Spills of Emulsified Fuels: Risks and Response is part of an evolving body of work conducted by the National Research Council (NRC) to help inform debate and decision-making regarding the ecological consequences of releases associated with the widespread use of fossil fuels. Like earlier NRC reports, it attempts to understand the chemical, physical, and biological behavior of a complex mix of compounds that make up various petroleum hydrocarbon-based fuels. The specific risk factors presented by emulsified fuels are difficult to characterize, mainly because there have been no spills of emulsified fuels to date, and thus there is little practical experience with these products.

The safety record of lightering (the transfer of petroleum cargo at sea from a large tanker to smaller ones) has been excellent in U.S. waters in recent years, as evidenced by the very low rate of spillage of oil both in absolute terms and compared with all other tanker-related accidental spills. The lightering safety record is likely to be maintained or even improved in the future as overall quality improvements in the shipping industry are implemented. Risks can be reduced even further through measures that enhance sound lightering standards and practices, support cooperative industry efforts to maintain safety, and increase the availability of essential information to shipping companies and mariners. Only continued vigilance and attention to safety initiatives can avert serious accidents involving tankers carrying large volumes of oil. Table of Contents Front Matter Executive Summary 1 Introduction 2 Lightering Primer 3 Lightering Vessels, Systems, and the External Environment 4 Procedures, Practices, and Human Factors 5 Conclusions and Recommendations Acronyms Appendix A: Biographies of Committee Members Appendix B: Committee Meetings, Subgroup Meetings, and Site Visits Appendix C: U.S. Coast Guard Data on Lightering Incidents, 1984 to 1996 Appendix D: Data on East Coast Lightering Operations and Incidents Appendix E: Data on West Coast Lightering Operations and Incidents Appendix F: Letter Regarding Chevron Shipping Company's Offshore Lightering Plans Appendix G: Lightering Zone Regulations Appendix H: Safety Checklists Appendix I: Statement of Task

Ocean harvests have plateaued worldwide and many important commercial stocks have been depleted. This has caused great concern among scientists, fishery managers, the fishing community, and the public. This book evaluates the major models used for estimating the size and structure of marine fish populations (stock assessments) and changes in populations over time. It demonstrates how problems that may occur in fisheries data--for example underreporting or changes in the likelihood that fish can be caught with a given type of gear--can seriously degrade the quality of stock assessments. The volume makes recommendations for means to improve stock assessments and their use in fishery management.

Despite our reliance on the ocean and its resources, it remains a frontier for scientific exploration and discovery. Seafloor observatories?unmanned systems of instruments, sensors, and command modules?will have power and communication capabilities to provide support for spatially distributed sensing systems and mobile platforms. Illuminating the Hidden Planet is a voyage to the bottom of the sea, advancing oceanographic science further through long time-series measurements, to discover the mysteries of the deep that have, until now, avoided scientific opportunity.

Sound has become a major tool for studying the ocean. Although the ocean is relatively opaque to light, it is relatively transparent to sound. Sound having frequencies below 1,000 Hertz (Hz) is often defined as low-frequency sound. The speed of sound is proportional to the temperature of the water through which it passes. Therefore, sound speed can be used to infer the average temperature of the water volume through which sound waves have passed. The relationship between water temperature and the speed of sound is the basis for the Acoustic Thermometry of Ocean Climate (ATOC) experiment. The ATOC experiment is designed to monitor the travel time of sound between sources off the coasts of Hawaii and California and several receivers around the Pacific Ocean in order to detect trends in ocean temperature and for other research and monitoring purposes. Some whales, seals, and fish use low-frequency sound to communicate and to sense their environments. For example, baleen whales and some toothed whales are known to use and respond to low-frequency sound emitted by other individuals of their species. Sharks are not known to produce low-frequency sound but are attracted to pulsed low-frequency sounds. Therefore, it is possible that human-generated low-frequency sound could interfere with the natural behavior of whales, sharks, and some other marine animals. Marine Mammals and Low-Frequency Sound is an updated review of the National Research Council 1994 report Low-Frequency Sound and Marine Mammals: Current Knowledge and Research Needs, based on data obtained from the MMRP and results of any other relevant research, including ONR's research program in low-frequency sound and marine mammals. This report compares new data with the research needs specified in the 1994 NRC report, focusing on the strengths and weaknesses of the data for answering important outstanding questions about marine mammal responses to low-frequency sound and identifies areas where gaps in our knowledge continue to exist. Table of Contents Front Matter Executive Summary 1 Introduction 2 Evaluation of the Marine Mammal Research Program 3 Assessment of Continuing Research Needs 4 Regulatory Issues 5 Findings and Recommendations References Appendix A Committee Biographies Appendix B Summary from NRC (1994) Appendix C Relevant U.S. Legislation and Regulations for Marine Mammals Appendix D OSHA Regulations Appendix E Glossary of Acronyms Appendix F Species Mentioned in This Report

