Title: Ocan Acidification and Coral Reefs: The Problem and Coral Reef Conservation Program Actions
1Ocan Acidification and Coral Reefs The Problem
and Coral Reef Conservation Program Actions
Drs. C. Mark Eakin, Dwight Gledhill NOAA Coral
Reef Watch Rusty Brainard, PIFSC
2Wide Range of Coral Reef Threats
- Human Population Growth
- Overfishing
- Coastal Development
- Lack of Laws / Enforcement
- Sedimentation (unnatural)
- Lack of Education
- Nutrient Enrichment
- Algal Competition
- Climate Change / Bleaching
- Habitat Destruction
- Tourism
- Ocean Acidification
- 2004 Survey 276 Coral Reef Scientists
- Kleypas and Eakin (2007, Bull. Mar. Sci.)
3Coral Reefs Under Rapid Climate Change and Ocean
Acidification
14 December 2007
O. Hoegh-Guldberg, P. J. Mumby, A. J. Hooten, R.
S. Steneck, P. Greenfield, E. Gomez, C. D.
Harvell, P. F. Sale, A. J. Edwards, K. Caldeira,
N. Knowlton, C. M. Eakin, R. Iglesias-Prieto, N.
Muthiga, R. H. Bradbury, A. Dubi, M. E. Hatziolos
Global Environment Facility / World Bank
4What is Coral Bleaching?
- Most of corals food comes from photosynthesis
- Corals can bleach due to stress
- Corals exposed to high temperatures and/or high
light become stressed - Corals eject their algae coral appears bleached
- If stress is mild or brief, corals recover,
otherwise they die
zooxanthellae
Scott R. Santos
Symbiotic algae
5(No Transcript)
6Surface Ocean Uptake of CO2
CO2
2007
www.niwascience
1/2 of total anthropogenic CO2 taken up by the
ocean, gt 25 each year
After Wolf-Gladrow et al., 1999
7Rising Atmospheric Carbon Dioxide
Current CO2 highest in 650,000 years of ice core
data and 24 million years from soil data
8Hotter, more acidic seas
?
Interglacial
Periods
Temperature (
o
C)
Glaciation
Atmospheric CO
(
ppm
)
2
www.gefcoral.org coralreefwatch.noaa.gov
Hoegh-Guldberg et al. 2007, Science
9The Rates are Important
Hoegh-Guldberg et al. 2007, Science
10480 ppm CO2 atm and 2C Thresholds for Coral
Reefs
Atmospheric CO2 (ppm)
200
800
400
300
600
Reefs not dominated by corals
Carbonate Threshold 480 ppm
C
Deviation from todays temperature (oC)
Thermal threshold (2oC)
B
A
Intact Coral Reefs
Coral communities (no carbonate production)
Interglacial
Today
Glaciation
0
100
200
300
400
500
Carbonate ion concentration (mmol kg-1)
- Estimated error 20-25 mmol.kg-1
Hoegh-Guldberg et al. 2007, Science
www.gefcoral.org coralreefwatch.noaa.gov
11480 ppm CO2 atm and 2C Thresholds for Coral
Reefs
Atmospheric CO2 (ppm)
200
800
400
300
600
Reefs not dominated by corals
Carbonate Threshold 480 ppm
C
Deviation from todays temperature (oC)
Thermal threshold (2oC)
B
A
Intact Coral Reefs
Coral communities (no carbonate production)
Interglacial
Today
Glaciation
0
100
200
300
400
500
Carbonate ion concentration (mmol kg-1)
- Estimated error 20-25 mmol.kg-1
Hoegh-Guldberg et al. 2007, Science
www.gefcoral.org coralreefwatch.noaa.gov
12Identifying the Needs
Workshop Recommendations
- Critical biological research needs
- Improved oceanic monitoring of OA
- Better characterization of carbonate chemistry
and impacts in coastal systems
13CRCP Priority Areas
- Characterize Coastal Carbon Environment
- Characterize Impacts
- Identify Management Responses
- Approach
- Time-series Stations
- Testbeds ? Permanent Stations
- Spatial Surveys
- Satellite Tools
- Ecosystem Observations
- Ecosystem Experiments Models
14CRCP Priority Areas
- Characterize Coastal Carbon Environment
- Characterize Impacts
- Identify Management Responses
- Approach
- Time-series Stations
- Testbeds ? Permanent Stations
- Spatial Surveys
- Satellite Tools
- Ecosystem Observations
- Ecosystem Experiments Models
15Future Changes in Reef Calcification
IPCC IS92a business-as-usual
- Coral Reef Calcification
- 1765 Adequate
- 2005
- 2100
After Feely et al (in press) with Modeled
Saturation Levels from Orr et al (2005)
16Future Changes in Reef Calcification
IPCC IS92a business-as-usual
- Coral Reef Calcification
- 1765 Adequate
- 2005 Marginal
- 2100
After Feely et al (in press) with Modeled
Saturation Levels from Orr et al (2005)
17Future Changes in Reef Calcification
IPCC IS92a business-as-usual
- Coral Reef Calcification
- 1765 Adequate
- 2005 Marginal
- 2100 Low
Calcification rates in the tropics may decrease
by 30 over the next century
After Feely et al (in press) with Modeled
Saturation Levels from Orr et al (2005)
18Oceanic Observing Tools
- Technological developments autonomous sensors
for carbonate system and PIC - Dissolution and its response to increased CO2
(including better understanding of thermodynamic
constants)
- Underway
- Platform deployed
- Autonomous
19Coastal Observing Tools
Coral Reef Ecosystem Division
Integrated Coral Observing Network
air temp light (PAR) wind spd wind dir bar press
pCO2 instrument and water sampler
water temp salinity light (PAR UVB) conductivity
- Additional CO2 parameter needed!
