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Coastal Futures 2014 London: 23 January
Phil Williamson Science Coordinator (NERC/UEA)
UK Ocean Acidification research programme
Ocean acidification update
"After much research effort, we now know a lot more than when we started – although it is mostly knowing how little we now know"
240 papers on OA 1624 citations
up to end of 2009
Scientific interest in ocean acidification began to 'take off' around 5 years ago
Scientific interest in ocean acidification began to 'take off' around 5 years ago since then there has been a six-fold increase in OA publications
240 papers on OA 1624 citations
~1500 papers on OA ~20,100 citations
up to end of 2009
up to end of 2013
ISI World of Science data (provisional for 2013)
3
3 3
Scientific interest in ocean acidification began to 'take off' around 5 years ago since then there has been a six-fold increase in OA publications with a major UK contribution
~1500 papers on OA ~20,100 citations
ISI World of Science data (provisional for 2013)
3
3 3
USA
UK
Aust'lia
Germ
japan
France
Canada
China
New Zealand 2%
Australia 11%
Germany 8%
Japan 4%
Canada 4%
France 4% China 3%
Sweden 2%
28 others 14%
UK 14%
USA 32%
First authorship of OA publications 2005-11
Peters et al (2012) The challenge to keep global warming below 2⁰C. Nature Climate Change (online 2 Dec)
Glo
bal
CO
2 e
mis
sio
ns
(Gt
C p
a)
Year
The driver for ocean acidification: increasing CO2 emissions due to human activities
Peters et al (2012) The challenge to keep global warming below 2⁰C. Nature Climate Change (online 2 Dec)
CO
2 in
atm
osp
her
e (p
pm
)
hence increased CO2 in the atmosphere…
Hawaii (Mauna Loa) South Pole
IPCC (2013) WG I, Summary for Policymakers, www.ipcc.ch
Peters et al (2012) The challenge to keep global warming below 2⁰C. Nature Climate Change (online 2 Dec)
… and increased CO2 in the upper ocean C
O2 in
up
per
oce
an (
μat
m)
CO2 in Atlantic Ocean CO2 in Pacific Ocean
CO
2 in
atm
osp
her
e (p
pm
)
IPCC (2013) WG I, Summary for Policymakers, www.ipcc.ch
Peters et al (2012) The challenge to keep global warming below 2⁰C. Nature Climate Change (online 2 Dec)
… and decreased upper ocean pH (increased H+)
pH 8.12
8.09
8.06
IPCC (2013) WG I, Summary for Policymakers, www.ipcc.ch
pH in Atlantic Ocean pH in Pacific Ocean
CO
2 in
up
per
oce
an (
μat
m)
CO
2 in
atm
osp
her
e (p
pm
)
acidic basic
Stomach acid
Coca cola Coffee
Distilled water
Surface seawater
Household bleach
pH scale: logarithmic
1 0 3 2 5 4 7 6 9 8 10 12 11 14 13
0.3 decrease in pH = doubling of H+ concentration (decrease is considered to be "acidification",
wherever on the scale it occurs)
acidic basic
Stomach acid
Coca cola Surface seawater
1 0 3 2 5 4 7 6 9 8 10 12 11 14 13
Pre-industrial
Present day pH scale for maps
pH scale: logarithmic
acidic basic
Stomach acid
Coca cola Surface seawater
1 0 3 2 5 4 7 6 9 8 10 12 11 14 13
Pre-industrial
Present day pH scale for maps
Projected for 2100 under ‘business as usual’
pH scale: logarithmic
Increased H+ is not the only change involved in ocean acidification
increase
increase
decrease
increase
Increased H+ is not the only change involved in ocean acidification
increase
increase
decrease
increase
HCO3+
CO32 -
0 +100 +200 +300
% change in atmos. CO2 %
cha
nge
in g
loba
l sur
face
oce
an
-10
0
0
+
100
+
200
Affects calcium carbonate saturation state (Ω): when Ω < 1.0, unprotected CaCO3 dissolves
H+
(acidity)
Increased H+ is not the only change involved in ocean acidification
increase
increase
decrease
increase
H+
(acidity)
HCO3+
CO32 -
0 +100 +200 +300
% change in atmos. CO2 %
cha
nge
in g
loba
l sur
face
oce
an
-10
0
0
+
100
+
200
Organisms (and ecosystem processes) may respond to any one - or all - of these interacting variables
Affects calcium carbonate saturation state (Ω): when Ω < 1.0, unprotected CaCO3 dissolves
Other ocean changes in a high CO2 world include higher temperatures & less oxygen
Direct effects of CO2 and pH
Indirect effects on:
Community processes
Food web & biodiversity
changes
Coastal protection
Climate processes
Ecosystems Ecosystem services
An
imal
s, p
lan
ts &
mic
rob
es
Peo
ple (co
sts & valu
es)
CO2 increase
Biogeo-chemical
processes
Impacts on organisms
(positive & negative)
Impacts on chemistry
Overview of ocean acidification impacts #1
Direct effects of CO2 and pH
Indirect effects on:
Impacts on organisms Community processes
Food web and biodiversity changes
DMS, dimethylsulphide; DMSP, dimethylsulphoniopropionate; Ω, CaCO3 saturation state.
