Over recent decades, the eastern North Pacific Ocean (ENP) has undergone significant climate-driven change, characterized by rising sea surface temperatures (SSTs), a northward expansion of the North Pacific Transition Zone (NPTZ), and more frequent marine heatwaves. Juvenile North Pacific loggerhead sea turtles (Caretta caretta), a highly mobile species sensitive to environmental variability, have emerged as a sentinel species within the region. When North Pacific loggerheads migrate from the eastern subtropical gyre to coastal habitat, they do so offshore of the Baja California Peninsula, Mexico. Analysis of an extensive satellite tracking data set (n=285,1997–2023) revealed no prior observations of juveniles entering the colder, nutrient-rich waters of the northern California Current System (CCS). However, the gradual northward shift of loggerhead foraging habitat has been observed in parallel with an increasingly oligotrophic NPTZ. In 2024, four of 28 satellite-tracked individuals deviated from historic migratory routes and entered the northern CCS. To understand the physical mechanisms that enabled these novel movements, we integrated SST, chlorophyll-a concentrations, and surface current conditions experienced by these individuals and compared them to historical records within the region. During September-October 2024, these turtles reached 45°N latitude, where they encountered strong eastward flow within the North Pacific Current (NPC), thermally suitable conditions, and enhanced productivity. These conditions created a transient, high-latitude migratory corridor into the northern CCS. While three of these turtles benefited from reaching enhanced forage habitat in the California Current System, one likely suffered cold-stunning upon entry into suboptimal waters. The other 24 turtles remained south of the NPC, in the subtropical gyre. Our study represents the first confirmed use of a new, northern CCS migratory corridor by juvenile North Pacific loggerhead sea turtles. These findings expand on the conceptual framework of the ‘thermal corridor hypothesis,’ which suggests that sea turtles opportunistically exploit anomalously warm conditions to reach foraging habitats along the North American coast. They also emphasize the role of additional environmental drivers, such as advective current systems, in these movements. Under accelerated climate change, such transient pathways may become increasingly prevalent, with significant implications for conservation planning and fisheries management.

Understanding what shapes ocean access and its contribution to human wellbeing is critical for equitable and sustainable marine resource management. Using a community-engaged research approach, we examine responses from 1691 surveys administered across central California (USA), an iconic coastline renowned for its biodiversity and cultural significance, to explore the factors mediating ocean use and benefits. We find that a) the ocean's subjective and relational contributions to human wellbeing outweighed material contributions; and b) these benefits are constrained for vulnerable communities and underserved populations by personal (e.g., lack of interest or affordability), physical-environmental (e.g., lack of infrastructure or exposure to pollution), and knowledge (e.g., how to safely and legally engage) barriers. Our results highlight how structural exclusion from ocean spaces limits wellbeing for marginalized groups, a critical feedback loop that may perpetuate inequality and degrade public health. Though California considers itself a world leader in ocean management, our findings indicate that there is more work to be done and offer actionable insight for advancing more inclusive and equity-centered approaches to coastal and ocean governance.

Introduction: Addressing ecological and social knowledge gaps is essential for the sustainable management of recreational fisheries. Costa Rica is internationally recognized as a premier sport fishing destination, particularly for billfish such as sailfish (Istiophorus platypterus) and blue marlin (Makaira nigricans). Despite their socioeconomic importance, major knowledge gaps remain in the dynamics of sport and tourist fisheries, hindering effective management. Fishers involved in tourist and sport fishing can provide valuable social-ecological insights into their fisheries and target species. Objectives: This paper seeks to identify the spatio-temporal patterns of billfish sport and tourist fishing activity along the Pacific coast of Costa Rica and to assess regional differences shaped by social and ecological factors, drawing on the knowledge and perceptions of fishers. Methods: We conducted semi-structured interviews with sport fishing captains (n=62) from private and charter operations across eight Pacific coast communities: Golfito and Puerto Jimenez in the Southern Pacific (n = 14); Quepos and Herradura in the Central Pacific (n = 34); and Tamarindo, Flamingo, Cuajiniquil, and El Jobo in the Northern Pacific (n = 14). Interviews included a participatory mapping activity to identify key fishing grounds for sailfish and blue marlin, along with a standardized questionnaire on fisher demographics, fishing seasonality, billfish and non-billfish species caught on the most recent trip (and their reported abundance), offshore distances of their most recent trip, and changes in fishing equipment and technology over time. Results: Analyses of fisher responses revealed nearshore fishing hotspots within 60 nautical miles of the Pacific coast of Costa Rica and regional differences in fishing seasonality, likely shaped by both oceanographic variability and tourism. Based on reported values, the Central Pacific exhibited the highest mean releases of sailfish and blue marlin and longest mean offshore distances in their most recent trip, compared to fishers operating in the Northern and Southern Pacific. Fishers in the Northern and Central Pacific reported overall improvements in fishing equipment and technology. Conclusions: These findings underscore the value of integrating fishers’ knowledge into fisheries research, enabling the management of billfish fisheries of Costa Rica to better reflect region-specific fishery dynamics. By capturing fishers’ lived experiences and observations, this study supports a participatory approach to billfish fisheries management in Costa Rica.

