Majority Statement

• Maria Cantwell

  Senator
  Read statement

  Majority Statement

  Maria Cantwell

  I’d like to welcome you all to this important hearing on the impacts of climate change and ocean acidification on living marine resources.  

   

  Today we are fortunate to have with us many of the top experts in the fields of ocean and climate science.  I’d like to thank each of you for being here; I look forward to hearing your testimony.

   

  Carbon Dioxide Emissions

  Since the start of the Industrial Revolution 200 years ago, humans have released over 1.5 trillion tons of carbon dioxide into the atmosphere.  Only now are we beginning to understand the implications of this.

   

  When scientists first started raising questions about our carbon dioxide emissions in the 1950s, very little was known about the possible consequences. 

  Some predicted that the carbon dioxide would accumulate in the atmosphere.  Others predicted that it would be absorbed by the world’s oceans. 

   

  Today, we know that both of those predictions were correct.

   

  Human-caused emissions have increased the global atmospheric carbon dioxide concentration by 35%.  In addition, over half a trillion tons of carbon dioxide have been absorbed by our oceans. 

   

  We’re already seeing the impacts of this on our ocean and coastal ecosystems.  If we continue with “business as usual,” the ecological, social, and economic consequences are likely to be severe.

   

  Carbon Dioxide in the Atmosphere: Global Warming

  After extensive scientific research, climate scientists now know that global warming is happening.  And it is happening because of human use of fossil fuels.

   

  We are seeing more results of global warming every day:

  ·        Year after year, our polar ice caps are receding

  ·        Glaciers are shrinking rapidly and even disappearing

  ·        Permafrost is melting

  ·        And to give one example from my home state, the Intergovernmental Panel on Climate Change recently reported that the mountain snowpack that feeds the Columbia River system is shrinking away, producing less and less water for the rivers every year. 

   

  While these easy-to-see impacts of global warming are highly disturbing, we are here today to examine impacts that are not quite as visible, but just as severe – those that occur beneath the surface of the ocean. 

   

  The impact of climate change on our coastal communities from sea level rise and increased storm intensity has been the focus of much attention. 

   

  But climate change also poses risks to our nation’s multi-billion dollar fishing industry. 

  In fact, global warming could threaten the very integrity of ocean ecosystems and possibly wipe out more vulnerable ecosystems like coral reefs. 

   

  These are frightening possibilities – but very real ones.  While it may not be easy to physically see the impacts of global warming in the ocean, it is vital that we examine them.  If we wait until these problems are too painful and too obvious to ignore, it will be far too late.

   

  Carbon Dioxide in the Oceans: Ocean Acidification

  While carbon dioxide is accumulating in our atmosphere, it is also being absorbed by our oceans. 

   

  Approximately one-third of our carbon dioxide emissions end up in the oceans.  For decades, we assumed that the oceans absorbed these greenhouse gases to the benefit of our atmosphere with no side-effect for the seas.

   

  Emerging science now shows we were wrong.

   

  Thanks in no small part to the work of our panelists, we now know that the absorption of carbon dioxide actually changes the very chemistry of the ocean:

   

  ·        Seawater becomes more acidic, and begins to withhold the basic chemical building blocks needed by many marine organisms. 

   

  ·        Coral reefs – the rainforests of the sea – cannot build their skeletons. 

   

  ·        In colder waters, scientists predict a more acidic ocean could dissolve the shells of the tiny organisms that make up the base of the ocean’s food chain.      

   

  When it comes to ocean acidification, we risk not just damaging the ocean’s ecosystem – we are threatening its very foundation. 

   

  The social and economic costs to the world’s fisheries and fishery-dependant communities are incalculable.   

   

  Managers at the local, state, and regional levels must be able to anticipate and develop strategies to address these threats.

   

  Washington State

  The dangers of global climate change and ocean acidification can be illustrated well with one brief example from my home state of Washington.

   

  As most of you probably know, Washington State is home to a number of important salmon populations.  Salmon are a $330 million industry in the Pacific, and a cultural icon of the Northwest. 

   

  As I mentioned earlier, global warming will continue to reduce the snowpack that feeds our rivers.  With each coming season there will be less water, and the water will probably get warmer. 

   

  Salmon rely on predictable and steady river flows for their survival.

   

  In the sea, young salmon depend on a food chain based on zooplankton.  As ocean acidification takes hold, these organisms may no longer be able to survive. 

   

  Conclusion

  Every coastal state can point to examples like this of the impacts of climate change on our ocean. And these examples are far too important to be ignored.

   

  Both global warming and ocean acidification have the same cause and the same solution: we must reduce our emissions of carbon dioxide. 

   

  If we fail to address the potential impact of global climate change and ocean acidification, we may be jeopardizing all of our hard-fought ocean conservation gains.

   

  Those are difficult words to hear, but they reflect a difficult reality. 

   

  Thank you all again for joining us today and for your hard work advancing this complicated, but necessary dialogue. 

   

  I look forward to your testimony.

                                                                                                                                       

  Senator Snowe, your opening remarks?

   

  ###

Minority Statement

• Ted Stevens

  Senator
  Read statement

  Minority Statement

  Ted Stevens

  To maintain sustainable fisheries, it’s important that we understand how changes to the ocean’s environment affects fish stocks.

   

  Much of the focus on Capitol Hill and in the media has centered on how climate change will affect life on land through higher temperatures, storms, and sea levels.  What many don’t realize is that the oceans may change as well, and if the predictions are accurate, these changes could have economic consequences.

   

  Warm ocean temperatures are causing widespread coral bleaching in the Caribbean.  In Alaska, some species are moving north.  There is concern on how these changes will affect our fisheries.

   

  However, we know very little about these changes.  We do not know how much of this change is due to natural variations and how much is manmade.  For example, in Alaska our fisheries have been impacted in the past due to natural variations in ocean temperature caused by Pacific decadal oscillation shifts in ocean currents.  Some fisheries in Alaska have flourished due to warmer temperatures while others have seen temporary declines.

   

  Today, we have several panelists who are concerned that the chemistry of sea water is changing and becoming more acidic.  This could have severe consequences for marine life and fisheries worldwide.  I hope our panelists can help the Committee identify the current gaps in knowledge.  We need to make sure the Federal agencies have their resources in the right places to study ocean acidification and climate change.

   

  I would also like to thank our panelist and, in particular, Dr. Gordon Kruse, who has traveled all the way from Juneau, Alaska to participate in today’s hearing.  Dr. Kruse has studied fisheries in Alaska for decades, most recently serving as chair of the Scientific and Statistical Committee of the North Pacific Fishery Management Council.  Their committee plays a vital role in what the Pew Commission has stated is “the best managed fishery in the world.”

   

  I also want to welcome Admiral Watkins.  It is always a pleasure to hear his thoughts on ocean policy.

   

  I look forward to the testimony, thank you very much.

• Olympia J. Snowe

  Senator
  Read statement

  Minority Statement

  Olympia J. Snowe

  Thank you, Madam Chair, for calling this critical hearing to discuss how climate change may affect the future of our oceans and their living marine resources.  I am pleased that this committee is so actively investigating the burgeoning issue of ocean acidification–a topic that in just a few short years has developed from a relatively unknown theory into what is potentially one of the most disconcerting aspects of ocean-related climate science.

              Lost in much of the discussion of climate change has been its potential impacts on the oceans’ corals, fish, and other species.  Recent research– much of it conducted by members of our esteemed panel of witnesses–has indicated that as a direct result of the precipitous increase in carbon dioxide in our atmosphere, our oceans are warming and becoming more acidic.  If we continue to allow emissions of carbon dioxide to increase, we could see drastic, worldwide impacts in our oceans, from species migration and coral bleaching to widespread extinctions.

              The oceans drive much of our Nation’s economy, as well as that of my home state of Maine.  Throughout our state’s history, stewardship of our marine resources has pervaded our maritime activities.  Nowhere is this more evident than in our lobster fishery, which for generations has engaged in self-imposed, sustainable fishing practices.  The result of that stewardship is a robust industry that landed over 270 million dollars worth of lobster in 2006.  Today, that fishery faces potential danger.  Not from the activities of our lobstermen, but from the potential effects of global climate change.

              In 1999, the lobstermen of Long Island Sound began pulling up pots full of dead lobster.  According to a study by Connecticut’s Sea Grant program, that fall, commercial landings from western Long Island Sound plummeted an astounding 99 percent from the previous year.  Nearly three-quarters of the Sound’s lobstermen lost all of their income that.  The study concluded that, quote “the physiology of the lobsters was severely stressed by sustained, hostile environmental conditions, driven by above average water temperatures,” endquote.  In other words, warming ocean temperatures created conditions that killed these lobsters and decimated the fishery. 

              The lobster industry’s collapse in Long Island Sound may be a harbinger for other fisheries.  Evidence is mounting that anthropogenic emissions of greenhouse gasses–carbon dioxide in particular–are disrupting the forces that drive our climate and in turn, our oceans.  Approximately a third to a half of global manmade carbon dioxide emissions have already been absorbed into the world’s oceans.  This amount will double by 2050, and all indications are that this will increase the acidity of the oceans’ surface and could initiate the largest change in pH to occur in as many as 200 million years.  Clearly, the consequences of such a shift could be catastrophic.  Which is why my colleague Senator Kerry and I introduced S. 485, the Global Warming Reduction Act of 2007.  This legislation is the only introduced climate bill that specifically calls for research to address the vulnerability of marine organisms throughout the food chain to increased carbon dioxide emissions.  It also requires an assessment of probability that such a change will cost us more than 40 percent of our coral reefs–delicate ecosystems that are especially vulnerable to both ocean acidification and warming.

              And coral reefs are just as integral to the economy and heritage of tropical states such as Florida and Hawaii as fisheries are to Maine.  In order to protect these resources, we must understand what is happening to them.  The final report of the U.S. Commission on Ocean Policy, chaired by Admiral Watkins who is testifying before us today, calls for development and implementation of a sustained integrated ocean observing system to provide the data necessary to understand the complex oceanic and atmospheric systems– including pH, temperature, salinity and the speed and direction of currents– that comprise our oceans.  I know the scientists here today also support that initiative, and I support it as well. 

              In each of the past two Congresses, I have introduced a bill to authorize an integrated ocean observing system and develop a National framework to oversee and our numerous, successful, independent regional observing systems.  Twice this bill has passed the Senate unanimously, but failed to pass the House.  I have introduced a new version of this bill–the Coastal and Ocean Observation Systems Act of 2007, S. 950– in the 110^th Congress, with sixteen bi-partisan co-sponsors, and I am working closely with members from both chambers to ensure that this bill becomes law as soon as possible.

              Mounting evidence linking carbon emissions to potentially devastating changes in the hydrology of our oceans compels us to act now to protect the future of the irreplaceable resources found beneath the waves.  I will continue to do everything in my power to provide our scientists with the requisite tools to carry our their research and ensure that we prevent further damage to these vital ecosystems.  I thank Doctors Feely, Conover, Doney, Kruse, and Hansen and Admiral Watkins for taking the time to engage in what I believe will be a fruitful and fascinating discussion, and I look forward to hearing all of your testimony.