Sediments, ice, corals, and trees are just some of the natural storehouses of information that help tell the complicated history of Earth?s climate. Paleoclimate researchers use these ?proxies,? in combination with numerical models, to gain understanding of the magnitudes, rates, and drivers of past climate variability with the goal of informing understanding of current and future change in Earth?s climate system. The Paleo Perspectives on Climate Change (P2C2) program of the National Science Foundation (NSF) has advanced paleoclimate research through proxy development, data-model comparisons, and synthesis work, and has facilitated interdisciplinary collaboration that has contributed to the growth of the field. This new publication highlights discussions at a June 2021 workshop that focused on identifying potential future paleoclimate research directions to further advance understanding of past climate and better inform the public and decision makers about the expected future. Table of Contents Front Matter Overview Introduction Understanding Past Climate Forcings and Sensitivity Glacial, Ocean, and Land Processes and Feedbacks Resolving Regional Climate Change: Advancing and Synthesizing Knowledge How the Paleoclimate Community Can Better Engage on BAJEDI Issues Closing Thoughts References Appendix A: Statement of Task Appendix B: Biographical Sketches of Planning Committee Members Appendix C: Workshop Agenda

Hurricane- and coastal-storm-related losses have increased substantially during the past century, largely due to increases in population and development in the most susceptible coastal areas. Climate change poses additional threats to coastal communities from sea level rise and possible increases in strength of the largest hurricanes. Several large cities in the United States have extensive assets at risk to coastal storms, along with countless smaller cities and developed areas. The devastation from Superstorm Sandy has heightened the nation's awareness of these vulnerabilities. What can we do to better prepare for and respond to the increasing risks of loss? Reducing Coastal Risk on the East and Gulf Coasts reviews the coastal risk-reduction strategies and levels of protection that have been used along the United States East and Gulf Coasts to reduce the impacts of coastal flooding associated with storm surges. This report evaluates their effectiveness in terms of economic return, protection of life safety, and minimization of environmental effects. According to this report, the vast majority of the funding for coastal risk-related issues is provided only after a disaster occurs. This report calls for the development of a national vision for coastal risk management that includes a long-term view, regional solutions, and recognition of the full array of economic, social, environmental, and life-safety benefits that come from risk reduction efforts. To support this vision, Reducing Coastal Risk states that a national coastal risk assessment is needed to identify those areas with the greatest risks that are high priorities for risk reduction efforts. The report discusses the implications of expanding the extent and levels of coastal storm surge protection in terms of operation and maintenance costs and the availability of resources. Reducing Coastal Risk recommends that benefit-cost analysis, constrained by acceptable risk criteria and other important environmental and social factors, be used as a framework for evaluating national investments in coastal risk reduction. The recommendations of this report will assist engineers, planners and policy makers at national, regional, state, and local levels to move from a nation that is primarily reactive to coastal disasters to one that invests wisely in coastal risk reduction and builds resilience among coastal communities. Table of Contents Front Matter Summary 1 Introduction 2 Institutional Landscape for Coastal Risk Management 3 Performance of Coastal Risk Reduction Strategies 4 Principles for Guiding the Nation's Future Investments in Coastal Risk Reduction 5 A Vision for Coastal Risk Reduction References Appendix A: Major U.S. Coastal Storms Since 1900 Appendix B: USACE Coastal Storm Damage Reduction Projects Appendix C: Biographical Sketches of Committee Members

The ocean is central to the health of the planet and the well-being of human societies, but ongoing depletion, disruption, and pollution threaten its future. The United Nations proclaimed 2021-2030 the Decade of Ocean Science for Sustainable Development (UN Ocean Decade) in recognition of the need to sustainably manage the Ocean. U.S. participation in the Decade, guided by the U.S. National Committee, included a call for "Ocean-Shots" - ambitious, transformational research concepts that draw from multiple disciplines. More than 100 Ocean-Shots were submitted. Conducted at the request of the White House Office of Science and Technology Policy and sponsored by NASA, this report identifies exciting themes from the Ocean-Shots that will galvanize action and inspire transformative, cross-disciplinary, and multi-generational participation in the Decade. Two foundational themes undergird how to go about science: An Inclusive and Equitable Ocean calls for the involvement of a diverse and representative ocean community, and An Ocean of Data recognizes the shift toward open access for data that is collected. Four topical themes - The Ocean Revealed, The Restored and Sustainable Ocean, Ocean Solutions for Climate Resilience, and Healthy Urban Sea - represent promising areas for research investments that are consistent both with the UN Ocean Decade Outcomes and U.S. ocean priorities.

