MAY 2016 ICES/PICES 6TH ZOOPLANKTON PRODUCTION …
Transcript of MAY 2016 ICES/PICES 6TH ZOOPLANKTON PRODUCTION …
Nicole Aberle, Henriette Horn,Aleksandra Lewandowska, Ulrich Sommer
MAY 2016ICES/PICES 6TH ZOOPLANKTON PRODUCTION SYMPOSIUM
BERGEN
Microzooplankton in a changing environment: shifts in phenology and
trophic relations
1
Kraberg et al. 2008
2
Climate changes effects on oceans
temperature
increase
elevated pCO2
elevated concentrations of
green house gases e.g. CO2
enhancedUV radiation
acidfication
sea levelrise
higher airtemperatures
changes in air pressure
higher storm frequencies
melting sea ice
salinity changes
changes incurrent systems
changes in upwhelling
anthropogenic impacts
temperature increase
elevated pCO2
elevated concentrations of
green house gases e.g. CO2
sun
enhancedUV radiat.
acidfication
sea levelrise
higher airtemperat.
changes in air pressure
higher storm frequ.
melting sea ice
salinity changes
changes incurrent systems
changes inupwhelling
anthropogenic impacts
3Warming: Aquatic food webs become more microbial
Sarmento et al.
Phil. Trans. R. Soc. B
2010;365:2137-2149
Microbial food webs in a warming ocean
DFG Priority Programme AQUASHIFT:
Kiel Plankton Mesocosm Cluster
Bacteria, Phyto- and Zooplankton, Biogeochemistry, Modelling
Experimental design
Baltic Sea spring bloom:
2005-2009
• Indoor mesocosms (1400 L): 12
• Temperatures (ΔT): 0 and 6°C
• Additional manipulations:
light regime and copepod density
• Treatments: 2 replicates each
0 40 80 120 160 200
Julian Days
0
4
8
12
16
20
Tem
pera
ture
in °
C
deltaT 6
deltaT 4
deltaT 2
deltaT 0
Spring temperature modell
0 40 80 120 160 200
Julian Days
0
4
8
12
16
20
Tem
pera
ture
in °
C
deltaT 6
deltaT 4
deltaT 2
deltaT 0
Spring temperature modell
Te
mpe
ratu
re in
°C
Julian day
Δ0°C: decadal mean (1993-2002)
Bio
ma
ss
Spring season
Spring scenario (temperate regions)
Seasonal succession patterns of spring plankton
Phytoplankton Microzooplankton Fish larvaeMesozooplankton
Heterotrophic processes are more vulnerable to
temperature changes than autotrophic ones
‘Metabolic Theory of Ecology’ (Brown et al. 2014)
Phenology shifts with warming
• Reduced time-lags between autotrophs and
heterotrophs with warming
• Shifts in timing (and magnitude) of MZP biomass
• Stronger top-down control of phytoplankton by MZP
• Alterations in energy transfer (enhanced dietary
competition between MZP and mesozooplankton)
WARMING
‘Trophic link’ ‘Trophic sink’
?
Day of the year
40 50 60 70 80 90 100
Cu
mu
lati
ve b
iom
ass (
%)
0
20
40
60
80
100
120
6°C: 64%
6°C: 48%
6°C: 32%
°C: 64%
°C: 48%
°C: 32%
Qend= 75% threshold
Qstart= 25% threshold
Qmedian= 50% threshold
Aberle et al. Mar Biol 2012→ Earlier timing of MZP in the mesocosms
7
MZP biomass (2008)
Time-lags between ciliates and phytoplankton
Bio
masse in µ
g C
L-1
Julianischer Tag
ΔT=0 ΔT=2 ΔT=4 ΔT=6
40 60 80 100 12040 60 80 100 12040 60 80 100 120
10-2
10-1
100
101
102
103
40 60 80 100 120
CilPhyto
Data: Sommer, Lengfellner, Aberle
Temperature treatment ΔT (°C)
Bio
ma
ss
(µg
C L
-1)
→ Reduced time-lags between phytoplankton and MZP with warming
8
Phenology shifts
Aberle et al. (Mar Biol, 2012)
6°C: 62%
Y A
xis
30
20
40
60
80
100
MZ
P b
iom
ass (
µg
C l
-1)
0
10
20
30
40
°C: 62%
Day of the year
40 50 60 70 80 90 100
Y A
xis
3
0
20
40
60
80
100
MZ
P b
iom
ass (
µg
C l
-1)
0
10
20
30
40
A
6°C: 57%
B
6°C: 49%
Co
pep
od
bio
mass (µ
g C
l-1
)
0
20
40
60
80
100
Ph
yto
pla
nkto
n b
iom
ass (µ
g C
l-1
)
1
10
100
1000
Col 1 vs Col 4 Col 14
Col 15
Col 1 vs Col 4
Col 9 vs Col 12
C
D
°C: 57%
Day of the year
40 50 60 70 80 90 100
Y A
xis
3
0
20
40
60
80
100
E
°C: 49%
Day of the year
40 50 60 70 80 90 100
Ph
yto
pla
nkto
n b
iom
ass (µ
g C
l-1
)
1
10
100
1000
Co
pep
od
bio
mass (µ
g C
l-1
)
0
20
40
60
80
100F
Copepods
small phytoplankton
Ciliates
Dinoflagellates
medium phytoplankton
→ Reduced temporal occurrence of MZP9
Phenology shifts (2008)
Hypotheses:
1. High overwintering copepod densities will affect MZP
biomass (size classes/community composition)
2. Warming at high copepod densities will lead to a strong
top-down control on MZP→ MZP functions as a ‘trophic link’
3. Warming at low copepod densities will lead to an earlier
timing of MZP and a shortened temporal occurrence → MZP functions as a ‘trophic sink’