Williamson & Turley (2011), after Tyrrell
Photosynthesis
Respiration, energetics and growth
C:N and C:P ratios
N2 fixation and nitrification
Sulphur metabolism (affecting DMSP & DMS)
Decrease in abundance of commercially-exploited
fish and shellfish
Changes in assemblage or abundance of:
• primary producers • secondary producers • decomposers
• habitat-structuring organisms
Decrease in food quality
Reduced biogenic CaCO3 production
Biogeochemical processes
Change in dissolved DMS
Reproduction, behaviour and survival
Impacts on chemistry Reduced Ω, shoaling of saturation horizon
Calcification
Reduced resilience to other environmentalpressures
Biodiversity loss due to reductions in reef habitat
Increased CaCO3 dissolution
Coastal protection Increased erosion due to reductions in reef habitat
Climate processes Reduced strength of
biological carbon pump
Change in N2O and DMS release affecting
climate forcing
Changes in dissolved NOx and NH3
Ecosystems Ecosystem services
CO2 increase
Overview of ocean acidification impacts #2 P
eop
le (costs &
values)
An
imal
s, p
lan
ts &
mic
rob
es
(original version of this diagram)
Overview of ocean acidification impacts #3
Short term
Long term
Single species Single stressor
(OA)
Multi-stressor
Local
Global
Days - weeks
Years PALAEO
Evolving framework for OA research
EXPERIMENTS
MODELS for scenario projections
Months
OBSERVATIONS
Multi-species
Ecosystem
Short term
Long term
Single species Single stressor
(OA)
Days - weeks
Evolving framework for OA research
EXPERIMENTS
Months
Short term
Long term
Single species Single stressor
(OA)
Multi-stressor
Evolving framework for OA research
EXPERIMENTS
Other relevant variables include temperature,
oxygen & food/nutrients:
Short term
Long term
Single species Single stressor
(OA)
Multi-stressor
Evolving framework for OA research
EXPERIMENTS
Multi-species
Ecosystem
Short term
Long term
Single species Single stressor
(OA)
Multi-stressor
Local
Global
Days - weeks
Years
Evolving framework for OA research
EXPERIMENTS
Months
OBSERVATIONS
Multi-species
Ecosystem
real world
Short term
Long term
Single species Single stressor
(OA)
Multi-stressor
Local
Global
Days - weeks
Years
Evolving framework for OA research
EXPERIMENTS
Months
OBSERVATIONS
Multi-species
Ecosystem
PALAEO
Short term
Long term
Single species Single stressor
(OA)
Multi-stressor
Local
Global
Days - weeks
Years PALAEO
Evolving framework for OA research
EXPERIMENTS
MODELS for scenario projections
Months
OBSERVATIONS
Multi-species
Ecosystem
pH
Time of day (hr)
O April
O May
O June
O July
O Aug
O Sep
Pho
to: J
ason
Hal
l-Spe
ncer
Diurnal and seasonal pH variability at Tatoosh Island WA, 2000-2007. Wootton et al (2008)
Physico-chemical variability In coastal waters and shelf seas, pH (and other carbon chemistry parameters) can vary greatly on daily and seasonal basis
pH
Time of day (hr)
O April
O May
O June
O July
O Aug
O Sep
Pho
to: J
ason
Hal
l-Spe
ncer
Diurnal and seasonal pH variability at Tatoosh Island WA, 2000-2007. Wootton et al (2008)
Physico-chemical variability In coastal waters and shelf seas, pH (and other carbon chemistry parameters) can vary greatly on daily and seasonal basis – also spatially
UKOA research cruise data 2011: underway near-surface pH (Rerolle et al)
pH
Blackford et al; Artioli et al (2012)
This variability can now be simulated in high resolution models
Daily pH range at seafloor
Present day : sea surface
pH
Pho
to: J
ason
Hal
l-Spe
ncer
Physico-chemical variability In coastal waters and shelf seas, pH (and other carbon chemistry parameters) can vary greatly on daily and seasonal basis – also spatially
Artioli et al (2012)
This variability can now be simulated in high resolution models, that can be used in climate change scenarios
Change in pH by 2100 (IPCC A1B)
Pho
to: J
ason
Hal
l-Spe
ncer
DpH
Aragonite saturation at sea
floor by 2100 (IPCC A1B
scenario)
Artioli et al (2013)
Physico-chemical variability In coastal waters and shelf seas, pH (and other carbon chemistry parameters) can vary greatly on daily and seasonal basis – also spatially
