain

region in Germany

3. General implications for the conservation management:

What are best habitats for future reintroduction?

1950 2000 2050 2100

TemperatureTemperatur

Niederschlag,

Laboratory experimentsTemperature control

Hypothesis for effects of

temperature on survival

and growth of FPMStatistical analysis

Empirical approaches

• Prediction of climate-driven changes

in mussel habitats

• Identify most suitable brooks for

reintroduction captive-bred FPM

Field studies in Vogtland brooks(2009-2019)

Bioindication

Discharge

Water temperature (data-Logger)

Turbidity…..

Meteorological Data

Station Bad Sohl (1950-2019)

Combined approach and methods

Air temperature

Precipitation

……Hydrological data Pegel Adorf

(1970-2019)

iDA Sachsen.de

Study area in Vogtland

Map „Fischregionen 2011“ (LfULG)

Rauner Bach (RB)

Eisenbach (EB)

Triebelbach(TB)

Tetterweinbach(TW)

Haarbach (HB)

GermanyMittelgebirgsregion: 550 m NN

Comparison of investigation years


2016

relatively cool summer

Rainfall: moderate in Jun/Jul and low in Aug

2017

no extremes, always sufficient rain

2018

Extreme flooding at the end of May,

during summer lack of precipitation and high air

temperatures

2019

Low rainfall throughout the summervery warm summer

0

30

60

90

120

Spring Summer

Rain

fall (

mm

/mon

th)

5

10

15

20

Mean

air

tem

pera

ture

( C

)

2016 2017 2018 2019

Long-term Mean Mittel: 1961 - 1990

Normal20162017

Flood2018

Low water in brooksSommer 2018 +2019Foto: T, Schiller TUD

• flow-through sediment cages

• in 5 streams

• each 15 PM of age 10-15

• control at 1. Juni and 31. August

• 2016 - 2019

In-situ Bioindikation mit semi-adulte FPM

© T

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Foto: A. Wagner TUD Foto: A. Wagner TUD


© T

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Lethale effects onsemiadult FPM

50%

60%

70%

80%

90%

100%

16 18 20 22 24 26

Überleben

Maxima Wassertemperatur ( C)

2016

2018

2017

2019

90%

95%

100%

0 20 40

Übe

rle

be

n

Abfluss Min Jun-Aug (l/s)

2017

2018

2019 Discharge<10 l/s und WT>25 C

increase in mortality

extreme flooding

no mortality

Max water temperature ( C)

Surv

ival

Surv

ival

Min discharge (l/s)

© T

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chille

r

gro= 48,3*exp(-0,5*((WT-14,75)/1,1)^2)

R=0,76

P<0,001

Temperature optimum ofsemiadulte PM

0

10

20

30

40

50

60

70

80

13 14 15 16 17

Wa

chstu

m (

µm

/d)

Wassertemperatur MW ( C)

semiadulte FPM_2016-2019

EB

HB

RB

TB

TW

0

10

20

30

40

50

60

70

13 14 15 16 17

Wachstu

m (µ

m/d

)

Wassertemperatur MW ( C)

2016

2018

2017

2019

Maximum growth

60 µm/d = 5,5 mm/Jahr

Temperature optimum 14,8 – 15,4 C

Gro

wth

(µ

m/d

)G

row

th (

µm

/d)

Water temperature ( C)


Factors cotrollinggrowth semi-adulter PM

2009-2014 data to bioindication from Michael Lange

• flow-through sediment cages

• in Rauner Bach

• Each 15 semiadulte FPM

• Control at 1. Juni and 31. August

• 2009 -2019

0

20

40

60

0 30 60 90 120 150

NS (mm/Monat)

0

20

40

60

15 16 17 18 19

Lufttemperatur MW ( C)


Wa

ch

stu

m (

µm

/d)

Factors cotrollinggrowth of

semi-adulter PMJun-Aug 2009-2019

High growth at

precipitation > 60 < 100 mm/month

> 8 rainy days/month

Average air temperature <17 C

R = 0,54P = 0,09

R = 0,78P = 0,007

Gro

wth

(µ

m/d

)

Air temperature ( C)

Rain (mm/month)

Risk of partial drying of the streams

2003, 2012, 2015,

2018, 2019



0

20

40

60

80

100

0 1 2 3 4 5 6 7 8 9 10 11 12

Rain

(m

m/m

on

th)

month

drying out (n=5)

suffient water (n=11)

Mittelwerte und SE der monatlichen

Niederschlagssumme (2002 -2019)

0

20

40

60

80

100

0 1 2 3 4 5 6 7 8 9 10 11 12

Rain

(m

m/m

on

th)

month

drying out (n=5)


0

20

40

60

80

100

0 1 2 3 4 5 6 7 8 9 10 11 12

Rain

(m

m/m

on

th)

month

drying out (n=5)


0

20

40

60

80

100

0 1 2 3 4 5 6 7 8 9 10 11 12

Rain

(m

m/m

on

th)

month

drying out (n=5)


Risk of partial drying of the streams

2003, 2012, 2015,

2018, 2019

Mean Values of monthly rain and SE

(2002 -2019)

Luft

tem

pera

tur

(°C

)

15

16

17

18

19

20

Data meteorology: Station Sohl (sklima.de)Groundwater level_Adorf (iDa Sachsen)

Nie

ders

chla

g J

ul-A

ug (

mm

/Monat)

0

20

40

60

80

100

120

140

160

180

Gru

ndw

assers

tand, m

in (c

m)

-135

-130

-125

-120

-115

-110

-105

P<0,001

P<0,001P=0,023

Luft

feuch

te (

min

) %

30

35

40

45

50

55

60

65

P<0,001

years with

drying up

Luft

tem

pera

tur

( C

)