We evaluated the effects of regional environment and body size on the nutritional traits of five small pelagic species differing in habitat use, feeding behavior, and importance as prey for top predators in the California Current Large Marine Ecosystem (CCLME). Northern anchovy (Engraulis mordax), bigfin lanternfish (Symbolophorus californiensis), market squid (Doryteuthis opalescens), and boreal clubhook squid (Onychoteuthis borealijaponica) were collected in the summer of 2021 in the northern and southern CCLME. Energy density (ED), lipid, and protein content (% wet weight) were calculated for each specimen via bomb calorimetry and proximate composition analysis. Energy values from the two methods were highly correlated. Bayesian linear modeling revealed that while environmental conditions (sea surface temperature, chlorophyll-a, and upwelling) differed significantly between northern and southern CCLME, nutritional value did not vary significantly by region-an effect that was consistent across species. Body size affected both mass-specific and whole specimen nutritional value, but the direction and magnitude of the relationship varied by species. While ED and % lipid increased rapidly with size in bigfin lanternfish and moderately with size in boreal clubhook squid, it was relatively consistent across size for anchovy and market squid. Fishes were more variable in ED and % lipid than squids, while % protein was highly variable across all specimens and increased significantly with size only in boreal clubhook squid. Our results highlight the importance of assessing drivers of prey quality to predicting predator foraging and nutrient flows under climate change.

Herbivorous fishes play a crucial role in the conservation of coral reefs threatened by thermal stress (e.g., marine heatwaves and long-term ocean warming) by helping to maintain reefs in a coral-dominated state via the removal of algae. However, as thermally sensitive ectotherms, rising thermal stress may also pose a serious threat to these fishes and the critical ecosystem functions they deliver. Here we evaluate the consequences of thermal stress on the capacity of a common herbivorous coral reef fish (Acanthurus triostegus) to control finely filamentous matrices of Caulerpa sertularioides and C. verticillata algae in Hawai'i, by characterizing in-vivo changes in metabolic demands, diurnal foraging rates, activity patterns and individual condition in a laboratory setting during winter (24.0±0.1°C), summer (27.5±0.1°C), and at the peak of a representative marine heatwave, (31.0±0.1°C). Rising temperatures caused significant increases in standard metabolic rate (from ~135 O2 kg-1 h-1 in winter to 224 O2 kg-1 h-1 at the peak of a marine heatwave), but not in the proportion of time spent active (~83-96%) or foraging (~2.4 bites min-1). Consequently, A. triostegus gained body mass during summer and winter, but lost ~0.8% body mass per day during the marine heatwave. Given marine heatwaves can last for weeks to months, these results indicate that while herbivorous coral reef fishes may continue to remove algae during periods of thermal stress, their ability to control many macroalga may be limited due to precipitous reductions in individual performance. Therefore, in addition to algal types, the thermal sensitivity in herbivorous reef fishes will need to be considered for the successful implementation of coral-algal management strategies in a warmer world.

Dana K Briscoe, Bianca S. Santos, Calandra N Turner Tomaszewicz, and Larry B Crowder, characterize emerging approaches to conserving endangered sea turtles across the globe. Sea turtles have declined due to direct harvest from eggs to adults, loss of nesting habitat, and bycatch in fisheries. Researchers globally have developed an extensive tool-kit to address the dramatic declines in sea turtles, and have developed focused conservation actions based on detailed understanding of the life histories and spatial dynamics leading to some success in recovering species, such as Kemp’s ridley. This chapter describes those successes and illuminates remaining challenges.