Many coastal areas of the United States are at risk for tsunamis. After the catastrophic 2004 tsunami in the Indian Ocean, legislation was passed to expand U.S. tsunami warning capabilities. Since then, the nation has made progress in several related areas on both the federal and state levels. At the federal level, NOAA has improved the ability to detect and forecast tsunamis by expanding the sensor network. Other federal and state activities to increase tsunami safety include: improvements to tsunami hazard and evacuation maps for many coastal communities; vulnerability assessments of some coastal populations in several states; and new efforts to increase public awareness of the hazard and how to respond.
Tsunami Warning and Preparedness explores the advances made in tsunami detection and preparedness, and identifies the challenges that still remain. The book describes areas of research and development that would improve tsunami education, preparation, and detection, especially with tsunamis that arrive less than an hour after the triggering event. It asserts that seamless coordination between the two Tsunami Warning Centers and clear communications to local officials and the public could create a timely and effective response to coastal communities facing a pending tsuanami.
According to Tsunami Warning and Preparedness, minimizing future losses to the nation from tsunamis requires persistent progress across the broad spectrum of efforts including: risk assessment, public education, government coordination, detection and forecasting, and warning-center operations. The book also suggests designing effective interagency exercises, using professional emergency-management standards to prepare communities, and prioritizing funding based on tsunami risk.

Regular use of sunscreens has been shown to reduce the risk of sunburn and skin cancer, and slow photoaging of skin. Sunscreens can rinse off into water where people are swimming or wading, and can also enter bodies of water through wastewater such as from bathing or showering. As a result, the ultraviolet (UV) filters - the active ingredients in sunscreens that reduce the amount of UV radiation on skin - have been detected in the water, sediment, and animal tissues in aquatic environments. Because the impact of these filters on aquatic ecosystems is not fully understood, assessment is needed to better understand their environmental impacts. This report calls on the U.S. Environmental Protection Agency to conduct an ecological risk assessment of UV filters to characterize the possible risks to aquatic ecosystems and the species that live in them. EPA should focus on environments more likely to be exposed such as those with heavy recreational use, or where wastewater and urban runoff enter the water. The risk assessment should cover a broad range of species and biological effects and could consider potential interacting effects among UV filters and with other environmental stresses such as climate change. In addition, the report describes the role of sunscreens in preventing skin cancer and what is known about how human health could be affected by potential changes in usage. While the need for a risk assessment is urgent, research is needed to advance understanding of both risks to the environment from UV filters and impacts to human health from changing sunscreen availability and usage. Table of Contents Front Matter Summary 1 Introduction 2 Introduction to Sunscreens and Their UV Filters 3 Problem Formulation: Sources, Settings, and Ecological Receptors 4 Fate, Transport, and Potential Exposure in the Environment 5 Bioaccumulation and Measured Concentrations of UV Filters in Biota 6 Review of Studies on the Effects of UV Filters in Aquatic Environments 7 Sunscreen, Preventive Health Behaviors, and Implications of Changes in Sunscreen Use for Public Health 8 Conclusions and Recommendations Appendix A: Committee Member Biographies Appendix B: UV Filter Usage Appendix C: UV Filter Water and Sediment Occurrence Data Appendix D: Supplementary Information for Bioaccumulation Appendix E: UV Filter Toxicity Data Tables Appendix F: Studies on Behavioral and Physiological Endpoints on Select Organic UV Filters Appendix G: Acronyms, Abbreviations, and Units References

