Worldwide, marine ecosystems have been lost and degraded due to anthropogenic disturbances. For example, oyster reefs have declined by at least ∼85%, coral reefs by ∼19%, seagrasses by ∼29%, North American salt marshes by ∼42%, and mangroves by ∼35% from the early 19th century. Deepwater reefs and deep-sea vents are not immune and have also been reduced in extent in many areas. Factors driving these losses include habitat destruction, pollution, invasive species, overfishing, trawling, mining and, more recently, climate change effects, such as ocean warming, species range changes and acidification. These habitat declines are occurring at a time when marine waters are being used at or near their maximum productive capacity to meet the contemporary needs of an ever-increasing human population. Because coastal and marine ecosystems generate some of the richest biodiversity hotspots on Earth, and provide critical ecosystem services, including storm protection, fisheries production, and carbon storage, over 1 billion US dollars have been spent globally in an attempt to halt and reverse observed declines. Early conservation efforts aimed at protecting these valuable and threatened habitats focused on reducing human impacts and physical stressors. However, with habitat degradation continuing and sometimes increasing in rate, it is now clear conservation alone will not be sufficient to protect and reestablish coastal ecosystems. Habitat restoration, although in existence for many decades, has recently been elevated as a new primary strategy to stem and even reverse coastal habitat loss. The call for increasing investment in restoration efforts has emerged with significant advances in propagule rearing and dispersion of habitat-forming organisms (e.g., oysters, seagrasses, corals). In addition, restoration resources are increasingly allocated by governments and/or large corporations with the aim to, for example, fix past landscape engineering efforts that had unintended environmental consequences. Such investments are being made to (i) provide jobs for those unemployed during economic downturns, (ii) restore ecosystems destroyed by natural disasters and stressors, (iii) increase coastal defense in response to increased frequency of intense storms, and/or (iv) compensate for pollution-and development-driven habitat degradation. Conservation practitioners have traditionally been skeptical to invest heavily in restoration at large-scales because of the high cost per area (10,000-5,000,000 US$/ha for coastal vs. 500-5,000 US$/ha for terrestrial systems) to replant coastal ecosystems and/or the high chance that the restored ecosystems will not live long (e.g. outplanted corals). For restoration to be effective and employed as a primary method of coastal conservation at relevant scales, we must improve its efficiency, lower costs and rapidly share and incorporate advances. One crucial step will be to identify when and where restoration attempts have been carried out according to state-of-art ecological theory and gauge their success. Another is generating synthesis studies that focus both within and across ecosystems to identify efficiencies, adaptations and innovations. Work that shows theoretical and methodological innovations in specific ecosystems as well as across systems will be critical to pushing all fields of MER forward. Although there is rapidly increasing interest and investment, the field of marine ecosystem restoration is just beginning to undergo synthesis. Therefore, the aim of this Research Topic is to bring together research contributions to help address this synthesis need, provide a spotlight for recent innovations, enhance our understanding of successful methods in marine ecosystem restoration and promote integration of ecological, sociological and engineering theory into restoration practices.

Tremendous changes have occurred this century in the nation's coastal habitats, in the way society views them, and in the way they are managed. This volume offers a complete, highly readable assessment of how scientific knowledge and coastal engineering capabilities can be more effectively used to protect and restore marine habitat. It addresses traditional and innovative uses of technology to protect remaining natural marine habitats, to enhance or restore those that have been altered, and to create marine habitat from lands used for other purposes. The use of dredged materials as a vital resource in protection and restoration work is explored. The book also explores organizational, management, and regulatory barriers to using the best available technology and engineering practice. Specific options for improvements are offered in each area.

