# Presentation: 321578

## Ocan 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**

## Wide 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.)**

## Coral Reefs Under Rapid Climate Change and Ocean Acidification

**Coral Reefs Under Rapid Climate Change and Ocean Acidification**

**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**

**14 December 2007**

## What is Coral Bleaching?

**What is Coral Bleaching?**

**Scott R. Santos**

**Symbiotic algae**

**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**

## Slide 5

## Surface Ocean Uptake of CO2

- CO2

- www.niwascience

- Surface Ocean Uptake of CO2

- ≈ 1/2 of total anthropogenic CO2
- 	taken up by the ocean,
- 	> **25% each year**

- After Wolf-Gladrow et al., 1999

- 2007

**Notes:**
However, only about half of the anthropogenic carbon released has remained in the atmosphere.  According to the findings of  two international ocean research programs, the World Ocean Circulation Experiment (WOCE) and the Joint Global Ocean Flux Study (JGOFS), that were in the 1990’s, about 30% of it has been taken up by the ocean. This represents in excess of 100 petagrams of carbon for the period between 1800 to 1994.

Much of this added carbon has been confined to the upper 1000 m making the impact on open ocean surface waters all the more potent and by some estimates may be the most dramatic change we’ve seen in surface water CO2 for more than 20 million years.

This rapid and pronounced rise in surface ocean CO2 is sometimes being referred to as that ‘other’ CO2 problem

## Rising Atmospheric Carbon Dioxide

**Rising Atmospheric Carbon Dioxide**

- Current CO2
- highest in 650,000 years of ice core data and 24 million years from soil data

**Notes:**
These graphs represent the Earth’s atmospheric CO2 concentration, as determined by (top graph) ice cores, and (bottom graph) various proxies.  The top graph shows the excellent record obtained by Petit et al. (1999) from the Vostok ice core.  This record goes back about 1⁄2 million years and shows about four glacial cycles.  Throughout that time, atmospheric CO2 remained within an envelope of about 200 to 300 ppmv.  Today, atmospheric CO2 concentration is about 370 ppmv, and it’s rising, with a projected doubling of atmospheric levels by the middle of this century.  
CO2 data extending back millions of years are scarce, but scientists have come up with some values based on the “leaf stomatal index” of fossil leaves (Royer et al. 2001), and various marine isotopes (Pearson and Palmer 2000).  These tend to indicate that atmospheric CO2 concentrations have remained below present values for about 24 million years.  This illustrates the statement that we are headed into a period for which there is no good analogue. 

## ?

**?**

**Hotter, more acidic seas**

**Temperature (**

**o**

**C)**

**Atmospheric CO**

**2**

**(**

**ppm**

**)**

**Interglacial**

**Periods**

**Glaciation**

**Hoegh-Guldberg et al. 2007, *****Science***

**www.gefcoral.org       coralreefwatch.noaa.gov**

## The Rates are Important

**Hoegh-Guldberg et al. 2007, *****Science***

## 480 ppm CO2 atm and 2°C: Thresholds for Coral Reefs

- Carbonate ion concentration
- mol kg-1)

- 500

- 300

- 400

- 200

- 0

- 100

- Coral communities
- (no carbonate production)

**Glaciation**

- Thermal threshold (+2oC)

- Carbonate
- Threshold 480 ppm

- Reefs not
- dominated
- by corals

**Interglacial**

- Deviation from today’s temperature (oC)

**Today**

- Estimated error ~20-25 mol.kg-1

- C

- A

- B

- 480 ppm CO2 atm and 2°C: Thresholds for Coral Reefs

- Intact Coral Reefs

**Hoegh-Guldberg et al. 2007, *****Science***

**www.gefcoral.org      coralreefwatch.noaa.gov**

- 200

- 800

- Atmospheric CO2 (ppm)

- 400

- 300

- 600

## 480 ppm CO2 atm and 2°C: Thresholds for Coral Reefs

- Carbonate ion concentration
- mol kg-1)

- 500

- 300

- 400

- 200

- 0

- 100

- Coral communities
- (no carbonate production)

**Glaciation**

- Thermal threshold (+2oC)

- Carbonate
- Threshold 480 ppm

- Reefs not
- dominated
- by corals

**Interglacial**

- Deviation from today’s temperature (oC)

**Today**

- Estimated error ~20-25 mol.kg-1

- C

- A

- B

- 480 ppm CO2 atm and 2°C: Thresholds for Coral Reefs

- Intact Coral Reefs

**Hoegh-Guldberg et al. 2007, *****Science***

**www.gefcoral.org      coralreefwatch.noaa.gov**

- 200

- 800

- Atmospheric CO2 (ppm)

- 400

- 300

- 600

## Identifying the Needs

_**Workshop Recommendations:**_

** ****Critical biological research needs**
** ****Improved oceanic monitoring of OA**
** ****Better characterization of carbonate chemistry and impacts in coastal systems**

**Notes:**
**Dwight**

In response to these finding and the important consequence they may hold for a variety of ecosystems even beyond coral reefs, a series of workshops have been convened to discuss the issue and identify current gaps that need to be addressed in assessing and predicting the full impacts of ocean acidification.

