Beyond boundaries: governance considerations for climate-driven habitat shifts of highly migratory marine species across jurisdictions

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.

SIMILAR CONTENT BEING VIEWED BY OTHERS UP TO 80% OF THREATENED AND COMMERCIAL SPECIES ACROSS EUROPEAN MARINE PROTECTED AREAS FACE NOVEL CLIMATES UNDER HIGH EMISSION SCENARIO Article Open

access 14 June 2024 CLIMATE-DRIVEN GLOBAL REDISTRIBUTION OF AN OCEAN GIANT PREDICTS INCREASED THREAT FROM SHIPPING Article Open access 07 October 2024 CLIMATE CHANGE TO DRIVE INCREASING

OVERLAP BETWEEN PACIFIC TUNA FISHERIES AND EMERGING DEEP-SEA MINING INDUSTRY Article Open access 11 July 2023 INTRODUCTION Climate change is rapidly altering our ocean and shifting the

distribution of animals within it1,2,3,4. Marine species’ movements and home ranges reflect their preferences for specific oceanographic and ecological conditions, which change as ocean

temperatures rise3,5. The world’s ocean is expected to experience substantial environmental change even under modest projected carbon emission scenarios. Average sea surface temperatures

have steadily increased by 0.11oC per decade since the 1970s6, and many species have already moved deeper or expanded poleward to stay within preferred environmental conditions7,8,9,10,11.

Marine species are undergoing shifts in spatial distributions at alarmingly fast rates, which can have widespread and severe ecological implications as community structures and food webs

change5,8,12,13. These redistributions also pose a significant challenge for human society, which may impact economic prosperity, food security, and the well-being of coastal communities

around the globe14,15,16. Proactively mitigating the effects of climate change on marine species requires a robust understanding of how a changing climate will impact species core habitat.

Projections of climate-driven habitat shifts provide insights on whether species will gain or lose core habitat based on species-specific environmental preferences and geographic

barriers2,17,18, however, geopolitical boundaries and differing governance regimes may influence species persistence within shifted areas9. Species will likely move across borders in the

coming decades9,19,20, becoming exposed to new regulations and threats with direct geopolitical and economic implications (_sensu_21,22). Notably, this may introduce governance challenges as

species move into new jurisdictional spaces19 and exit former ones23. Climate-change-induced habitat shifts can push species into governance situations where countries and regions are

unprepared, driving biodiversity loss, creating geopolitical conflicts, and accelerating political issues19. Such changes may also push species into areas beyond national jurisdiction, where

international bodies and agreements, such as regional fisheries management organizations, remain generally unprepared to sustainably manage the shifting movements of humans and marine

species. The transboundary nature of migratory species can further complicate management given their habitat use across multiple geopolitical boundaries. Complex movements that include broad

spatial distributions within exclusive economic zones (EEZ; 200 nautical miles from shore) of multiple nations as well as areas beyond national jurisdictions (ABNJ)21 underscore the need

for robust international coordination to help sustainably manage biodiversity, particular in the face of global change. However, developing and implementing coordinated policies among

countries can be difficult due to differing national priorities, complex legal infrastructure, and power imbalances24. Further, while multiple management bodies (e.g., regional fisheries

management organizations) and multilateral environmental agreements (e.g., the Convention on Migratory Species) do exist with specific conservation measures for migratory marine species,

coordinated international cooperation and compliance across the entire migratory range of these highly mobile animals, including areas within and beyond jurisdictions, remains a challenge25.

Given that these species inhabit different areas during various life-stages, properly protecting species across these ecologically interconnected regions remains crucial for ensuring

population survival26. As climate change continues to alter the distribution of shared species between countries, identifying specific cases where species’ transboundary movements may shift

is critical for informing where proactive, sustainable co-management initiatives may be most needed. This present study seeks to highlight how we can expand efforts to better understand the

impacts of climate change on species’ habitat use by considering the governance implications of potential habitat redistributions across jurisdictions. This is illustrated through a case

study example using data from Tagging of Pacific Predators (TOPP) program, a collection of biologging data collected from across the North Pacific used to identify habitat hotspots27. Hazen

et al. 2. Expanded upon these efforts, coupling species-specific habitat models from the TOPP dataset with climate change projections developed at the Geophysical Fluid Dynamics Laboratory

