2
Major Research Questions in 2030

One of the committee’s primary tasks was to “identify major research questions anticipated to be at the forefront of ocean science in 2030 based on national and international assessments, input from the worldwide scientific community, and ongoing research planning activities” (see Box 1.1). In response to this charge, a range of recent government plans, task force documents, research planning assessments, disciplinary reports, and primary literature (e.g., NSF, 2001; USCOP, 2004; JSOST, 2007; CEQ, 2010) were reviewed by the committee. From these documents, and from information gathering sessions with experts in ocean science and policy, the committee identified 32 compelling science questions that are anticipated to be at the forefront of ocean science in 2030, ranging from broad global challenges that require both interdisciplinary and multidisciplinary research to regional, local, or discipline-specific topics. These questions are clearly relevant for 2010 but are not simple issues that will result in solutions with a few more years of intensive effort. Instead, they reflect challenging scientific problems that will likely take decades to solve, especially if only limited resources are available.

The act of defining research questions that will still be relevant in 2030 has many challenges. Almost certainly, new discoveries and technological advances will alter the research landscape, redefining or even providing answers for some questions. It is nearly impossible to anticipate the nature of such transformational discoveries and even more difficult to pose questions that anticipate their impacts. Instead, the committee (guided by the planning assessments cited above) focused on questions that are likely not only to still be relevant, but even more pressing in 2030. For example, nearly 20 years ago Policy Implications of Greenhouse Warming (NRC, 1992) posed a series of research issues associated with geoengineering schemes as potential avenues to mitigate climate change. The past few years have seen numerous workshops and reports devoted to developing geoengineering research agendas as a response to climate change (e.g., IPCC, 2005; The Royal Society, 2009). The science has certainly advanced over the two decades between these reports, but compelling science questions on the viability and impacts of these options remain.

Although such a list of questions can never be exhaustive, the committee feels these are comprehensive enough to capture the major infrastructure needs for 2030. As discussed in Chapter 1, these questions are organized within the context of four overarching societal drivers: enabling stewardship of the environment, protecting life and property, promoting sustainable economic vitality, and increasing fundamental scientific understanding. These drivers are similar to critical themes identified in Charting the Course of Ocean Science in the United States for the Next Decade: An Ocean Research Priorities Plan and Implementation Strategy (listed in Chapter 1). This chapter also aligns with several priority objectives of the National Ocean Policy (CEQ, 2010; E.O. 13547), discussed in greater detail within specific science questions.

ENABLING STEWARDSHIP OF THE ENVIRONMENT

In the next 20 years, significant anthropogenic environmental impacts are very likely, given the magnitude of the growing world population1 (De Souza et al., 2003; Rockstrom et al., 2009). However, increased understanding of the ocean’s physical, chemical, and biological responses, particularly in the context of anthropogenic forcing factors (e.g., climate change, resource extraction and utilization, waste production and nutrient pollution), has potential to limit many adverse impacts.

Human activities, from fishing to energy extraction, are having impacts on all regions of the ocean, from estuaries to the deep ocean. However, perhaps the most significant and striking impacts are found in coastal and polar regions. The coastal zone, an area vulnerable to multiple stressors, is of particular societal and environmental significance. Although



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2 Major Research Questions in 2030 One of the committee’s primary tasks was to “identify advanced over the two decades between these reports, but major research questions anticipated to be at the forefront compelling science questions on the viability and impacts of ocean science in 2030 based on national and international of these options remain. assessments, input from the worldwide scientific community, Although such a list of questions can never be exhaus- and ongoing research planning activities” (see Box 1.1). In tive, the committee feels these are comprehensive enough to response to this charge, a range of recent government plans, capture the major infrastructure needs for 2030. As discussed in Chapter 1, these questions are organized within the task force documents, research planning assessments, dis- context of four overarching societal drivers: enabling ciplinary reports, and primary literature (e.g., NSF, 2001; stewardship of the environment, protecting life and USCOP, 2004; JSOST, 2007; CEQ, 2010) were reviewed by property, promoting sustainable economic vitality, and the committee. From these documents, and from information increasing fundamental scientific understanding. These gathering sessions with experts in ocean science and policy, the committee identified 32 compelling science questions drivers are similar to critical themes identified in Charting that are anticipated to be at the forefront of ocean science the Course of Ocean Science in the United States for the Next in 2030, ranging from broad global challenges that require Decade: An Ocean Research Priorities Plan and Implemen- both interdisciplinary and multidisciplinary research to re- tation Strategy (listed in Chapter 1). This chapter also aligns gional, local, or discipline-specific topics. These questions with several priority objectives of the National Ocean Policy are clearly relevant for 2010 but are not simple issues that (CEQ, 2010; E.O. 13547), discussed in greater detail within will result in solutions with a few more years of intensive ef- specific science questions. fort. Instead, they reflect challenging scientific problems that will likely take decades to solve, especially if only limited ENABLING STEWARDSHIP OF THE ENVIRONMENT resources are available. The act of defining research questions that will still be In the next 20 years, significant anthropogenic envi- relevant in 2030 has many challenges. Almost certainly, new ronmental impacts are very likely, given the magnitude of the growing world population1 (De Souza et al., 2003; discoveries and technological advances will alter the research landscape, redefining or even providing answers for some Rockstrom et al., 2009). However, increased understanding questions. It is nearly impossible to anticipate the nature of of the ocean’s physical, chemical, and biological responses, such transformational discoveries and even more difficult particularly in the context of anthropogenic forcing factors to pose questions that anticipate their impacts. Instead, the (e.g., climate change, resource extraction and utilization, committee (guided by the planning assessments cited above) waste production and nutrient pollution), has potential to focused on questions that are likely not only to still be rel- limit many adverse impacts. evant, but even more pressing in 2030. For example, nearly Human activities, from fishing to energy extraction, are 20 years ago Policy Implications of Greenhouse Warming having impacts on all regions of the ocean, from estuaries to (NRC, 1992) posed a series of research issues associated the deep ocean. However, perhaps the most significant and with geoengineering schemes as potential avenues to miti- striking impacts are found in coastal and polar regions. The gate climate change. The past few years have seen numerous coastal zone, an area vulnerable to multiple stressors, is of workshops and reports devoted to developing geoengineering particular societal and environmental significance. Although research agendas as a response to climate change (e.g., IPCC, 2005; The Royal Society, 2009). The science has certainly 1 http://www.census.gov/ipc/www/idb/worldpop.php. 11