Mark and myself attended one of the most recent of these held in St. Petersburg, Fl last year.  The workshop was jointly sponsored by NOAA, NSF and the USGS and provided a long list of recommendations to the community.

Among the recommendations given are a series of both basic research and monitoring needs specifically related to corals and their environments.

While in some instances NOAA has already in place or in development the necessary observing systems that can be adapted to identified needs, there is still considerable deficiency in coverage and technology.

## CRCP Priority Areas:

**CRCP 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**

## CRCP Priority Areas:

**CRCP 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**

## Future Changes in Reef Calcification

*After Feely et al (in press) with Modeled Saturation Levels from Orr et al (2005)*

**Future Changes in Reef Calcification**

- _Coral Reef Calcification_
-  1765 **Adequate**
-  2005
-  2100

- IPCC IS92a ‘business-as-usual’

**Notes:**
**Mark**

## Future Changes in Reef Calcification

*After Feely et al (in press) with Modeled Saturation Levels from Orr et al (2005)*

- _Coral Reef Calcification_
-  1765 **Adequate**
-  2005 **Marginal**
-  2100

- IPCC IS92a ‘business-as-usual’

**Future Changes in Reef Calcification**

**Notes:**
**Mark**

## Future Changes in Reef Calcification

*After Feely et al (in press) with Modeled Saturation Levels from Orr et al (2005)*

- _Coral Reef Calcification_
-  1765 **Adequate**
-  2005 **Marginal**
-  2100 **Low**

- IPCC IS92a ‘business-as-usual’

- Calcification rates in the tropics may decrease by 30% over the next century

**Future Changes in Reef Calcification**

**Notes:**
**Mark**

## Oceanic Observing Tools

**Dissolution and its response to increased CO****2**** (including better understanding of thermodynamic constants)**

**Oceanic Observing Tools**

** ****Underway**
** ****Platform deployed**
** ****Autonomous**

**Notes:**
First, carbonate system monitoring

## Coastal Observing Tools

**pCO****2**** instrument**
**and water sampler**

**air temp**
**light (PAR)**
**wind spd**
**wind dir**
**bar press**

**water temp**
**salinity**
**light (PAR & UVB)**
**conductivity**

*Coral Reef Ecosystem Division*

*Integrated Coral Observing Network*

-  **Additional CO****2**** parameter needed!**

**Coastal Observing Tools**

**Notes:**
**Dwight**
Other types of observing systems NOAA currently has available include the CRED network of instruments in the Pacific and the ICON/CREWS stations in the Caribbean.  While the CRED network throughout the NWHI currently includes a variety of moored instruments with telemetry that monitor a suite of oceanographic and meteorological parameters, they currently do not monitor any parameters specific to the carbonate systems such as the pCO2 sensor deployed in Kaneohe Bay.  In contrast, several ICON stations in the Caribbean have been outfitted with rather crude CO2 sensors such as the one shown here.  These lack the sophistication of the PMEL system deployed in Kaneohe Bay and we’re currently working to validate the data their gathering. 

## Ocean Acidification of the Greater Caribbean Region 

- Ocean 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, p<0.0001) over the past decade.**

**Notes:**
Two new high resolution sea surface temperature (SST) analysis products have been developed using optimum interpolation (OI). The analyses have a spatial grid resolution of 0.25° and temporal resolution of 1 day. One product uses Advanced Very High Resolution Radiometer (AVHRR) infrared satellite SST data. The other uses AVHRR and Advanced Microwave Scanning Radiometer (AMSR) on the NASA Earth Observing System satellite SST data. Both products also use in situ data from ships and buoys and include a large-scale adjustment of satellite biases with respect to the in situ data. Two products are needed because there is an increase in signal variance when AMSR became available in June 2002 due to its near all-weather coverage. For both products, the results show improved spatial and temporal resolution compared to previous weekly 1° OI analyses. 
The AVHRR-only product uses Pathfinder AVHRR data (currently available from January 1985 through December 2005) and operational AVHRR data for 2006 onwards. Pathfinder AVHRR was chosen, when available, because it agrees better with the in situ data. The AMSR+AVHRR product begins with the start of AMSR data in June 2002. In this product, the primary AVHRR contribution is in regions near land where AMSR is not available. However, in cloud-free regions, use of both infrared and microwave instruments can reduce systematic biases because their error characteristics are independent. A description of the OI analysis can be found in Reynolds, R. W., T. M. Smith, C. Liu, D. B. Chelton, K. S. Casey and M. G. Schlax, 2007: Daily High-resolution Blended Analyses. (J. of Climate, In press)

