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Abstract The mobile nature of migratory marine animals across jurisdictional boundaries can challenge the management of biodiversity, particularly under global environmental change. While projections of climate-driven habitat change can reveal whether marine species are predicted to gain or lose habitat in the future, geopolitical boundaries and differing governance regimes may influence animals’ abilities to thrive in new areas. Broad geographic movements and diverse governance approaches elicit the need for strong international collaboration to holistically manage and conserve these shared migratory species. In this study, we use data from the Tagging of Pacific Predators program to demonstrate the feasibility of using climate-driven habitat projections to assess species’ jurisdictional redistribution. Focusing on four species (shortfin mako shark, California sea lion, northern elephant seal, and sooty shearwater), we calculate the projected change in core habitat across jurisdictional boundaries throughout the century and highlight associated management implications. Using climate-driven habitat projections from the period of 2001 to 2010, and an RCP 8.5 climate scenario, we found that all four species are projected to face up to a 2.5-10% change in core habitat across jurisdictions in the Northeast Pacific, with the greatest gains of core habitat redistribution within the United States exclusive economic zone and in areas beyond national jurisdiction. Overall, our study demonstrates how efforts to understand the impacts of climate change on species’ habitat use should be expanded to consider how resulting shifts may provoke new management challenges in a legally bounded, yet physically borderless ocean. We discuss governance implications for transboundary habitat redistribution as highly migratory marine species potentially shift across legal jurisdictions, including new ocean areas beyond national judications, considerations which are applicable within and beyond this Pacific case study. Our study also highlights data needs and management strategies to inform high-level conservation strategies, as well as recommendations for using updated tagging data and climate models to build upon this approach in future work.

Abstract Planning of marine areas has spread widely over the past two decades to support sustainable ocean management and governance. However, to succeed in a changing ocean, marine spatial planning (MSP) must be ‘climate-smart’— integrating climate-related knowledge, being flexible to changing conditions, and supporting climate actions. While the need for climate-smart MSP has been globally recognized, at a practical level, marine managers and planners require further guidance on how to put it into action. Here, we suggest ten key components that, if well-integrated, would promote the development and implementation of sustainable, equitable, climate-smart MSP initiatives around the globe.

The accelerated pace of climate-driven shifts is surpassing the temporal scope of conventional field research, potentially leading to a disconnect between ecosystem changes and scientific data collection. Climate change is producing rapid transformations within dynamic marine ecosystems, with a pronounced effect on high trophic-level species such as loggerhead sea turtles (Caretta caretta). We present a new model for data collection using ethnobiological methods, emphasizing how local community members can contribute to expanding scientific knowledge via context-informed observations, to document species occurrences beyond their anticipated habitats during climatic anomalies. In rapidly changing conditions, local expert knowledge can complement conventional scientific methods, providing high-quality data with extensive coverage—especially for elusive species—and yielding insight into potential emerging phenomena that may otherwise go unnoticed. Conventional methods for predicting distribution shifts in rare species are vulnerable to spatial biases, favoring predictions based on the most probable habitats. We present the case study of a live sea turtle sighting by a local expert in Monterey Bay, California, USA, identified post hoc as a loggerhead, to illustrate methods which can be transferred and applied to other rare and highly migratory marine species such as marine mammals, sharks, and seabirds. This emerging framework incorporates diverse knowledge sources and methodologies in monitoring climate-driven ecological shifts, enriching conservation strategies, enhancing our understanding of complex ecosystems, and contributing to robust evidentiary standards for rare species observations.

Abstract Trait-based frameworks are increasingly used for predicting how ecological communities respond to ongoing global change. As species range shifts result in novel encounters between predators and prey, identifying prey ‘guilds’, based on a suite of shared traits, can distill complex species interactions, and aid in predicting food web dynamics. To support advances in trait-based research in open-ocean systems, we present the Pelagic Species Trait Database, an extensive resource documenting functional traits of 529 pelagic fish and invertebrate species in a single, open-source repository. We synthesized literature sources and online resources, conducted morphometric analysis of species images, as well as laboratory analyses of trawl-captured specimens to collate traits describing 1) habitat use and behavior, 2) morphology, 3) nutritional quality, and 4) population status information. Species in the dataset primarily inhabit the California Current system and broader NE Pacific Ocean, but also includes pelagic species known to be consumed by top ocean predators from other ocean basins. The aim of this dataset is to enhance the use of trait-based approaches in marine ecosystems and for predator populations worldwide.