An estimated 8 million metric tons (MMT) of plastic waste enters the world's ocean each year - the equivalent of dumping a garbage truck of plastic waste into the ocean every minute. Plastic waste is now found in almost every marine habitat, from the ocean surface to deep sea sediments to the ocean's vast mid-water region, as well as the Great Lakes. This report responds to a request in the bipartisan Save Our Seas 2.0 Act for a scientific synthesis of the role of the United States both in contributing to and responding to global ocean plastic waste. The United States is a major producer of plastics and in 2016, generated more plastic waste by weight and per capita than any other nation. Although the U.S. solid waste management system is advanced, it is not sufficient to deter leakage into the environment. Reckoning with the U.S. Role in Global Ocean Plastic Waste calls for a national strategy by the end of 2022 to reduce the nation's contribution to global ocean plastic waste at every step - from production to its entry into the environment - including by substantially reducing U.S. solid waste generation. This report also recommends a nationally-coordinated and expanded monitoring system to track plastic pollution in order to understand the scales and sources of U.S. plastic waste, set reduction and management priorities, and measure progress. Table of Contents Front Matter Summary 1 Introduction 2 Plastic Production and Global Trade 3 Plastic Waste and Its Management 4 Physical Transport and Pathways to the Ocean 5 Distribution and Fate of Plastic Waste in the Ocean 6 Tracking and Monitoring Systems for Ocean Plastic Waste 7 Interventions for U.S. Contributions to Global Ocean Plastic Waste References Appendixes Appendix A: Biographies of the Committee on the United States Contributions to Global Ocean Plastic Waste Appendix B: Definitions and Acronyms Appendix C: Legal Framework Appendix D: Estuary Table Appendix E: Global Instruments and Activities Relevant to Ocean Plastic Pollution

Atlantic salmon in Maine, once abundant but now seriously depleted, were listed as endangered under the federal Endangered Species Act (ESA) in November 2000. The listing covers the wild fish in eight Maine rivers as a single "distinct population segment." The controversy in Maine that accompanied the listing led Congress to request the National Research Council's (NRC's) advice on the science relevant to understanding and reversing the declines in Maine's salmon populations. The charge to the NRC's Committee on Atlantic Salmon in Maine included an interim report focusing on the genetic makeup of Maine Atlantic salmon populations. This is the interim report. Understanding the genetic makeup of Maine's salmon is important for recovery efforts, because the degree to which populations in Maine differ from adjacent populations in Canada and the degree to which populations in different Maine rivers and tributaries differ from each other affect the choice of recovery options that are most likely to be effective. This report focuses only on questions of genetic distinctiveness. The committee's final report will address the broader issues, such as the factors that have caused Maine's salmon populations to decline and the options for helping them to recover.

Marine mammals face a large array of stressors, including loss of habitat, chemical and noise pollution, and bycatch in fishing, which alone kills hundreds of thousands of marine mammals per year globally. To discern the factors contributing to population trends, scientists must consider the full complement of threats faced by marine mammals. Once populations or ecosystems are found to be at risk of adverse impacts, it is critical to decide which combination of stressors to reduce to bring the population or ecosystem into a more favorable state. Assessing all stressors facing a marine mammal population also provides the environmental context for evaluating whether an additional activity could threaten it. Approaches to Understanding the Cumulative Effects of Stressors on Marine Mammals builds upon previous reports to assess current methodologies used for evaluating cumulative effects and identify new approaches that could improve these assessments. This review focuses on ways to quantify exposure-related changes in the behavior, health, or body condition of individual marine mammals and makes recommendations for future research initiatives. Table of Contents Front Matter Summary 1 Introduction 2 Estimating Exposure and Effects of Sound on Wildlife 3 Current Understanding of Stressors 4 Assessing Interactions Among Stressors 5 Modeling the Population Consequences of Exposure to Multiple Stressors 6 Interactions Among Stressors and Challenges to Understanding Their Cumulative Effects 7 Early Warning Signs of Risk to Populations 8 Approaches to Assess Cumulative Impacts References Appendix A: Workshop Agenda Appendix B: Relevant Laws and Regulations Appendix C: Committee and Staff Biographies Appendix D: Glossary

The Earth system - the atmospheric, hydrologic, geologic, and biologic cycles that circulate energy, water, nutrients, and other trace substances - is a large, complex, multiscale system in space and time that involves human and natural system interactions. Machine learning (ML) and artificial intelligence (AI) offer opportunities to understand and predict this system. Researchers are actively exploring ways to use ML/AI approaches to advance scientific discovery, speed computation, and link scientific communities. To address the challenges and opportunities around using ML/AI to advance Earth system science, the National Academies convened a workshop in February 2022 that brought together Earth system experts, ML/AI researchers, social and behavioral scientists, ethicists, and decision makers to discuss approaches to improving understanding, analysis, modeling, and prediction. Participants also explored educational pathways, responsible and ethical use of these technologies, and opportunities to foster partnerships and knowledge exchange. This publication summarizes the workshop discussions and themes that emerged throughout the meeting. Table of Contents Front Matter Overview Introduction Emerging Approaches for Using, Interpreting, and Integrating ML/AI for Earth System Science Challenges and Risks of Using ML/AI for Earth System Science Identifying Future Opportunities to Accelerate Progress Closing Thoughts References Appendix A: Statement of Task Appendix B: Planning Committee Biographies Appendix C: Workshop Agenda

