OceanAcidification—Management_McLeod.indd Page 276 12/28/11 4:10 PM user-f494 /203/BER00002/Enc82404_disk1of1/933782404/Enc82404_pagefiles

Ocean Acidifi cation— Management

The increasing carbon dioxide (CO2 ) concentration in When hydrogen ions are released in seawater, they the Earth’s atmosphere is absorbed by the oceans and combine with carbonate ions (forming bicarbonate), leads to changes in ocean carbon chemistry. This thereby lowering the carbonate ion concentration. process of ocean acidifi cation results in a range of Carbonate ions are the building blocks (calcifi ers) for the biological and socioeconomic impacts. Accelerating shells and skeletons of many marine organisms, such as

acidifi cation under current rates of CO2 emissions is corals, crustaceans (e.g., lobsters and crabs), and mollusks expected to compromise the function of global marine (e.g., clams and oysters). Lowering the pH thus reduces ecosystems during this century. Management actions the saturation state of calcium carbonate, which makes it are urgently needed to help counteract these impacts. harder for organisms to form the calcium carbonate needed for their shells. Calcifi cation, or the process of “shell build-

he concentration of carbon dioxide (CO 2 ) in the ing,” depends on the availability (saturation) of carbonate T Earth’s atmosphere has increased dramatically since ions in seawater. Th e calcifi cation rates of marine calcifi ers the Industrial Revolution (from around 280 parts per mil- are generally sensitive to a decline in carbonate ion concen- lion [ppm] in preindustrial times to 392 ppm in 2011), pri- tration. More specifi cally, changes in the carbonate ion marily due to human activities such as the burning of fossil concentration in the oceans can aff ect the saturation fuels and land-use activities (IPCC 2007). Th is buildup of state—and hence biological availability—of several forms

CO 2 is recognized as one of the primary causes of global of calcium carbonate that these species depend on for shell climate change. Over the last few decades, only half of the building, including calcite, aragonite, or high-magnesian

CO2 released by human activities has remained in the calcite (Feely, Doney, and Cooley 2009). atmosphere; 25 percent has been absorbed into the oceans Currently, calcifying marine organisms in most areas of (Sabine et al. 2004). Th is absorptive capacity of the oceans the ocean surface can build skeletons and shells because has helped to buff er the impacts of global warming associ- the water is saturated with calcium carbonate (Pelejero,

ated with increased atmospheric CO 2 emissions, but it has Calvo, and Hoegh-Guldberg 2010). Th e pH of the ocean come at a cost in the form of ocean acidifi cation. surface waters has already decreased, however, by about

When atmospheric CO 2 dissolves into seawater, car- 0.1 units since the beginning of the Industrial Revolution bonic acid is formed, and hydrogen ions are released. As (Feely et al. 2004), reducing the saturation of aragonite or a result, the pH of the ocean surface waters decreases, calcite that these organisms need. Because the pH scale is making it more acidic. On the 14-point pH scale, lower logarithmic, a 1-unit decrease in pH is equivalent to a ten- numbers (0–6.9) designate acidic water, while higher fold increase in acidity. Ocean pH is projected to drop an

numbers (7.1–14) designate basic water; a pH of 7.0 is additional 0.4 pH units by 2100 under a high CO 2 emis- neutral. Oceans are naturally slightly basic (on average, sion scenario (IPCC 2007), with carbonate saturation lev- . pH 8.1), and acidifi cation via CO2 uptake is expected els potentially falling below those required to sustain coral to drive pH as low as 7.6 by the end of this century. Th is reef accretion (Royal Society 2005; Hoegh-Guldberg et al. pH change will aff ect the ocean carbon chemistry system, 2007; Silverman et al. 2009). Such changes in the carbon and the biological and ecological processes that depend chemistry of the open ocean probably have not occurred on it in numerous ways. for more than 20 million years (Feely et al. 2004).