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12 CRITICAL INFRASTRUCTURE FOR OCEAN RESEARCH AND SOCIETAL NEEDS IN 2030 it comprises only about 8 percent of Earth’s surface, this raising sea level (Nicholls and Cazenave, 2010). Even if area supports more than 25 percent of total global primary these fundamental effects were perfectly understood and production and yields nearly 90 percent of present world predicted, there would still be issues related to regional sea fisheries production (Ryther, 1969; Sherman, 1994). Ocean- level rise that depend strongly on local conditions (Milne et related activities and industries provided over 2.3 million al., 2009), including subsidence, tides, and storm activity. jobs in 2004.2 About 35 percent of the world’s population Tides and storms contribute to local inundation, so the most currently lives within 100 km of a shoreline (Nicholls and damaging effects of a higher sea level will likely be felt Small, 2002); this number is projected to grow to 75 percent more frequently. Seasonal effects could be significant, as in a few decades (Vitousek et al., 1997). Over two-thirds of runoff contributes to flooding in areas of high precipitation. the world’s largest cities, with populations greater than 1.6 For low-lying coastal communities, sea level rise will be a million, are located in coastal areas. These are often in the threat to societal infrastructure (e.g., streets, buildings, sew- vicinity of estuaries or coastal wetlands, accounting for more age, drinking water supplies, gas, electricity [Nicholls and than 50 percent of wetland loss (Walker, 1990; Anderson and Cazenave, 2010]). Ports and naval facilities, in particular, Magleby, 1997). Coastal governance issues (e.g., coordina- will need to address the impact of sea level rise and chang- tion and support of ocean and coastal management; coastal ing dynamics of coastal erosion and sedimentation in order and marine spatial planning3) are currently at the forefront to maintain effective operations. Also of concern are more of both public attention and national priorities (CEQ, 2010); than 200 existing marine laboratories that currently provide and this is not expected to decrease by 2030. support for a wide range of ocean research and education The polar regions will almost certainly also be of pro- activities (Sebens, 2009), which will have to adapt to coast- found importance in the next 20 years, as noted by inclu- line changes as a result of rising sea level. On regional and sion in the National Ocean Policy (NOP) objectives (CEQ, global scales, ocean temperature and therefore sea level will 2010; E.O.13547). Although they do not have significant continue to change in response to natural, interannual modes populations in numbers, they are presently subjected to rapid of climate variability such as the El Niño-Southern Oscilla- environmental changes (e.g., warming, sea ice reduction, tion (ENSO), and many of these changes will be irreversible changes in freshwater fluxes) that may have great impacts over both short and long time scales (Solomon et al., 2009). for commercial activity, including resource extraction and transportation. These also require special considerations How Will Climate Change Influence Cycles of Primary when discussing ocean infrastructure needs. The following Production? 13 questions were chosen to encompass a broad range of issues regarding environmental stewardship from the poles Major changes have and will continue to take place in to the equator. the world’s ocean (e.g., changes in temperature, stratifica- tion, circulation, oxygen distributions, trace metals inputs, and pH) (e.g., Sarmiento et al., 2004; Doney et al., 2009; How Will Sea Level Change on a Range of Spatial and Reid et al., 2009; Keeling et al., 2010; Steinacher et al., Temporal Scales and What Are the Potential Impacts? 2010). These changes all have direct and indirect impacts The trapping of heat by anthropogenic greenhouse gases on ecosystem processes, including limitation of primary is likely to lead to sea level rise on a wide range of spatial production by nutrients, shifts in the major phytoplankton and temporal scales (NRC, 2010b). As so many people groups that dominate open ocean waters, and changes in live and work near sea level, sea level study and prediction zooplankton behavior and distributions (Reid et al., 2009). will continue to be a topic of active research in the coming Global trends in primary productivity have been linked to decades. In 2007, the Intergovernmental Panel on Climate changes in surface temperature and mixed layer dynamics Change (IPCC) estimated sea level rises between 0.18 and (Behrenfeld et al., 2006; Martinez et al., 2009; Chavez et al., 0.6 m by 2100 (IPCC, 2007). More recent estimates that take 2011). While some of the basin-scale trends are correlated into account ice melt on Greenland and western Antarctica with natural oscillatory cycles (e.g., the North Atlantic Oscil- increase these estimates to between 0.8 and 2.0 m (Pfeffer lation, Pacific Decadal Oscillation), the exact mechanisms et al., 2008). Increased heat in the ocean-atmosphere system that force changes in ecosystem productivity are still uncer- causes sea level rise in two ways: (1) a warmer ocean is less tain (Martinez et al., 2009). Indeed, a recent study concludes dense, and thus has more volume even if its mass remains that long (~40 years) records of persistent, high-quality, constant; (2) melting of ice on land adds mass to the ocean, global-scale data are needed to separate decadal oscillations from climate effects on ocean productivity (Henson et al., 2009; Chavez et al., 2011). 2 http://www.oceaneconomics.org. Modulation of the surface ocean ecosystem’s composi- 3 According to the Final Recommendations of the Interagency Ocean tion, stock, and productivity influences the biological pump Policy Task Force (CEQ, 2010), U.S. coastal and marine spatial planning “is a comprehensive, adaptive, integrated, ecosystem-based, and transparent that functions to transport atmospheric carbon dioxide spatial planning process, based on sound science, for analyzing current and (CO2) incorporated into organic carbon into the deep ocean anticipated uses of ocean, coastal, and Great Lakes areas.”

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13 MAJOR RESEARCH QUESTIONS IN 2030 (Sarmiento and Gruber, 2006). However, the link between and are a major threat to marine biodiversity (Carlton and surface productivity, fluxes to depth, and the rate at which Geller, 1993; Molnar et al., 2008). Invasive species have this material degrades in the ocean interior is currently not transformed marine habitats around the world, caused human well understood and quantified (Burd et al., 2010). The chal- disease, and led to significant ecological and economic dam- lenge of understanding the ocean’s role in the global carbon age (Takahashi et al., 2008). Many marine species have been cycle and its response to a changing environment requires transported to nonnative areas by ship ballast water or hulls. an expanded scale of observation in both space and time By 2030, it is predicted that commercial shipping will be (K.S. Johnson et al., 2009; Chavez et al., 2011). Global- able to exploit seasonal ice-free Arctic shipping routes (e.g., scale observations of phytoplankton stock, functional group Wilson et al., 2004; Stroeve et al., 2008); this may exacerbate distributions, and productivity are currently constrained by, the movement of invasive species and have other impacts and limited to, remotely sensed ocean color, which senses (e.g., vessel whale strikes). The foundations for a quantitative only the near-surface conditions of the ocean. New obser- global assessment of the impacts of invaders and their routes vational strategies are needed to study and understand the of introduction will likely be in place by 2030, but additional link between phytoplankton productivity, carbon export, and information will be needed to develop large-scale strategies climate forcing. necessary to prevent future introductions while adapting to existing invaders. The combination of large-scale biogeographical shifts, How Will Marine Ecosystem Structure, Biodiversity, and changes in local community structure caused by ocean warm- Population Dynamics Be Shaped by a Changing Ocean ing and acidification, and impacts from invasive species will Environment? have far-reaching consequences for marine biodiversity, Interactions between climatic forcing and anthropogenic ecosystem structure, and population dynamics. Yet many of changes in greenhouse gas concentrations affect global ocean the current changes and their impacts remain unreported, circulation, which in turn influences global climate (e.g., for lack of comprehensive global marine ecosystem moni- Broecker, 1997; Clark et al., 2002; Sutton and Hodsen, toring efforts. In order to provide effective stewardship of 2005). These interactions will have an impact on ecosystem the marine environment, infrastructure that can quantify dynamics. Changes in species composition, species distribu- ecosystem changes and manage human activities in response tion, or trophic interactions, which can be caused by shifts is a need for 2030. in the geographic range of ecosystem components, may result in alterations of ecosystem resilience and productiv- How Will Marine Organisms and Ecosystems Be Affected ity (Pereira et al., 2010). The degree of genetic connectivity by Ocean Acidification? and species-specific life history characteristics mediate the resiliency of populations and communities and the ability to Marine biogeochemistry and ecosystems are likely to recover from both human and natural sources of disturbance. be affected by the chemical changes related to increasing Studies of the mechanisms of genetic connectivity (both dissolved CO2 in the ocean, as well as the attendant ocean passive transport of gametes or early life stages and active acidification (Feely et al., 2004; Fabry et al., 2008; NRC, movements of older individuals) are needed to identify the 2010d). Lower carbonate saturation states are apt to lead to space and time scales of biological and physical processes less calcification, diminishing alkalinity removal from the that link populations and communities, and to identify factors surface ocean into the deep ocean. Over thousands of years, that enhance or limit gene flow and dispersal. lower carbonate saturation will lessen the sedimentation of Community response to disturbance is also determined calcium carbonate (CaCO3), altering the carbonate compen- by patterns of species interactions. For example, disturbance sation depth (where dissolution equals supply) and lysocline of corals or other habitat-forming organisms may have a depth (where seafloor carbonate dissolution begins and larger impact on the community than a similar magnitude accelerates as a function of increasing depth). The response of disturbance to other taxa (Sebens, 1994). Similarly, the of biological productivity to the diverse factors affected by removal of important predators in some ecosystems has been ocean acidification is likely to alter the global ocean nutrient shown to significantly alter abundances in different trophic distribution. levels (e.g., their prey, their prey’s prey, other predators Phytoplankton may respond directly to increased dis- of their prey [Wootten, 1994; Estes and Duggins, 1995]). solved CO2 through faster carbon uptake when other factors Ecosystem-based management approaches, such as that are not limiting (Riebesell, 2004). Many phytoplankton and advocated by the NOP (CEQ, 2010), are presently being zooplankton species are sensitive to other chemical changes developed in part to address these issues. associated with decreasing pH (e.g., trace metal speciation Disturbances to species composition and distribution changes, which affects the bioavailability of essential metals include invasive species, which can displace native species, such as iron or zinc, and the toxicity of other elements such as change community structure and food webs, alter funda - copper and arsenic; Shi et al., 2010). However, understanding mental processes such as nutrient cycling and sedimentation, how these complex ecosystems respond to ocean acidifica-