The Bureau of Ocean Energy Management (BOEM) manages the energy and mineral resources on the outer continental shelf. BOEM's environmental program, by producing environmental studies and conducting environmental assessments, ensures that environmental protection is a critical element of BOEM's decision making. This report addresses BOEM's aspirations to conduct a first-in-class science program within their Environmental Studies Program (ESP). This report describes attributes identified by the committee of a first-in-class, use-inspired, management-oriented science program (in this case, BOEM's ESP and its connection to the broader BOEM environmental program). The report recommends that BOEM develop procedures and conduct regular evaluations to assess whether and how well its environmental program meets the attributes of a first-in-class program and identify areas for improvement. It also outlines a framework for conducting such an evaluation. The report contains guidance and examples drawn from a workshop series with BOEM's peer agencies and other science programs, as well as other information gathering efforts. The guidance contained in this report is offered to BOEM as a starting point for developing more detailed processes for evaluating and improving its program. Table of Contents Front Matter Attributes of a First-in-Class Environmental Program: A Letter Report Appendix A: Statement of Task Appendix B: Committee on the Assessment and Advancement of Science in the Bureau of Ocean Energy Management's Environmental Studies Program Appendix C: Workshop Series Agenda Appendix D: Acknowledgments Appendix E: References

The ocean has absorbed a significant portion of all human-made carbon dioxide emissions. This benefits human society by moderating the rate of climate change, but also causes unprecedented changes to ocean chemistry. Carbon dioxide taken up by the ocean decreases the pH of the water and leads to a suite of chemical changes collectively known as ocean acidification. The long term consequences of ocean acidification are not known, but are expected to result in changes to many ecosystems and the services they provide to society. Ocean Acidification: A National Strategy to Meet the Challenges of a Changing Ocean reviews the current state of knowledge, explores gaps in understanding, and identifies several key findings. Like climate change, ocean acidification is a growing global problem that will intensify with continued CO2 emissions and has the potential to change marine ecosystems and affect benefits to society. The federal government has taken positive initial steps by developing a national ocean acidification program, but more information is needed to fully understand and address the threat that ocean acidification may pose to marine ecosystems and the services they provide. In addition, a global observation network of chemical and biological sensors is needed to monitor changes in ocean conditions attributable to acidification. Table of Contents Front Matter Summary 1 Introduction 2 Effects of Ocean Acidification on the Chemistry of Seawater 3 Effects of Ocean Acidification on the Physiology ofMarine Organisms 4 Effects of Ocean Acidification on Marine Ecosystems 5 Socioeconomic Concerns 6 A National Ocean Acidification Program References Appendix A: Committee and Staff Biographies Appendix B: Acronyms Appendix C: The Effect of Ocean Acidification on Calcification in Calcifying Algae, Corals,and Carbonate-dominated Systems Appendix D: Summary of Research Recommendations from Community-based References

Accurate and timely environmental information can provide a tactical advantage to U.S. naval forces during warfare. This report analyzes the current environmental information system used by the U.S. Navy and Marine Corps and recommends ways to address uncertainty and leverage network-centric operating principles to enhance the value of environmental information.

Coral reef declines have been recorded for all major tropical ocean basins since the 1980s, averaging approximately 30-50% reductions in reef cover globally. These losses are a result of numerous problems, including habitat destruction, pollution, overfishing, disease, and climate change. Greenhouse gas emissions and the associated increases in ocean temperature and carbon dioxide (CO2) concentrations have been implicated in increased reports of coral bleaching, disease outbreaks, and ocean acidification (OA). For the hundreds of millions of people who depend on reefs for food or livelihoods, the thousands of communities that depend on reefs for wave protection, the people whose cultural practices are tied to reef resources, and the many economies that depend on reefs for fisheries or tourism, the health and maintenance of this major global ecosystem is crucial. A growing body of research on coral physiology, ecology, molecular biology, and responses to stress has revealed potential tools to increase coral resilience. Some of this knowledge is poised to provide practical interventions in the short-term, whereas other discoveries are poised to facilitate research that may later open the doors to additional interventions. A Research Review of Interventions to Increase the Persistence and Resilience of Coral Reefs reviews the state of science on genetic, ecological, and environmental interventions meant to enhance the persistence and resilience of coral reefs. The complex nature of corals and their associated microbiome lends itself to a wide range of possible approaches. This first report provides a summary of currently available information on the range of interventions present in the scientific literature and provides a basis for the forthcoming final report. Table of Contents Front Matter Summary 1 Introduction 2 Genetic and Reproductive Interventions 3 Physiological Interventions 4 Coral Population and Community Interventions 5 Environmental Interventions 6 Conclusion References Glossary Appendix A: Committee and Staff Biographies Appendix B: Information-Gathering Meeting Agendas