of the National Oceanic and Atmospheric Administration under RCP 8.528 to assess how species movements may change throughout the 21st century. Here, we build upon that work to consider where

in geopolitical space these habitat changes are predicted to occur by evaluating changes in the proportion of core habitat within and beyond national jurisdictions for a subset of species

in the northeast Pacific (Fig. 1), including shortfin mako shark (_Isurus oxyrinchus_), California sea lion (_Zalophus californianus_), northern elephant seal (_Mirounga angustirostris_),

and sooty shearwater (_Ardenna grisea_). Importantly, given several limitations associated with the underlying dataset, our study does not intend to provide a robust modeling analysis for

the Pacific predators case study, but rather illustrate an approach that can be used in future work to assess how the management responsibility for transboundary species may change. We then

discuss governance considerations given the potential transboundary redistribution of highly migratory species, as well as highlight opportunities for improving data and management needs.

RESULTS The monthly overlap between projected species core habitats and jurisdictional areas in the northeast Pacific Ocean, including areas beyond and within national jurisdictions, were

assessed for the four focal species from 2001 to 2100 at a monthly, 1o resolution using habitat suitability predictions and core habitat thresholds outputs generated in Hazen et al. 2. The

climate-driven habitat projections were geographically constrained to the species-specific domains of the original tagging data, study areas that included varying Pacific coast portions of

the EEZs of the United States (including the western continental region, Alaska, Hawaii, and Johnston Atoll), Canada, and Mexico (Fig. 1). All species except California sea lions had core

habitats within both areas of national jurisdiction and ABNJ during both the first and last decade of the century (Fig. 2). The core habitat of California sea lions was narrowest in scope

and found to remain exclusively within the EEZs of the continental U.S. and Mexico; however, this data is likely not representative as the tagging efforts were limited to two breeding

colonies (see Block et al. 27). On the other hand, sooty shearwaters had the broadest spatial distribution and were the only species that included core habitat within the U.S. EEZs of Alaska

and Johnston Atoll. Deviations from the average monthly proportion of core habitat within jurisdictional waters up to 2100 varied among species. Five-year averages of deviations across

jurisdictional areas varied ±10% from the beginning to the end of the century (Fig. 3). Northern elephant seals experienced the greatest increase in the proportion of core habitat within

ABNJ by 2100, while also decreasing their proportion of core habitat in Mexico and the U.S. Sooty shearwaters exhibited an opposite trend, where proportions of core habitat decreased in ABNJ

by the end of the century, while increasing in Mexico and the U.S. Mako sharks experienced a modest decrease in core habitat within ABNJ and Mexico, but increased within U.S. waters.

Changes in the proportion of projected core habitat of California sea lions between the U.S. and Mexico were negligible. Only two species (elephant seal and sooty shearwater) had core

habitat in Canada, but there was little change in relative proportion over time. Results at the yearly and monthly levels can be found in the Supplemental Materials (Fig. S1). DISCUSSION As

climate-driven habitat shifts introduce new governance challenges throughout the ocean29, assessing projected species distributions across geopolitical boundaries can aid in identifying

high-level conservation challenges and provide focus areas for management. This study used existing data to demonstrate the feasibility of spatially assessing habitat redistribution as it

relates to national jurisdictions, to discern if animals’ core habitat shift within or beyond these geopolitical borders. We apply this method specifically to a case study using projections

of climate-driven habitat change for select species in the Northeast Pacific under an RCP 8.5 climate scenario. All four species evaluated are projected to face up to a 2.5-10% change in

core habitat across jurisdictions throughout the century, with the greatest gains projected within the U.S. EEZ as well as in ABNJ. Recognizing various limitations associated with the

underlying dataset, our study aims to provide an example of an analytical approach that can be used in future work with updated projections of species distribution shifts. Understanding

where such climate-driven shifts may occur in relation to jurisdictional boundaries can help inform international resource management and identify where proactive, climate-smart management

actions, both nationally and internationally, may be needed. Below, we provide a high-level assessment of governance considerations given potential climate-driven redistribution of highly

migratory marine species across jurisdictions, applicable within and beyond the Pacific case study. We then discuss data needs, management considerations, and recommendations for building