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14 CRITICAL INFRASTRUCTURE FOR OCEAN RESEARCH AND SOCIETAL NEEDS IN 2030 How Do the Distributions and Fluxes of Organic Carbon tion is extremely limited. Laboratory experiments and field Components Evolve in an Altered Ocean? observations suggest that calcifying organisms and commu- nities (e.g., planktonic foraminifera, coral reefs, and oyster Carbon has a vital role for supporting all life on reefs) can be affected by present ocean acidification levels Earth. Dissolved organic carbon (DOC) in the ocean is and will be strongly disturbed by doubled atmospheric CO2 one of the largest pools of fixed carbon on the planet, ap - (e.g., Anthony et al., 2008; De’ath et al., 2009). The impact proximately equal to the amount of CO2 in the atmosphere of these disturbances on community food webs, however, (Hedges, 2002). Fluxes of organic carbon may be expected is unknown. Of particular concern is the ability of corals to to change markedly in a warmer climate (Riebesell et al., respond to increased ocean acidity, because they form habitat 2009). This is of significance because fixed carbon can be for many ecologically and commercially important species converted into sugars during photosynthesis and is then (Hoegh-Guldberg et al., 2007). There are also direct chemical usable by heterotrophs. The amount of carbon residing in responses to ocean acidification. Decreased pH would affect this pool is thought to have changed by two to three orders both organic and inorganic chemical speciation of trace met- of magnitude over geologic times scales (Rothman et al., als that form strong oxyhydroxide complexes such as iron, 2003). In the modern ocean, DOC exported to the ocean aluminum, and thorium, and alter the kinetics of reactions. interior contributes about 20 percent of the global ocean Extreme shifts in pH (comparable to that expected in the biological pump (Hansell and Carlson, 2002). This export 22nd century [Caldeira and Wickett, 2003]) could affect the occurs largely by overturning circulation, which is likely stable redox state by altering the uptake ratios of elements to be altered because of future changes in ocean stratifica - and their subsequent recycling from biological debris. How- tion; the DOC fields and export in a more stratified ocean ever, it has also been suggested that, with the exception of will be considerably different than what is observed today. calcification, other major biogeochemical cycles will not be Much of the DOC in the ocean has resisted qualitative and affected by ocean acidification (Joint et al., 2011). quantitative analysis, as the microbial processes that con - trol its composition and abundance are enigmatic (Hedges How Will Climate Change Influence the Distribution of et al., 2000). Turnover in some components is extremely Chemical Elements? fast, while much of the material has an apparent 14C age of thousands of years (Druffel et al., 1992). Thus, models Climate change is likely to influence the distribution of of global carbon cycling are limited by knowledge of the chemical elements through ocean circulation and temperature, time scales for DOC cycling in the ocean. The processes biogeochemical responses to the physical climate, and altera- that regulate interactions of this material with the microbial tions in weathering and transport of key nutrients. A warmer ecosystem are just beginning to be understood. Emerging climate will tend to stabilize upper ocean stratification, dimin- new analytical tools provide scientists with the capability to ish vertical mixing, and reduce the upward flux of nutrients directly probe composition and rates of change of a broad and productivity (e.g., Reid et al., 2009; Sarmento et al., spectrum of components in the DOC pool (Mopper et al., 2010). However, an altered climate is also likely to affect wind 2007). These capabilities can be linked with environmental patterns and hence the positions and strengths of currents, genomics and studies of protein structure and expression to upwelling zones, and the timing of seasonal transitions; these greatly expand the understanding and predictive capabili - changes are more difficult to predict without very high resolu- ties regarding the vast pool of DOC in a changing climate tion coupled ocean-atmosphere models and data to force and (Kujawinski, 2011). constrain them. All other things staying constant, warmer sur- face water will contain less oxygen, leading to lower oxygen at How Will Ocean Circulation and the Distribution of Heat depth. Reduced oxygen will lead to the expansion of denitri- in the Ocean and Atmosphere Respond to Natural and fication zones and a long-term (thousands of years) reduction Anthropogenic Drivers? in the oceanic nitrate inventory, although this could be offset by high anthropogenic fixed nitrogen emissions (Keeling et The ocean’s capacity to transport, store, and exchange al., 2010). Changes in winds and continental climate could huge amounts of heat with the atmosphere has a profound alter the flux of dust and atmospheric aerosols into the ocean, effect on the climate system—both natural and anthropo- influencing the distribution of high-nutrient, low-chlorophyll genic. Natural climate variability orchestrates large changes regions (Jickells et al., 2005). Additionally, climate-induced in weather and climate over much of the globe on interan- changes in temperature, salinity, and pH will affect mineral nual and longer time scales (Joyce, 2001; Visbeck et al., solubility (e.g., CaCO3) and trace element speciation (Reid 2001; Trenberth et al., 2002; Kerr, 2005). One such example et al., 2009). The effect of climate change and anthropogenic is ENSO, a recurring change in the distribution of heat on emissions in continental settings will alter weathering and the equator that involves weakened upwelling in the eastern transport by rivers, with potentially large consequences for Pacific and attendant warming (Philander, 1990). Impacts the coastal ocean, and in the longer term (many thousands of of ENSO are felt in fisheries off Peru, western U.S. coastal years), for the entire ocean.

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15 MAJOR RESEARCH QUESTIONS IN 2030 How Will Changes at Coastal Boundaries Alter Physical waters, precipitation across North America, hurricanes strik- and Geochemical Processes? ing the southeastern United States, and sometimes in global- scale atmospheric conditions (McPhaden, 1999). Basin-scale Changes in coastal boundaries include both gradual and changes in sea surface temperature (SST) of the subtropical abrupt alterations of the shoreline, wetlands, and seafloor. North Pacific have a dominant mode (the Pacific Decadal Os- These can be natural changes such as erosion or deposition, cillation), with known effects on precipitation (Davis, 1976; subsidence, faulting, and storm or tidal surges, or they can Mantua et al., 1997). Ocean warming due to anthropogenic be consequences of human activities. Anthropogenic changes climate change involves both trapping of heat by green- to coastal boundaries include creation of artificial boundar- house gases and its redistribution. A complete knowledge ies (e.g., breakwaters, jetties), modifications to wetlands of the ocean’s energy balance, as well as the redistribution and rivers (e.g., infilling, channelization, subsidence due to of heat by ocean currents, is fundamental to understanding oil and gas activity, damming and reduced sediment sup- the climate system’s response to natural and anthropogenic ply), and potential impacts from climate change (e.g., sea drivers. The ocean’s boundary currents, especially those on level rise and loss of coastline; e.g., Nicholls and Cazenave, the western sides of basins, are key to poleward heat transport 2010). Physical and geochemical fluxes across the coastal (Bryden and Imawaki, 2001). In turn, it is expected that the boundaries include, but are not limited to, significant air-sea increased heat and freshwater added to the ocean will affect interactions, riverine and groundwater inputs to the ocean, the stratification, currents, and ocean conveyor belt. Future and saltwater intrusion to the coastal zone. These processes research surrounding this question is likely to focus on sus- occur at a wide range of scales, from the submeter scale to tained observations, analysis of changes as they occur, and many kilometers. Included in this range is the submeso - improved modeling for prediction. scale, where variability is spatially intermittent with highly energetic regions depending on proximity of varying water How Will Alterations in the Global Water Cycle Influence masses and currents. Understanding physical processes at the Ocean? the submesoscale promises improved prediction of chemical and biological distribution at coastal boundaries. Meanwhile, Alteration in the global water cycle is a crucial is - time scales for dynamically important coastal processes also sue for civilization. The ocean is the main reservoir of span orders of several magnitudes, from seconds to months free water on the planet, containing 97 percent of Earth’s or even years, and effects can accumulate over time. water (Baumgartner and Reichel, 1975). It accounts for 86 percent of global evaporation and 78 percent of global How Will Coastal Ecosystems and Communities Respond precipitation (Schmitt, 1995, 2008) and is central to regu - to Multiple Stressors? lating the water cycle. Because the vapor pressure of water is an exponentially increasing function of temperature, Coastal regions throughout the nation and world are alterations in the water cycle can be expected and have simultaneously affected by a number of significant stressors. already been documented with climate change (e.g., Curry Human activity (e.g., agriculture, sewage treatment, runoff) et al., 2003; Boyer et al., 2006; Yu, 2007). Water evaporates alters both the concentration and composition of nutrients more readily from a warmer ocean, so an intensification of entering marine systems (Peierls et al., 1991; Howarth et al., the water cycle and changes in the distribution of salinity 1996). Excessive amounts of nitrogen and phosphorus are en- are expected with anthropogenic warming. Cloud-climate tering streams and rivers, eventually reaching estuarine and feedbacks, which will remain a major research challenge, coastal waters and causing eutrophication, which can result are an important element of understanding changes to the in harmful algal blooms and episodes of hypoxia (Anderson global water cycle. Freshening of the high-latitude ocean et al., 2002). Chemical pollutants can severely affect the through increasing input of freshwater from melting will biology of marine organisms. A variety of commercially increase ocean stratification (e.g., Schmitt, 2008), suppress- important species bioaccumulate toxic pollutants, while ing mixing and greatly affecting nutrient supplies and ocean other species’ reproductive traits are impacted by estrogenic ecosystems. Increased stratification could also slow down chemicals from human activity (Morel et al., 1998; Vos et the ocean conveyor belt, which will affect the large-scale al., 2000). Coastal development and recreational activities flux of freshwater, heat, and carbon dioxide in the ocean have led to habitat loss and degradation for many species (e.g., Yashayaev and Clarke, 2008). Ocean salinity feeds including fish, marine mammals, and seabirds, particularly back on the circulation and mixing (Schmitt, 2008) and in coral reef and sea grass communities. Commercial and thus has influence on ecosystems and future climate states. recreational fishing affect coastal ecosystems, both through In addition, distributions of SST are good predictors of the removal of target species and the unintentional bycatch rainfall on land (Schmitt, 2008). Large changes in drought of other organisms (Stevens et al., 2000; Pauly et al., 2002). and flood patterns will affect both ecosystems and societal Marine shipping is introducing many nonnative species to infrastructure. coastal areas (Ruiz et al., 2000). On top of these near-term