20Ocean Acidification of the Greater Caribbean
Region
Modeled fields of annual mean aragonite
saturation state, Gledhill et al. (in review)
- Satellite and in situ observations are being
coupled to model changes in surface ocean
chemistry as a consequence of "ocean
acidification". - The annual mean ?arg is declining at a rate of
-0.12 0.007 ?arg decade-1 (r2 0.97, RMSD
0.007, plt0.0001) over the past decade.
21Ocean Acidification Test-Bed
FY08-FY12 Project Goals
1. Standardize approach and methodologies 2.
Identify critical thresholds, impacts, and water
chemistry trends 3. Characterize the temporal and
spatial variability in carbonate system
parameters 4. Ecological forecasting of OA stress
to reefs.
22NOAA CRIMP - CO2 BuoyKaneohe Bay
Coastal Observing Tools
- 18 months of high resolution autonomous pCO2
- Richard Feely (PMEL)
23Integrated Observing
- F. Chavez
24CRCP Priority Areas
- Characterize Coastal Carbon Environment
- Characterize Impacts
- Identify Management Responses
- Approach
- Time-series Stations
- Testbeds ? Permanent Stations
- Spatial Surveys
- Satellite Tools
- Ecosystem Observations
- Ecosystem Experiments Models
25Critical Research Needs
Ecosystem Effects Food webs Competition CaCO3-depe
ndent communities
Species-Level Effects Fitness survival Multiple
life-stages Adaptation
Individual Organism Interaction with T,
Irradiance, Nutrients Calcification
mechanisms Calcification-Photosynthesis Link
26Decreased Calcification with Increasing Ocean
CO2
Pre-industrial
modern
2100
150
Since anthropogenic CO2 has already lowered the
carbonate ion concentration by 15, these
systems are already being affected by
anthropogenic CO2.
100
Calcif. mmol/m2/d
50
Net growth
0
0
100
200
300
400
Net dissolution
2-
,
CO
3
-50
250
1200
500
m
pCO
,
atm
2
After Turley et al., 2005
27Ocean Acidification Impacts on Corals and Reefs
- Three Options for Corals
- - Grow (extend) more slowly
- - Build more brittle skeletons
- - Divert energy from other processes
- (reproduction, healing damage, etc.)
Consequence - Changed balance between
construction and erosion - Reduced ability to
keep up with rising sea level
28Recent Work -- from HIMB
- Doubled CO2 yields
- 16 reduced calcification in Montipora capitata
- 78 reduction in crustose coralline algae (CCA)
recuitment - 10X reduction in CCA cover
- Loss of mass in CCA rhodoliths
- 10X reduction in vermetid gastropod recruits
- 2X increase in non-calcifying algal cover
- No change in Pocillopora damicornis recruits
29Impact of Reduced Growth
Hoegh-Guldberg et al. 2007, Science
30Theres Much at Stake
- Food (subsistence, fisheries)
- Industry (tourism)
- Coastal protection
- Biodiversity
31CRCP Priority Areas
- Characterize Coastal Carbon Environment
- Characterize Impacts
- Identify Management Responses
- Approach
- Time-series Stations
- Testbeds ? Permanent Stations
- Spatial Surveys
- Satellite Tools
- Ecosystem Observations
- Ecosystem Experiments Models
32Two Part Solution2) Reduce Local Stressors
- Driven by US Coral Reef
- Task Force
- Result of international
- workshop, research,
- and planning
- Addresses local reef
- management in light
- of changing climate
- Available at coralreef.noaa.gov
33Short-term Opportunities for Coral Bleaching
Management
- Local managers can
- Reduce bleaching
- Reduce light stress
- Cool reefs, increase mixing
- Increase survival
- Improve water quality
- Reduce disease prevalence
- Aid recovery
- Coral fragmentation
- Encourage recruitment
- Protect ecosystem functions (herbivory)
34A Reef Managers Guide to Ocean Acidification
- Local managers can ?
- Increase ? CO32-, HCO3-
- CO2 sequestration /
- Accelerated Limestone Weathering?
- (Rau et al.)
- Cool reefs, increase mixing
- Increase survival
- ?
- Aid recovery
- ?
35Priority Areas
- Characterize Chemical Environment
- Characterize Impacts
- Identify Management Responses
- Approach
- Time-series Stations
- Testbeds ? Permanent Stations
- Spatial Surveys
- Satellite Tools
- Ecosystem Observations
- Ecosystem Experiments Models
36Thank You
coralreefwatch.noaa.gov