Luft

feuchte

Min

(%

)

Pre

cip

ita

tio

n(m

m/m

on

th)

Gru

ndw

assers

tand M

in (

cm

)

Data: Jul-Aug 2002-2019

One-Way ANOVA

Years with drying-up n=5years without drying-up n=11

Min

air

hum

idity

(%)

Air

tem

pera

ture

( C

)

Min

gro

undw

ate

rle

vel(c

m)

years without

drying upyears with

drying up

years without

drying up


Trend to decreasing groundwater levels

1. Mai.

31. Mai.

1. Jul.

31. Jul.

31. Aug.

30. Sep.

31. Okt.

1970 1980 1990 2000 2010 2020

Sta

rt G

Wsta

nd

>120cm

0

30

60

90

120

150

1970 1980 1990 2000 2010 2020

Dau

er

GW

sta

nd

>120cm

(d

)

1. Jun

1. Sep

1. Okt

1. Nov

1. Aug

Periods with extremely low groundwater levels start earlier in the year and last longer

Data meteorology : Station Sohl (sklima.de)groundwater levels_Adorf (iDa Sachsen)

Sta

rt g

roundw

ate

rle

vel

>12

0cm

Dura

tion (

days)

of

the

pe

rio

d

with

gro

undw

ate

rle

vel>

12

0cm

0

200

400

600

800

1000

1200

1400

-4 -2 0 2 4 6 8 10 12

Life cycle


May NovSepJul

Length

(µm

)

Months after dropping of brown trout

Metamorphosis at the

gill of brown troutFPM lives in the hyporheic zone

Foto: F. Grunicke TUDFoto: F. Grunicke TUD Foto: A. Kuhr TUD

© T

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chille

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In-situ bioindication with0+ PM

• In each brook 6-9 cylindrical tubes

mesh size of 0.42 mm

• filled with brook-specific gravel (2-6

mm)

• 50 post-parasitic mussels

• Exposed to 5 brooks and buried in

the sediment at a depth of 5 cm

• From Juni bis 31. August

• 2017 -2019

0

2

4

6

8

10

13 14 15 16 17

Wa

chstu

m (

µm

/d)

Wassertemperatur in -5cm ( C)

2019

2018

2017

growth = -35,373 + (2,483 * WT)

R2 = 0,73

P < 0,001

Temperature control ofgrowth of 0+PM

© T

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chill

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Gro

wth

(µ

m/d

)

Water temperature in -5 cm ( C)

0%

20%

40%

60%

80%

100%

600 800 1000 1200 1400 1600 1800

Su

rviv

al

du

rin

g 1

. w

inte

r

Length at the end of 1. growing season (µm)

LP_2017

LP_2018

WE_Wi2017

DGR_2018

NonlinearRegression

© T

. S

chille

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Influence of length in autumn on survival of

0+PM during first winter

Sigmoidal Regression:

Surv_wi = 0,97/(1+exp(-(L-1107)/97,2))

R2= 0,92

P<0,001

Survival during autumn+winter

Two Way Analysis of Variance

Startlänge p<0,001

Temperature winter p=0,91

0,5

1

1,5

13 14 15 16 17

Len

gth

at

the e

nd

of

1.

gro

win

g s

eason

(m

m)

0%

20%

40%

60%

80%

100%

13 14 15 16 17

Su

rviv

al

du

rin

g 1

. w

inte

r

Water temperature -5 cm (Jun-Aug) ( C)

© T

. S

chille

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Estimated effect of water temperatures during

summer on survival of 0+PM during first winter

15 C during summer

corresponds to a survival of 50%

Wa

ter

Te

mp

era

ture

(°C

)

8

10

12

14

16

18

20

22

EB16

EB17

EB18

HB16

HB17

HB18

RB16

RB17

RB18

TB16

TB17

TB18

TW16

TW17

TW18

WB16

WB17

WB18

GB16

GB17

GB18

2016 2017 2018

Wa

ter

tem

pe

ratu

re(

C)

10

12

14

16

18

20

EB GBWBTWTBRBHB

Water temperatures during summer (Jun, Jul, Aug) 2016-2018

Logger(Tinytag)

Mean water temperature of river Lutter: 15.7 C

(Data: M. Lange)

too

co

ld

Lut

Bottleneck in mussel conservation strategy

krenal and epi-rhitral of rivers more suitable for the FPM in terms of morphology

and water quality compared to the meta- or hyporhitral, but often too cold

Adorf: 14,1 / 15,7

Mühlhausen: 13,6 / 15,3

Oelsnitz: 15,4 / 15,9

Rauner Mühle: 12,3 / 12,8

Mean Water temperatures(iDA) (Jun-Aug) 2002-2016: Cold years Air temp<16 Cwarm years Air temp>16 C

Reservoir

Small tributariesJB: 11,4 / 13,4Wer 12,1 / 13,9

Temperature in krenal and

rhithral

Otto Baer 1995

Weiße Elster 1800

© J

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chneid

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TW: 15,1 / 17,1

Conclusions to hazard factors


Semiadulte Muscheln

Low rain or at less than 8 days/month Decrease of ground water levels Discharge <10 l/s Water temperatures >24 C

Age-0 FPM Average water temperatures during summer <15 C

Increasing probability of streams drying out.

For a successful freshwater mussel conservation approach, it is

crucial to consider consequences of climate warming.


Foto: T. Schiller TUD

© T

. S

chill

er

Many thanks to all partners, to our advisory boards and

to the supporters in the state ministries and offices.

For further information see www.flussmuschel.de

Thank you very much for your attention!

Documents

Predicting impacts of climate change on survival and growth …...Predicting impacts of climate change on survival and growth of freshwater pearl mussels in Vogtland (Germany) Jointly