To achieve goals for climate and economic growth, "negative emissions technologies" (NETs) that remove and sequester carbon dioxide from the air will need to play a significant role in mitigating climate change. Unlike carbon capture and storage technologies that remove carbon dioxide emissions directly from large point sources such as coal power plants, NETs remove carbon dioxide directly from the atmosphere or enhance natural carbon sinks. Storing the carbon dioxide from NETs has the same impact on the atmosphere and climate as simultaneously preventing an equal amount of carbon dioxide from being emitted. Recent analyses found that deploying NETs may be less expensive and less disruptive than reducing some emissions, such as a substantial portion of agricultural and land-use emissions and some transportation emissions. In 2015, the National Academies published Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration, which described and initially assessed NETs and sequestration technologies. This report acknowledged the relative paucity of research on NETs and recommended development of a research agenda that covers all aspects of NETs from fundamental science to full-scale deployment. To address this need, Negative Emissions Technologies and Reliable Sequestration: A Research Agenda assesses the benefits, risks, and "sustainable scale potential" for NETs and sequestration. This report also defines the essential components of a research and development program, including its estimated costs and potential impact. Table of Contents Front Matter Summary 1 Introduction 2 Coastal Blue Carbon 3 Terrestrial Carbon Removal and Sequestration 4 Bioenergy with Carbon Capture and Sequestration 5 Direct Air Capture 6 Carbon Mineralization of CO2 7 Sequestration of Supercritical CO2 in Deep Sedimentary Geological Formations 8 Synthesis Glossary Acronyms and Abbreviations References Appendix A: Committee Bios Appendix B: Disclosure of Conflict of Interest Appendix C: Coastal Blue Carbon:Macroalgae Appendix D: CO2 Flux Calculation Appendix E: Carbon Mineralization Appendix F: Geologic Storage

Many factors contribute to variability in Earth's climate on a range of timescales, from seasons to decades. Natural climate variability arises from two different sources: (1) internal variability from interactions among components of the climate system, for example, between the ocean and the atmosphere, and (2) natural external forcings, such as variations in the amount of radiation from the Sun. External forcings on the climate system also arise from some human activities, such as the emission of greenhouse gases (GHGs) and aerosols. The climate that we experience is a combination of all of these factors. Understanding climate variability on the decadal timescale is important to decision-making. Planners and policy makers want information about decadal variability in order to make decisions in a range of sectors, including for infrastructure, water resources, agriculture, and energy. In September 2015, the National Academies of Sciences, Engineering, and Medicine convened a workshop to examine variability in Earth's climate on decadal timescales, defined as 10 to 30 years. During the workshop, ocean and climate scientists reviewed the state of the science of decadal climate variability and its relationship to rates of human-caused global warming, and they explored opportunities for improvement in modeling and observations and assessing knowledge gaps. Frontiers in Decadal Climate Variability summarizes the presentations and discussions from the workshop. Table of Contents Front Matter Overview Introduction Challenges in Examining Climate Trends Modes and Mechanisms of Internal Variability The Role of External Forcing Overcoming Data Limitations Toward Predictability Frontiers and Research Opportunities References Appendix A: Statement of Task Appendix B: Planning Committee Biographical Sketches Appendix C: Workshop Agenda Appendix D: Workshop Participants Appendix E: Panel Presentation Abstracts Appendix F: Song Lyrics