276

www.berkshirepublishing.com © 2012 Berkshire Publishing Group, all rights reserved. OceanAcidification—Management_McLeod.indd Page 277 12/28/11 4:10 PM user-f494 /203/BER00002/Enc82404_disk1of1/933782404/Enc82404_pagefiles

OCEAN ACIDIFICATION—MANAGEMENT • 277

Changes in ocean acidity vary globally. High-latitude twenty-fi rst century (Gattuso et al. 1998; Kleypas et al. surface waters (waters near and right below the North and 1999; Marubini and Atkinson 1999). Since then, the South Poles) have a naturally low concentration of carbon- eff ects of ocean acidifi cation on marine organisms and

ate ions because atmospheric CO 2 is more soluble in colder ecosystems have become increasingly evident through seas. As a result, these waters experience a higher degree of experimental and observational research. Ocean acidi- ocean acidifi cation than warmer ocean waters and are fi cation has demonstrable impacts on a number of therefore likely to become undersaturated with respect to biological and ecological processes in many marine aragonite before tropical and subtropical waters (Feely et al. groups—including phytoplankton, corals, other inverte- 2004). Models suggest that oceanic waters will be under- brates, and fi shes—around the globe (Kroeker et al. saturated with respect to aragonite by 2020 in the Arctic 2010). Most studies have focused on impacts of ocean Ocean and by 2050 in the Southern Ocean surrounding acidifi cation on calcifi cation (shell building) and dissolu- Antarctica (Orr et al. 2005; Steinacher et al. 2009). tion (shell dissolving or disruptions in formation), but Tropical coral reefs are also vulnerable to ocean acidi- impacts on other processes such as early life-history fi cation. Some globally important coral reef regions, such stages are reported with increasing frequency (Dupont as the Great Barrier Reef, the Coral Sea, and the and Th orndyke 2009; Albright and Langdon 2011). For

Caribbean Sea, are projected to attain dangerously low example, ocean acidifi cation can lead to excessive CO 2

states of aragonite saturation more rapidly than other levels in the blood (CO 2 toxicity) of fi sh and cephalopods regions such as the Central Pacifi c Ocean (Hoegh- and signifi cantly reduced growth and fecundity in some Guldberg et al. 2007). Despite global ocean acidifi cation invertebrates (Orr et al. 2005). For species with long gen- patterns, a number of local-scale ecological processes eration times, slower growth and lower fecundity can aff ect the rate and geographic scale of ocean acidifi cation. lead to population declines. Recent works indicate that Large variations in pH and aragonite saturation states ocean acidifi cation may lead to sensory and neurological have been documented on some coral reefs. On Heron dysfunction in marine fi sh larvae—that is, they can’t Island Reef in the Great Barrier Reef, Australia, for “smell” the reef and thus fail to distinguish predators example, variations in pH and aragonite saturation state from parents (Munday et al. 2010). over the course of one day were greater than the predicted Importantly, ocean acidifi cation doesn’t aff ect all changes that ocean acidifi cation will cause for the oceans marine organisms equally. Some hard corals have linear globally by the middle of the century (Anthony et al. responses while others show accelerating responses to 2008; 2011). Th ese results suggest that although general reductions in carbonate ion concentration (Reynaud patterns in aragonite saturation are evident for open et al. 2003; Jury, Whitehead and Szmant 2009; Rodolfo- oceans, they will vary signifi cantly both spatially and Metalpa et al. 2010). While accelerating responses may temporally as a result of reef-scale processes. result in a catastrophic tipping point for some species, it Climate change and ocean acidification challenge is not yet possible to defi ne such critical points for indi- marine conservation managers and research scientists vidual species or broader ecosystem changes. Th e ability because they force them to try to manage global threats at to defi ne tipping points is limited because most studies local scales. Unlike other global stressors, such as increas- on ocean acidifi cation impacts are based on experimen- ing sea surface temperature that leads to bleaching (visible tal work over short time scales and for a single species. whitening) and widespread mortality of coral reefs, ocean Little is known about how populations and ecosystems acidifi cation is largely an invisible, insidious environmental will respond to ocean acidifi cation, the combined eff ects problem. Because of the relatively recent awareness of the from other stressors (e.g., pollution, overfi shing, increas- threat of ocean acidifi cation, little guidance for managing ing ocean temperatures), and the ability of organisms to its impacts exists. Further, the majority of research is adapt. Th e variety of responses of marine organisms is focused on addressing the responses of marine organisms partially the result of the wide variety of processes that to changes in ocean chemistry or on projecting global-scale ocean acidifi cation aff ects, such as dissolution and cal- changes in ocean chemistry; little emphasis has been placed cifi cation rates, growth rates, development, and survival on developing management or policy recommendations to (Kroeker et al. 2010). Th is variation in responses makes address these impacts (but see Mcleod et al. 2008). predicting the impacts of ocean acidifi cation on species and marine ecosystems complex. Despite these com- plexities, however, recent studies indicate that, overall, Impacts of Ocean Acidifi cation ocean acidifi cation will harm calcifying marine organ- isms (Hendriks, Duarte, and Alvarez 2010; Kroeker A number of groundbreaking studies conducted in the et al. 2010). late 1990s predicted that coral reefs would show dramatic Whereas recent studies have explored the biological responses to changes in ocean chemistry during the impacts of ocean acidifi cation on marine organisms, less