              Thank you, Madam Chair.

Testimony

• Dr. Scott Doney

  Senior Scientist

  Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institute
  Read statement

  Testimony

  Dr. Scott Doney

  WRITTEN TESTIMONY OF

  SCOTT C. DONEY, Ph.D.

  WOODS HOLE OCEANOGRAPHIC INSTITUTION[1]

   

  HEARING ON

  Effects of Climate Change and Ocean Acidification on Living Marine Resources

   

  BEFORE THE

  COMMITTEE ON COMMERCE, SCIENCE AND TRANSPORTATION

  SUBCOMMITTEE ON OCEANS, ATMOSPHERE,

  FISHERIES AND COAST GUARD

  UNITED STATES SENATE

   

  MAY 10, 2007

   

   

  Introduction

  Good morning Madame Chair, Ranking Member Snowe and members of the Subcommittee.  Thank you for giving me the opportunity to speak with you today on global climate change, ocean acidification and the resulting impacts on fisheries and living marine resources.  My name is Scott Doney, and I am a Senior Scientist at the Woods Hole Oceanographic Institution in Woods Hole MA.  My research focuses on interactions among climate, the ocean and global carbon cycles, and marine ecosystems. I have published more than 90 peer-reviewed scientific journal articles and book chapters on these and related subjects.  I serve on the U.S.  Carbon Cycle Science Program Scientific Steering Group and the U.S. Community Climate System Model Scientific Steering Committee, and I am chair of the U.S. Ocean Carbon and Climate Change Scientific Steering Group and the U.S. Ocean Carbon and Biogeochemistry Scientific Steering Committee. 

   

  For today’s hearing, you have asked me to discuss the mechanisms by which greenhouse gases impact the ocean, coastal environment, and living marine resources, gaps in our current scientific understanding, and implications for resource management including adaptation and mitigation strategies. My comments are based on a broad scientific consensus as represented in the current scientific literature and in community assessments such as the 2007 Intergovernmental Panel on Climate Change (IPCC) reports (IPCC, 2007a; 2007b; 2007c).

   

  Over the past two centuries, human activities have resulted in dramatic increases in atmospheric carbon dioxide and other greenhouse gases. There is broad scientific consensus that these excess greenhouse gases are altering our planet’s climate and acidifying the ocean. These findings are confirmed by real-world observations and supported by theory and numerical models.  Climate change and acidification trends will accelerate over the next several decades unless there is deliberate action to curb greenhouse emissions. Rising atmospheric carbon dioxide and climate change produce upper-ocean warming, sea-ice retreat, sea-level rise, ocean acidification, altered freshwater distributions, and maybe even stronger storms.

   

  Growing evidence suggests that these human-driven climate change and acidification will strongly impact ocean ecosystems as well. Further pressure will be put on living marine resources, such as fisheries and coral reefs that we depend upon for food, tourism and other economic and aesthetic benefits. We have an opportunity now to limit the negative impact of climate change and acidification in the future. This will require a comprehensive ocean management strategy that incorporates scientific understanding of climate change and acidification from the start. This strategy will also require a balance between adaptation to climate change and acidification that are unavoidable, and mitigation to reduce the rise in greenhouse gases and resulting impacts.

   

  Greenhouse Gases and Climate Change

  At the most basic level, the balance between incoming sunlight and outgoing infrared radiation (i.e., heat) determines Earth’s climate. The greenhouse gas carbon dioxide (CO₂) plays a key role by absorbing infrared radiation and thus trapping heat near the Earth’s surface much like a blanket. Other trace greenhouse gases such as methane (CH₄), nitrous oxide (N₂O), and chlorofluorocarbons (CFCs) are also important to warming, equivalent to about half of that from carbon dioxide, because molecule for molecule they absorb more infrared radiation than carbon dioxide. Other factors involved in human-driven climate change include aerosols and land vegetation.

   

  Over the last two centuries, atmospheric carbon dioxide has increased by more than 30%, from 280 to 380 ppm (part per million) by 2007. The main source is fossil-fuel combustion with contributions from cement production, agriculture and deforestation. Many economic and climate models predict atmospheric carbon dioxide values as high as 700 to 1000 ppm, about triple preindustrial levels, by the end of the twenty-first century. The Earth has not experienced carbon dioxide levels that high for the past several million years. Other trace greenhouse gas levels are growing as well due to land-use, agriculture and industrial practices. These greenhouse gases persist in the atmosphere for years to decades, meaning that they will remain and accumulate in the atmosphere, impacting the global climate for a long time to come. In contrast, aerosols in the lower atmosphere are removed on time-scales of a few days to weeks, and their climatic impacts, mostly cooling, are concentrated near their sources.

   

  Greenhouse gases dominate over other human-driven climate perturbations, and the increased heating translates into changes in climate properties such as surface temperature, rainfall, sea-level and storm frequency and strength. The climate change resulting from an increase in greenhouse gases can be amplified by other climate processes. For example, ocean warming leads to a large retreat in Arctic sea-ice, which further strengthens warming because the dark water surface can then absorb more sunlight than the highly reflective ice. The largest unknowns at present arise from cloud dynamics. Numerical model climate projections for this century show global mean surface temperature increasing, with a range of +1.1 to 6.4°C (+2.0 to 11.5°F) above late 20^th century levels. This large temperature range is somewhat misleading as a significant fraction of the variation depends on human behavior, specifically how much carbon dioxide and other gases we emit to the atmosphere in the future. The lowest temperature projections occur only when emissions are reduced sharply over the next few decades.

   

  The largest projected temperature changes are concentrated over the continents and at higher latitudes during the winter season, but some level of warming will occur globally, over the ocean, and year-round. Sea-level is estimated to rise due to thermal warming and melting glaciers and ice sheets by an additional +0.18 to 0.59 m (+0.6 to 1.9 feet) by 2100. Many simulations suggest a general strengthening of the water cycle, with increased precipitation in the tropics and high latitudes, drier conditions in the subtropics, and an increased frequency of extreme droughts and floods. Other common features of a warmer climate are more El Niño-like conditions in the Equatorial Pacific, a melt back of polar sea-ice and glaciers, and a slowdown in the formation of ocean deep water at high latitudes.

   

  The Changing Ocean Environment

  Global warming should be called ocean warming, as more than 80% of the added heat resides in the ocean. Clear alterations to the ocean have already been detected from observations. The magnitude and patterns of these changes are consistent with an attribution to human activities and not explained by natural variability alone. Global average land and ocean surface temperatures increased at a rate of about 0.2°C/decade over the last few decades (Hansen et al., 2006), and ocean temperatures down to 3000 m (10,000 feet) depth are also on the rise. Averages rates of sea-level rise over the last several decades were 1.8±0.5 mm/y, with an even larger rate (3.1±0.7 mm/y) over the most recent decade. Higher precipitation rates are observed at mid to high latitude and lower rates in the tropics and subtropics. Corresponding changes have been measured in surface water salinities. One of the most striking trends is the decline in Arctic sea-ice extent, particularly over the summer. September Arctic ice-cover from 2002-2006 was 18% lower than pre-1980 ice-cover (http://www.arctic.noaa.gov/detect/ice-seaice.shtml), and some models predict near ice-free conditions by 2040. Recent studies of the Greenland ice sheet highlight an alarming increase in surface melting over the summer, and percolation of that melt water to the base of the ice sheet where the melt-water could lubricate ice flow and potentially greatly accelerate ice loss and sea-level rise. These new findings have not been full incorporated into projected sea-level rise estimates, which thus may be underestimated.

   

  Over half of human carbon dioxide emissions to the atmosphere are absorbed by the ocean and land biospheres (Sarmiento and Gruber, 2002), and the excess carbon absorbed by the ocean results in increased ocean acidity. The physical and chemical mechanisms by which this occurs are well understood. Once carbon dioxide enters the ocean, it combines with water to form carbonic acid and a series of acid–base products, resulting in a lowering of pH values. The amount and distribution of human-generated carbon in the oceans are well determined from an international ocean survey conducted in the late 1980s and early 1990s (Sabine et al., 2004). The rate of ocean carbon uptake is controlled by ocean circulation. Most of the excess carbon is found in the upper few hundred meters of the ocean (upper 1200 feet) and in high-latitude regions, where cold dense waters sink into the deep ocean. Surface water pH values have already dropped by about 0.1 pH units from preindustrial levels and are expected to drop by an additional 0.14-0.35 units by the end of the 21st century (Orr et al., 2005).

   

  Climate Change and Ocean Acidification Impacts on Marine Ecosystems

  Climate change and ocean acidification will exacerbate other human influences on fisheries and marine ecosystems such as over-fishing, habitat destruction, pollution, excess nutrients, and invasive species. Thermal effects arise both directly, via effects of elevated temperature and lower pH on individual organisms, and indirectly via changes to the ecosystems on which they depend for food and habitat. Acidification harms shell-forming plants and animals including surface and deep-water corals, many plankton, pteropods (marine snails), mollusks (clams, oysters), and lobsters (Orr et al., 2005). Many of these organisms provide critical habitat and/or food sources for other organisms. Emerging evidence suggests that larval and juvenile fish may also be susceptible to pH changes. Marine life has survived large climate and acidification variations in the past, but the projected rates of climate change and ocean acidification over the next century are much faster than experienced by the planet in the past except for rare, catastrophic events in the geological record.

   

  One concern is that climate change will alter the rates and patterns of ocean productivity. Small, photosynthetic phytoplankton grow in the well-illuminated upper ocean, forming the base of the marine food web, supporting the fish stocks we harvest, and underlying the biogeochemical cycling of carbon and many other key elements in the sea. Phytoplankton growth depends upon temperature and the availability of light and nutrients, including nitrogen, phosphorus, silicon and iron. Most of the nutrient supply to the surface ocean comes from the mixing and upwelling of cold, nutrient rich water from below. An exception is iron, which has an important additional source from mineral dust swept off the desert regions of the continents and transported off-shore from coastal ocean sediments. The geographic distribution of phytoplankton and biological productivity is determined largely by ocean circulation and upwelling, with the highest levels found along the Equator, in temperate and polar latitudes and along the western boundaries of continents.

   

  Key climate-plankton linkages arise through changes in nutrient supply and ocean mixed layer depths, which affect the light availability to surface phytoplankton. In the tropics and mid-latitudes, there is limited vertical mixing because the water column is stabilized by thermal stratification; i.e., light, warm waters overlie dense, cold waters. In these areas, surface nutrients are typically low, which directly limits phytoplankton growth. Climate warming will likely further inhibit mixing, reducing the upward nutrient supply and thus lowering biological productivity. The nutrient-driven productivity declines even with warmer temperatures, which promote faster growth. At higher latitudes, phytoplankton often have access to abundant nutrients but are limited by a lack of sunlight. In these areas, warming and reduced mixed layer depths can increase productivity.