The response of aquatic and terrestrial organisms to climate change can depend on biological sex. A key challenge is to unravel the interactive effects of sex and climate change at the individual and population levels and the cascading effects on communities. This new understanding is essential to improve climate adaptation and mitigation strategies.

As global climate change reorganizes marine ecosystems, understanding how predators will respond to variable prey resources is critical to forecasting future community dynamics. Prey traits that affect the foraging process and recur across unrelated taxa offer a means to better anticipate predator resource use by simplifying complex foraging dynamics. Here we compare taxonomic and trait-based indicators of resource use and selection for albacore tuna (Thunnus alalunga), a commercially valuable pelagic predator undergoing climate-driven range shifts. We synthesized datasets from 2005 to 2019 to evaluate diets of albacore tuna in relation to prey availability estimates from shipboard surveys in the California Current Large Marine Ecosystem. Analyses with these data reveal that albacore and trawl surveys sample different aspects of the pelagic system, with albacore consuming a subset of taxa identified within trawls. Albacore consistently selected coastal prey that are schooling, undefended, silvered and countershaded, and have high energy density — suggesting that ecological mechanisms driving albacore foraging outcomes may be conserved across time and space. Ecological traits mediating predator-prey interactions consistently distinguished albacore diets from assemblages sampled by trawls across years and regions. We demonstrate that a traits-based approach simplifies taxonomically diverse predator-prey interactions and may be a valuable tool to facilitate predictions of prey resource use in changing environments.

Turbidity from land-based runoff has been identified as a possible driver of coral bleaching refugia, as particulate matter in turbid habitats may block excessive irradiance and alter the food supply to corals during ocean heatwaves. However, negative effects of turbidity have also been documented worldwide, and high-resolution data across reef regions are required to identify habitats where turbidity is harmful or helpful during heatwaves. We monitored turbidity across five Main Hawaiian Islands during a 2019 ocean heatwave using Planet Dove satellites (3.7 m spatial resolution, extracted at 100 m resolution) to examine relationships between turbidity and coral bleaching occurrence and severity. We also attributed turbidity to urban and non-urban land uses to determine how turbidity associated with different human activities affects coral bleaching. We found that, while turbidity had a negative relationship with coral bleaching severity, this effect weakened at higher temperatures, especially in rural areas. However, turbidity maintained a slightly negative effect on bleaching severity in urban settings. In addition, while thermal stress was the predominant driver of bleaching occurrence, interactions between temperature and local variables like turbidity and wave energy were the most significant drivers of bleaching severity. This study represents one of the first high-resolution analyses of turbid refugia at large spatial scales. We show how new data sources from remote sensing can provide scalable yet context-specific information to coastal managers addressing land-sea runoff.

The end of the long and winding road towards a milestone new treaty focused on the conservation and sustainable use of marine biodiversity beyond national jurisdiction (BBNJ) is near. The BBNJ treaty has the potential to dramatically transform environmental stewardship in the high seas, making it essential that vigorous support towards a strong treaty continues, without weakening the agreement’s full potential. Historically, the dialogue surrounding the BBNJ negotiations has focused on the agreement’s environmental and conservation-related impacts. Here, we begin to highlight the many diplomatic, economic, and social benefits of a vigorous and equitable BBNJ treaty. We found that strong support for the BBNJ treaty could strengthen multilateral institutions and bolster international cooperation towards common environmental goals. It could also enhance the health of shared marine ecosystems and resources and drive truly sustainable ocean-based economic growth. Finally, the treaty provides an opportunity to engage equity as a key principle, to begin tackling global ocean inequalities in a meaningful way. Together, we find that the new treaty has the potential for widespread and diverse benefits for all member nations. It is past time for the international community to address the global governance gap in the high seas in an ambitious and equitable manner.