www.berkshirepublishing.com © 2012 Berkshire Publishing Group, all rights reserved. OceanAcidification—Management_McLeod.indd Page 278 12/28/11 4:10 PM user-f494 /203/BER00002/Enc82404_disk1of1/933782404/Enc82404_pagefiles

278 • THE BERKSHIRE ENCYCLOPEDIA OF SUSTAINABILITY: ECOSYSTEM MANAGEMENT AND SUSTAINABILITY

emphasis has been placed on assessing the socioeconomic time scales. As a result, there are major research gaps impacts. Because ocean acidifi cation aff ects marine regarding ocean acidifi cation’s larger importance, includ- organisms’ abilities to form shells, it may decrease the ing how ocean acidifi cation will aff ect many ecologically abundance of commercially important shellfi sh species or economically important species and communities, how such as clams, oysters, and sea urchins, aff ecting the it will aff ect a variety of physiological and biogeochemi- human communities that depend upon these resources cal processes, and what the potential will be for organ- for food and/or livelihoods (Cooley, Kite-Powel, and isms to adapt to projected changes in ocean chemistry Doney 2009). Ocean acidifi cation may thus aff ect human (Boyd et al. 2008). communities through a loss of goods and services pro- Th e science needed to address these gaps will probably vided by ecosystems such as coral reefs—for example, take decades to fully develop. Waiting to take manage- tourism revenues, fi sheries, coastal protection, and cul- ment action until the science is complete, however, may tural values. Such goods and services are valued in bil- put critical marine ecosystems at risk. Local actions can lions of dollars (Burke et al. 2011). Th e Great Barrier and should be taken now to protect marine ecosystems. Reef, for example, contributes more than $5 billion annu- Such actions include reducing the other stressors that ally to the Australian economy (Access Economics aff ect most marine ecosystems, such as declining water 2005). quality, coastal pollution, and overfi shing of important Additional research is needed to assess the deeper species and functional groups, such as herbivores socioeconomic impacts of ocean acidifi cation in coun- (Hughes et al. 2003). Reducing land-based sources of tries whose communities directly depend upon natural pollution, such as nutrient runoff from agriculture and marine resources for survival (Cooley and Doney sediment runoff from coastal development, is particularly 2009). Such research could provide motivations for important for managing the impacts of ocean acidifi ca- action that extend beyond ocean acidifi cation and cli- tion, because nutrients like phosphorus and nitrogen and mate change, because economic analyses and models of land-based carbon inputs can lower pH and aragonite ocean acidifi cation’s impacts on fi sheries and tourism saturation states in coastal and oceanic waters (Andersson, are necessary to understand the true comprehensive Mackenzie, and Lerman 2006). To achieve these goals,

costs of action or inaction to reduce global CO 2 emis- marine management eff orts must be integrated with sions (Fulton et al. 2011). land-use and coastal-zone planning and practices to help reduce pollutant inputs. More generally, the reduction of stressors on marine ecosystems supports ecosystem Potential Management Options health and will better allow marine organisms to channel resources to growth, calcifi cation, and reproduction Th e most critical action needed to address ocean acidifi - rather than to repairing damage and recovering from dis-

cation is to stabilize atmospheric CO 2 concentrations. ease (Mcleod et al. 2008). Reviews suggest that policies that allow the global aver- Current ocean acidifi cation research is exploring dif-

age atmospheric concentration of CO2 , currently ferences in the sensitivity of marine species and habitats approaching 393 ppm to reach or surpass 500 ppm of to changes in ocean chemistry. If scientists can identify

