effects of temperature and heavy metal pollution on fucus serratus søren laurentius nielsen...

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Effects of temperature and heavy metal pollution on Fucus serratus

Søren Laurentius Nielsen

Roskilde University

Why bother?

Why bother?

• They can form extensive populations• They provide food and shelter for animals

and substratum for epiphytic algae• We know they are affected by temperature

and various forms of pollution

But what about germlings?

HD Nielsen et al., 2003

They may very well be more susceptible to environmental stressors than adult algae

Questions

• How will climate change interact with anthropogenic pollution to affect Fucus?

• Is the effect on germlings more pronounced?

Experimental setup

• Four temperatures: 6, 12, 17 and 22 °C• Copper as a ”model pollutant”

– 0, 100 and 1000 nM total copper, corresponding to 0, 42 and 422 nM free Cu2+

– Baltic straits open water and polluted harbor waters respectively

• A 4x3 setup for with germlings as well as Fucus fronds

Results: Adult Fucus

• Growth:

0,00

0,50

1,00

1,50

2,00

2,50

3,00

3,50

6 12 17 22

RG

R (

% d

-1)

Temperature (˚C)

Results: Adult Fucus

• Maximum quantum yield, Fv/Fm:

Results: Adult Fucus

• Maximum photosynthesis, ETRmax:

Results: Adult Fucus

• Non-photosynthetis quenching, NPQ:

Results: Fucus germlings

• Survival:

0,00

0,20

0,40

0,60

0,80

1,00

1,20

6 12 17 22

Re

lati

ve s

urv

iva

l

Temperature (˚C)

Results: Fucus germlings

• Growth:

0

100

200

300

400

500

600

700

800

6 12 17 22

Rh

izo

id le

ng

th (

µm

)

Temperature (˚C)

Results: Fucus germlings

• Maximum quantum yield, Fv/Fm:

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

6 12 17 22

Temperature (˚C)

Fv/F m

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

18.00

6 12 17 22

Temperature (˚C)

ET

Rm

ax

mo

l e

- m-2 s-1 )

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

6 12 17 22

Temperature (˚C)

NP

Qm

ax

Results: Fucus germlings

• Maximum photosynthesis, ETRmax:

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

6 12 17 22

Temperature (˚C)

Fv/F m

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

18.00

6 12 17 22

Temperature (˚C)

ET

Rm

ax

mo

l e

- m-2 s-1 )

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

6 12 17 22

Temperature (˚C)

NP

Qm

ax

Results: Fucus germlings

• Non-photosynthetic quenching, NPQ:

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

6 12 17 22

Temperature (˚C)

Fv/F m

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

18.00

6 12 17 22

Temperature (˚C)

ET

Rm

ax

mo

l e

- m-2 s-1 )

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

6 12 17 22

Temperature (˚C)

NP

Qm

ax

Conclusions:

• Adult Fucus:– Only the growth is affected and only by

temperature– Photosynthetic parameters not affected, so

effect on growth must be due to loss processes and/or effect on cell division

Conclusions:

• Fucus germlings:– Effect on survival, growth and photosynthetic

parameters– Effect of both temperature and metal– Survival decreases with increasing

temperature, synergistic effect of metal– Temperature has positive effect on growth and

photosynthesis, counteracted by metal

Conclusions:

• Need to include early life stages in assessments of effects of climate change and pollution on fucoid algae

• Only including adult algae can lead to overloking effects important for population maintainance and survival

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