outline phytoplankton 101 climate change and altered ocean properties where and when?
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What will be the impact of ocean acidification relative to climate change effects on oceanic biota? Philip Boyd NIWA / Otago Centre of Chemical and Physical Oceanography. OUTLINE Phytoplankton 101 Climate change and altered ocean properties Where and when? Winners and losers? - PowerPoint PPT PresentationTRANSCRIPT
What will be the impact of ocean acidification relative
to climate change effects on oceanic biota?
Philip BoydNIWA / Otago Centre of
Chemical and Physical Oceanography
OUTLINEa) Phytoplankton 101b) Climate change and altered ocean propertiesc) Where and when?d) Winners and losers?e) How to quantify the change?
Doney Nature (2006)
The take home message
OCEAN ACIDIFICATION will have a pronounced influence on the New Zealand EEZ – but it is not the only game in town.
All environmental controls on phytoplankton will be altered by climate change
Phytoplankton are the base of coastal and offshore ecosystems and marine living resources
Altered productivity of the EEZAltered foodwebsAltered flows of energyAltered marine resources
‘Phytoplankton 101’
Rutger
>
They fix half of the carbonin the Biosphere
They form the base of marine foodwebs
Phytoplankton and Mixology 101
TemperatureLightNutrientsCO2
Trace metals
Courtesy Scott Nodder (NIWA)
Plant nutrient gradients in our waters
Climate change and the ocean
TODAY TOMORROWCO2
pH
Other factors will also change The supply of nutrients from the atmosphere
Boyd & Doney 2002
Boyd et al. (2008)
Climate change - from global to regional impacts
Projected changes over the next 50 years
Where within the EEZ will climatechange have the greatest impact?
4 million km2
Warm & cold currentsA range of water bodiesDifferent ecosystems Nitrate
Chlorophyll
Increasing climate variability and change
Their impact differs between water masses of the EEZ
Projected ocean temperature trends over next 50 years
Climate variability Climate change
Boyd/Doney (unpublished)
Different phytoplankton groupsdominate in different water masses &support different ecosystems
Non-calcifying phytoplankton dominate stocks within the EEZ
However, rising oceanic CO2 levelswill also impact non-calcifyingphytoplankton.
Both directly and in concert with otherfactors that will be altered by climate change
Synechococcus Photosynthesis versus Lightinterplay of temperature and CO2
A
Light intensity (mol m-2 s-1)0 100 200 300 400 500 600 700 800 900 1000
g C
g
Ch
l-1
h-1
0
2
4
6
8
10
12
ControlHigh CO2High TemGreenhouse
Fu et al. 2006
pCO2 and Fe availability: interactive effects on N2 fixation rates
Fe-replete
0
1e-8
2e-8
3e-8
Fe-limited
pCO2 (ppm)
190 380 750
N2 f
ixat
ion
(n
mo
l cel
l-1
ho
ur-
1 )
0
1e-8
2e-8
3e-8
N2 f
ixat
ion
(n
mo
l cel
l-1
ho
ur-
1 )
Fu et al. 2008
So if the sky is falling
Where and when will change happen?
Who is in each water massThe winners vs. the losers?
How to quantify the change?
A
Light intensity (mol m-2 s-1)0 100 200 300 400 500 600 700 800 900 1000
g C
g
Ch
l-1
h-1
0
2
4
6
8
10
12
ControlHigh CO2High TemGreenhouse
Fe-replete
0
1e-8
2e-8
3e-8
Fe-limited
pCO2 (ppm)
190 380 750N
2 fi
xati
on
(n
mo
l cel
l-1
ho
ur-
1 )
0
1e-8
2e-8
3e-8
N2
fixa
tio
n (
nm
ol c
ell-
1 h
ou
r-1 )
Experiments provide a means to rankthe impacts of these different and concurrent changes in ocean properties
ultimate proximate
Temperature > Light > Iron > Silicate > Nutrients > CO2
a) Physiological-based ranking schemes
(From Boyd, Strezpek, Fu & Hutchins, submitted)
S.OceanDiatoms
Linking these three questions
Winners and losers?
Where and when?
How to quantify the change?
A
Light intensity (mol m-2 s-1)0 100 200 300 400 500 600 700 800 900 1000
g C
g
Ch
l-1
h-1
0
2
4
6
8
10
12
ControlHigh CO2High TemGreenhouse
CO2
pH
A Climate Change Atlas for the New Zealand EEZ is required
To assess both the impact of Ocean Acidification but also of other climate change effects on the biota
Doney Nature (2006)
The take home message
OCEAN ACIDIFICATION will have a pronounced influence on the New Zealand EEZ – but it is not the only game in town.
All environmental controls on phytoplankton will be altered by climate change
Phytoplankton are the base of coastal and offshore ecosystems and marine living resources
Altered productivity of the EEZAltered foodwebsAltered flows of energyAltered marine resources