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16 CRITICAL INFRASTRUCTURE FOR OCEAN RESEARCH AND SOCIETAL NEEDS IN 2030 ecosystem stressors, communities will also have to respond of how a shifting ocean will affect regional and local marine to potential changes in temperature, acidity, and ultraviolet food webs. exposure due to climate change (Halpern et al., 2008). The cumulative effects of these various stressors will likely affect What Advances Will Be Made in Prediction and Mitigation ecosystems in complex ways that cannot be predicted by sim- of Oil Spills and Industrial Accidents in the Ocean? ply adding the effects of each individual component (Crain et al., 2008). This highlights the importance of efforts that With the future expansion of commercial activities develop ecosystem-based monitoring and management tools in coastal waters and the ocean, ocean sciences must be for marine resources but also shows the inherent challenges prepared to address accidents and spills. The U.S. Coast involved in effectively implementing these tools. Guard’s National Response Center reports that there were over 34,000 spill incidents of all types in 2010.4 Perhaps of greatest concern are oil spills. In the 25-year period of What Are the Critical Interactions Among Ocean, Ice, 1974-1997, there were 742 oil tanker spills worldwide that Land, and Atmosphere in Polar Regions and How Will released more than 1,000 barrels (136 metric tons) of oil They Influence Physical and Biological Changes? each (NRC, 2007b). In U.S. waters more than 70,000 barrels One of the most dramatic signs of rapid change in polar (~9,800 metric tons) of oil or refined petroleum products are regions is the observed decrease in sea ice cover in the Arctic spilled every year on average (NRC, 2003b). In April 2010, Ocean; between 1979 and 2009 the annual minimum extent the explosion and sinking of BP’s Gulf of Mexico Deepwater of Arctic sea ice cover decreased at a rate of ~11 percent per Horizon oil platform resulted in an unprecedented disaster, decade (Stroeve et al., 2008). These changes in the extent with 60,000 barrels (~8,200 metric tons) of oil per day issu- and concentration of sea ice can alter the seasonal distribu- ing from the deepwater well for 87 days (National Commis- tions, geographic ranges, patterns of migration, nutritional sion on the BP Deepwater Horizon Oil Spill and Offshore status, reproductive success, and ultimately the abundance Drilling, 2011). and stock structure of several fish, marine mammals, and sea- Spill responses include deployment of mechanical bird species (e.g., Tynan and DeMaster, 1997). Furthermore, containment and recovery systems (e.g., booms, skimmers) because the albedo (surface reflectivity) of snow and ice is or nonmechanical methods (e.g., surface burning, oil dis- several times that of ocean water, loss of sea ice increases persants). Dispersants act to reduce break up and dilute the the amount of solar radiation that is absorbed by the Arctic oil by mixing it into the ocean. The biological and physical Ocean, warming the surface waters and creating a positive processes that determine the ultimate fate of dispersed oil, feedback cycle that causes even more sea ice to melt and and its potential toxicity to the marine environment, are thus amplifying warming trends. Along the West Antarctic poorly understood (National Commission on the BP Deep- Peninsula, midwinter surface atmospheric temperatures have water Horizon Oil Spill and Offshore Drilling, 2011). Of increased by 6°C (5.4 times the global average) during the particular concern is the fate of dispersed oil in areas with past half century, 87 percent of the glaciers are in retreat, and high suspended solids, as it is unknown how chemically the concentration of winter sea ice has decreased (Ducklow dispersed oil interacts with suspended sediments, over both et al., 2007, and references therein). Heat from the ocean is short and long terms, compared to naturally dispersed oil implicated as a major driver for the deglaciation, as increased (NRC, 2005). supply of heat associated with Upper Circumpolar Deep Wa- The danger of possible oil spills in the Arctic will be an ter flux is believed to be associated with strengthening winds issue of future interest. Decreasing Arctic sea ice (Stroeve over the Southern Ocean. The increased heat is itself partly et al., 2008) as a result of climate change will attract greater a consequence of anthropogenic activity (greenhouse gas amounts of commercial shipping and oil and gas exploration. emissions and/or ozone depletion). Atmosphere-ocean-ice An Arctic oil spill is likely to be much more difficult to con- interplay at the West Antarctic Peninsula results in a positive tain than in other regions: spills in or under ice-covered areas feedback that amplifies and sustains atmospheric warming. would be harder to track, would require different techniques Rapid climate changes in polar regions are triggering than those in open water, and harsh, remote conditions would pronounced shifts and reorganizations in regional ecosys- increase the difficulty of getting spill recovery assets in place. tems and biogeochemical cycles (Moline et al., 2008). While A related issue is the existence of more than 8,500 sunk- large ecosystem changes have been detected (e.g., shifts from en vessels worldwide (Michel et al., 2005), three-quarters marine mammal to pelagic fish [Grebmeier et al., 2006]), of which date back to World War II (Hamer, 2010). These linking shifts in the physical system to biological changes shipwrecks could harbor between 2.5 and 20 million tons remains difficult; however, overcoming this gap is a critical of oil (Michel et al., 2005), as well as hazardous chemicals step in establishing any level of predictive skill (Schofield and munitions. The lower estimate of oil contained within et al., 2010a). The complexity of marine ecosystems, com- bined with chronic undersampling, limits the understanding 4 http://www.nrc.uscg.mil/incident_type_2000up.html (accessed October 2010).