   

  A synthesis of climate-change simulations shows broad patterns with declining low-latitude productivity, somewhat elevated high-latitude productivity, and pole-ward migration of marine ecosystem boundaries as the oceans warm; simulated global productivity increased by up to 8.0% (Sarmiento et al., 2004). While not definitive proof of future trends, similar relationships of ocean stratification and productivity have been observed in year to year variability of satellite ocean color data, a proxy for surface phytoplankton (Beherenfeld et al., 2006); satellite data for 1997-2005 from GeoEYE and NASA’s Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) show that phytoplankton declined in the tropics and subtropics during warm phases of the El Niño-Southern Oscillation (ENSO) marked by higher sea surface temperatures and ocean stratification. Ecosystem dynamics are complex and non-linear, however, and new and unexpected phenomena may arise as the planet enters a new warmer and unexplored climate state. Ocean nitrogen fixation, for example, is concentrated in warm, nutrient poor surface waters, and it may increase under future more stratified conditions, enhancing overall productivity.

   

  Changes in total biological productivity are only part of the story, as most human fisheries exploit particular marine species, not overall productivity. The distributions and population sizes of individual species are more sensitive to warming and altered ocean circulation than total productivity. Temperature effects arise through altered organism physiology and ecological changes in food supplies and predators. Warming and shifts in seasonal temperature patterns will disrupt predator-prey interactions; this is especially important for survival of juvenile fish, which often hatch at a particular time of year and depend up on immediate, abundant source of prey. Temperature changes will also alter the spread of diseases and parasites in both natural ecosystems and marine aquaculture. Warming impacts will interact and perhaps exacerbate other problems including over-fishing and habitat destruction.

   

  Food-web interactions are often complicated, and we should expect that some species will suffer under climate change while others will benefit. Broadly speaking though, warm-water species are expected to shift poleward, which already appears to be occurring in some fisheries (Brander, 2006). Biological transitions, however, may be abrupt rather than smooth. Large-scale regime shifts have been observed in response to past natural variability. Regime shifts involve wholesale reorganizations of biological food-webs and can have large consequences from plankton to fish, marine mammals and sea-birds. Thus, rather subtle climate changes or ocean acidification may have the potential to disrupt commercially important species for either fisheries or tourism. Decadal time-scale regime shifts have been documented in the North Pacific, and in the Southern Ocean observations show a large-scale replacement of krill, a food source for mammals and penguin, by gelatinous zooplankton called salps.

   

  A number of other factors also need to be considered. Species that spend part of their life-cycle in coastal waters will be impacted by degradation of near-shore nursery environments, such as mangrove forests, marshes and estuaries, because of sea-level rise, pollution and habitat destruction. Rainfall and river flow perturbations will alter coastal freshwater currents, affecting the transport of eggs and larvae. Some of the largest fisheries around the world, for example off Peru and west coast of Africa, occur because of wind-driven coastal upwelling, which may be sensitive to climate change. Warming will reduce gas solubility and thus increases the likelihood of low oxygen or anoxia events already seen in some estuaries and coastal regions, such as off the Mississippi river in the Gulf of Mexico.

   

  Knowledge Gaps and Ocean Research Priorities

  Accurate projections of climate change and ocean acidification impacts on living marine resources hinge on several key questions: 1) how will greenhouse gas and aerosol emissions and atmospheric composition evolve in the future? 2) how sensitive are regional-scale ocean physics and chemistry to these changes in atmospheric composition? and 3) how will individual species and whole-ocean ecosystems respond? Fossil fuels are deeply intertwined in the modern global economy, and carbon dioxide emissions depend upon changing social and economic factors that are not well known: global population, per capita energy use, technological development, national and international policy decisions, and deliberate climate mitigation efforts. Future projections of atmospheric carbon dioxide levels are also relatively sensitive to assumptions about the behavior of land and ocean carbon sinks, which are expected to change due to saturation effects and responses to the modified physical climate (Fung et al., 2005). Climate change on local and regional scales is more relevant for people and ecosystems than global trends. While progress is being made, improved and better-validated regional ocean climate forecasts remain a major need for future research.

   

  Even when predictions about the physical environment are well known, significant knowledge gaps exist about ocean ecology, hindering the creation of the skillful forecasts needed to guide ocean management decisions. While not precluding taking action now to address climate change and ocean acidification, better scientific understanding will help refine ocean management in the long-term. Several elements need to be pursued in parallel: improved on-going monitoring of ocean climate and biological trends; laboratory and field process studies to quantify biological climate sensitivities; historical and paleoclimate studies of past climate events; and incorporation of the resulting scientific insights into an improved hierarchy of numerical ocean models from species to ecosystems.

   

  Rapid advances in in-situ sensors and autonomous platforms, such as moorings, floats and gliders, are revolutionizing ocean measurements, and ocean observing networks are being constructed for coastal and open ocean regions (e.g., Gulf of Maine Ocean Observing System http://www.gomoos.org/; Pacific Coast Ocean Observing System http://www.pacoos.org/; National Science Foundation Ocean Observing Initiative http://www.ooi.org). The number of historical, multi-decadal ocean time series is limited, but their scientific utility is almost unrivalled. Federal commitment is needed for continued, long-term investment in ocean monitoring and enhanced coordination across observing networks.

   

  In a similar vein, satellite measurements provide an unprecedented view of the temporal variations in ocean climate and ecology. The ocean is vast, and the limited number of research ships move at about the speed of a bicycle, too slow to map the ocean routinely on ocean basin to global scales. By contrast, a satellite can observe the entire globe, at least the cloud free areas, in a few days. The detection of gradual climate-change trends is challenging, and the on-going availability of high-quality, climate data records is not assured during the transition of many satellite ocean measurements from NASA research to the NOAA/DOD operational NPOESS program. For example, the present NASA satellite ocean color sensors, needed to determine ocean plankton, are nearing the end of their service life, and the replacement sensors on NPOESS may not be adequate for the climate community. Further, refocusing of NASA priorities away from earth science may dramatically limit or full preclude new ocean satellite missions need to characterize ocean climate and biological dynamics.  

   

  We need to know if there are climatic tipping points or thresholds beyond which climate change may induce rapid and dramatic regime shifts in ocean ecosystems. Many current scientific studies examine climate sensitivities of species in isolation; the next step involves examining responses of species populations, communities of multiple interacting species, and entire ecosystems to realistic size perturbations. Experiments on plankton and benthic communities can be conducted under relatively controlled conditions in mesocosms (large enclosed volumes such as aquarium or floating bags deployed at sea) or by deliberate open-water perturbations studies. Both approaches will benefit from further directed technological developments. Larger mobile species require different approaches such as using past climate events as analogues for human-driven climate change. Biology models are pivotal to ocean management. They are being improved progressively by incorporating new information from laboratory and field experiments and by comparing model forecasts with real-world data. It is often as important to identify where the models do poorly as where they do well because research can then be focused on resolving these model errors.

   

  Climate Adaptation, Mitigation, and Ocean Management

  Given the potential for significant negative impacts of climate change and ocean acidification on living marine resources, we need to develop comprehensive local, national and international ocean management strategies that fully incorporate climate change and acidification trends and uncertainties. The strategies should follow a precautionary approach that accounts for the fact that ocean biological thresholds are unknown. The strategies should include improved scientific information for decision support, adaptation to reduce negative climate change and acidification impacts, and mitigation to decrease the magnitude of future climate change and acidification.

   

   Currently the United States and other countries invest significant resources in monitoring the ocean and improving scientific understanding on many of the physical, chemical and biological processes relevant to climate change and acidification. However, this wealth of data and information is typically not in a form that is easily accessible by ocean resource managers and other stakeholders, ranging from private citizens and small-businesses to large corporations, NGOs and national governments. For example, even state-of-the-art climate projections typically resolve climate patterns at relatively coarse spatial resolutions and include either relatively simple ocean biology or no ocean biology at all. In contrast, decision makers need information tailored to specific local fisheries and ecosystems. The national climate modeling centers should be encouraged to create on a routine basis targeted ocean biological-physical forecasts on seasonal to decadal time-scales, building on nested regional models, probabilistic and ensemble modeling of uncertainties, and downscaling methods developed for related applications (e.g., agriculture, water-resources). The utility of such forecasts and their uncertainties will be maximized if stakeholders are involved in their design from the onset and if the model results are translated into more accessible electronic forms that are widely distributed to the public.

   

  A second challenge is to create more adaptive ocean management strategies that emphasize complete and transparent discussion on the risks and uncertainties from climate change and ocean acidification. Some amount of climate change and acidification is unavoidable because of past greenhouse emissions, and even under relatively optimistic scenarios for the future, substantial further ocean impacts should be expected at least through mid-century and beyond. Decisions will need to be made in the face of uncertainty, relying on for example the precautionary principle to limit future risk. Climate change trends are growing in magnitude, but will still be gradual compared with natural interannual variability; management policies must include both types of variations and uncertainties. Empirical approaches developed from historical data cannot be used in isolation because climate change will shift the baseline for ocean biological systems. Serious efforts should be directed at reducing other human factors such as overfishing and habitat destruction to allow more time ecosystems and social systems to adapt. Mechanisms such as marine reserves, that protect specified geographical locations, need to account for the fact that ecosystem boundaries will shift under climate change. Procedures also need to be in place to monitor over time the effectiveness of ocean conservation and management policies, and that information and improved future climate forecasts should be used to modify and adapt management approaches. 

   

              The third challenge is to pursue climate mitigation approaches that limit the emissions of carbon dioxide and other greenhouse gases to the atmosphere or that remove fossil-fuel carbon dioxide that is already in the atmosphere. Stabilizing future atmospheric carbon dioxide at moderate levels to minimize climate change impacts will require a mix of approaches, and no single mechanism will solve the entire problem. Emissions of carbon dioxide can be reduced through energy conservation and transition to alternative, non-fossil fuel based energy sources (wind, solar, nuclear, biofuels). Attention also needs to be placed in the near-term on limiting other greenhouse gases such as chlorofluorocarbons, which may provide additional time to tackle the more challenging issues associated with carbon. Progress is being made on approaches that would remove carbon dioxide at power plants so that it can be sequestered in subsurface geological reservoirs (e.g., old oil and gas fields, salt domes).

   

  Mitigation approaches have also been proposed using ocean biology, but these methods should only be pursued if critical questions are resolved on their effectiveness and environmental consequences. Biological mitigation strategies are based on the fact that plants and some marine microbes naturally convert carbon dioxide into organic matter during photosynthesis. Enhancing biological carbon removal can reduce atmospheric carbon dioxide if the additional organic matter is stored away from the atmosphere for multiple decades to a century or longer. The deep-ocean is one such reservoir because it exchanges only slowly with the surface and atmosphere. Thus one potential mitigation method would be to fertilize the surface ocean phytoplankton so that they produce and export more organic carbon into the deep ocean. In many areas of the ocean, phytoplankton grow is limited by the trace element iron, which is very low in surface waters away from continents and dust sources. About a dozen scientific experiments have been conducted successfully showing that adding iron to the surface ocean causes a phytoplankton bloom and temporary drawdown in surface water carbon dioxide. But there remain outstanding scientific questions about whether iron resulted in any enhanced long-term carbon storage in the ocean.

