XVth Congress of the European Society for Evolutionary Biology, Lausanne, Switzerland, August 10th–14th 2015 [email protected]
Climate change responses in canopy-forming seaweedsJueterbock A.1, Hoarau G.1
1 Faculty of Biosciences and Aquaculture, University of Nordland, Bodø, Norway
Background Climate change affects seaweed meadows on temperate rocky shores
Canopy-forming seaweeds provide foundational habi-
tat for diverse ecosystems. Along their southern
edges of distribution, however, seaweeds are threat-
ened with extinction due to climate change. To pre-
dict the impact of climate change on temperate and
sub-polar seaweed meadows, we used a multidisci-
plinary approach integrating ecological (migration,
acclimation) and evolutionary (adaptation) responses
to increased temperatures.
year 1999 year 2010
90% abundance decline in Fucus serratus
Migration Niche modeling [1], [4]
Present-day conditions [5]OccurrencesVariable 1
Variable 2Variable 3
Realized niche space
2100
Species Distribution
predictionsRange-limiting
factors
TE
MP
ER
AT
ER
EG
ION
AR
CT
ICR
EG
ION
Biggest ecological changes expected in the
warm temperate and Arctic regions
A1B SREC predictions to year 2200
(intermediate CO2 emission scenario)
Fucus serratus
Fucus
vesiculosus
Ascophyllum
nodosum
Fucus distichus
Min
imum
SS
T(◦
C)
Mean
SS
T(◦
C)
Max.
SS
T(◦
C)
Mean
SAT
(◦C
)M
in.
Diff.
Atten.
(m−
1 )M
ean
Salin
ity
(PS
U)
Mean
Nitra
te(m
oll−
1 )M
in.
Chlo
rophyll
(mg/
m3 )
Mean
Calc
ite
(mo
l/m
3 )
SST (◦C)SAT (◦C)
Variable 1Variable 2
Variable 3
Acclimation Heat-stress response [3]
Sampling of Fucus serratusNorway
Denmark
Brittany
Spain
Acclimation at 9◦C, 4 weeks
Heat stress, > 6 individuals/population
1h Stress 24h Recovery
9◦C
20◦C24◦C28◦C32◦C36◦C
T (◦C)
Time
Highest risk of extinction from an ancient
glacial refugium in Spain.
Risk to lose unique genetic variation
Constitutive shsp gene expression
before heat shock
23 weeks acclimation
7 weeks acclimation
Norm
aliz
ed
expre
ssio
n
High constitutive
stress in Spain
Heat shock response of shsp gene expression
after 24h recovery
Fold
change Reduced
responsiveness
in Spain
Adaptation Genetic changes [2]
Adaptive responsiveness highest in Brittany
and likely insufficient in Spain
Sampling of Fucus serratus
(50-75 indiviuals/population)
∼ year 2000 ∼ year 2010
Sp
atia
l(e
nviro
nm
en
tal)
effe
cts
Temporal changes
1 decade of
selection
Genotyping for 31 microsatellite markers
(20 EST-linked)
Effective population size Ne
(Reflecting adaptive capacity))
∼ 2000 ∼ 2010
18
6320723
Norway
DenmarkBrittanySpain
32
6121026
Allelic richness∼ 2000 ∼ 2010
3.1
4.68.04.0
Norway
DenmarkBrittanySpain
3.3
4.87.94.6
Significant
decline
Temporal outlier loci
0%
6%23%13%
Norway
DenmarkBrittanySpain
References[1] Jueterbock, A.; Tyberghein, L.; Verbruggen, H.; Coyer, J.A.; Olsen, J.L. & Hoarau, G. (2013): Climate change impact on seaweed meadow distribution in the North Atlantic rocky intertidal.
Ecology; Evolution 5(3):1356–1373
[2] Jueterbock, A. (2013): Climate change impact on the seaweed Fucus serratus, a key foundational species on North Atlantic rocky shores. PhD Thesis, University of Nordland
[3] Jueterbock, A.; Kollias, S.; Smolina, I.; Fernandes, J.M.O.; Olsen, J.L.; Coyer, J.A. & Hoarau, G. (2014): Thermal stress resistance of the brown alga Fucus serratus along the North-Atlantic
coast: Acclimatization potential to climate change. Marine Genomics 24393606
[4] Jueterbock, A.; Smolina, I.; Coyer, J.A. & Hoarau G. (In Preparation): The fate of arctic Fucus distichus under climate change: an ecological niche modeling approach.
[5] Tyberghein, L.; Verbruggen, H.; Pauly, K.; Troupin, C.; Mineur, F. & De Clerck, O. (2011): Bio-ORACLE: a global environmental dataset for marine species distribution modelling. Global Ecol.
Biogeogr. 21(2):272–281
Conclusions
Opening of new seaweed habitat in the Arctic and disappearance of seaweed habitat from warm-temperate regions can disturb species interactions
and ecosystem services in the associated rocky-shore ecosystems. The integration of plastic and adaptive responses improved the predictive power of
our niche models to project range shifts and extinction risks under climate change. The remaining key question is whether the adaptive potential of
seaweeds is high enough to save their southern centers of genetic variation in ancient glacial refugia.
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