Test for the combined effects of warming and densities of
overwintering copepods on MZP biomass and phenology
Warming & overwintering copepod densities
11
Aberle et al. (MEPS 2015)→ MZP bloom intensity was highly affected by copepod density
→ Strong suppression of MZP (especially ciliates <30 µm) at elevated
temperatures
Top-down control by copepods
Initial copepod density (copepods L-1
)
1,5 4 6
Blo
om
in
ten
sit
y (
BP a
t D
ma
x)
in µ
g C
l-1
-50
0
50
100
150
200
250
300
D 6°C: 1.5 cop L-1
_A
D 6°C: 4 cop L-1
_A
D 6°C: 10 cop L-1
_A
D 6°C: 1.5 cop L-1
_B
D 6°C: 4 cop L-1
_B
D 6°C: 10 cop L-1
_B
Linear regression D 6°C
D 0°C: 1.5 cop L-1
_A
D 0°C: 4 cop L-1
_A
D 0°C: 10 cop L-1
_A
D 0°C: 1.5 cop L-1
_B
D 0°C: 4 cop L-1
_B
D 0°C: 10 cop L-1
_B
Linear regression D 0°C
D 6°C
r²= 0.67
b= -36,9
D 0°C
r²= 0.87
b= -112.3
1.5 4 10
Initial copepod density (copepods l-1)
MZ
P b
loo
min
ten
sit
y(µ
g C
l-1
)
Kraberg et al. 2008
12
Effects of warming & ocean acidification (OA)
temperature
increase
elevated pCO2
elevated concentrations of
green house gases e.g. CO2
enhancedUV radiation
acidfication
sea levelrise
higher airtemperatures
changes in air pressure
higher storm frequencies
melting sea ice
salinity changes
changes incurrent systems
changes in upwhelling
anthropogenic impacts
temperature increase
elevated pCO2
elevated concentrations of
green house gases e.g. CO2
sun
enhancedUV radiat.
acidfication
sea levelrise
higher airtemperat.
changes in air pressure
higher storm frequ.
melting sea ice
salinity changes
changes incurrent systems
changes inupwhelling
anthropogenic impacts
Will OA affect lower food web dynamics?
Phytoplanktonn
Microzooplankton
Mesozooplankton
Bacteria
POCDOC
HNF
Warming vs. OA: an indoor mesocosm study (BIOACID II 2012-2015)
• 12 mescocosms filled with Baltic
Sea plankton communities
• Two different temperatures levels:
cold and warm (Δ 6°C)
• CO2 gradients: 500 ppm (low) to
max. 3000 ppm (high)
Will the combined effects of warming and OA induce
direct or indirect effects on the phenology, community
composition and carrying capacity of MZP?
Horn et al. (ICES J Mar Sci 2015)
Ciliate biomass (BIOACID II 2012)
cold warm
→ Warming: earlier timing and higher growth rates
→ No effects of pCO2 on total ciliate biomass
Species composition (BIOACID II 2012)
Horn et al. (ICES J Mar Sci 2015)
Cil
iate
bio
ma
ss
(%)
Low CO2 High CO2
Cold
Warm
→ No effect of pCO2 conditions
→ Changes in MZP composition and succession
patterns with warming
Species composition (BIOACID II 2013)
Horn et al. (ICES J Mar Sci 2015)
Cil
iate
bio
ma
ss
(%)
Horn et al. (unpublished data)
• Warming affects MZP timing, growth, community
composition and succession
• Warming leads to reduced time-lags between
phytoplankton and MZP
• Reduced temporal occurrence of MZP with warming
• Stronger top-down control by copepods on MZP at high
temperature conditions
• High tolerance of MZP to changes in pCO2 (peak timing,
biomass and community composition remained
unaffected)
Conclusions: OA & warming
• Co-operating partners of the AQUASHIFT
Kiel Mesocosm Cluster
• T. Hansen, S. Schröder & C. Rautenstrauch
for technical support
19
Phytoplanktonn
Microzooplankton
Mesozooplankton
Bacteria
POCDOC
HNF
Key role of microzooplankton (MZP)
Traditionally the role of micrograzers
as phytoplankton consumers has
been neglected
Zooplankton grazing on phytoplankton
21
60% of the primary production consumed daily by
MZP and only 10% by mesozooplankton
Calbet et al. 2008
Warming will lead to:
1. Reduced time-lags between autotrophic and
heterotrophic processes with warming
2. Shifts in timing and magnitude of MZP biomass
3. Stronger top-down bloom control by MZP
4. Enhanced trophic overlap and dietary competition
between MZP and mesozooplankton
WINTER WARMING SZENARIO
22
Hypotheses
23
Aberle et al. (Mar Biol, 2012)
→ Strong suppression of the ciliate Lohmaniella oviformis
PZP community composition
6°C
Initial copepod density (copepods L-1
)
Y D
ata
0
50
100
150
200
250
0°C
Initial copepod density (copepods L-1
)
PZ
P b
iom
as
s (
µg
C l
-1)
0
50
100
150
200
250
A B
1.5 4 10 1.5 4 10
Myrionecta rubra
Lohmaniella oviformis
Protoperidinium bipes
Protoperidinium pellucidum
Gyrodinium spp.