The North Pacific Loggerhead sea turtle (Caretta caretta) undergoes one of the greatest of all animal migrations, nesting exclusively in Japan and re-emerging several years later along important foraging grounds in the eastern North Pacific. Yet the mechanisms that connect these disparate habitats during what is known as the “lost years” have remained poorly understood. Here, we develop a new hypothesis regarding a possible physical mechanism for habitat connectivity – an intermittent “thermal corridor” – using remotely sensed oceanography and 6 juvenile loggerhead sea turtles that formed part of a 15 year tracking dataset of 231 individuals (1997–2013). While 97% of individuals remained in the Central North Pacific, these 6 turtles (about 3%), continued an eastward trajectory during periods associated with anomalously warm ocean conditions. These few individuals provided a unique opportunity to examine previously unknown recruitment pathways. To support this hypothesis, we employed an independently derived data set using novel stable isotope analyses of bone growth layers and assessed annual recruitment over the same time period (n = 33, 1997–2012). We suggest evidence of a thermal corridor that may allow for pulsed recruitment of loggerheads to the North American coast as a function of ocean conditions. Our findings offer, for the first time, the opportunity to explore the development of a dynamic ocean corridor for this protected species, illuminating a longstanding mystery in sea turtle ecology.

Abstract The U.S. Congress is currently discussing the Shark Fin Sales Elimination Act to eliminate shark fin trade at the federal level. This bill was introduced in 2017 and has been proceeding very slowly in Congress because of mixed reviews from the scientific community. Debate exists on whether shark conservation and management are effectively addressed with tightened trade controls for imported shark products or blanket bans that outright end U.S. participation in the shark fin trade. Here we contribute to this debate with a review and analysis of economic, nutritional, ethical, and legal arguments, as well as of the shark fisheries status and shark fin trade. We show that the United States has a limited commercial interest in shark fisheries and contributes to the shark fin trade mainly as a facilitator. A fin trade ban has few tangible economic drawbacks but would have a considerable conservation impact. While making all shark fisheries sustainable is the ultimate goal, in practice this objective is far from achievable everywhere in the world. Conversely, banning shark fin trade is an interim measure that nations like the United States can take with negligible cost and can truly impact the biggest driver of shark exploitation globally.

Abstract In October 2016, the international community made history by adopting the world's largest marine protected area in the Ross Sea, Antarctica—by consensus. Achieving this feat required trade‐offs and compromise among the 24‐Member States (plus the European Union) comprising the Commission for the Conservation of Antarctic Marine Living Resources. The process took 5 years of intense international negotiations and more than 10 years of scientific planning. Based on interviews with national delegations and other stakeholders, 5 years of participatory observation of Commission meetings (2012–2016), and analysis of hundreds of documents, we present unique insights that explain the conditions that stalled or facilitated the adoption of the Ross Sea MPA. These included economic interests, geopolitics, an erosion of trust, high‐level diplomacy, and the compromises that were ultimately necessary. We reflect on lessons learned as the world considers how to achieve future large‐scale conservation successes in the global commons.

Human access routes to coastal subsistence resources are being altered in Arctic regions as temperatures warm. The accessibility dimension of climate impacts on coastal resources is critical to food sovereignty and resilience of Indigenous Arctic communities, yet the issue of access is understudied relative to food availability. This issue also has implications for the role of governmental agencies in mediating resource access in a changing landscape. We examined the role of climate stressors in affecting access to customary and traditional foods (subsistence) by Indigenous (Iñupiat) communities within and near Arctic National Parklands. We apply access theory to better understand (1) the climate stressors that most impact access to coastal animals and harvest areas, (2) how they affect the availability and reliability of harvest of coastal species, and (3) the mechanisms that facilitate or constrain access to coastal subsistence resources. Our study employed a combination of expert interviews and synthesis of pre-existing environmental time series data in the communities of Kotzebue and Kivalina, Alaska. We found that chronic climate stressors (sea ice retreat, coastal erosion, and changes in weather) most impacted harvest access. To mediate these changes, harvesters ubiquitously reported the use of access mechanisms including capital, knowledge, technology, and social identity; social relations, authority, and time were also reported at high rates. Potential adaptations in these communities include increased reliance on technology and capital to access animals despite landscape changes (e.g., using boats in the absence of sea ice), switching species or relying on social networks for sharing resources when animals become harder to find, and exploring alternatives to harvesting (such as growing food) in response to increasing access challenges. Our findings highlight the stewardship and sovereignty of Indigenous communities as a basis for resilience in a rapidly changing environment.