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17 MAJOR RESEARCH QUESTIONS IN 2030 reduce phosphorus and decrease seasonal eutrophication these shipwrecks is at least twice as much as the Deepwater (Stigebrandt and Gustafsson, 2007). Horizon spill (Hamer, 2010). PROTECTING LIFE AND PROPERTY What Are the Potential Impacts on the Ocean from Geoengineering? The protection of life and property is a compelling societal objective. The research that supports this objective Geoengineering can be classified as deliberate actions continues to focus on predicting and mitigating natural haz- that modify environmental processes in order to mitigate ards associated with the solid earth (e.g., earthquakes and other environmental impacts that result from human activi - volcanoes) and weather (e.g., severe storms and drought). ties (The Royal Society, 2009) and are generally considered In addition, several new areas have become more prominent global in scope (NRC, 1992). Many projects presently either because of recent catastrophic events (e.g., tsunamis) being discussed focus on storing CO2 in the ocean, either or growing concerns related to climate change and variability by (1) pumping liquid CO2 into the deep ocean or into the (e.g., sea level rise and ocean acidification). The predic- subseafloor, (2) enhancing weathering reactions of CO2 tion and mitigation of adverse human health outcomes has with carbonate or silicate minerals and storing the products emerged as a major area of research related to climate change in the ocean, or (3) accelerating natural mechanisms of science. Societal concerns, combined with the potential ocean carbon uptake by seeding the ocean with nutrients, for significant advancement in prediction and mitigation, thus removing CO2 from the atmosphere. Direct injection are likely to drive interest in these six research areas well of CO2 into the deep ocean will decrease acidification of beyond 2030. surface waters but will exacerbate the problem at depth as a result of CO2 leaks or natural seepage back to the ocean floor (Caldeira and Wicket, 2003; Blackford et al., How Does Strain Accumulate in Underwater Volcanoes 2009). Early experiments on deep sea communities suggest and Offshore Fault Zones and What Is Needed for Better that they may be more sensitive to changes in pH due to Forecasting of Major Events? increased CO2 than shallow water communities (Barry et The effects of offshore earthquakes can be monumental, al., 2004). In addition, elevated dissolved CO2 concentra- whether direct (e.g., ground shaking and rupture) or indirect tions may impose a physiological strain on marine animals, (e.g., triggering a tsunami). Many of the largest earthquakes especially in hypoxic regions, which are likely to expand in the world occur offshore.5 In the United States, major off- as the ocean absorbs anthropogenic CO2 or it is injected shore seismic hazards span the west coast from California to into the ocean as part of geoengineering projects (Peltzer Alaska, including the offshore component of the San Andreas and Brewer, 2008; Brewer and Peltzer, 2009). Enhanced Fault as well as the Cascadia and Alaska subduction zones. weathering reactions avoid the major pH changes (and Although paleoearthquake data can constrain occurrence ensuing acidification) associated with storing CO 2 directly intervals, earthquakes still cannot be predicted. In the next in the ocean, but are potentially expensive and require two decades, there is likely to be progress on this front, as extensive mining of source materials (The Royal Society, earthquake early warning methods that detect the beginning 2009). Perhaps the most discussed nutrient addition project of a large fault rupture based on initial portions of the primary is iron fertilization (Cullen and Boyd, 2008), which follows (compressional) waves have recently been developed (Allen the principle that growth rates and biomass accumulation et al., 2009, and references therein). This allows for a warn- by phytoplankton are limited by the availability of iron in ing to be issued before the arrival of larger, more damaging as much as 40 percent of the world ocean (Moore et al., secondary (shear) waves. As observations that are collected 2002). If iron could be added to these deficient areas (via close to earthquake epicenters provide extra information ship or other platform), it would increase plankton growth that can strengthen early event warning systems (McGuire, rates and perhaps increase removal of carbon dioxide from 2008; Yamada and Mori, 2009), instrumenting offshore the atmosphere (Coale et al., 1996). These types of experi - seismic hazards could improve prediction and detection of ments would result in a deliberate modification of marine potentially damaging offshore earthquakes. ecosystems, which could shift many open ocean areas The majority of seafloor volcanism occurs along the from a low-biomass, low-primary productivity condition global mid-ocean ridge spreading network, within ocean to moderate productivity (similar to the coastal ocean). It island arc environments, and at hot spots. Shallow, large is difficult to predict the impacts of this activity with cer- volcanoes common in arc, back-arc, and hotspot environ - tainty, but concerns have been raised about the formation ments can present significant environmental hazards. One of low-oxygen areas and harmful plankton blooms (Cullen historic example of this was the 1883 Krakatou eruption and Boyd, 2008) and the potential limited impact of fixing in Indonesia, which changed global climate through its carbon in the deep ocean (e.g., de Baar et al., 2005). Other geoengineering projects at more modest scales have also been discussed, such as reoxygenation of the Baltic Sea to 5 http://earthquake.usgs.gov/earthquakes/eqarchives/year/byyear.php.

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18 CRITICAL INFRASTRUCTURE FOR OCEAN RESEARCH AND SOCIETAL NEEDS IN 2030 How Can Understanding and Prediction of the Path and eruption of ash and gases (The Krakatoa Committee of Intensity of Severe Storms Be Improved? the Royal Society, 1888; Self and Rampino, 1981) and led to a tsunami that killed 36,000 people living around Hurricanes and other severe weather events have the the Sunda Strait (Kious and Tilling, 1996). Understanding largest economic impact of any natural hazards (Kunkel et of how strain accumulates in the seafloor, the spatial and al., 1999). Prediction of hurricane and tropical storm paths temporal evolution of crustal movement, and the migration has improved; however, progress is still needed in the predic- and release of magma and volatile elements is critical to tion of the intensity of such severe weather (NRC, 2010f). developing predictive models of volcanic eruptions, and While climate variability and change may influence severe possibly lessening their impacts. weather, this remains an area of active research (Bader et al., 2008; NRC, 2010b). According to the IPCC’s Fourth Assess- How Can Understanding and Prediction of Tsunamis Be ment Report (Pauchiri and Reisinger, 2007), it is more likely Improved? than not that there is a human contribution to the observed trend of hurricane intensification since the 1970s. Although Tsunamis can result from earthquakes, submarine and there is increasing certainty of the link between climate aerial landslides, volcanic eruptions, and in rare instances change and more intense hurricanes and tropical storms, meteorite impacts that rapidly displace large volumes of the effects of climate change on their frequency remains water in the ocean. Generally, damaging tsunamis are caused unclear (Bender et al., 2010; Knutson et al., 2010). ENSO by earthquakes greater than magnitude 7 (NRC, 2011b). events in the Pacific, which occur every 4-7 years, tend However, catastrophic submarine landslides caused both by to suppress hurricane activity in the Atlantic, particularly volcanic eruptions, large-scale collapse of volcanic islands, inhibiting the formation of major hurricanes (Category 3 earthquakes, or other slope instabilities can also lead to or higher). Climate change also has potential to impact the tsunami generation; historic mega-tsunamis reaching 365 m distribution, frequency, and intensity of other forms of severe above sea level have been related to flank collapse (Moore weather (e.g., coastal flooding), with great impacts on coastal et al., 1989, 1994; Clague et al., 2002; McMurtry et al., populations. Increased storm frequency and severity will also 2004; Pérez-Torrado et al., 2006). Tsunami waves can be increase risks to all maritime operations. Ports, ships, and centimeters to tens of meters tall, last over a period of several offshore structure (e.g., oil platforms and wind farms) will hours, and cause flooding of low-lying areas, greatly affect- need to be designed and engineered to withstand extreme ing coastal communities. The December 2004 Sumatran conditions and to ensure crew safety and environmental earthquake and resulting tsunami fundamentally changed protection. As demonstrated by the 2005 devastation of the the global perception of tsunami threat, with the loss of Gulf Coast by Hurricane Katrina, especially in the context more than 200,000 lives and billions of dollars in property of a changing climate, hurricane prediction and mitigation of damage (Schiermeier and Witze, 2009). The ability to predict impacts will remain a top priority for ocean and atmospheric the initiation of tsunami waves remains as elusive as the science. ability to predict earthquakes and landslides; however, once a tsunami-generating event has occurred, the arrival time of How Will the Extent and Characteristics of Sea Ice and the first waves can be predicted for a given site within a few Icebergs Change in the Future and How Can the Impacts minutes. This is the same timeframe in which a “near-field” of Sea Ice Change Be Mitigated? tsunami (one that originates near an at-risk community) can occur. Tsunami models have also performed reasonably well Sea ice collisions create pressure ridges that rise several in forecasting tsunami wave heights since the installation meters above sea level and descend tens of meters below of an open ocean sea level observing network; however, the air-sea interface (Williams et al., 1975; Wadhams and near real time wave height forecasts are only available with Horne, 1980; Wadhams, 1988), posing a collision hazard to considerable delay on the order of a fraction of an hour or ships transporting personnel and materials within the Arctic more (NRC, 2011b). While efforts to create a global warn- and Southern oceans, as well as the North Atlantic, Bering ing system and educate at-risk communities have expanded Sea, and Great Lakes. Climate change has led to significant significantly since the 2004 tsunami, the next two decades thinning of ice shelves at both poles (Pritchard et al., 2009), are likely to see increased population growth and property causing ice shelf collapse in both the Antarctic (Scambos development along the coast. Maintaining the tsunami warn- et al., 2009) and Arctic (Copland et al., 2007) that release ing systems, and educating this population about high-risk, hazardous chunks of ice into the Southern and Arctic oceans. low-probability events like tsunamis will remain a challenge Declining sea ice cover, as noted in the Arctic (NOAA Arctic (NRC, 2011b). Report Card, 2010) also has implications for sea level rise (Shepherd et al., 2010). Since 1979, satellites have moni- tored the changing extent of ice in and around the polar seas (Zwally et al., 2002; Stroeve et al., 2007, and references