The North Pacific Transition Zone (NPTZ) is known as a global marine hotspot for many endangered and commercially significant highly mobile marine species. In the last few decades, the region has undergone unprecedented physical and biological transformations in response to climate variability and change. Although it is anticipated that many highly mobile species will need to adapt and shift their distributions, current predictions have relied on short-term data sets or modeled simulations. This has left a critical gap in our understanding of long-term (decadal or longer) change and species’ responses within the NPTZ. Here, we integrate nearly 3 decades of satellite tracking data from a climate sentinel, the juvenile North Pacific loggerhead sea turtle (Caretta caretta), with concurrent observations of sea surface temperature (SST) and chlorophyll-a concentrations to examine higher trophic level response to climate-induced changes within the eastern bounds of the NPTZ. Between 1997–2024, the NPTZ has warmed by 1.6°C and experienced an approximately 19% decline in mean surface chlorophyll-a concentration, a proxy for reduced productivity, resulting in a 28% (1.65 million km2) increase in total oligotrophic habitat in the eastern NPTZ. Over the same period, the average latitude of loggerhead sea turtle foraging habitat in the NPTZ has shifted northwards by 450–600 km. This represents a distributional shift rate of 116–200km/decade. In most years both the southern and northern range limits for the loggerhead turtle have shifted northward in tandem, indicating a habitat range shift rather than a range expansion. Our findings reveal significant physical and biological change to the NPTZ over the last quarter century and the first empirical evidence illustrating the substantial spatial response of a highly mobile megafaunal species. As the NPTZ continues to become more oligotrophic, these insights can provide vital information for dynamic conservation and management strategies within this critically important ecosystem.

Coral reefs provide important economic benefits to coastal businesses, supporting recreation and tourism and protecting property from storms. Yet, these benefits are at risk worldwide as corals decline rapidly, and investment in restoration is lacking. With their direct dependence on coral health, coastal businesses may represent an important sector for funding coral restoration; however, it is unclear whether businesses perceive coral reef services as valuable or themselves as reef stewards. We measured business perceptions of coral health and value in Hawaiʻi and identified traits correlated with business decisions to participate in coral restoration at three payment thresholds. We found that businesses see limited economic value in coral reefs. In areas where corals provide substantial ecosystem services (flood protection, tourism revenue), businesses did not consistently rate coral value as high. Nonetheless, businesses showed strong willingness to pay for coral restoration, which was linked to pro-nature motives, reputation, and Native Hawaiian ownership. Results highlight key strategies for engaging private entities in coral restoration.

Understanding the factors influencing ocean access and its contribution to human wellbeing is critical for equitable and sustainable marine resource management. Here, using a community-engaged research approach, we examine responses from 1691 surveys administered across central California (USA), an iconic coastline renowned for its biodiversity and cultural significance, to explore the factors mediating ocean use and benefits. We find that a) the ocean’s subjective (mean index score = 4.31,) and relational (mean = 4.02) contributions to human wellbeing outweighed material (mean =3.75; +/- 0.001) dimensions; and b) these benefits are constrained for vulnerable communities and underserved demographics due to the existence of personal (e.g., lack of interest or affordability) and knowledge (e.g., where to go and/or how to safely and legally engage) barriers. Our results highlight how structural exclusion from ocean spaces limits wellbeing for marginalized segments of society, a critical feedback loop which may perpetuate inequality and degrade public health. Though California is often considered a world leader in protecting and managing ocean environments, we argue that there is more work to be done and provide actionable insight to advance more inclusive and justice-centered approaches to coastal and ocean governance

Climate change-related shifts in marine resource availability and species behavior are increasing rates of human-wildlife conflict (HWC). Although this trend poses significant risks to both human livelihoods and conservation efforts, strategies to resolve HWC focus largely on ecological outcomes, overlooking key impacts and contributions of human resource users. Here, we draw on the case study of whale entanglement in the Dungeness crab (Metacarcinus magister) fishery in California, U.S.A. to demonstrate the promise of integrating – and the consequences of neglecting – the voice and expertise of fishing communities. Semi-structured interviews with 27 commercial fishermen across nine towns in California revealed the diverse sociocultural impacts of HWC – often converging on livelihood and identity losses – as well as fishermen’s potential role in addressing HWC as long-time experts in the marine ecosystem. Our findings highlight pathways for achieving human-wildlife coexistence, underscoring the need to engage the knowledge and lived experience of local communities affected by HWC.

Comprehensive spatial planning in international waters is key to achieving ocean sustainability

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 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.

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.