   

  As with any other mitigation approach on land or in the sea, the scientific and policy communities need to work closely to assure that the following questions are answered for large-scale commercial ocean fertilization. Is the method effective in removing carbon from the atmosphere, can the removal be validated, and how long will it remain sequestered? Could the method result in unintended consequences such as enhanced emissions of other, more powerful greenhouse gases (in the case of iron fertilization potentially nitrous oxide and perhaps methane)? What are the broad ecological consequences, and could carbon mitigation efforts conflict with maintaining living marine resources and fisheries? Systematic approaches to verify effectiveness and environmental impacts need to be put in place to assure a level playing field for commercial mitigation and carbon credit trading systems.

   

  Conclusions

  Over the past two centuries, human activities have resulted in the build up in the atmosphere of excess carbon dioxide, other greenhouse gases and aerosols. There is now significant evidence that these changes in atmospheric composition are altering the planet’s climate. Human-driven climate change is expected to accelerate over the next several decades, leading to extensive global warming, sea-ice retreat, sea-level rise, ocean acidification, and alterations in the freshwater cycle. As the reality of climate change is becoming clearer, the emphasis shifts toward understanding the impact of these climate perturbations on society and on natural and managed ecosystems.

   

  Marine fisheries and ocean ecosystems are susceptible to global warming and ocean acidification. While ocean biological responses will vary from region to region, some broad trends can be identified including poleward shifts in warm-water species and reduced formation of calcium carbonate by corals and other shell-forming plants and animals. For fisheries, climate change impacts will interact and perhaps exacerbate other problems including over-fishing and habitat destruction. Management strategies are needed balancing adaptation to an evolving climate and mitigation to reduce the magnitude of future climate change and atmospheric carbon dioxide growth. Decision support tools should be developed for marine resource managers that incorporate the emerging scientific understanding on climate change, focusing on impacts over the next several decades. Systematic testing is required on the effectiveness and environmental consequences of climate mitigation approaches, such as deliberate iron fertilization, designed to sequester additional carbon in the ocean.

   

  Thank you for giving me this opportunity to address this Subcommittee, and I look forward to answering your questions.

   

  Selected References

  Brander, K. (2006) Assessment of Possible Impacts of Climate Change on Fisheries. Externe Expertise für das WBGU-Sondergutachten “Die Zukunft der Meere--zu warm, zu hoch, zu sauer”, Berlin WBGU, 27pp.

   

  Fung, I., S.C. Doney, K. Lindsay, and J. John, 2005: Evolution of carbon sinks in a changing climate, Proc. Nat. Acad. Sci. (USA), 102, 11201-11206, doi:10.1073/pnas.0504949102.

   

  Hansen, J., M. Sato, R. Ruedy, K. Lo, D.W. Lea, and M. Medina-Elizade, 2006: Global temperature change, Proc. Nat. Acad. Sci. USA, 103, 14288-14293, 10.1073/pnas.0606291103.

   

  IPCC, (2007a) The Physical Science Basis, Summary for Policymakers, Contributions of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, 18pp., (http://www.ipcc.ch/).

   

  IPCC, (2007b) Impacts, Adaptation and Vulnerability, Summary for Policymakers, Contributions of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, 22pp., (http://www.ipcc.ch/).

   

  IPCC, (2007c) Mitigation of Climate Change, Summary for Policymakers, Contributions of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, 36pp., (http://www.ipcc.ch/).

   

  Orr, J.C., V.J. Fabry, O. Aumont et al. (2005) Anthropogenic ocean acidification over the twenty-first century and its impact on marine calcifying organisms, Nature, 437, 681-686, doi:10.1038/nature04095.

   

  Sabine, C. L., R. A. Feely, N. Gruber et al. (2004) The oceanic sink for anthropogenic CO₂, Science, 305, 367–371.

   

  Sarmiento, J. L. and N. Gruber (2002) Sinks for anthropogenic carbon, Physics Today, August, 30-36.

   

  Sarmiento, J. L., et al. (2004) Response of ocean ecosystems to climate warming, Global Biogeochem. Cycles, 18, GB3003, doi:10.1029/2003GB00213

  
  

  ---

  [1] The views expressed here do not necessarily represent those of the Woods Hole Oceanographic Institution

• Dr. David O. Conover

  Dean and Director

  Marine Science Research Center, Stony Brook University
  Download Testimony (23.29 KB)

• Dr. Lara J. Hansen

  Chief Scientist

  Climate Change Program, World Wildlife Fund
  Download Testimony (51.19 KB)

• Admiral James D. Watkins USN (Ret.)

  Co-Chair

  Joint Ocean Commission Initiative
  Read statement

  Testimony

  Admiral James D. Watkins USN (Ret.)

  Testimony

  of

  Admiral James D. Watkins, U.S. Navy (Ret.)

   

  Chairman, U.S. Commission on Ocean Policy

  Co-Chair, Joint Ocean Commission Initiative

   

  Before the

   

  Committee on Commerce, Science, and Transportation

  Subcommittee on Ocean, Atmosphere, Fisheries, and Coast Guard

  U.S. Senate

   

  Room 253 Russell Senate Office Building

  Washington, D.C

  May 10, 2007

  10:00 a.m.

   

   

  Madame Chair, Senator Snowe and members of the Subcommittee: Thank you for the invitation to testify at today’s hearing.   I appear before you today representing the interests of the U.S. Commission on Ocean Policy as well as the Joint Ocean Commission Initiative, which I co-chair with Leon Panetta.  The Joint Initiative is a collaborative effort of members of the U.S. Commission on Ocean Policy and the Pew Oceans Commission. The purpose of the Joint Initiative is to advance the pace of change for meaningful ocean policy reform.

   

  Leon and I believe that this is an important hearing and hopefully is the first of many hearings that will examine the fundamental role oceans play in global climate change, as well as the impact climate change is having on our oceans and coasts.  We trust that the Members of the Committee will work closely with the multitude of other congressional committees that share jurisdiction over climate change related issues and will champion the need for greater attention to governance needs and the commitment of resources to support ocean-related science, management, and education. 

   

  Multi-jurisdictional problems, such as climate change, are becoming more common.  In the work of our commissions, we found almost the identical problem in the effort to deal with the many problems facing our oceans, coasts, and Great Lakes.  The lack of governance regimes capable of reaching across the diversity of congressional committees and federal agencies is severely hampering our capacity to deal with these issues.  Thus, while I understand that today’s hearing is focused on the issue of the increasing acidification of the oceans and the impact on living marine resources, I appreciate the opportunity to speak to the broader issue of the role of oceans in climate change and the importance of pursing strategies now to help coastal communities adapt to the inevitable changes that will occur in the coming years.

   

  Oceans Role in Climate Change

   

  As public awareness of climate change and its potential economic and environmental consequences has increased, so has the level of urgency to take action to mitigate the causes of this change and to make preparations to adapt to its impacts.  Unfortunately, few people fully appreciate the fundamental role oceans play in regulating climate through their capacity to store and distribute heat and their role in the carbon cycle.  As a nation, we are even less knowledgeable about the ramification of this change on the health of coastal and pelagic ecosystems and their capacity to provide the services upon which we’ve come to rely. This lapse has resulted in limited understanding of the complexity of ocean-related physical, geochemical, and biological/ecological processes that are influencing and being influenced by the ongoing change.  The consequences of this lack of knowledge are significant.  Policy makers struggle to evaluate alternatives to address climate change because the levels of uncertainty associated with the short- and long-term impacts of proposed options are relatively high and the science underpinning these decisions is inadequate.  Clearly, a more coherent strategy is needed to address climate change, and a core element of such a strategy must include increased attention to the role of the oceans.

   

  Oceans are key drivers in the Earth’s heat and carbon budgets, storing one thousand times the heat of the atmosphere and absorbing a third of all anthropocentric carbon dioxide generated over the last few centuries.  Furthermore, oceans not only store heat, but transport it around the globe, as well as vertically through the water column in ocean basins, making it a driving force of climate change.  While our knowledge of physical oceanographic processes is further advanced than that of geochemical and biological processes, it is still rudimentary due to the lack of a comprehensive monitoring regime.  As a result, we have ocean circulation and heat flux models that clearly indicate major changes are in progress.  However, we still lack a clear understanding of these processes on a global scale, and are even less knowledgeable about activities occurring along the highly dynamic coastal margins, where ecological and economic health are of the greatest importance to humans and many of the impacts of climate change –such as sea level rise and coastal storms— will be directly felt.

   

  Further complicating the situation is the lack of understanding of the interrelationship among the physical, geochemical, and biological processes.  As today’s hearing clearly demonstrates, we need to know the implications of ocean acidification on marine ecosystems –such as phytoplankton communities, coral reefs, and fish larva. We also need to know the rate of ice sheet melt and its impact on coastal communities, polar ecosystems, and regional weather patterns.

   

  The complex relationship between oceans and climate change, as we currently understand it, cries out for reform in two core areas, governance and science.  Congress must respond to the chorus of criticism directed at the lack of a coherent strategy and framework for addressing the challenges facing our oceans and coasts.  This strategy, in turn, must be integrated into a broader national initiative to deal with climate change. It is incumbent upon Congress to take this opportunity to look beyond parochial interests and issue-specific legislation, and work toward a governance regime and management policies that place greater emphasis on cooperation and collaboration within the federal government, while capitalizing on the wealth of scientific expertise and resources that reside outside the federal system.

   

   

  Governance

   

  The complexity and breadth of issues associated with efforts to understand, mitigate, and adapt to climate change make it essential that the nation have a coherent and comprehensive strategy to guide this work.  This is a daunting challenge given the multitude of governmental and nongovernmental entities that have a vested interest this issue and its long-term impact on the health and viability of the nation’s economy and environment.   The ocean community has been struggling with this same problem, albeit on a slightly smaller scale.  But the challenge remains the same, we need for a new federal governance regime that moves away from the stove-piped, command and control organization in which individual departments and agencies formulate policies and budgets that are reviewed by the Office of Management and Budget and then sent to Congress for a similar review by the appropriate committee of jurisdiction.  While there is a continuing effort to integrate programs and activities, it is the exception not the rule.  In addition, the budget process often discourages interagency cooperation as funding for multi-agency programs is subject to cuts or reductions during internal agencies budget negotiations, compromising the integrity of the broader strategy and promoting further competition among federal and nongovernmental players.