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19 MAJOR RESEARCH QUESTIONS IN 2030 therein), but cloud cover limits the ability of satellites to al., 1991). For example, ENSO significantly increases the precisely map the distribution of sea ice and icebergs, and flood frequency for coastal California (Andrews et al., 2004), existing models cannot accurately predict where ice will be while other regions are affected by more severe droughts found. In addition to posing collision hazards, large icebergs (Philander, 1990). Changes in these precipitation patterns have grounded in the shoals off McMurdo Station (Robinson have been linked to epidemics of malaria on the Indian et al., 2010), hampering efforts to resupply that important subcontinent and South America (Bouma and van der Kaay, Antarctic scientific station. Along the Arctic and sub-Arctic 1996; Bouma and Dye, 1997). In East Africa, Rift Valley Fever6 (a viral zoonosis) epidemics have coincided with coastlines, the reduced span of shore-fast ice leads to greater exposure to storm surges; as a result, many shorelines are unusually high rainfall associated with ENSO-related Pacific eroding rapidly with attendant loss of societal infrastructure and Indian Ocean SST anomalies (Linthicum et al., 1999). to the native communities that live there (ACIA, 2004). In and around the Arctic Ocean, climate-related changes are having diverse effects on human populations and their physical and physiological well-being. Arctic environmental What Is the Role of Coastal Pollutants and Pathogens on change has already adversely affected critical ecosystems Human and Ecosystem Health? that many native communities are dependent on for their Humans are significantly altering the coastal environ- livelihoods. The decreasing time available to use shore-fast ment, with many actions that have potential to negatively ice as a platform (Druckenmiller et al., 2009) in combina- affect human health. There is a growing need to identify the tion with a general decrease in sea ice extent (Stroeve et al., source, transport, fate, and impact of chemicals in common 2007) has resulted in shorter seasons for subsistence hunters use by industry, agriculture, and households that are eventu - to find bears, walruses, and seals, which are staples of many ally discharged into coastal waters. Anthropogenic activity indigenous diets (ACIA, 2004). The net result of these fac- has changed the concentration and composition of nutrients tors, in combination with other societal forcing functions, entering marine systems (Peierls et al., 1991; Howarth et al., is a migration of some indigenous populations out of Arctic 1996), leading to degraded coastal water quality. Increased communities. Beyond these examples of direct effects, indi- nutrients lead to greater growth of phytoplankton and mac- rect impacts such as changes in ecosystem health or sea level roalgal biomass, which heightens turbidity, depletes oxygen, are discussed throughout this chapter. decreases marine biodiversity, and alters ecosystem structure and function (NRC, 2000a; USCOP, 2004). This has been PROMOTING SUSTAINABLE ECONOMIC VITALITY linked to increased frequency and intensity of harmful algal The United States, with over 12,000 miles of coastline,7 blooms around the world (Hallagraeff, 1993; Pearl, 1997; Anderson et al., 2002; Babin et al., 2008). Harmful algal has strong economic ties to the ocean. Traditional uses, such blooms can lead to devastating fish and mammal kills, and as oil and gas extraction, fisheries, and recreation, are still can sicken and even kill humans (Anderson, 1994; Glibert large components of the ocean economy. Other activities, et al., 2005). Another form of pollution, sewage discharge in including aquaculture, wind power, and marine hydrokinetic coastal waters, can lead to increased levels of pathogens and resources, are likely to become much more important in the viruses, which can be unsafe both for human exposure and next two decades. Scientific research that identifies oceanic for a variety of marine life (e.g., Goyal et al., 1984; Lipp et resources in the broader context of impacts that might be al., 2001). The production and use of traditional (e.g., PCBs incurred through utilization will promote this societal objec- [polychlorinated biphenyls], heavy metals) and emerging tive. Sustainability of these resources for future generations contaminants is also likely to continue into the future. Many is of great importance, as is minimizing adverse impacts on emerging contaminants, including compounds such as flame the marine environment. The next three questions examine retardants, insect repellents, pharmaceuticals (e.g., steroids, these important future issues. hormones, antibiotics, analgesics), and domestic waste (e.g., detergents, fragrances, caffeine) persist in the environment, How Can Humanity Ensure Sustainable Food Production in accumulate in tissues, and can be toxic to humans and aquatic the Ocean? life. Others interfere with hormone systems governing re- production and growth (Morel et al., 1998; Vos et al., 2000). The ocean and inland waters provide about 20 percent of the protein supply for a growing human population (UNFAO, 2009). Overexploitation of fisheries stocks and How Do Changes in the Coupled Ocean-Climate System unsustainable fishing practices have created significant Affect Human Health and Welfare? threats to marine biodiversity (Myers and Worm, 2003; Broad-scale shifts in the ocean-climate system are Pauly et al., 2003; Worm et al., 2006, 2009) and to food likely to affect human health patterns. ENSO is associated with changes in precipitation patterns across the globe with 6 http://www.who.int/mediacentre/factsheets/fs207/en/. major implications for human health and welfare (Glantz et 7 http://shoreline.noaa.gov/_pdf/Coastline_of_the_US_1975.pdf.

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20 CRITICAL INFRASTRUCTURE FOR OCEAN RESEARCH AND SOCIETAL NEEDS IN 2030 security in some parts of the world. Global wild fishery percent of national oil production and 11 percent of natural gas production in 2009.8 In recent years, there has been catches leveled off in the 1980s (Pauly et al., 2002) and some experts fear large-scale extinctions of commercially increasing oil production in deep waters (greater than 1,000 important species (Dulvy et al., 2003). Since the 1980s, per- ft), especially in the Gulf of Mexico (USCOP, 2004). The person seafood production has kept pace with population scope of energy extraction is likely to continue to incorporate growth only because of the growth of aquaculture produc - deeper waters, as well as smaller reservoirs and additional, tion. Even with better management of wild fish stocks, alternative sources. aquaculture is expected to play an increasingly important One such source is methane hydrate, an ice-like sub- role in future global seafood supply (UNFAO, 2009). Both stance formed from a combination of gas and water at high wild capture fisheries and aquaculture production have the pressures and low temperatures. Burning methane produces potential to create significant impacts on ocean systems. less carbon dioxide than other fossil fuel combustion, and its Trawling and other benthic fisheries can severely impact abundance in U.S. continental margins and permafrost could communities through the destruction of seafloor habitat provide greater energy security for the United States (NRC, (Thrush and Dayton, 2002). Overfishing of predatory spe - 2004a, 2010e). Although most methane hydrate is found at cies can fundamentally alter food webs, which has the low concentrations and is not currently economically viable, potential both to impede recovery efforts for the stocks more concentrated methane hydrate accumulations (found and to lead to jellyfish blooms that further affect fisheries in deepwater marine and Arctic sands [Boswell and Collett, (Scheffer et al., 2005; Purcell et al., 2007). Characteristics 2006]) could be likely targets for a future economic resource. of deep sea fish (e.g., slow growth rates and maturation, However, potential degassing of methane hydrate at atmo- long life, and low birth rates [Devine et al., 2006]) make spheric conditions is a technical challenge for recovery and them susceptible to overfishing, although the full impacts could affect the global carbon cycle. of removing these deep-sea species from the food web are There is also international interest in mining seafloor mas- not yet well known (Koslow et al., 2000). Aquaculture is sive sulfide deposits that contain economically valuable miner- responsible for the introduction of a variety of nonnative als (Hoagland et al., 2010). In some cases, such as oil and gas species, and the animal waste products from some opera - production, resource utilization in the ocean is driven by the tions are a significant source of water pollution (Wu, 1995; difficulty of satisfying demand with economically accessible Ruiz et al., 2000). In addition, many aquaculture programs terrestrial resources. involve the farming of carnivorous species that rely on fishmeal and fish oil (NRC, 2011a), increasing total fishing What Is the Ocean’s Potential as a Source of Renewable pressure in other fisheries (Naylor et al., 2000). Research Energy? into potential methods for sustainably managing fisheries, such as monitoring the status of fish stocks and their role Commercial activity in the ocean is growing and may in ecosystems, creating accurate catch limits, and establish- possibly become an important part of the U.S. energy portfo- ing marine protected areas, will be critical to ensure future lio, especially the unique opportunities to harness renewable food production from the ocean. Equally important is the energy. These include installations of wind farms in coastal goal of maintaining ocean biodiversity, which may be dif - environments, development of marine hydrokinetic power ficult to achieve while also maximizing fisheries (Brander, (from waves, tides, ocean currents, and ocean thermal gradi- 2010). Management strategies that enable both sustainable ents), and siting of solar collectors on a large scale. Renew- fisheries and biodiversity conservation are needed and able energy activities, like offshore wind farms and marine will require improved environmental and fisheries data re - hydrokinetic systems, exploit unique properties of the ocean; sources and substantially better modeling capabilities. The in this case, higher wind speeds that occur over the ocean use of ocean space for farming finfish, shellfish, and algae as compared to land or strong wave energy or tidal currents (Goldburg et al., 2001; NRC, 2010c) will also need to be at certain locations (e.g., Bay of Fundy, Hudson River). In balanced against competing energy, national security, and each case, the economic viability of these sources will be recreational needs. enhanced by matching optimal environmental conditions with appropriate energy infrastructure design. Each of these uses will have some associated environmental and societal How Can Humanity Maximize Energy and Mineral impacts in addition to their significant economic value: Resource Extraction, While Minimizing Adverse habitat disturbance or destruction, injury or fatalities for Environmental Impacts? birds and marine organisms, aesthetic concerns, and changes For the foreseeable future, traditional oil and natural gas to indigenous cultures. Comprehensive coastal and marine extraction will continue to fill a significant proportion of U.S. spatial planning (such as that outlined in the NOP [CEQ, energy needs (e.g., Musial and Butterfield, 2004; Greene et 2010]) will be needed to manage these and other compet- al., 2007). The U.S. outer continental shelf is a major focal point for energy industries, accounting for an estimated 30 8 http://www.boemre.gov/stats/PDFs/OCSProductionTemplate2009.pdf.