CO 2 are likely to be extremely risky for corals reefs (e.g., species or habitats that are less vulnerable to the impacts Hoegh-Guldberg et al. 2007). Th us, ocean acidifi cation of ocean acidifi cation, these could become priorities for provides another impetus for comprehensive and eff ective inclusion in marine protected areas (MPAs). Less vul-

global policies to address CO 2 emissions. nerable areas may include coral reefs in carbonate rich Unfortunately, reducing global emissions is beyond areas, such as places where there are raised reefs and the scope of marine conservation managers. A more limestone islands, extensive reef fl ats, patch reef/coral immediate need is to identify and implement local actions head complexes, and carbonate sediment deposits. that support marine ecosystem (e.g., coral reef) health in Other candidate areas for increased protection through the face of global threats such as ocean acidifi cation. A MPAs may be high-diversity reef complexes that are study by the National Research Council (2010, 85), well fl ushed by oceanic water, because these infl uxes of Ocean Acidification: A National Strategy to Meet the fresh oceanic water bring higher total alkalinity and Challenges of a Changing Ocean , reviewed the current state saturation states that support reef and shell building. of the knowledge of ocean acidifi cation and stated that Well-fl ushed areas may be more vulnerable in the “there is not yet enough information on the biological, future, however, if ocean acidifi cation causes signifi cant ecological, or socioeconomic eff ects of ocean acidifi cation decreases in the pH of oceanic waters. Th erefore, a to adequately guide management eff orts.” Th is conclusion strategy of spreading the risk by selecting examples of is based on the fact that most research has focused on the coral reef areas in a variety of ocean chemistry and impacts of ocean acidifi cation on few species over short oceanographic regimes is a useful MPA design

www.berkshirepublishing.com © 2012 Berkshire Publishing Group, all rights reserved. OceanAcidification—Management_McLeod.indd Page 279 12/28/11 4:10 PM user-f494 /203/BER00002/Enc82404_disk1of1/933782404/Enc82404_pagefiles

OCEAN ACIDIFICATION—MANAGEMENT • 279

approach. By protecting multiple examples of such reef and sulfur (Doney et al. 2007), and eutrophication areas, MPA managers are helping to ensure that these resulting from land-use changes and agriculture, a pro- ecosystems are more likely to survive climate and other cess where a body of water (in this case the ocean) human threats. receives excess nutrients that stimulate algal growth Coral reefs located in areas with high variability in (Borges and Gypens 2010). Th e processes that aff ect seawater temperature are thought to be less vulnerable to coastal carbonate chemistry are complex and not well thermal stress and associated bleaching and mortality resolved, and improved understanding is needed to caused by increases in sea surface temperature manage the responses of marine organisms, ecosystems, (McClanahan et al. 2007). If reefs in areas with high and industries in coastal areas (National Research natural variability in ocean chemistry are also less vul- Council 2010). nerable to ocean acidifi cation, then managers could pri- Th e mitigation of local causes of ocean acidifi cation oritize reefs in these areas for inclusion in MPAs. In the using existing environmental laws has been proposed absence of such information, MPA managers may choose recently (Kelly et al. 2011). Local and state governments to locate MPAs in a range of ocean chemistry regimes have the authority and capacity to address many stress- (including areas with high and low variability). ors that can exacerbate ocean acidifi cation conditions in Additionally, selecting reefs in a variety of pH coastal waters. For example, enforcement of the US and aragonite saturation regimes increases Clean Water Act can help ensure that precipi- the chances that managers will iden- tation runoff and associated pollutants, tify and protect corals that are accli- which can increase acidifi cation, are lim- mated to a variety of pH conditions ited. Controlling coastal erosion can and spreads the risk of any coral help reduce nutrient and sediment species’ survival being compro- loading of water; such coastal inputs mised by ocean acidifi cation. also may be enriched with fertilizers Actions that address threats that can increase acidifi cation, pro- such as increasing sea level, viding another reason for reducing increasing sea surface tempera- them. Changes in land-use pat- ture, and ocean acidifi cation terns, such as changes in deforesta- must be incorporated into tion practices, can reduce direct

MPA management plans to and indirect CO 2 emissions, run- reduce the impacts of increas- off , and other threats. Enforcing ing atmospheric concentrations federal emission limits for pollut-

of CO 2 on marine species and ants such as nitrogen oxide and sul- ecosystems. It is also important fur oxide (e.g., from coal-fired to develop and test the effi cacy of power plants) can help reduce ocean innovative interventions that acidification impacts in coastal reduce the eff ects of ocean acidifi ca- waters (Kelly et al. 2011). Despite the tion on high-priority areas and species. clear benefi ts of minimizing additional