Palaeo- studies: global OA has happened before
E.g. at Palaeocene-Eocene Thermal Maximum (PETM)
At PETM onset, ~35% of benthic foraminifera became extinct
Note: i) rate of OA change was then 10 times slower than now; ii) recovery time was ~10,000 yr
Zeebe & Ridgwell, 2011
Projected anthropogenic release: 5000 Gt C
Estimated PETM release: 3000 Gt C
Anthropogenic
PETM
0 2000 4000 6000 8000 10000 Years
Sur
face
oce
an Ω
6 4 2 0
25
20
15
10
5
0
Rel
ease
Gt C
per
yr
Foster et al 2013
Photo: Jason Hall-Spencer
Species diversity 30 50
PETM
increase
increase
decrease
increase
+18%
0
-18%
-33%
-45%
-55%
-63%
Res
pons
e ch
ange
(lo
g sc
ale)
Metadata analysis based on single-species studies
Effect of 0.4 pH decrease; all taxa combined
Kroeker et al. 2010
Photo: Jason Hall-Spencer
Survival
Calcification
Growth Photosynthesis
Reproduction
Kroeker et al. 2013
Not tested or too few studies
Enhanced <25%
95% CI overlaps 0
Reduced <25%
Reduced >25%
Photo: Jason Hall-Spencer
Metadata analysis based on single-species studies
Not tested or too few studies
Enhanced <25%
95% CI overlaps 0
Reduced <25%
Reduced >25%
Photo: Jason Hall-Spencer
Such analyses need to be carefully interpreted!
Kroeker et al. 2013
Metadata analysis based on single-species studies
Early life stages – embryos, larvae and juveniles – are much more sensitive to OA than adults
Echinoderm studies (sea urchins, brittle stars and starfish)
Intra-taxon variability in response to OA
Photo: Jason Hall-Spencer
Additive impacts of temperature and high CO2 for cold-water coral Lophelia pertusa
34
1
1.5
2
2.5
3
3.5
4
9, 380 12, 380 9. 750 9, 1000 12, 750
Res
pir
atio
n
μmol O
2 g
-1 t
issu
e d
ry w
eig
ht h
-1
Control
1 stressor
2 stressors
Preliminary data: Hennige & Murray
Temp: 9°C 12°C 9°C 9°C 12°C CO2 380 380 750 1000 750 ppm
Multi-stressor studies show that interactions can be additive/synergistic or antagonistic
Photo: Jason Hall-Spencer
Additive impacts of temperature and high CO2 for cold-water coral Lophelia pertusa
35
1
1.5
2
2.5
3
3.5
4
9, 380 12, 380 9. 750 9, 1000 12, 750
Res
pir
atio
n
μmol O
2 g
-1 t
issu
e d
ry w
eig
ht h
-1
Control
1 stressor
2 stressors
Preliminary data: Hennige & Murray
Temp: 9°C 12°C 9°C 9°C 12°C CO2 380 380 750 1000 750 ppm
Multi-stressor studies show that interactions can be additive/synergistic or antagonistic
But multi-factor experiments are complex (and food quality/quantity may be critical)
Multi-species and ecosystem-scale experiments
Mesocosms and Free Ocean CO2 Enrichment (FOCE) studies: ecologically more realistic, but high cost for multi-factor replicates
High CO2 vents (in the Mediterranean, USA, Japan, and Papua New Guinea) show dramatic biodiversity loss and community shifts, favouring seagrasses and non-calcified algae
Photo: Jason Hall-Spencer
Natural experiments at ecosystem-scale
Impact of OA on ecosystem function
Ecosystem services and socio-economics: Loss of tropical coral reefs is likely to be the greatest societal impact of ocean acidification, with costs estimated at ~ US $1,000 billion per year (Brander 2012)
Ecosystem services and socio-economics: Loss of tropical coral reefs is likely to be the greatest societal impact of ocean acidification, with costs estimated at ~ US $1,000 billion per year (Brander 2012) Costs of other OA impacts – on fisheries, aquaculture, food web structure and climate regulation – are not yet well-defined
Impact of OA on ecosystem function
Observational requirements
Urgent need to develop global observing network for OA and ecosystem response, linked to existing observing systems
UK work by Cefas, Marine Scotland,
NOC, PML and university research
groups
Coastal Futures 2014 London: 23 January
Phil Williamson [email protected]
Main recent achievements
• Importance of multiple stressors • Improved techniques • Awareness of biological variability • Awareness of chemical variability • Importance of scope for adaptation • Insights from palaeo- studies • Development of ecosystem-level studies
with acknowledgements to UKOA researchers, funders & others