Gymnodinium spp.
Tintinnida
Rimostrombidium sp.
Euplotes sp.
Time course of small algae (yellow), diatoms (green), ciliates (red),
dinoflagellates (black) and copepods (blue)
∆6°C
∆0°C
Q10=2 Q10=4 Q10=6
5 15 25 35 450
500
1000
1500
a
5 15 25 35 450
500
1000
1500
b
5 15 25 35 450
500
1000
1500
c
5 15 25 35 450
500
1000
1500
d
5 15 25 35 450
500
1000
1500
e
5 15 25 35 450
500
1000
1500
f
Aberle et al.
Mar Biol 2012
→ With increasing Q10 of copepods a tighter coupling between PZP
and copepods occurs (strong top-down control of PZP) 24
Predator prey model (2008)
Relationship MZP-copepods
Klauschies et al. (Mar Biol 2012)
0.5 1 1.5 2 2.50
0.5
1
1.5
2
log10
mean biomass COP
log
10 m
ean b
iom
ass C
S
a (high-light)
0 1 2 3-2
-1
0
1
log10
mean biomass COP
log
10 m
ean b
iom
ass C
L
b (high-light)
0 0.5 1 1.5 2 2.5-0.5
0
0.5
1
1.5
2
log10
mean biomass COP
log
10 m
ean b
iom
ass D
INO
c (high-light)
0.5 1 1.5 2-0.5
0
0.5
1
log10
mean biomass COP
log
10 m
ean b
iom
ass C
S
d (low-light)
0 0.5 1 1.5 2-1
-0.5
0
0.5
1
log10
mean biomass COP
log
10 m
ean b
iom
ass C
L
e (low-light)
0.5 1 1.5 2-2
-1.5
-1
-0.5
log10
mean biomass COP
log
10 m
ean b
iom
ass D
INO
f (low-light)
• Mean biomass of small (CS) and large ciliates (CL) and
heterotrophic dinoflagellates (DINO)
• Black (ΔT=4°C, ΔT=6°C) and grey (ΔT=0°C, ΔT=2°C) linear regressions
(P<0.05)
→ Strong suppression by coperpods
log
10
me
an
bio
ma
ss
log
10
mean
bio
mass
log
10
mean
bio
mass
log10 mean COPEPOD biomass
small ciliates large ciliates heterotrophic dinoflagellates
Phytoplankton: green
MZP: orange
Copepods: grey areas26
Aberle et al. (Mar Biol, 2012)→ No top-down control of MZP at low temperatures + copepod
density
Plankton succession (2009)
6°C: 10 cop L-1
co
p b
iom
as
s (µ
g C
l-1
)
0
5
10
15
20
25
30
flu
ore
sc
en
ce
(in
viv
o)
0.1
1
10
100
1000CB
PZ
P b
iom
as
s (
µg
C l-1
)
0.1
1
10
100
1000A
D
6°C: 1.5 cop L-16°C: 4 cop L-1
°C: 10 cop L-1
Day of the year
40 50 60 70 80 90
co
p b
iom
as
s (µ
g C
l-1
)
0
5
10
15
20
25
30
flu
ore
sc
en
ce
(in
viv
o)
0.1
1
10
100
1000F
°C: 4 cop L-1
Day of the year
40 50 60 70 80 90
E
°C: 1.5 cop L-1
Day of the year
40 50 60 70 80 90
PZ
P b
iom
as
s (
µg
C l-1
)
0.1
1
10
100
1000
Co
pe
po
db
iom
as
s(µ
g C
l-1
)
MZ
P b
iom
as
s(µ
g C
l-1
)
Winder et al. Mar Biol 2012 → Advanced peak timing of PZP 27
Peak timing (2005-2009)
Winder et al.
Mar Biol 2012
Winder et al.
Mar Biol 2012
→ No impact on peak magnitudes of PZP 28
Peak magnitude (2005-2009)