Anthropogenic interventions and actions upon the marine habitat pose threats to a range of species of economic and conservation concern. The dynamic nature of marine ecosystems offers a difficult challenge to incorporate spatial and temporal distributions of different species, and the interactions among species and human activities into a formal management framework. Each country has its own priorities when it comes to management of the marine resources (e.g. conservation, food security, sustainable fisheries, and optimization of revenue). Therefore, a key hurdle is to create tools adequate for use within an Ecosystem Approach to Management (EAM) and Ecosystem-based Management (EBM) framework, that meet local and regional needs. Models can provide insights regarding ecosystems dynamics and generate tools for management applications, including the estimation of optimal conditions and frameworks, assessing current conditions relative to baselines, exploring the effects of potential management decisions and delimiting areas where monitoring efforts of species of concern or "choke species" should be concentrated. The present work focuses on all these elements with the aim to provide modeling and visualization capacity to management decision making. My dissertation had two main objectives, divided in two case studies in distinct geographic and data availability settings. The first was to develop spatial models to promote the adequate monitoring of species of conservation concern (SOC) within a data-limited setting in two multiuse marine protected areas (MPAs) in the Amazon Delta, Northern Brazil by: 1) collecting SOC available data; 2) developing GIS-based suitability models; and 3) generating baseline knowledge for future management strategies of SOCs. The second objective was to study alewife (Alosa pseudoharengus) role within a data-rich setting in the Northeast U.S. large marine ecosystem (NEUS LME) and the Gulf of Maine (GOM) marine ecosystem by: 1) developing food-web based ecosystem models; 2) assessing the impacts of anadromous forage fish restoration; 3) testing riverine and marine-based management strategies to promote their recovery. For the data-limited studies, I found that extreme data scarcity impeded our ability to develop a model for the Environmental Protection Area (EPA) of Algodoal-Maiandeua, Northern Brazil. However, it allowed us to show preliminary data of sea turtles' observations and fixed fishing gears in the EPA, giving basis to the future develop of spatially explicit models. While for the second multiuse MPA, the Soure Marine Extractive Reserve (MER), we were able to successfully develop a spatial explicit suitability model focused on monitoring priority areas for SOCs. Our results show that 30% of the MER is under medium, high and extremely high monitoring priority, allowing more effective development of monitoring design for SOCs. For the data-rich setting, I found that the full restoration of alewife in the NEUS LME could lead to a 50% potential biomass increase for small pelagics, 26% for fisheries target species, and approximately 69% for SOCs. This provided a more stable picture for the middle trophic level forage species and lead to major potential biomass changes for SOCs. I also found that fishing effort reduction alone did little to promote alewife recovery in the GOM marine ecosystem. However, when river to ocean connectivity was added to fishing effort reductions. The alosine (alewife, blueback herring, and American shad) group showed a major response. As a whole, my dissertation captures a range of management approaches from data-limited to data-rich systems, using modeling approaches to optimize decision making.

With the health of the world’s oceans threatened as never before, it is becoming increasingly apparent that Marine Protected Areas (MPAs) play a vitally important role in protecting marine and coastal habitats. Management of Marine Protected Areas: A Network Perspective draws on the results of a major EU-sponsored research project related to the establishment of networks of MPAs in the Mediterranean and Black Seas that transpired from February 2011 to January 2016. Featuring contributions by leading university- and national research institute-based scientists, chapters utilize the latest research data and developments in marine conservation policy to explore issues related to ways in which networks of MPAs may amplify the effectiveness and conservation benefits of individual areas within them. Topics addressed include the broader socio-economic impacts of MPAs in the Mediterranean and Black Seas; the use of Marine Spatial Planning (MSP) to resolve conflicts between marine resource use and protection; special protection measures under the EU’s Marine Strategy Framework Directive (MSFD); ecological value assessments in the Black Sea; the Ecosystem Approach (EA) for managing marine ecosystems; MPAs along Turkey’s Black Sea coast; MPAs and offshore wind farms; and managing and monitoring MPA networks within and between the Black and Mediterranean Seas. Timely and important, Management of Marine Protected Areas: A Network Perspective offers invaluable insights into the role of MPAs in preserving the welfare and long-term viability of our world’s oceans.

The authors are hopeful. Rather than lamenting the persistent conflicts in global marine ecosystems, they instead sought out examples where managers were doing things differently and making progress against great odds. They interviewed planners, managers, community members, fishermen, and environmentalists throughout the world to find the best lessons for others hoping to advance marine conservation. Their surprising discovery? Successful marine management requires not only the right mix of science, law, financing, and organizational structure, but also an atmosphere of collaboration--a comfortable place for participants to learn about issues, craft solutions, and develop the interpersonal relationships, trust, and understanding needed to put plans into action. This volume is the first practical guide for the marine conservation realm. In a unique collection of case studies, the authors showcase successful collaborative approaches to ecosystem-based management. The authors introduce the basic concepts of ecosystem-based management and five different pathways for making progress from community to multinational levels. They spotlight the characteristics that are evident in all successful cases --the governance structures and social motivations that make it work. Case analyses ranging from the Gulf of Maine to the Channel Islands in Southern California comprise the bulk of the book, augmented by text boxes showcasing examples of guiding documents important to the process. They devote several ending chapters to discussion of the interpersonal relationships critical to successful implementation of marine ecosystem-based management. The book concludes with a discussion of the implications for policy and on-the-ground practice. This book offers a hopeful message to policy makers, managers, practitioners, and students who will find this an indispensable guide to field-tested, replicable marine conservation management practices that work.>.