Such interventions include CO 2 capture stressors on coastal ecosystems through and storage strategies. Th e geographic scale, time enforcement of existing environmental laws, frame, and economic and environmental costs and ben- such actions are inadequate to reverse the impacts of efi ts of these interventions must be explored further ocean acidifi cation at a global scale. before they can be implemented. To help conservation managers identify and protect marine species and communities that are most likely to survive changes in ocean chemistry, additional research Research Needs and Next Steps is needed to investigate the response of organisms, popu- lations, and communities to ocean acidifi cation. Further, A number of priority research needs should be addressed research exploring the capacity of marine organisms to to support the management of ocean acidifi cation. While acclimatize or adapt to changes in ocean chemistry will models can project changes in ocean chemistry at global be important in understanding their susceptibility to and regional scales, these models do not take coastal pro- future changes. Th e ability to identify species that are less cesses into account. Coastal areas already experience vulnerable to changes in ocean chemistry is also useful to extreme variability in water chemistry because of natural support aquaculture programs, because such species may and human inputs, such as acidic discharge of river water be used for selective breeding. Field studies that docu- (Salisbury et al. 2008), atmospheric deposition of nitrogen ment changes in ecosystem structure and function over

www.berkshirepublishing.com © 2012 Berkshire Publishing Group, all rights reserved. OceanAcidification—Management_McLeod.indd Page 280 12/28/11 4:10 PM user-f494 /203/BER00002/Enc82404_disk1of1/933782404/Enc82404_pagefiles

280 • THE BERKSHIRE ENCYCLOPEDIA OF SUSTAINABILITY: ECOSYSTEM MANAGEMENT AND SUSTAINABILITY

natural pH gradients are also useful for highlighting Indicator Species; Large Marine Ecosystem (LME) thresholds that trigger widespread ecological and biolog- Management and Assessment; Marine Protected Areas ical changes. Th e ability to identify indicators of regime (MPAs); Pollution, Nonpoint Source; Pollution, Point shifts (e.g., from coral to algal dominance) helps marine Source; Regime Shifts; Resilience managers take actions to avoid such shifts or cope with them (Anthony et al. 2011). No impact occurs in isolation, so studies need to F URTHER READING address the interactive eff ects of multiple stressors. Access Economics Pty Limited. (2005). Measuring the economic and Marine ecosystems currently must deal with changes in fi nancial value of the Great Barrier Reef Marine Park . Canberra, ocean pH in addition to increasing sea surface tempera- Australia: Access Economics Pty Limited for Great Barrier Reef tures, changes in sea level, and other human impacts such Marine Park Authority. as pollution, coastal development, and overfi shing. It may Albright, Rebecca, & Langdon, Chris. (2011). Ocean acidifi cation impacts multiple early life history processes of the Caribbean coral be challenging for researchers to attribute ecosystem Porites astreoides. Global Change Biology , 17 (7), 2478–2487. changes to a specifi c stressor given the suite of challenges Andersson, Andreas; Mackenzie, Fred; & Lerman, Abraham. (2006). Coastal ocean CO -carbonic acid-carbonate sediment system of facing marine ecosystems. Managers, however, need the 2 ability to understand how species, communities, and eco- the Anthropocene. Global Biogeochemical Cycles , 20, GB1S92. doi:10.1029/2005GB002506 systems respond to ocean acidifi cation in concert with Anthony, Kenneth R. N.; Kline, David I.; Diaz-Pulido, Guillermo; additional stressors in order to predict changes and Dove, Sophie; & Hoegh-Guldberg, Ove. (2008). Ocean acidifi ca- develop appropriate management responses. tion causes bleaching and productivity loss in coral reef builders. Decision makers need socioeconomic research on the Proceedings of the National Academy of Sciences of the United States of America , 105 (45), 17442–17446. impacts of ocean acidifi cation, the projected timing of Anthony, Kenneth, et al. (2011). Ocean acidifi cation and warming impacts, and ways to increase adaptability and resilience will lower coral reef resilience. Global Change Biology , 17 (5), of socioeconomic systems. To prioritize research and 1798–1808. mitigation and adaptation activities, assessments of the Borges, Alberto, & Gypens, Nathalie. (2010). Carbonate chemistry in the coastal zone responds more strongly to eutrophication than to cost of ocean acidifi cation on marine ecosystems and ocean acidifi cation. Limnology and Oceanography , 55 (1), 346–353. resources are essential. More broadly, the public needs Boyd, Phillip, et al. (2008). Climate-mediated changes to mixed-layer educational and informational materials that communi- properties in the Southern Ocean: Assessing the phytoplankton cate the implications of ocean acidifi cation on marine response. Biogeosciences , 5 (3), 847–864. Burke, Lauretta; Reytar, Kathleen; Spalding, Mark; & Perry, Alison. ecosystems and dependent communities, and that (2011). Reefs at risk revisited . Washington, DC: World Resources emphasize actions that can be taken to reduce these Institute. impacts. Cooley, Sarah, & Doney, Scott. (2009). Anticipating ocean acidifi ca- Th e ecological, biological, and socioeconomic impacts tion’s economic consequences for commercial fi sheries. Environmental Research Letters , 4 (2), 024007. of ocean acidifi cation pose signifi cant challenges to Cooley, Sarah; Kite-Powel, Hauke; & Doney, Scott. (2009). Ocean marine species and the human communities who depend acidifi cation’s potential to alter global marine ecosystem services. Oceanography , 22 (4), 172–181. upon them for food and livelihoods. Anthropogenic CO 2 emissions must be dramatically reduced to mitigate these Doney, Scott, et al. (2007). Impact of anthropogenic atmospheric nitrogen and sulfur deposition on ocean acidifi cation and the impacts. Our best hope for tackling the challenge of inorganic carbon system. P r o c e e d i n g s o f t h e N a t i o n a l A c a d e m y ocean acidifi cation is the implementation of a suite of of Sciences of the United States of America , 104 (37), four key management actions: (1) curb and stabilize 14580–14585. Dupont, Sam, & Th orndyke, Michael. (2009). Impact of CO -driven atmospheric CO concentrations; (2) protect marine spe- 2 2 ocean acidifi cation on invertebrates early life-history—What we cies and areas likely to be less vulnerable to ocean acidi- know, what we need to know and what we can do. Biogeosciences