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21 MAJOR RESEARCH QUESTIONS IN 2030 ing activities in the ocean. The optimization of renewable rently understood why Earth has plates or what the relation- energy production while minimizing impact represents an ships might be between plate tectonics and Earth’s abundant important, emerging area of research. water, continents, and life. Further study of Earth’s interior can help determine what the surface environment was like in the past and predict what it might become in the future. INCREASING FUNDAMENTAL SCIENTIFIC UNDERSTANDING What Are the Plausible Rates and Magnitudes of Climate Beyond their societal objectives, investigating the sci- Change? ence research questions posed in the previous sections will, in turn, contribute to increases in fundamental understanding Earth history contains a rich and diverse record of of the ocean and its relationship to the Earth system. Funda- climate change, operating across a broad spectrum of time mental research, even if not directly applicable to a problem scales (Ruddiman, 2010). Given the evidence for significant of societal relevance, has considerable merit in its own right. anthropogenic influence on the climate system, better un- It has a long history of producing discoveries that advance derstanding of the rates at which climate changes and the scientific understanding, many of which eventually lead to climate system’s sensitivity to various factors have become an increased ability for stewardship of the environment, extraordinarily important to society. For example, sea level protection of life and property, and promotion of sustainable was more than 120 m lower than present at the peak of the economic vitality. An essential component is understanding- last glacial period about 20,000 years ago (Church et al., driven research, which provides a foundation to increase 2008), then rose between 19,000 and 7,000 years ago (Lam- current knowledge of the ocean in order to improve predic- beck and Chappell, 2001). From approximately 2,000 years tive capability. There is also a compelling need for human ago to about 1900, sea level changed very little (Lambeck exploration, both to understand how Earth functions and to et al., 2004), but anthropogenic increases of greenhouse unravel the many remaining mysteries on the nature of physi- gas concentrations are now causing sea level rise. The rate cal, biological, chemical, and geological processes that occur and magnitude of future climate change is closely tied to and interact. These 10 fundamental questions range widely the expected impacts both on human and natural systems, in scope and scale, from entire Earth system processes to and many of the changes may be largely irreversible within individual organisms. millennial time scales (Solomon et al., 2009). Therefore, an increasing ability to predict future climate change and to better understand uncertainties in climate prediction is also How Does Earth’s Interior Work, and How Does It an urgent societal need. Clarifying possible rates of climate Affect Plate Boundaries, Hotspots, and Other Surface change is critical to understanding potential resiliency of Manifestations? global marine ecosystems. High-resolution oceanic and ter- Understanding of Earth’s interior is critical to a range of restrial paleoclimate records help assess rates and magnitude societal issues, including earthquake detection and hazard as- of past climate change in the context of Earth’s surface, sessment; the development of volcano and tsunami warning atmospheric composition, and variations in solar input, and systems; the role and effect of fluids in Earth’s crust; energy may provide analogues for predicted future change. At the and mineral resource exploration; and even nuclear test same time, describing changes in the modern climate system, monitoring and treaty verification (Forsyth et al., 2009). The while focusing on areas of greatest uncertainty in current past four decades of geophysical research have established climate processes, is likely to improve predictive skill and that heat from Earth’s deep interior powers convection in its increase understanding of complex interplay of processes liquid outer core, generating a planetary magnetic field, and within the climate system. that heat in the solid mantle drives plate tectonics. Mantle convection also regulates the chemical composition of the How Can the Effects of Ocean and Atmosphere surface layers, drives the exchange of materials between Interactions be Better Parameterized? the planetary surface and its deep interior, and produces chemical fluxes into the ocean and atmosphere. Although it Interactions between the ocean and atmosphere are is known that the mantle and core are in constant convective complex and multilayered: the atmosphere imparts momen- motion, their motion can neither be precisely described nor tum to the ocean; precipitation and evaporation affect ocean confidently calculated with respect to past differences (NRC, salinity; heat and gas exchange between the atmosphere 2001, 2008b). Patterns of convection are poorly understood, and ocean; dust containing nutrients and toxins is deposited although there may be internal boundaries resulting from from the atmosphere to the ocean; cloud condensation nuclei chemical differentiation within the mantle, with mineralogi- are injected into the atmosphere from the ocean; sunlight is cal phase changes controlled by pressure and temperature attenuated by the atmosphere and infrared radiation emit- (Forsyth et al., 2009). Finally, although plate tectonic theory ted from the ocean is trapped by the atmosphere. These explains many surface features of the planet, it is not cur- interactions directly and indirectly affect physical, chemical,

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22 CRITICAL INFRASTRUCTURE FOR OCEAN RESEARCH AND SOCIETAL NEEDS IN 2030 and biological processes in the ocean. The atmosphere is is concentrated in space and time, as at ocean fronts or under driven by SST, so knowledge of the upper ocean is needed storms. The study and prediction of such events is an ongoing for prediction of climate and weather, including improved research question. hurricane prediction. Ocean circulation is largely driven by winds, so accurate knowledge of wind stress is essential to How Does Fluid Circulation Within the Ocean Crust the specification and prediction of currents at all scales. In Impact Chemistry and Biology of the Subseafloor and the addition, wind-driven ocean waves modulate fluxes of many Hydrosphere? properties (e.g., gas exchange). All of these fluxes are essen- tially turbulent, requiring parameterization to relate them on The oceanic crust is the largest fractured aquifer system larger-scale, easier-to-measure quantities, and to be repre- on the planet. Fluid circulation through the crust and over- sented in models. Ocean-atmosphere interactions also drive lying sediments generates enormous chemical fluxes in the the coupled biogeochemical system. In polar regions, sea ice ocean, profoundly alters the composition of basement rock, acts as a porous layer between the ocean and atmosphere, as and supports a potentially vast subseafloor biosphere (Fisher, well as a source of gas fluxes, even in winter. The surface 2005; Fisher and Wheat, 2010). Hydrothermal flow sig- ocean microlayer regulates particle and gas exchange into nificantly influences the thermal, mechanical, and chemical the overlying atmosphere. Both the microlayer and seawater state of subducting tectonic plates, impacting seismicity and below it produce and concentrate organic compounds that volcanism (e.g., Gill, 1981; Peacock and Wang, 1999). High- are potentially ejected into the air; however, limited mea- temperature hydrothermal fluids are produced at mid-ocean surements of the resulting aerosols’ organic compositions ridge vent systems, but low-temperature fluid circulation constrain current understanding and modeling. occurs in approximately half of the seafloor crust (Parsons and Sclater, 1977; Fisher and Von Herzen, 2005), accounting for two to three orders of magnitude more seawater circula- What Processes Dominate Mixing in the Ocean and on tion than the mid-ocean ridge (Davis and Elderfield, 2004). What Space and Time Scales? Off-axis fluids within the seafloor can be transported laterally Observation, theoretical understanding, and parameter- tens of kilometers (Fisher et al., 2003), which has implica- ization of mixing are essential to climate prediction. The tions for microbial connectivity and movement in the sub- ocean is a global turbulent fluid, with length scales ranging seafloor. Despite its importance for global-scale processes in from ocean basins to molecules and time scales from sec- the ocean, the subsurface fluid flow system is undersampled onds to centuries or longer. All of these scales interact, so and its biogeochemical impacts are not yet well resolved. that mixing processes occurring at small scales end up af- fecting global circulation. However, mixing processes must How Does the Deep Ocean Biosphere Inform the Origin be parameterized in ocean climate models, as they occur at and Evolution of Life? scales too small to be directly simulated, given the resolution of present-day models. The ocean is also a highly anisotropic Ocean sciences will continue to play a leading role in fluid, with vertical gradients much stronger than horizontal understanding the fundamental, unresolved questions of gradients. Maintenance of the vertical stratification requires how Earth’s life began and has evolved over time. The late- mixing to balance the upwelling that occurs through the deep 1970s discovery of submarine hydrothermal vents fueled by ocean (Munk, 1966). Ocean observations of turbulent mixing undersea volcanoes (Spiess et al., 1980) led to the hypothesis have established that there is relatively small diffusivity in that life may have originated in these hot spring systems the interior ocean (Gregg, 1989), while substantial mixing is (Corliss et al., 1981). Since that time, more than 200 active found in surface and bottom boundary layers and in regions vent systems have been discovered, and studies of these en- of flow over rough topography (Davis et al., 1981; Polzin et vironments have profoundly changed thinking on where and al., 1997; Sanford and Lien, 1999). Sources of energy for under what conditions life exists on Earth (e.g., Wilcock et mixing are dominated by the wind and the tide. Tidal mix- al., 2004; Kelley et al., 2005; Martin et al., 2008). The field ing has received a great deal of attention because the time of astrobiology uses limits from vent environments (e.g., scale is predictable and amenable to observation (Rudnick temperature, pressure, salinity) to guide the search for life et al., 2003). Wind is an important energy source (Wunsch on other planets (Woodruff and Baross, 2007). It also uses and Ferrari, 2004), whether it occurs directly through the advancements in molecular sciences and in experimental surface mixed layer or indirectly through mesoscale eddies analyses focused on abiotic synthesis of organic compounds, spun off of major ocean currents. The study and parameter- which have driven new hypotheses about the conditions ization of horizontal stirring of the ocean, the submesoscale necessary for life and its evolution (e.g., Shock et al., 1990; (scales of kilometers), and subgridscale processes for ocean Cody et al., 2004). Beyond the vents, the most extensive models (Fox-Kemper and Ferrari, 2008) are central to cli- populations of microscopic life may exist in vast, largely mate predication and likely to remain important. One of the unexplored areas of oceanic crust and sediment away from properties of turbulence is intermittence, so that variability active mid-ocean ridge systems. Using ocean drilling core