   

  But don’t take my word for it. There are a number of credible entities that have recognized that governance problems are impeding the nation’s capacity to respond to some of its most pressing challenges and have recommended solutions. Earlier this spring the National Research Council (NRC) responded to a request from the White House Climate Change Science Program to identify lessons learned from past global change assessments.  In its report, the NRC cited the lack of a long-term strategic framework for meeting the climate change research mandate as an outstanding weakness of the current system.[1]  

   

  Testimony by former administration officials who oversaw the climate change research program reiterated these concerns last Thursday in a hearing before a House Energy and Commerce Subcommittee, where recommendations were made to establish a program office with a sense of permanence, the political power to make decisions across agencies, and the authority over budgets.[2]  These recommendations closely track those made by the two ocean commissions, which advocated for a new management regime, based in the Executive Office of the President that would have the authority to coordinate efforts and guide the distribution of resources throughout the federal government in an integrated system that reached across jurisdictional boundaries of individual agencies. 

   

  Such a vision was partially implemented in the ocean community when the President established the Committee on Ocean Policy (COP).  However, the COP’s charge is limited to coordination.  It lacks institutional independence and a leader charged with resolving interagency disputes and representing the interest of individual agency ocean programs in the budget process.  Consequently, efforts to move a new national ocean policy forward have languished and the ocean community’s capacity to contribute toward the scientific and management needs to address climate change have been compromised.

   

  Similar problems exists in Congress, where cross-cutting issues such as oceans and climate fall under the jurisdiction of multiple committees and subcommittees.  Take the case of ocean acidification.  The Commerce Committee clearly has jurisdiction; however, the Environment and Public Works Committee has authority over water pollution and water quality issues, the Energy and Natural Resources Committee has a role regarding emissions from energy facilities, which are a major source of CO2, and the Committee on Appropriations funds authorized activities.  The same diversity of oversight authority exists in the House, significantly complicating efforts to develop a comprehensive strategy to address climate change. In the 108^th Congress, the U.S. Commission on Ocean Policy identified a total of 58 standing committees and subcommittees having jurisdiction over ocean-related issues in the House and Senate.[3]   An early assessment of the 110^th Congress shows little change or consolidation.

   

  Further evidence of support for a more coherent approach to science-related policy issues is reflected in the growing interest in reestablishing an Office of Technology Assessment (OTA).  OTA was a congressional office charged with providing nonpartisan research on technical and scientific issues pending before Congress, but was closed in 1995.  As Congress struggles with increasingly sophisticated and complex technical issues such as biomedical research and climate change, an entity such as OTA can provide timely and issue specific guidance that would complement the more exhaustive, costly and time consuming review process performed by the National Academies.  Congress relies on credible and readily available information to make informed policy decisions.  Right now, the lack of information on oceans and coasts, or a clear strategy for collecting and translating this information into products and services useful to decision makers and managers, is hobbling Congress’ ability to perform its role.

   

  Thus, the focus must turn to improving our capacity to more accurately assess the processes and phenomena influencing climate change and society’s impact on such processes and phenomena.  This will require much greater attention and support being devoted to the broader problem of designing and implementing a strategy that balances resources among basic and applied research, monitoring and analysis, and modeling.  This strategy must also be expanded to incorporate support for translating and utilizing this information to evaluate the effectiveness of mitigation, adaptation, and other management actions aimed at meeting the goals of increasing the resiliency of coastal communities and ecosystems.

   

  Given the complexity and interdisciplinary nature of the issues surrounding climate change, progress toward these goals will require changes in the operation and coordination of federal agencies and the federal budget process.  The National Oceanic and Atmospheric Administration (NOAA) is the logical lead federal agency to oversee the climate change science program; however, public and private confidence in the agency is lacking.  This is due, in great part, to the outdated organizational structure of the agency and the lack of resources that have been provided to fulfill its expanding mandate.   The opportunity is ripe to reevaluate and realign NOAA’s programs along its core functions, which include: assessment, prediction and operations; scientific research and education; and marine resource and area management.  This step, taken in combination with an effort to enhance the oversight role of the President’s Committee on Ocean Policy, would lay the foundation for a major transition in the ocean and atmospheric policy that would be of enormous long-term benefit to Congress and the public.

   

  Congress should also take advantage of this opportunity to address science agency mission and funding inconsistencies that are hampering the collection and synthesis of long-term data measurements.  While NASA and NSF are charged with developing new approaches to collecting, analyzing, and integrating data, NOAA has the charge –but lacks the technical expertise and fiscal resources— to maintain increasingly important remote and in situ observation platforms capable of sustained data collection (the compilation of long-term data sets). These long-term data sets are crucial to understanding the rate of change over an extended period.  Further exacerbating the situation is a disjointed data management system that is preventing scientists from fully utilizing data that are currently being collected.  Given the consolidation of science agencies (NOAA, NASA, and NSF) responsible for ocean and atmospheric research under the jurisdiction of the Commerce Committee and its sister appropriations subcommittee, the opportunity exists to more closely link their complementary programs through both the authorization and appropriations processes.  While this proposal may disturb many of those in the community who have a vested interest in programs associated with the individual agencies, in the long-term their collaboration is essential if our nation is to succeed in making progress toward understanding and responding to climate change while also restoring the health of our oceans and coasts.

   

  Clearly, a careful reevaluation of the governance regime guiding climate and ocean-related science and management programs is needed to overcome the obstacles that are currently hampering efforts to develop a comprehensive response to climate change.  Whatever action Congress takes, it should look beyond the current models and existing organizational structure to ensure that both ocean and climate change programs are broad-based and charged with developing a balanced strategy that incorporates science, management and outreach.  Anything less will perpetuate an approach that has proven to be ineffective and is now jeopardizing the health and welfare of current and future generations.

   

   

  Science

   

  Credible scientific information is essential as the nation begins the process of developing a new regime to mitigate and adapt to climate change.  Better science, when linked with improved risk management and adaptive management strategies will help guide a process that must deal with the relatively high levels of uncertainty surrounding mitigation alternatives and the range of impacts associated with climate change.  A much more comprehensive and robust science enterprise –one that incorporates a better understanding of the oceans’ role in climate change— is required to more accurately predict the rate and implications of change at the global-through-local level, as well as to enable more thorough evaluation of options for mitigating and accommodating this change.

   

  While the United States is making a significant financial commitment to understanding climate change, the inadequacy of the current strategy has become clear and reform is urgently needed.  Research that has been primarily focused on physical science and validation of climate change must expand to incorporate greater attention to the role and contributions of biogeochemical and ecological processes, as well as interactions among these three processes.  This will require a significant commitment of new resources and will increase the complexity of the science strategy to understand and respond to climate change.  However, these actions cannot be avoided if the science community is going to be responsive to Congress’ need for credible scientific information to guide its decision making process.

   

  One of the first steps should be a commitment to building a comprehensive environmental monitoring system.  We are supposedly well on our way to fulfilling our international commitment to support climate observing systems –which according to the most recent report from the Climate Change Science Program is over 50 percent complete.  However, support for this system is in trouble, which is compounded by the fact that considerably fewer resources are dedicated to supporting an ocean-focused component of the observing system.  A recent NRC study found that remote sensing satellite programs in NASA are at great risk and that the next generation of satellites is generally less capable than the current, rapidly diminishing system.  Projected budgets show U.S. investment in these capabilities falling by 2012 to its lowest level in two decades. [4]  Support for a dedicated ocean observing program appeared in the President’s budget for the first time this year, at the level of $16 million, a fraction of what Congress has been providing in recent years. 

   

  As a consequence our knowledge of physical ocean-related processes is limited, and our capacity to understand biogeochemical and ecological processes languishes due to the lack of capacity to study, much less monitor and model these systems and their responses to change.  The expert scientific witnesses appearing before the Subcommittee today have testified to this fact, presenting us with quantifiable data that human have contributed to the increased acidification of the oceans and that there are very real and potentially damaging consequences associated with this change.  Yet, the ocean scientific community does not have access to funding to support large-scale field experiments, study environments that are naturally more acidic, or more fully examine the geologic record to understand past events that may have resulted in similar conditions.

   

  It is now obvious that enhanced and integrated observing systems are a key element underlying a robust ocean and climate science strategy.  From a research perspective this need was clearly articulated in the release of the Administration’s Ocean Research Priorities Plan and Implementation Strategy in January, in which the deployment of a robust ocean-observing system was highlighted as a critical element of the plan.  Such an observing system will require a commitment to deploy and maintain infrastructure and instrumentation, such as satellites, research vessels, buoys, cabled underwater observatories, and data management networks.  A sustained, national Integrated Ocean Observing System (IOOS), backed by a comprehensive research and development program, will provide invaluable economic, societal, and environmental benefits, including improved warnings of coastal and health hazards, more efficient use of living and nonliving resources, safer marine operations, and a better understanding of climate change.  However, the value of this system will be fully realized only if an adequate financial commitment is also provided to support integrated, multidisciplinary scientific analysis and modeling using the data collected, including socioeconomic impacts.  Unfortunately, support for the lab and land-based analysis of the data derived from these systems is often inadequate, diminishing the value of these programs, while support for socioeconomic analysis is virtually nonexistent.

   

  The lack of a comprehensive climate change response strategy and supporting governance regime that integrates fundamental research and development, monitoring and analysis, and modeling efforts is a major weakness in our national effort.  It must be immediately addressed to ensure that policy makers have the scientific information necessary to guide their deliberation regarding both mitigation and adaptation strategies.   Congress should develop legislation, perhaps with guidance from the National Research Council, requiring the development of a comprehensive science strategy that incorporates support for ocean-related sciences with a focus on enhancing the predictive capacity of physical and ecological models.  This advancement is necessary to provide policy makers and the public with the information necessary to make informed decisions regarding the collateral impact of potential mitigation strategies –such as carbon sequestration in or under the oceans or biofuel production that results in increased runoff of agricultural pollutants into coastal watersheds— and strategies for increasing the resiliency of coastal communities and marine ecosystems to climate generated impacts.

   

   

  Conclusion

   

  The recent elevation of national conversation surrounding climate change and its economic and environmental implications validate similar discussions voiced by the ocean community upon the release of the U.S. Commission and Pew Commission reports.  At the heart of the matter is the need for more a robust science enterprise capable of advancing our understanding of the processes that drive our planet and can better guide the decisions of policy makers.  The integration across agencies and scientific disciplines, with a focus of developing products and services useful to policy makers and the public, will only occur if we succeed in implementing and integrating new governance regimes for climate change and ocean policy that facilitates greater collaboration, including resources and expertise outside of the federal system. 

   

  This transition must be well thought out and deliberate, perhaps pursuing a phased approach such as that recommended in the U.S. Commission report.  In it, we recommended that the initial focus be on strengthening NOAA, followed by a realignment and consolidation of ocean programs that are widely distributed throughout the federal government.  The final phase would be the consolidation of natural resource oriented programs under a single agency.  This approach responds to the recommendation of the Volker Commission, which identified the proliferation and distribution of agencies and programs throughout the federal government as a major hindrance to efficiency and effectiveness of the federal system.[5]

   

  I am appealing to you publicly, as Leon and I have done in private to many of you, to take up the mantle of governance reform in the ocean community.  It is the critical first step in the process toward realigning and focusing the resources and energy of the ocean community toward restoring the health and viability of our oceans and coasts.  I understand it will be difficult, but increased public awareness and concern about the health of the environment has provided us with a unique and timely opportunity to leave a lasting legacy, one we can appreciate when sitting on a beach --free of closure and swimming advisory signs-- on a sunny summer afternoon with our children or grandchildren while looking out over the horizon of a sparkling blue sea.