fi cation; (3) explore and apply CO 2 capture and storage Discussions , 6 , 3109–3131. Feely, Richard, et al. (2004). Impact of anthropogenic CO on the methods where feasible; and (4) use existing environmen- 2 CaCO system in the oceans. Science , 305 (5682), 362–366. tal laws to control stressors that exacerbate ocean acidifi - 3 Feely, Richard A.; Doney, Scott C.; & Cooley, Sarah R. (2009). Ocean cation conditions in coastal waters. acidifi cation: Present conditions and future changes in a high-CO 2 world. Oceanography , 22 (4), 36–47. Elizabeth McLEOD Fulton, Elizabeth A., et al. (2011). Lessons in modelling and manage- Th e Nature Conservancy ment of marine ecosystems: Th e Atlantis experience. Fish and Fisheries , 12 (2), 171–188. Kenneth R. N. ANTHONY Gattuso, Jean-Pierre; Frankignoulle, Michel; Bourge, Isabelle; Romaine-Lioud, S.; & Buddemeier, W. (1998). Eff ect of calcium Australian Institute of Marine Science carbonate saturation of seawater on coral calcifi cation. Global and See also Catchment Management; Coastal Management; Planetary Change , 18 (1–2), 37–46. Hendriks, Iris; Duarte, Carlos; & Alvarez, Marta. (2010). Ecological Restoration; Eutrophication; Fisheries Vulnerability of marine biodiversity to ocean acidifi cation: A meta- Management; Food Webs; Global Climate Change; analysis. Estuarine, Coastal and Shelf Science , 86 (2), 157–164.

www.berkshirepublishing.com © 2012 Berkshire Publishing Group, all rights reserved. OceanAcidification—Management_McLeod.indd Page 281 12/28/11 4:10 PM user-f494 /203/BER00002/Enc82404_disk1of1/933782404/Enc82404_pagefiles