As changes in climate, governance, and organization reshape the dynamics of small-scale fisheries around the globe, the persistence of many local livelihoods appears contingent upon the ability of resource users to respond and adapt. Though significant scholarship has considered the limiting roles of resources and infrastructure, recent research has highlighted the importance of local learning and knowledge. Rather than being driven by forces exogenous to local communities, it is increasingly recognized that adaptation may be limited by perceptions and processes within them. Here, we explore knowledge production and adaptive response within a small-scale fishery in the central Gulf of California following system perturbation. Using mixed methods from the natural and social sciences, we (1) identify local drivers of social-ecological change, (2) document knowledge concerning their causes and consequences across a diverse group of small-scale fishermen, and (3) identify patterns of intracultural agreement and disagreement associated with divergent adaptive response. Results indicate that perceptions of social-ecological change were heterogeneous and that gear ownership and target species diversification were critical factors in determining the cultural models through which fishermen understood and responded to changes in the resource system. Unlike other user groups, owner-operator fishermen pursuing generalist livelihood strategies held consensus beliefs regarding changes to system structure and function and demonstrated increased ability to modify fishing tactics with the best practices for sustainable use. Our findings highlight how local knowledge can be used to assess the proximate impacts of external drivers of change and provide insight into the cultural models influencing in situ decision-making and adaptive response within modern fishery systems.

The United States has been at the forefront of marine resource stewardship since the 1970s when Federal officials began to implement a series of national policies aimed at the conservation and management of public trust resources in the ocean. Beginning with the establishment of the National Oceanic and Atmospheric Administration in 1970, soon followed by several pieces of landmark legislation, this era marked the start of a continuing effort to integrate ecosystem science with marine resource management. Among the most important bipartisan legacies of this effort has been the steady expansion of marine managed areas in U.S. coastal and ocean waters. This legacy is being challenged as the Trump Administration considers whether to alter or eliminate the nation's Marine National Monuments and National Marine Sanctuaries.

Species distribution models (SDMs) have become key tools for describing and predicting species habitats. In the marine domain, environmental data used in modeling species distributions are often remotely sensed, and as such have limited capacity for interpreting the vertical structure of the water column, or are sampled in situ, offering minimal spatial and temporal coverage. Advances in ocean models have improved our capacity to explore subsurface ocean features, yet there has been limited integration of such features in SDMs. Using output from a data-assimilative configuration of the Regional Ocean Modeling System, we examine the effect of including dynamic subsurface variables in SDMs to describe the habitats of four pelagic predators in the California Current System (swordfish Xiphias gladius, blue sharks Prionace glauca, common thresher sharks Alopias vulpinus, and shortfin mako sharks Isurus oxyrinchus). Species data were obtained from the California Drift Gillnet observer program (1997–2017). We used boosted regression trees to explore the incremental improvement enabled by dynamic subsurface variables that quantify the structure and stability of the water column: isothermal layer depth and bulk buoyancy frequency. The inclusion of these dynamic subsurface variables significantly improved model explanatory power for most species. Model predictive performance also significantly improved, but only for species that had strong affiliations with dynamic variables (swordfish and shortfin mako sharks) rather than static variables (blue sharks and common thresher sharks). Geospatial predictions for all species showed the integration of isothermal layer depth and bulk buoyancy frequency contributed value at the mesoscale level (

External drivers increasingly impact small-scale fisheries worldwide. As globalization accelerates the flow of information, commodities, and capital across geographic space, neoliberal reforms have fueled the development of the international seafood trade. Small-scale fisheries traditionally driven by local forces and market demands are increasingly nested within the broader structures of global markets and international institutions. Building on existing work that integrates social-ecological systems thinking and critical social science theory, we address how globalization has transformed the social fabric of coastal fishing communities and consider the implications for institutional and environmental integrity. Using small-scale fisheries across the Gulf of California as an empirical example, we extend a theory of small-scale fisheries interactions proposed by development scholars to incorporate global market forces, considering how drivers operating at multiple temporal and geographic scales have influenced outcomes in one of the world's most diverse and productive marine ecosystems. We suggest that neoliberal reforms promoting the growth and development of an export-oriented seafood industry have restructured the relationships between small-scale fishermen, coastal communities, and the marine environment. As the benefits of trade liberalization have been captured by local elites, small-scale fishermen have been left increasingly vulnerable to the shocks and uncertainties associated with political, economic, and environmental change. By situating our findings within an emerging body of scholarship documenting parallel dynamics across diverse geographies, we argue that efforts to avoid and/or mitigate the tragedy of the commons within small-scale fishery systems must address the relationships between global markets, social and economic inequality, and local capacities for self-organization and collective action.