   

  Madame Chair and Members of the Subcommittee, I appreciate the opportunity to appear before you today, and look forward to working with you to address the ocean and coastal issues raised in this hearing. I would be happy to answer any questions that you may have. 

   

  
  

  ---

  [1] Analysis of Global change Assessments: Lesson Learned.  National Research Council 2007

  [2] Hearing before the House Science and Technology Committee, Subcommittee on Energy and the Environment; Reorienting the U.S. Global Change Research Program Toward a User-Driven Research Endeavor. http://science.house.gov/publications/hearings_markups_details.aspx?NewsID=1798

  May 3, 2007.

  [3] U.S. Commission on Ocean Policy, Appendix F. 2004

  [4] Earth Science and Applications for Space: National imperatives for the Next Decade and Beyond, NRC 2007.

  [5] National Commission on the Public Service: Urgent Business for America: Revitalizing the Federal Government for the 21st Century http://www.brookings.edu/gs/cps/volcker/volcker_hp.htm 2004

• Dr. Gordon H. Kruse

  President's Professor of Fisheries

  School of Fisheries and Ocean Sciences
  Read statement

  Testimony

  Dr. Gordon H. Kruse

  THE WRITTEN TESTIMONY OF

   

  GORDON H. KRUSE, Ph.D.

  UNIVERSITY OF ALASKA FAIRBANKS

  SCHOOL OF FISHERIES AND OCEAN SCIENCES, JUNEAU CENTER

  JUNEAU, ALASKA

   

  HEARING ON

  THE EFFECTS OF CLIMATE CHANGE AND OCEAN ACIDIFICATION ON LIVING MARINE RESOURCES

   

  BEFORE THE

  SENATE COMMITTEE ON COMMERCE, SCIENCE, AND TRANSPORTATION

  SUBCOMMITTEE ON OCEANS, ATMOSPHERE, FISHERIES, AND COAST GUARD

  UNITED STATES SENATE

   

  RUSSELL SENATE OFFICE BUILDING, ROOM 253

  MAY 10, 2007

   

  Introduction

   

  Madam Chair and members of the Committee, it is my honor to testify to you this morning. My name is Gordon Kruse. Since 2001, I have been the President’s Professor of Fisheries and Oceanography at the School of Fisheries and Ocean Sciences, University of Alaska Fairbanks. Prior to my current position, I directed the marine fisheries research program for the Alaska Department of Fish and Game for 16 years, where I was the lead science advisor to the State of Alaska on state and federal marine fishery management. I have been a member of the Scientific and Statistical Committee (SSC) of the North Pacific Fishery Management Council (NPFMC’s) for seven years, including the two most recent years as chair (2005-2006) and the two prior years as vice-chair (2003-2004). I served an additional 11 years as a member of the NPFMC’s Crab Plan Team and Scallop Plan Team and co-authored the original crab and scallop Fishery Management Plans. I am the current chair of the Fishery Science Committee for the North Pacific Marine Science Organization (PICES), an international marine science organization involving China, Japan, South Korea, Russia, Canada and the U.S.

   

  Objectives of Testimony

   

  My objectives are to discuss: (1) potential mechanisms and effects of climate change on living marine resources in Alaska, (2) future outlook for these resources and implications for management under continued global warming, and (3) uncertainties associated with gaps in our understanding that require further research.

   

  Importance of Marine Ecosystems off the Coast of Alaska

   

  Alaska is unique in that it is bounded by three large marine ecosystems: the North Pacific Ocean, Bering Sea, and Arctic Ocean (including the Beaufort and Chukchi Seas). These are some of the world’s most productive ecosystems, supporting thousands of marine mammals, millions of seabirds, and trillions of fish and shellfish belonging to hundreds of species.

   

  These Arctic and subarctic oceans provide priceless ecosystem services, including human use. Since before recorded history, Native Alaskans have depended on the bounty of these ecosystems for their very existence. Still today, many of these communities remain as subsistence-based (barter) economies, and their harvests of fish, shellfish, mammals and other resources (e.g., bird eggs, kelp) provide the majority of their diets.

   

  These ecosystems support extremely valuable commercial fisheries that provide both U.S. food security and foreign exports that contribute toward the national balance of trade. More than half of the total U.S. fishery landings come from the waters off Alaska. In 2005, landings from Alaska totaled 5.7 billion pounds, representing 59% of the total 9.6 billion pounds landed in the U.S. (NMFS 2007). While important fisheries occur in the Gulf of Alaska and Aleutian Islands, most of this catch is taken from the eastern Bering Sea, owing to its broad, highly productive continental shelf. In 2005, the nation’s top seafood port was again Dutch Harbor-Unalaska, accounting for 888 million pounds of landings worth $283 million exvessel (before value-added processing). Moreover, seven of the nation’s top 20 seafood ports are located in Alaska. The Bering Sea supports the world’s largest fishery (walleye pollock), largest flatfish fishery (yellowfin sole), and largest salmon (sockeye) fishery. Other valuable commercial fisheries target a diversity of species of crabs, rockfishes, flatfish (flounders and soles), cod, halibut, herring, and other fish and invertebrates. These same waters provide world-class recreational fishing opportunities for non-resident visitors and Alaskan residents alike for salmon, halibut, rockfish and other species.

   

  Resource Sustainability versus Variability

   

  In their report to the nation, the Pew Oceans Commission (2003) noted that Alaska’s fisheries were “arguably the best managed fisheries in the country. With rare exception, the managers have a record of not exceeding acceptable catch limits set by scientists. In addition, the North Pacific Fishery Management Council and Alaska Board of Fisheries have done more to control bycatch and protect habitat from fishing gear than any other region of the nation.” The sustainability of groundfish, salmon and other fishery resources in Alaska is tied directly to conservative, science-based fishery management.

   

  Nonetheless, there are clear historical cases of overharvest and resultant collapse of living marine resources, even in Alaska – examples include the Steller’s sea cow (hunted to extinction in 1768), northern fur seal (1700s – early 1800s and again in the late 1800s – early 1900s), great whales (mid 1800s – mid 1900s), sea otters (mid 1700s – early 1900s), yellowfin sole (1960s), and Pacific ocean perch (1960s – 1970s). Causes of recent declines in Steller sea lions, northern fur seals, shrimp, and king, Tanner and snow crabs are much less clear. Although human effects have been implicated in many of these recent examples and undoubtedly humans have contributed to varying degrees, a large body of scientific evidence has emerged in support of climate change as being primarily responsible for major shifts in the marine ecosystems off Alaska. Environmental variability affecting marine ecosystems occurs over a wide range of time scales; the scales most relevant to most marine animal populations are seasonal to decadal and longer. Owing to our rather short history (few decades) of research and monitoring of marine organisms in Alaska, much of our outlook for impacts of global warming on marine ecosystems is based upon our understanding of the mechanisms and effects operating on shorter time scales, as summarized below.

   

  Effects of Seasonal Climate Variability on Living Marine Resources in Alaska

   

  Seasonal climate variability is vital to the productivity of temperate, subarctic and Arctic marine ecosystems. In these regions, there is a seasonal “battle” between winds that mix deep, nutrient-rich waters into the photic zone and solar heating that warms the upper layers of the ocean, causing thermal stratification that retains microscopic plants (phytoplankton) in the upper layers of the ocean where they can grow under sufficient light penetration and nutrient concentrations.

   

  In the spring, when solar heating wins the battle, an intense bloom of large phytoplankton occurs, providing large amounts of food to microscopic animals (zooplankton) that, in turn, bloom in abundance. This sequential burst in abundance of phyto- and zooplankton serves as food to higher trophic levels, including the planktonic early life stages (larvae) of many commercially important species of fish and shellfish, as well as adults of some species of planktivorous marine mammals (e.g., humpback whales) and seabirds (e.g., crested auklet). In other words, this spring bloom fuels the engine that supports much of the productivity of marine ecosystems in Alaska. The timing of herring spawning, hatching of red king crab larvae, and outmigration of salmon smolts are tied to this remarkable annual event. As summer progresses, nutrients in the warm upper layers of the ocean become depleted, overall production tends to decline, and other species of small phytoplankton adapted to low-nutrient conditions become prevalent.

   

  In the fall, as winds strengthen and solar heating diminishes, the water column mixes, stability breaks down and a smaller fall bloom may occur. However, phytoplankton are mixed to deeper waters where light levels are too low to sustain net growth and the engine that fuels the marine ecosystem slows down. In winter, productivity is low, but, even at this time of year some species (e.g., some flatfish) have adapted strategies for optimum survival as winter spawners. In the following spring, the cycle is repeated again.

   

  Each species has evolved unique life history strategies to be successful in these seasonally dynamic marine ecosystems. For many species of marine fish and invertebrates, their success depends upon the synchrony in time and space of their early life stages (eggs and larvae) with abundances of suitable food, the abundance (or lack thereof) of predators, and ocean currents that carry them (advection) to nursery areas most amenable to their survival. Likewise, the success of seabird and marine mammal populations depends largely upon the ability of adults to secure adequate prey while feeding their young on rookeries.

   

  Effects of Interannual and Decadal Climate Variability on Living Marine Resources in Alaska

   

  El Niño

   

  Although an understanding of seasonal variability in environmental variables is important toward understanding the strategies by which species thrive within marine ecosystems, it is the year-to-year (interannual) variability in climate and ocean processes that determines how animal populations change over time. One important component of interannual variability that occurs every 2-7 years is El Niño/La Niña, an oscillation of a coupled ocean-atmosphere system in the tropical Pacific having important consequences for weather in the North Pacific and around the globe. Prominent features of an El Niño include the relaxation of the trade winds and a warming of sea surface temperature in the equatorial eastern Pacific, extending along the U.S. west coast into Alaskan waters. Species more typical of subtropical and tropical waters extend their distributions into Alaska during El Niño events. For instance, during the 1997-1998 El Niño, albacore tuna were caught off Kodiak Island and ocean sunfish were observed in the northern Gulf of Alaska (Kruse 1998). Global surface mean temperature anomalies provided by NOAA’s National Climate Data Center suggest that El Niños became more intense and more frequent in the latter half of the 20^th Century, quite possibly as a manifestation of global warming. Thus, range extensions and first-time sightings of southern species have become more common in recent years.