As of 2021, atmospheric carbon dioxide levels have reached historically unprecedented levels, higher than at any time in the past 800,000 years. Worldwide efforts to reduce emissions by creating a more efficient, carbon-free energy system may not be enough to stabilize the climate and avoid the worst impacts of climate change. Carbon dioxide removal (CDR) strategies, which remove and sequester carbon from the atmosphere, likely will be needed to meet global climate goals. The ocean, covering 70% of the Earth's surface, includes much of the global capacity for natural carbon sequestration; the ocean also holds great potential for uptake and longerterm sequestration of human-produced CO2. This report builds on previous work from the National Academies to assess what is currently known about the benefits, risks, and potential for responsible scale-up of six specific ocean-based CDR strategies as identified by the sponsor, ClimateWorks Foundation. It describes the research needed to advance understanding of those approaches and address knowledge gaps. The resulting research agenda is meant to provide an improved and unbiased knowledge base for the public, stakeholders, and policymakers to make informed decisions on the next steps for ocean CDR, as part of a larger climate mitigation strategy; it is not meant to lock in or advocate for any particular approach. Table of Contents Front Matter Summary 1 Introduction 2 Crosscutting Considerations on Ocean-based CDR R&D 3 Nutrient Fertilization 4 Artificial Upwelling and Downwelling 5 Seaweed Cultivation 6 Recovery of Marine Ecosystems 7 Ocean Alkalinity Enhancement 8 Electrochemical Engineering Approaches 9 Synthesis and Research Strategy References Acronyms and Abbreviations Appendix A: Committee Biographies Appendix B: Workshop and Meeting Public Presentations to the Committee

A central goal of U.S. fisheries management is to control the exploitation of fish populations so that fisheries remain biologically productive, economically valuable, and socially equitable. Although the Magnuson-Stevens Fishery Conservation and Management Act led to many improvements, a number of fish populations remained overfished and some fisheries were considered economically inefficient. In response, Congress amended the Act in 2006 to allow additional management approaches, including Limited Access Privilege Programs (LAPPs) in which individuals receive a permit to harvest a defined portion of the total allowable catch for a particular fish stock. This report examines the impacts of LAPPs on mixed-use fisheries, defined as fisheries where recreational, charter, and commercial fishing sectors target the same species or stocks. The report offers recommendations for NOAA's National Marine Fisheries Service (NMFS) and the Regional Fishery Management Councils (the Councils) who oversee and manage federally regulated fisheries. For each of the five mixed-use fisheries included in the report, the committee examined available fisheries data and analyses and collected testimony from fishery participants, relevant Councils, and NMFS regional experts through a series of public meetings. Table of Contents Front Matter Executive Summary Summary 1 Introduction 2 Individual Quota Systems and LAPPs 3 Progress in Meeting Goals of LAPPs and Magnuson-Stevens Fishery Conservation and Management Act as Determined by Program Reviews 4 Ecological Impacts of LAPPs in Mixed-Use Fisheries 5 Social and Economic Effects for Commercial Participants in Mixed-Use Fisheries 6 Social and Economic Effects of LAPPs for Recreational Fishery Stakeholders in Mixed-Use Fisheries 7 Broader Community Social and Economic Effects 8 Addressing the Impacts of LAPPs in Mixed-Use Fisheries References Appendix: Committee Biographies

Marine recreational fishing is a popular activity enjoyed by more than 9 million Americans annually and is a driver of the American ocean-or blue-economy. To ensure that fish populations are not overexploited, the NOAA Fisheries' Marine Recreational Information Program (MRIP) monitors recreational catch through a variety of in-person, telephone, mail-in, and other surveys. NOAA Fisheries' management of recreational catch also must take into account annual catch limits (ACLs) established to prevent overfishing for all managed species in federal waters. While MRIP has worked to improve recreational catch surveys over the past decade, the surveys were never designed to meet the demands of in-season management of ACLs. In some cases, estimates of harvest have triggered accountability measures such as early season closures and reductions in future recreational ACLs, which have been a source of contention with the recreational fishing community. This report presents approaches for optimizing MRIP data and complementary data for in-season management and considers alternatives for managing recreational fisheries with ACLs to better serve both social and economic management objectives. Table of Contents Front Matter Summary 1 Introduction 2 The U.S. Fisheries Management and Assessment Framework 3 Existing Recreational Fisheries Surveys and ACL-Based Fisheries Management 4 Optimizing Use of MRIP Data and Complementary Data for In-Season Management 5 Alternative Management Strategies for Recreational Fisheries Appendix A: Multiple-Frame Methods Appendix B: Leveraging Covariances and Conditionals Appendix C: Contemporaneous Correlation SUR Model Appendix D: Bayesian Methods Appendix E: Rare-Event Species: Normal or Poisson? Appendix F: Rare-Event Species: Inverse Sampling Appendix G: Rare-Event Species: Uninformative Priors and Bayes' Rule Appendix H: Defining and Managing Outliers in MRIP Output: An Order Statistics Approach