## Ocean Acidification Test-Bed

**Ocean 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.**

## NOAA CRIMP - CO2 BuoyKaneohe Bay

- 18 months of high resolution autonomous pCO2

***-  Richard Feely (PMEL)***

- Coastal Observing Tools

## Integrated Observing 

**Integrated Observing **

*** ******- F. Chavez***

**Notes:**
**Dwight**

At NOAA Coral Reef Watch we’re making use of these sensors in the Caribbean by coupling them to satellite observations offshore.  By comparing the variability of CO2 in waters offshore to that of neighboring coral reefs, we’ll be able to characterize how these ecosystems effect their surrounding carbonate chemistry and be able to track changes that may occur in their community structure in response to ocean acidification.  We hope to be able advance this concept to other regions including the NWHI in coming years.  We hope to be able to provide this information to the reef management community and coral researchers in an automated and timely fashion.  The regional offshore pCO2 is modeled from a suite of satellite observations including sea surface temperature, surface winds and ocean color.  This is then compared against observations of pCO2 overlying neighboring coral reefs.  The difference reflects the influence these reefs impart on the surrounding water that is partly a function of their calcification providing us what we term a Reef Metabolic Index.

## CRCP Priority Areas:

**CRCP 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**

## Critical Research Needs

- Interaction with T, Irradiance, Nutrients
- Calcification mechanisms
- Calcification-Photosynthesis Link

**Ecosystem Effects**
- Food webs
- Competition
- CaCO3-dependent communities

**Species-Level Effects**
- Fitness & survival
- Multiple life-stages
- Adaptation

**Notes:**
**Dwight**
In addition to these important monitoring efforts, there is also considerable need for basic research to better understand the physiological response.  Experiments need to be carried out at multiple scales to illicit not only the specific mechanism that’s responsible for these observed responses but also to evaluate the interaction of multiple environmental conditions such as temperature and nutrients.  These experiments need to be up scaled ultimately to the ecosystem level.  The experiments will range from simple aquaria to large scale mesocosms.   

## Decreased Calcification with Increasing Ocean CO2 

**-50**

**0**

**50**

**100**

**150**

**0**

**100**

**200**

**300**

**400**

**CO**

**3**

**2-**

**, **

**Calcif. mmol/m****2****/d**

**1200**

**500**

**250**

**pCO**

**2**

**, **

****

**atm**

*After Turley et al., 2005*

- Pre-industrial

- modern

- Since anthropogenic CO2 has already lowered the carbonate ion concentration by ~15%, these systems are already being affected by anthropogenic CO2.

**Net **
**growth**

**Net **
**dissolution**

- 2100

## Ocean 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**

**Notes:**
**Mark**

## Recent Work -- from HIMB

**Doubled CO****2**** 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**

## Impact of Reduced Growth

**Hoegh-Guldberg et al. 2007, *****Science***

## There’s Much at Stake

**There’s Much at Stake**

**Food (subsistence, fisheries)**
**Industry (tourism)**
**Coastal protection **
**Biodiversity**

## CRCP Priority Areas:

**CRCP 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**

## Two Part Solution:2) 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**

**Two Part Solution:****2) Reduce **_**Local**_** Stressors**

## Short-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) **

**Short-term Opportunities for Coral Bleaching Management**

## A Reef Manager’s Guide to Ocean Acidification

** ****Increase Ω CO****3****2-****, HCO****3****-**** **
** ****CO****2**** sequestration / **
**	****Accelerated Limestone Weathering?**
**	****(Rau et al.)**
** ****Cool reefs, increase mixing**
** ****Increase survival**
** ****?**
** ****Aid recovery**
** ****?**

**A Reef Manager’s Guide to Ocean Acidification**

## Priority Areas:

**Priority 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**

## Thank You

**coralreefwatch.noaa.gov**