   

  Beyond the curiosity of such unusual sightings, more far-reaching marine ecosystem changes can be associated with El Niño events. Coincident with the 1997-1998 El Niño, salmon run failures occurred in western Alaskan river systems imposing severe economic and social hardships in some western Alaskan communities (Kruse 1998). A federal disaster was declared by the U.S. President. Also, in 1997, the first-ever massive bloom of coccolithophores (a non-nutritious microscopic phytoplankton covered with calcium carbonate platelets) was observed in the eastern Bering Sea. The bloom was so dense and expansive, that it was easily observed by satellites orbiting the Earth. A massive die-off of short-tailed shearwaters was associated with reduced availability of their preferred prey (euphausiids). Murres, a dive-feeding seabird, produced fewer offspring, likely because dense coccolithophore concentrations obscured their vision and ability to feed. It is important to recognize that these ecosystem effects were likely the product of an unusual combination of El Niño, decadal climate variability, global warming, and other atypical regional conditions. However, this suite of climatic conditions set the stage for repeated coccolithophore blooms in the eastern Bering Sea for half a dozen years after this initial event.

   

  Decadal Climate Regime Shifts

   

  Much marine ecosystem research in Alaska since the 1980s has documented decadal climate variability patterns that have led to regime shifts every 10-30 years. The Pacific Decadal Oscillation (PDO) is one index of such shifts, based on warm-cold patterns of sea surface temperature in the northern North Pacific Ocean. Some have likened the warm phase of the PDO to an extended El Niño situation. For instance, ocean temperatures in the northeast Pacific were typically warm in the mid 1920s – mid 1940s, cool during the mid 1940s – late 1970s, and warm since then. The opposite pattern was experienced in the northwestern Pacific.

   

  The regime shift of the late 1970s has been particularly well studied. Since the late 1970s, Alaskan waters have experienced more frequent winter storms associated with an intensified Aleutian Low Pressure System, increased freshwater discharge into the Gulf of Alaska, a stronger Alaska Coastal Current (which flows in a counter-clockwise fashion around the gulf), and warmer ocean temperatures. These changes appeared to have altered the flux of nutrients, leading to a marked increase in the biomass of zooplankton in the Gulf of Alaska. Other major ecosystem changes associated with this regime shift include a decline in forage fishes, crabs, and shrimps and increases in the abundances of salmon and groundfish (Anderson and Piatt 1999). Some research supports the hypothesis that declines in a number of populations of marine mammals and seabirds are related to observed shifts in marine food webs (e.g., decline in forage fish) in Alaska. However, as with any complex ecosystem with limited monitoring, the evidence is less than conclusive.

   

  Decadal-scale variability in the extent of sea ice formation has had profound effects on the Bering Sea marine ecosystem. Sea ice forms and melts seasonally spreading from the northern to southern Bering Sea shelf waters. Timing of the spring bloom depends heavily on ice formation and melt. In years of extensive ice coverage, the ice thaws more slowly and melt water stratifies the upper water column with buoyant, low salinity water. If this stratification occurs sufficiently late (e.g., April), then sunlight is adequate at that time of year to cause an early spring bloom near the ice edge. However, there is a dearth of zooplankton in this cold melt water, so much of the phytoplankton sinks ungrazed to the seafloor where it benefits bottom-dwelling (benthic) species, such as clams, crabs and other invertebrates. On the other hand, in years when ice is thin and less extensive, it melts in February or March; the lesser amount of freshwater is inadequate to stratify the water column and sunlight is too weak at that time of year to support a plankton bloom. In such years, the spring bloom is delayed until May or June after the sun has had sufficient time to heat a stratified layer of warmer water. Warmer ocean temperatures at this time of year support growth of the zooplankton community and much of the phytoplankton production is grazed by water column (pelagic) species, such as walleye pollock.

   

  Sea ice in the southeast Bering Sea has declined markedly from covering 6-7 months in the late 1970s to spanning just 3-4 months each winter since the 1990s. As the ice-edge bloom may account for a large fraction of the total annual primary production in the eastern Bering Sea, there is considerable concern that declines in productivity have occurred with reductions in sea ice since the late 1970s. Although long-term records of phytoplankton are lacking, declines in summer zooplankton have been clearly documented in the eastern Bering Sea by the Japanese research vessel Oshoro Maru since at least 1990.

   

  Effects of Global Warming on Living Marine Resources in Alaska

   

  Terrestrial Impacts of Global Warming in Alaska

   

  Increases in global air and sea temperatures have been clearly documented since the 1800s. On land, observed changes in Alaska are dramatic and well known, including retreat of nearly all glaciers, melting of permafrost and associated structural damage to buildings and roads, and increased insect outbreaks (e.g., spruce bark beetle) in coniferous forests and an associated increase in frequency of forest fires. Along the coast of western Alaska, higher sea levels and lack of shore-fast sea ice in winter has led to extensive coastal erosion during storms, prompting the imminent costly relocation of dozens of Native villages.

   

  Climate and Oceanographic Changes with Global Warming

   

  A composite land-ocean index of global temperature provided by NASA shows that temperature changes since the 1880s reflect the combined influences of the two major frequencies already discussed – El Niños (every 2-7 years) and decadal variability (10-30 years) – plus a long-term increase in temperature associated with global warming (≥ 100 years). Because our history of research and monitoring of marine organisms is very short (decades) relative to the century-long time scale associated with global warming, the outlook for living marine resources under continued global warming is based largely upon our rather limited understanding of recent variability and mechanisms associated with those observed changes.  The outlook for these marine resources also depends upon the accuracy of future projected changes in temperature, precipitation and winds from climate forecast models.

   

  Based on the working group of the Intergovernmental Panel on Climate Change in 2007, the near-term projection is for an average global increase of 0.2 C per decade over the next two decades. The Arctic has been warming twice as fast as the rest of the globe since the mid 1800s, and this accelerated trend is projected to persist for the higher latitudes into the foreseeable future. Based on these IPCC models, increased precipitation is also very likely in the higher latitudes. High-latitude changes in wind patterns are also projected, but specific details in the projections concerning storm frequency and intensity are somewhat less certain.

   

  Shifts in Species Distribution and Abundance

   

  Each species has its own preferred optimum temperatures within a wider range of temperatures suitable for its growth and survival. With warming ocean temperatures, species at the southern end of their distributions (e.g., snow crabs in the southeastern Bering Sea) are expected to contract, whereas those at the northern ends of their distributions (e.g., Pacific hake in southeastern Alaska) are expected to expand northward.

   

  Increased temperatures may benefit some species and disfavor others. With the warming experienced in the last two decades, in-river temperatures in British Columbia have exceeded 15 C, which causes stress in sockeye salmon, increasing susceptibility to disease and impairing reproduction. Studies have shown that mortality is positively related to temperature and river flow in Fraser River sockeye salmon. Turning back to the poor salmon runs in western Alaska in 1997-1998 mentioned earlier, among other potential causes, anecdotal reports found a high incidence of a parasite, called Ichthyophonus. Infected fish did not dry properly when smoked (a common means of preservation by subsistence users) and had white spots on internal organs and muscle. Follow-up studies found that 25-30% of adult chinook salmon returning to the Yukon River in 1999-2002 were infected (Kocan et al. 2003).  Many of the diseased fish appear to have died before spawning. The spread and pathogenicity of this parasite is correlated with Yukon River water temperature in June, which increased from 11 to 15 C over 1975 to 2002 at Emmonak (river mile 24). Such examples of adverse impacts of increasing temperatures on salmon may become more common in Alaska with continued global warming.

   

  Warming temperatures are expected to increase the northward migration of piscivorous predators into the future. Pacific mackerel and jack mackerel, species common to the coast of California, have extended their distributions into British Columbia in recent warm years. The productivity of Pacific mackerel populations is favored during warm years off California. Mackerel compete with and prey on juvenile salmon; reduced survival of sockeye salmon on the west coast of Vancouver Island is correlated with the abundance and early arrival of Pacific mackerel in British Columbia. The impact of mackerel predation and competition with salmon is a concern for Alaska. Mackerel have already been encountered in Southeast Alaska by salmon troll fishermen.

   

  There are additional concerns about the northward extension of other predators, such as spiny dogfish in Alaska. A colleague from the University of Washington and I have an ongoing project to evaluate the evidence for an increase in dogfish abundance, as well as to evaluate the life history and productivity of dogfish and management implications in Alaska. Bycatch of dogfish is an increasing problem to fishermen, particularly in the salmon gillnet and halibut/sablefish longline fisheries in Alaska. On the one hand, dogfish bycatch causes gear damage (gillnet) and hook competition for more valuable species (sablefish and halibut), but, on the other hand, this species could provide new economic opportunities (dogfish supply the fish and chips industry in Europe). Determination of sustainable harvest levels is problematic for this abundant species that has a low rate of annual productivity associated with delayed maturity and low reproductive rate.  

   

  In the Bering Sea, the centers of distribution of adult female red king crab and snow crab have shifted to the north since the late 1960s and early 1970s, likely due to increases in bottom temperature (Loher and Armstrong 2005, Orensanz et al. 2004, Zheng and Kruse 2006). The larval stages of both species are planktonic – subject to passive drift. Given the northward flow of prevailing ocean currents and the probable fixed location of juvenile nursery areas, the northward shift of females has most likely adversely affected the ability of these populations to supply young crabs to the southern end of their distribution in recent decades. At the same time, warming ocean temperatures have allowed predators of young crabs, such as Pacific cod, rock sole, and skates, to shift their distributions to the north. So, the young stages of crab not only have to deal with settlement into suboptimal habitats, but they have to navigate the gauntlet of increased predation by groundfish. These two mechanisms may be leading reasons why crabs have generally faired poorly since the late 1970s regime shift. For these same two reasons, crabs may continue to fair poorly under continued global warming. On the other hand, groundfishes like pollock and cod may continue to benefit.

   

  One species that seems to have benefited greatly from conditions since the late 1970s is the arrowtooth flounder, a species at its highest recorded levels of abundance and still increasing. This species is a voracious predator that consumes large amounts of pollock, cod, and other commercially valuable groundfish and shellfish. Unfortunately, the flesh of the arrowtooth flounder has low market value owing to enzymes that degrade the flesh quality. So, future warm ocean conditions may continue to result in a shift from commercially valuable species, like pollock and cod, to this species, which has low market value.

   

  Other predatory species that may increase in Alaska with continued global warming include seasonal predators, such as albacore tuna. This species would provide new economic opportunities in Alaska, perhaps to the detriment of salmon fisheries.

   

  Restructuring of Ecosystems

   

  Earlier, I discussed the role of sea ice extent on funneling energy to the benthic ecosystem (early spring bloom) or the pelagic ecosystem (late spring bloom). Although the trend since the late 1970s has been toward a late spring bloom favoring pelagic species (such as pollock) in the southeastern Bering Sea, the spring bloom remains largely an ice-edge bloom in the northern Bering Sea, where the ecosystem remains benthic dominated (e.g., clams). This benthic production is essential for a number of charismatic species, such as walruses and spectacled eiders that feed on benthic clams and other bivalves. All, or nearly all, of the world’s populations of spectacled eiders overwinter in a small area between St. Lawrence Island and St. Matthew Island in the eastern Bering Sea. In the past decade with an increase in air and ocean temperatures and a reduction in sea ice, there has been a reduction in benthic prey populations and a displacement of marine mammals (Grebmeier et al. 2006). With a commensurate increase in pelagic fishes, the northern Bering Sea is shifting from a benthic to a pelagic ecosystem, posing risks to benthic prey-dependent species of seabirds and marine mammals. This benthic to pelagic trend is expected to increase and expand northward with continued global warming.