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23 MAJOR RESEARCH QUESTIONS IN 2030 samples, microbial activity has been documented at depths abyssopelagic (4,000 to 7,000 m) zones (Robison, 2004, of over 500 m beneath the seafloor (Parkes et al., 1994), 2009; Heino et al., 2010; Wiebe et al., 2010). This lack of and the total amount of carbon associated with subseafloor knowledge is even more notable since the bathypelagic zone bacteria and archaea exceeds that of any other ecosystem on accounts for 60 percent of the ocean’s volume, making it Earth (Gold, 1992; Whitman et al., 1998). Genetic and func- the largest marine habitat on Earth. Comprehensive under- tional diversity of the deep ocean biosphere, conditions under standing of deep-sea biodiversity has eluded oceanographers which organisms can live and thrive, and their contributions because of the fragility, rarity, small size, and/or systematic to oceanic carbon and other biogeochemical cycles are just complexity of many taxa, as well as the difficulty in sampling beginning to be explored. the more mobile larger invertebrates and fish (Sutton et al., 2008, 2010). For many groups, there are long-standing and unresolved questions of species identification, systematic What Regulates the Diversity and Rates of Molecular and relationships, genetic diversity and structure, and biogeog- Biochemical Evolution in the Ocean? raphy (e.g., G. Johnson et al., 2009). The past two decades have revealed staggering mo- The global geographic scale of the investigations lecular, biochemical, and species diversity in the ocean, r equired to address these issues, as well as the three- a complexity that is reshaping views of the structure of dimensional complexity of the world ocean, make complete oceanic food webs (e.g., Delong and Karl, 2005). Studies knowledge of marine deep-sea biodiversity and ecosystem in the 1970s underestimated the number of microorganisms dynamics challenging. New technologies and advanced sen- by three orders of magnitude; marine viruses (arguably the sors will play a significant role in developing fundamental most abundant and diverse form of life on Earth) were only knowledge about deep-sea ecosystems. However, physical appreciated in the 1980s (e.g., Fuhrman, 1999). The Census access to remote regions of the ocean and the deep-sea inte- of Marine Life,9 which operated from 2000 to 2010, detected rior will still be required to discover and observe the organ- numerous new megafauna species, and mass sequencing of isms living in these areas, and to understand their interactions microbes in the oligotrophic Sargasso Sea revealed more and dynamics. than a million protein-encoding genes and discovered a large number of new genes (Venter et al., 2004). Despite this What Are the Modes and Roles of Sensory Systems and progress, existing biodiversity has still not been quantified Intra- and Interspecies Communication in Structuring nor have robust abundance estimates been achieved, and it Marine Ecosystems? is not well understood how physical, chemical, and biologi- cal factors maintain diversity. Interpreting microorganism Marine organisms have extraordinary abilities to sense complexity is further complicated by potentially high rates of and respond to their surroundings and, in many cases, to lateral gene transfer and mutation, which suggest high rates actively communicate within or between species. These of molecular evolution in the ocean (Frigaard et al., 2006; sensory processes underlie many observed spatial and tem- Oliver et al., 2008). How this molecular evolution translates poral patterns that cannot be explained by ocean physics or into the innovation of new species and biochemical pathways chemistry. Basic sensory systems used to perceive environ- is an open question. Oceanographers are drawing upon rapid mental conditions and communicate within and between advances in technology from the medical sciences to perform species include vision (e.g., light vs. dark, complex colors, techniques such as genome sequencing, quantification of patterns, shapes, movements), hearing (acoustic signals of protein structure and expression, and metabolite analysis in varying wavelength and sound patterns), chemosensory order to address marine problems. It is anticipated that the (waterborne “smell,” surface-bound “taste” compounds), resulting data sets will help scientists more accurately study and somatosensory (e.g., physical contact, temperature, body the evolution, biochemistry, physiology, and diversity of position, pain). These mediate all fundamental biological and marine organisms. ecological processes, spanning from reproduction to habitat selection and predator-prey interactions. For example, sea anemones perceive chemical signals from other anemones What Is the Biodiversity of the Deep-Sea Pelagic that have been wounded by predators and respond with a Ecosystem? characteristic defensive contraction (Howe and Sheikh, Understanding ocean ecosystem dynamics and pre- 1975); packs of dolphins utilize sonar to coordinate swim- dicting changes over time requires knowledge of species ming behavior, aggregating prey in small spatial zones to diversity, distribution, and abundance throughout the ocean minimize grazing effort (Benoit-Bird et al., 2004); and bio- (Pereira et al., 2010). Although species living in the ocean’s luminescence in the deep ocean has been hypothesized to upper reaches are relatively well known, far less can be said help increase reproductive success and/or provide protection about species in the bathypelagic (1,000 to 4,000 m) and against predators (e.g., Haddock et al., 2010). Communica- tion is also found commonly in microbial systems, where quorum-sensing bacteria produce and release chemical- 9 http://www.coml.org/.

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24 CRITICAL INFRASTRUCTURE FOR OCEAN RESEARCH AND SOCIETAL NEEDS IN 2030 signal molecules that increase in concentration as a function services provided by nature that are essential for human of cell density to stimulate gene expression of neighboring sustainability (Costanza et al., 1997). These fall into three bacteria. Communication can regulate a diverse array of categories: renewable natural capital (e.g., species, ecosys- physiological activities (e.g., symbiosis, virulence, compe- tems), replenishable natural capital (e.g., oxygenated air, tence, conjugation, antibiotic production, motility, sporula- freshwater), and nonrenewable natural capital (e.g., fossil tion, biofilm formation; Miller and Bassler, 2001). Because fuels, minerals; Rees, 1996). The current human population these sensory mediated processes are central to evolutionary is living beyond sustainable means provided by renewable life histories, population dynamics, and community ecology, and replenishable natural capital and is sustainable only by a more complete understanding will be central to predicting use of nonrenewable resources (Daily and Ehrlich, 1992). marine organisms’ responses to various ocean environmen- For example, industrialized fisheries, which are calculated tal changes in the future and for developing sustainable to dramatically reduce community biomass in less than two ecosystem-based management strategies. decades (Myers and Worm, 2003), represent a domain in which carrying capacity issues are already clear and may turn some renewable resources into nonrenewable capital. How Does the Ocean Contribute to Earth’s Carrying Nutrient pollution related to terrestrial agriculture and ocean Capacity? aquaculture also affects carrying capacity, because they are Earth’s carrying capacity, or maximum number of implicated in the development of oxygen minimum zones organisms that can be supported without undergoing envi- and hypoxia (e.g., Turner and Rabalais, 1994; Diaz and ronmental degradation,10 is dynamic and ultimately finite. Rosenberg, 2008) and raise concerns about coastal pollution With a human population that is projected to exceed 9 bil- (e.g., Costa-Pierce, 1996), respectively. Oil and gas produc- lion by 2050 (UN, 2009), people have become the dominant tion and mineral extraction, other nonrenewable resources consumer of most of the world’s major ecosystems (Rees, on time scales of human development, can have significant 2003). However, the human population needs more than impacts on the ocean environment. More research is needed ecosystem products; there are many ecological goods and into the ocean’s contributions to human carrying capacity, especially with regards to oxygen production, climate mod- eration, carbon removal from the atmosphere, and production 10 An alternate definition is “the amount of use an area, resource, facility, of food and mineral resources. or system can sustain without deterioration in quality (NRC, 2002).