OCEAN ACIDIFICATION—MANAGEMENT • 281

Hoegh-Guldberg, Ove, et al. (2007). Coral reefs under rapid climate Munday, Philip, et al. (2010). Replenishment of fi sh populations is change and ocean acidifi cation. Science , 318 (5857), 1737–1742. threatened by ocean acidifi cation. Proceedings of the National Hughes, Terry P., et al. (2003). Climate change, human impacts, and Academy of Science, 107 , 12930–12934. the resilience of coral reefs. Science , 301 (5635), 929–933. National Research Council (US) Committee on the Development of Intergovernmental Panel on Climate Change (IPCC). (2007). Climate an Integrated Science Strategy for Ocean Acidifi cation Monitoring, change 2007: Synthesis report . New York: Cambridge University Research, and Impacts Assessment. (2010). Ocean acidifi cation: A Press. national strategy to meet the challenges of a changing ocean. Jury, Christopher P.; Whitehead, Robert F.; & Szmant, Alina M. Washington, DC: National Academies Press. (2010). Eff ects of variations in carbonate chemistry on the calcifi - Orr, James C., et al. (2005). Anthropogenic ocean acidifi cation over cation rates of Madracis auretenra (5 Madracis mirabilis sensu Wells, the twenty-fi rst century and its impact on calcifying organisms. 1973): Bicarbonate concentrations best predict calcifi cation rates. Nature , 437 , 681–686. Global Change Biology , 16 (5), 1632–1644. Pelejero, Carles; Calvo, Eva; & Hoegh-Guldberg, Ove. (2010). Paleo- Kelly, Ryan P., et al. (2011). Mitigating local causes of ocean acidifi ca- perspectives on ocean acidifi cation. Trends in Ecology and Evolution , tion with existing laws. Science, 332 (6033) , 1036–1037. 25 (6), 332–344.

Kleypas, Joan A., et al. (1999). Geochemical consequences of increased Reynaud, Stephanie, et al. (2003). Interacting eff ects of CO 2 partial atmospheric carbon dioxide on coral reefs. Science , 284 (5411), pressure and temperature on photosynthesis and calcifi cation in a 118–120. scleractinian coral. Global Change Biology , 9 , 1660–1668. Kroeker, Kristy; Kordas, Rebecca; Crim, Ryan; & Singh, Gerald. Rodolfo-Metalpa, Riccardo; Martin, Sophie; Ferrier-Pagès, Christine; & (2010). Meta-analysis reveals negative yet variable eff ects of ocean Gattuso, Jean-Pierre. (2010). Response of the temperate coral

acidification on marine organisms. Ecology Letters , 13 (11), Cladocora caespitosa to mid- and long-term exposure to p CO2 and tem- 1419–1434. perature levels projected for the 2100 AD. Biogeosciences, 7 , 289–300. Marubini, Francesca, & Atkinson, Marlon. (1999). Eff ects of lowered Royal Society. (2005). Ocean acidifi cation due to increasing atmospheric pH and elevated nitrate on coral calcifi cation. Marine Ecology carbon dioxide . Policy document 12/05. London: Th e Royal Society. Progress Series , 188 , 117–121. Sabine, Christopher L., et al. (2004). Th e oceanic sink for anthropo-

McClanahan, Timothy R.; Ateweberhan, Mebrahtu; Muhando, genic CO2 . Science , 305 , 367–371. Christopher A.; Maina, Joseph; & Mohammed, Mohammed S. Salisbury, Joseph; Green, Mark; Hunt, Chris; & Campbell, Janet. (2007). Eff ects of climate and seawater temperature variation on (2008). Coastal acidifi cation by rivers: A threat to shellfi sh? EOS, coral bleaching and mortality. Ecological Monographs , 77 (4), Transactions, American Geophysical Union , 89 (50), 513. 503–525. Silverman, Jacob; Lazar, Boaz; Cao, Long; Caldeira, Ken; & Erez, Mcleod, Elizabeth, et al. (2008). Th e Honolulu Declaration on Ocean Jonathan. (2009). Coral reefs may start dissolving when atmo-

Acidifi cation and Reef Management. Arlington, VA: Th e Nature spheric CO2 doubles. Geophysical Research Letters , 36 , L05606. Conservancy; Gland, Switzerland: Th e World Conservation Union doi:10.1029/2008GL036282 (IUCN). Retrieved September 20, 2011, from http://www. Steinacher, Marco, et al. (2009). Projected 21st century decrease in icriforum.org/sites/default/files/honolulu_declaration_with_ marine productivity: A multi-model analysis. Biogeosciences , 7 , appendices.pdf 979–1005.

www.berkshirepublishing.com © 2012 Berkshire Publishing Group, all rights reserved.