   

  Loss of sea ice in the Bering Sea is likely to have major impacts on ice-dependent marine mammal species, such as ring seals and bearded seals. Ring seals excavate caves (lairs) under the ice in which they raise their young for protection from the weather and predators. Ring and bearded seals feed on a variety of invertebrates and fishes. Both seals are major components of the diet of polar bears. Polar bears also have the capacity to kill larger prey, such as walruses, a species with seasonal migrations also tied to the advance and retreat of sea ice. Therefore, it seems very likely that the loss of sea ice associated with global warming will have serious impacts on these ice-dependent marine mammals.

   

  Potential for Invasive Species

   

  An additional area of concern under global warming is invasive species. With increasing ocean temperatures, cold thermal barriers to warm-water invasive species may become removed. One key species of concern is the European green crab, a species that is native to the North and Baltic Seas. Unintentionally introduced as an invasive species, the green crab has consumed up to 50% of manila clams in California, and it was blamed for the collapse of the soft-shell clam industry in Maine. This species has the potential to alter an ecosystem by competing with native fish and seabirds. Its recent arrival on the U.S. west coast and potential to expand northward with global warming causes concerns for Alaska with respect to our Dungeness crab fishery and aquaculture farms for oysters and clams.

   

  Changes in Seasonal Production Cycle

   

  Increased temperatures may result in earlier stratification, perhaps advancing the timing of the spring bloom. In such case, the continued success of some species depends upon their ability to spawn earlier so that their early life history stages continue to match the spring bloom. Additionally, greater heat in the ocean may lead to prolonged summer-like conditions favorable to small phytoplankton that thrive in low nutrient conditions, including some phytoplankton species that produce toxins, such as paralytic shellfish poisoning. Food chains based on small phytoplankton (typical of summer) tend to be less productive than those based on large phytoplankton (typical of the spring bloom), because they require more steps of energy conversions along the food chain to support upper trophic level species, such as seabirds, marine mammals, and commercially important fish including cod and halibut. So far, this seasonal cycle outlook is based solely upon increased temperatures; other important considerations are the forecasted future changes in storm frequency and intensity. If greater storminess in the Gulf of Alaska and Bering Sea is associated with global warming, then the increased mixing could somewhat compensate for the tendency for increased stratification caused by warmer temperatures, perhaps resulting in little change in the timing of the spring bloom. However, in such case, given the temperature control of the rate of many physiological processes (including reproduction) of cold-blooded marine fish and invertebrates, a challenge for many species will be to maintain current spawning timing despite warming temperature conditions.

   

  Ocean Acidification

   

  As greenhouse emissions continue to increase, the ocean soaks up more and more CO₂, which when dissolved in water, becomes carbonic acid. Such increases lower the pH of seawater, causing a critical concern for species with calcium carbonate skeletons. Preliminary results of studies in Alaska indicate that declining seawater saturation of calcium carbonate induced by ocean acidification may make it more difficult for larval blue king crabs to harden their shells (J. Short, NMFS, Auke Bay Laboratory, pers. comm.).  Juvenile king crabs had substantially increased mortality, slower growth, and slightly less calcified shells when exposed to undersaturated seawater conditions projected for their rearing habitat within the coming century in the North Pacific Ocean.  These preliminary results indicate that continued increasing carbonation of the ocean surface layer as a result of increasing atmospheric CO₂ may directly affect recruitment of commercially important shellfish. Other witnesses on this panel have outstanding expertise on ocean acidification and will speak in much greater detail on this topic.

   

  Management and Economic Implications

   

  One need not look further than the Bering Sea pollock fishery in 2006 for an example of the sort of management implications expected under global warming. During the B (fall) fishing season, pollock were farther north and west than normal. Diesel fuel prices were high. The at-sea (factory trawler fleet) sector has the ability to conduct 7-10 day fishing trips and a byproduct of their fish harvests is fish oil, which they burn in their boilers and generators. On the other hand, smaller shore-based vessels only have capacity for 2-4 day trips and they cannot produce fish oil. The northward shift of pollock, typical of expectations under global warming, had relatively small impact on the at-sea sector, but had significant adverse impacts on the shore-based fleet, owing to reduced access to the resource and increased operational costs. Under northward shifts in fish resources, the shore-based fleet will need to shift to a mothership-type fishery or will need to relocate plants in new northern ports at greater investment of capital. 

   

  Over the near term, the NPFMC is currently considering management actions with respect to the potential northward expansion of pelagic and other fishery resources into the northern Bering Sea and Arctic Ocean. One major problem is that current surveys do not extend into the northern Bering Sea, much less the Arctic, so allowance of fisheries to follow the fish north would be conducted under increased uncertainty, perhaps at greater risk to previously unexploited benthic resources, which in turn could place sensitive populations of marine mammals (e.g., walrus) and seabirds (e.g., spectacles eider) as risk.  At its June 2007 meeting, the NPFMC is scheduled to take action on a proposal to define and mitigate essential fish habitat in the eastern Bering Sea including an SSC proposal to allow fishing in the northern Bering Sea only under an experimentally designed study to test fishing impacts upon which future decisions can be based. Over the longer term, the NPFMC is considering management options for the Arctic Ocean, perhaps under a new Arctic Fishery Management Plan. Management options for the Arctic are constrained by a serious lack of information on the marine fish and invertebrate resources in this region. The reliance of species of marine mammals and seabirds, as well as Native communities, on the living marine resources of these northern areas, heightens the gravity of management decisions for the Arctic Ocean.

   

  Long-term forecasts of the implications of global warming and fisheries management in Alaska are highly speculative, given present levels of understanding. Just as there was a reorganization of marine ecosystems after the regime shift of the late 1970s, marine ecosystems off Alaska might be expected to reorganize again, perhaps to a new unobserved state, in response to a climate regime shift associated with continued global warming. If so, then a commensurate reorganization of the fishing industry is to be expected. Uncertainty increases as conditions (e.g., temperature, percent sea ice cover) move outside the range of historical observations. Under science-based management, increasing uncertainty typically translates into more precaution. Thus, more precautionary management under greater uncertainty, coupled to the increasing use of ecosystem-based fisheries management, will likely result in more conservative fish harvests in Alaska in the future.

   

  Data Gaps and Research Needs

   

  Predictions of future changes of marine ecosystems for the Gulf of Alaska, Aleutian Islands, and eastern Bering Sea are uncertain, partly owing to gaps in our understanding of mechanisms affecting the dynamics of living marine resources and partly due to uncertainties in climate forecast models at the level of detail necessary for the Alaska region. A combination of improved monitoring, process-oriented studies, modeling, and policy development are recommended to improve our ability to forecast and address likely future marine ecosystem changes in Alaska:

   

  • Arctic baselines – very few data are available on the abundance, distribution, and life history of marine species in the northern Bering Sea and Arctic. It is critical at this time to establish baseline understanding of community structure and function before the Arctic region is perturbed by human impacts and climate change.

   

  • Integrated Ocean Observing Systems – establishment of routine observing systems for physical and biological features of marine ecosystems off Alaska is essential to monitoring the effects of global climate change.

   

  • Studies of physiology and life history. Models only go so far; the biology and life history of many species off Alaska are poorly known, including functional relationships between their growth and survival and environmental conditions. In order to understand the effects of global warming and human effects on these populations and associated ecosystem consequences, it is essential to invest in studies of basic biology, life history, and physiology of poorly studied northern marine species. Physiological studies can reveal a great deal about the impacts of increasing temperature on the scope for growth and survival of northern species.

   

  • Coupled climate-ecosystem and climate-fisheries forecasting models. It is imperative to establish explicit linkages between climate forecast models and regional ecosystem and fishery models so that outlooks for changes in marine ecosystems and fisheries can be made more quantitative and less qualitative. In June 2007, PICES will convene a workshop on linking climate and fisheries forecasts, but this is just a very initial step in a process that will require substantial efforts.

   

  • Ecosystem approach to management. Climate change is just one of a suite of both human and naturally occurring factors that need to be considered in the management of living marine resources. Effective management of marine resources off Alaska will become increasingly complex, given the uses of these resources by coastal Native communities and higher trophic level species (e.g., birds and mammals). Potential for increased marine transportation and oil and gas exploration and development further heighten the need for an ecosystem approach to management.

   

  Thank you, Madam Chair, for the opportunity to speak to you and your committee today. I would be pleased to answer any questions you or other committee members may have.

   

  References

   

  Anderson, P.J., and J.F. Piatt. 1999. Community reorganization in the Gulf of Alaska following ocean climate regime shift. Marine Ecology Progress Series 189: 117-123.

  Grebmeier, J.M., J.E. Overland, S.E. Moore, E.V. Farley, E.C. Carmack, L.W. Cooper, K.E. Frey, J.H. Helle, F.A. McLaughlin, and S.L. McNutt. 2006. A major ecosystem shift in the northern Bering Sea. Science 311: 1461-1464.

  Kocan, R., P. Hershberger, and J. Winton. 2003. Effects of Ichthyophonus on survival and reproductive success of Yukon River chinook salmon. U.S. Fish and Wildlife Service, Office of Subsistence Management, Final Report 01-200.

  Kruse, G.H. 1998. Salmon run failures in 1997-1998: A link to anomalous ocean conditions? Alaska Fishery Research Bulletin 5(1): 55-63.

  Loher, T., and D.A. Armstrong. 2005. Historical changes in the abundance and distribution of ovigerous red king crabs (Paralithodes camtschaticus) in Bristol Bay (Alaska), and potential relationship with bottom temperature. Fisheries Oceanography 14: 292-306.

  NMFS (National Marine Fisheries Service). 2007. Fisheries of the United States, 2005. National Marine Fisheries Service, Current Fishery Statistics 2005, Silver Spring, MD.

  Orensanz, J., B. Ernst, D.A. Armstrong, P. Stabeno, and P. Livingston. 2004. Contraction of the geographic range of distribution of snow crab (Chionoecetes opilio) in the eastern Bering Sea: an environmental ratchet? CalCOFI Report 45: 65-79.

  Pew Oceans Commission. 2003. America’s living oceans: charting a course for sea change. A report to the nation: recommendations for a new ocean policy. Arlington, VA.

  Zheng, J., and G.H. Kruse. 2006. Recruitment variation of eastern Bering Sea crabs: climate forcing or top-down effects? Progress in Oceanography 6

• Dr. Richard A. Feely

  Supervisory Oceanographer

  National Oceanic and Atmospheric Administration (NOAA)
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