In the United States (U.S.), the Fishery Conservation and Management Act of 1976, now known as the Magnuson-Stevens Fishery Conservation and Management Act (MSFCMA), was the first major legislation to regulate federal fisheries in the U.S. Fishery Conservation Zone (later designated as the U.S. exclusive economic zone). The re-authorization of the MSFCMA passed by Congress in 2006 included additional mandates for conserving and rebuilding fish stocks and strengthening the role of scientific advice in fisheries management. Approximately 20% of the fisheries that have been assessed are considered overfished according to the September 2012 stock status Report to Congress prepared by the U.S. National Oceanic and Atmospheric Administration (NOAA). Overfished refers to a stock that is below the minimum stock size threshold, commonly set to half the stock size at which maximum sustainable yield (MSY) is achieved. Under the provisions of the MSFCMA, rebuilding plans for overfished stocks should take no more than 10 years, except when certain provisions apply. Rebuilding mandates have led to substantial reductions in catch and effort for many fisheries, raising concerns about the consequent social and economic impacts to the fishing communities and industry. Evaluating the Effectiveness of Fish Stock Rebuilding Plans in the United States reviews the technical specifications that underlie current federally-implemented rebuilding plans, and the outcomes of those plans. According to this report, fisheries management has evolved substantially since 1977 when the U.S. extended its jurisdiction to 8 200 miles, in the direction of being more prescriptive and precautionary in terms of preventing overfishing and rebuilding overfished fisheries. However, the trade-offs between precaution and yield have not been fully evaluated. Evaluating the Effectiveness of Fish Stock Rebuilding Plans in the United States discusses the methods and criteria used to set target fishing mortality and biomass levels for rebuilding overfished stocks, and to determine the probability that a particular stock will rebuild by a certain date. This report will be of interest to the fishing industry, ecology professionals, and members of Congress as they debate the renewal of the Magnuson-Stevens Fishery Conservation and Management Act. Table of Contents Front Matter Summary 1 Introduction 2 U.S. Fisheries Management and the Law 3 Review of Federally Implemented Rebuilding Plans 4 Technical Considerations in Developing Rebuilding Plans 5 Ecosystem Considerations 6 Human Dimensions of Rebuilding 7 Looking Forward References Appendix A: Committee and Staff Biographies Appendix B: List of Acronyms Appendix C: Time Series Plots

Whether the result of an oil well blowout, vessel collision or grounding, leaking pipeline, or other incident at sea, each marine oil spill will present unique circumstances and challenges. The oil type and properties, location, time of year, duration of spill, water depth, environmental conditions, affected biomes, potential human community impact, and available resources may vary significantly. Also, each spill may be governed by policy guidelines, such as those set forth in the National Response Plan, Regional Response Plans, or Area Contingency Plans. To respond effectively to the specific conditions presented during an oil spill, spill responders have used a variety of response options?including mechanical recovery of oil using skimmers and booms, in situ burning of oil, monitored natural attenuation of oil, and dispersion of oil by chemical dispersants. Because each response method has advantages and disadvantages, it is important to understand specific scenarios where a net benefit may be achieved by using a particular tool or combination of tools. This report builds on two previous National Research Council reports on dispersant use to provide a current understanding of the state of science and to inform future marine oil spill response operations. The response to the 2010 Deepwater Horizon spill included an unprecedented use of dispersants via both surface application and subsea injection. The magnitude of the spill stimulated interest and funding for research on oil spill response, and dispersant use in particular. This study assesses the effects and efficacy of dispersants as an oil spill response tool and evaluates trade-offs associated with dispersant use. Table of Contents Front Matter SUMMARY 1 INTRODUCTION 2 FATE AND TRANSPORT 3 AQUATIC TOXICOLOGY AND BIOLOGICAL EFFECTS 4 HUMAN HEALTH CONSIDERATIONS 5 TOOLS FOR DECISION MAKING 6 COMPARING RESPONSE OPTIONS 7 RESEARCH AND DECISION-MAKING PROTOCOLS REFERENCES APPENDIX A: COMMITTEE AND STAFF BIOGRAPHIES APPENDIX B: DISCLOSURE OF UNAVOIDABLE CONFLICT OF INTEREST APPENDIX C: ACRONYMS AND ABBREVIATIONS APPENDIX D: MINORITY REPORT APPENDIX E: CONSULTANTS' REPORT APPENDIX F: META-ANALYSIS OF AQUATIC TOXICITY DATA