The science needed to understand highly migratory marine mammal, sea bird, and sea turtle species is not adequately addressed by individual data collections developed for a single region or single time period. These data must be brought together into a common, global map based on a coherent, interoperable, and openly accessible information system. This need was clearly articulated by the National Oceanographic Partnership Program (NOPP) and the Alfred P. Sloan Foundation when they co-sponsored a new effort to directly address this issue in 2002. The result is OBIS-SEAMAP: the world data-center for marine mammal, sea bird, and sea turtle information. OBIS-SEAMAP brings together georeferenced distribution, abundance, and telemetry data with tools to query and assess these species in a dynamic and searchable environment. In a second round of NOPP support that began in 2007, the National Science Foundation is helping expand this effort into new technologies and data types. To date, the OBIS-SEAMAP information system includes more than 2.2 million observation records from over 230 data sets spanning 73 years (1935–2008), and growth of this data archive is accelerating. All of these data are provided by a growing international network of individual and institutional data providers.

Coral reefs are among the most diverse ecosystems on the planet but are declining because of human activities. Despite general recognition of the human role in the plight of coral reefs, the vast majority of research focuses on the ecological rather than the human dimensions of reef ecosystems, limiting our understanding of social relationships with these environments as well as potential solutions for reef recovery. General frameworks for social-ecological systems (SESs) have been advanced, but system-specific approaches are needed to develop a more nuanced view of human-environmental interactions for specific contexts and resource systems, and at specific scales. We synthesize existing concepts related to SESs and present a human dimensions framework that explores the linkages between social system structural traits, human activities, ecosystem services, and human well-being in coral reef SESs. Key features of the framework include social-ecological reciprocity, proximate and underlying dimensions, and the directionality of key relationships and feedback loops. Such frameworks are needed if human dimensions research is to be more fully integrated into studies of ecosystem change and the sustainability of linked SESs.

Marine historical ecology provides historic insights into past ocean ecosystems that are crucial to effectively confronting the declining health and resilience in marine ecosystems. A more 'peopled' approach to marine historical ecology is necessary, given the heightened emphasis on human dimensions in marine management. This study examined the historical ecology of Hawaiian coral reef ecosystems through oral histories of diverse ocean experts, representing six traditional, local, and scientific knowledge systems. Based on 61 in-depth interviews with these ocean experts, historical trends, abundance, and distribution over 80 years and a 50-mile region for 271 species emerged. Analyzing trends by ecological guild, e.g., herbivores, proved inappropriate to these data; rather, based on qualitative analyses, five distinct trends encompassing nearly all species emerged in what we term "social-ecological guilds." Ocean expert's observations of change were surprisingly consistent, regardless of their knowledge system, whereas perceptions of change varied widely. The historical picture was far broader and richer when the contributions of six knowledge systems were incorporated, compared to that of any one alone. Social-ecological guilds also matter critically from a management perspective, because understanding how experts from a multiplicity of perspectives observe, interpret, and respond to ecological change can help managers anticipate responses to management activities and perhaps to design better management strategies.

In order to examine the scientific feasibility of area closures for sea turtle protection, we determined the spatial dynamics of sea turtles for the U.S. Gulf of Mexico by analyzing National Marine Fisheries Service (NMFS) aerial survey data in September, October, and November of 1992, 1993, and 1994. Turtle sightings were grouped into depth zones and NMFS fishery statistical zones, and strip transect methods were used to estimate the relative abundance of sea turtles in each subzone. Average shrimping intensity was calculated for each subzone for all months of 1992, 1993, and 1994, as well as for the months and locations of the aerial survey. The spatial overlap of sea turtle abundance and shrimping intensity suggested regions where interactions are likely to occur. Sea turtles were observed at much higher rates along the coast of Florida than in the Western Gulf; the highest density of sea turtles was observed in the Florida Keys region (0.525 turtles/km2). Shrimping intensity was highest in the Western Gulf along the coast of Texas and Louisiana, for both annual and fall estimates. Among alternative management scenarios, area closures in conjunction with continued Turtle Excluder Device (TED) requirements would probably best prevent sea turtles from future extinction. By implementing shrimping closures off of South Padre Island, Texas, a potential second nesting population of Kemp's ridleys (Lepidochelys kempi) could be protected. Closing waters where shrimping intensity is low and sea turtle abundance is high (e.g., South Florida waters) would protect sea turtles without economically impacting a large number of shrimpers.