Simplifying complex species interactions can facilitate tracking and predicting functional responses to ecological stressors. This is important for highly migratory pelagic predators, exploiting diverse prey fields as they respond to dynamic environments. We reconstructed the historical resource use of albacore tuna ( Thunnus alalunga ) globally from the 1900s to 2015 and confirmed highly biodiverse diets with 308 prey species, and an additional 238 taxa at coarser taxonomic resolution. We synthesised prey diversity into seven functional trait guilds using hierarchical divisive clustering algorithms as a function of four traits that describe habitat use and influence predator–prey encounter rates – prey habitat association vertically in the water column, horizontally along the coastal to pelagic gradient, seasonal and diel vertical migratory behaviour. We explored variability in historical composition of albacore diets across geographies based on species identity, individual trait information and functional trait guilds using a multi‐matrix modelling framework. Taxonomic information remains important for trophic ecology, however, species‐based diet composition in albacore tuna was highly variable across geographies and years sampled, making interpretation of these patterns difficult. By simplifying species identity into habitat‐based traits, we highlight changes in prey resources consumed, such as the historical importance of near‐surface epipelagic prey resources from coastal to oceanic habitats, and seasonally migrating continental shelf prey, with less frequent pulses of deeper water and demersal taxa. Trait information and trait guilds serve as useful classification frameworks for identifying functionally redundant food web linkages across biodiverse prey, and will prove useful in tracking predators' foraging responses to changing resource availability.

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.

Over recent years, recognition of the need to develop climate-smart marine spatial planning (MSP) has gained momentum globally. In this roundtable discussion, we use a question-and-answer format to leverage diverse perspectives and voices involved in the study of sustainable MSP and marine conservation under global environmental and social change. We intend this dialogue to serve as a stepping stone toward developing ocean planning initiatives that are sustainable, equitable, and climate-resilient around the globe. A necessidade de desenvolver processos de ordenamento do espa & ccedil;o marinho (OEM) que sejam inteligentes do ponto de vista clim & aacute;tico tem sido amplamente reconhecida internacionalmente nos & uacute;ltimos anos. Na presente mesa-redonda, adoptou-se um formato de pergunta-resposta para promover uma discuss & atilde;o sobre os desafios envolvidos na conserva & ccedil;& atilde;o dos ecossistemas marinhos e no desenvolvimento de planos de OEM sustent & aacute;veis, num contexto de altera & ccedil;& otilde;es ambientais e sociais globais. Foram debatidas diversas perspectivas e ouvidas v & aacute;rias vozes, com o objetivo de contribuir para um OEM sustent & aacute;vel, equitativo e resiliente & agrave;s altera & ccedil;& otilde;es clim & aacute;ticas a n & iacute;vel global. En los & uacute;ltimos a & ntilde;os se ha reconocido internacionalmente la necesidad de desarrollar procesos de planificaci & oacute;n espacial marina (PEM) clim & aacute;ticamente inteligentes. En esta mesa redonda se utiliza un formato de preguntas y respuestas para promover una discusi & oacute;n sobre los desaf & iacute;os que implica la conservaci & oacute;n de los ecosistemas marinos y el desarrollo de PEM sostenibles en un contexto de cambios ambientales y sociales globales. Se presentaron y debatieron diversas perspectivas y voces con el objetivo de contribuir a una PEM sostenible equitativa y resiliente al clima a nivel global.

The global marine aquarium trade has created new local markets across the planet, including in Indonesia, now the second-largest exporting country of marine aquarium fish in the world. Participating in the global aquarium trade has been touted as a potentially sustainable addition to fisher livelihoods, but scant data exist showing the numbers of fish coming off the reef and how those fish contribute to income. To determine how participants in the trade incorporate aquarium species in their livelihoods, we examine source-level aquarium fish collecting and trading data in the Banggai Archipelago, a region in Central Sulawesi that has become a significant source for popular aquarium, also known as ornamental, fish species. Using a sustainable livelihoods lens, we examine this data to understand how participants in the aquarium trade both contribute to as well as benefit from the trade and consider how their participation relates to emerging Blue Justice principles. From one year of buying and selling data at the fisher, intermediary buyer, and regional trader levels, we show that catching and selling fish for the aquarium trade represents an average of nearly 20% of their gross annual income and provides added diversity and flexibility to fisher and trader livelihoods in the region, especially during seasons of rough weather. We suggest that managers of an impending marine protected area in the region would do well to consider how to sustain these livelihood benefits.