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 p.williamson@uea.ac.uk

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