upon this approach in future work. GOVERNANCE CONSIDERATIONS FOR TRANSBOUNDARY HABITAT REDISTRIBUTIONS In this case study, we found that the core habitat of all four species is projected to

shift across jurisdictions throughout the end of the century, adding to a growing body of literature suggesting that climate-driven habitat redistributions may shift species across

geopolitical boundaries19,30,31. Collaborative management approaches that transcend national borders will be key to allow for flexible, yet coordinated governance strategies as species needs

change25. The Convention on the Conservation of Migratory Species of Wild Animals (CMS) is the primary international legal instrument focused on the protection of migratory species and

their habitats. It provides a global framework to enable the adoption of global or regional agreements relevant to HMS (e.g., Agreement of Conservation of Albatrosses and Petrels, Agreement

on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and contiguous Atlantic Area), as well as less formal memorandums of understanding (e.g., Pacific Islands Cetaceans,

Indian Ocean and Southeast Asia Marine Turtles)25. Such bilateral and multilateral environmental agreements can aid in the conservation of migratory species through area-based conservation

measures such as marine protected areas (MPAs). However, the effectiveness of these approaches hinge on the careful design of spatial networks that adequately capture enough ecologically

interconnected areas used by migratory marine species26. Establishing connective spatial management partnerships that transcend national borders and consider these linkages32, such as the

Eastern Tropical Pacific Marine Corridor, a voluntary transboundary network of MPAs created by Ecuador, Costa Rica, Colombia and Panama33, or and the Baja to Bering Initiative, which seeks

to establish a network of MPAs within the neighboring EEZs of Canada, Mexico, and the U.S34, are key for the effective conservation of these highly mobile species. While regional MPA

networks are becoming more common32, many are geographically limited within the political boundaries of a country35. High seas MPAs are sparse; examples include the South Orkney Islands

South Shelf MPA and Ross Sea MPA, implemented through the Convention on the Conservation of Antarctica Marine Living Resources, as well as the OSPAR MPA network established by the Convention

for the Protection of the Marine Environment of the North-East Atlantic36. Notably, the presence of potential core habitat for many species within ABNJ through the end of the century (Fig.

2), and the projected increase in this proportion for some (Fig. 3), also highlight the need for increased international collaboration around the conservation and sustainable use of marine

biodiversity within international waters. Adopting conservation measures for marine migratory species while they are in ABNJ has long been a challenge37, however these spaces continue to be

a significant habitat for highly migratory animals21. For example, some migratory marine species can spend up to three-quarters of their annual cycle in ABNJ21. Both northern elephant seals

and sooty shearwaters are estimated to spend over 65% of the year within the Pacific high seas21, and mako sharks move into the high seas waters of the central subtropical gyre21,38, where

they may face threats from direct and indirect interactions with multiple types of fishing gear39,40,41,42. Our results suggest the ABNJ may continue to be an important habitat for the four

Pacific predators we assessed, highlighting the need to bolster marine management within the high seas. The new United Nations Agreement under the UN Convention on the Law of the Sea for the

conservation and sustainable use of marine biodiversity of areas beyond national jurisdiction (BBNJ) can help support the capacity for more holistic and effective ocean governance

initiatives in international waters. After almost 20 years of informal and formal discussions, the treaty was successfully adopted in June 2023. Notably, one of the four key focus areas

within the BBNJ treaty includes area-based management measures and tools, providing a legal foundation for establishing international MPAs that may overcome democratic and scientific

challenges associated with implementation through existing regional treaties36. The BBNJ treaty could help address some regulatory and governance gaps in ABNJ by expanding opportunities to

establish MPAs, including ecologically connected networks for migratory marine species, as well as implementing other area-based management tools for fishing, shipping, and other ocean

activities, to protect core habitat as well as densely used migratory corridors. Further, the BBNJ treaty also provides an opportunity to establish an ocean governance framework that guides

the international community in collaboratively tackling the challenges of global change by operationalizing climate-resilient principles. This can include advancing capacities for countries

to consider adaptive strategies for managing biodiversity that address the impacts of climate change and the complications that may arise with shifting stocks. The BBNJ treaty can also

complement existing conservation agreements relevant to the management of migratory species. While the CMS does emphasize the role of transboundary conservation measures, it has focused

primarily on areas within national jurisdictions. The BBNJ treaty has the potential to strengthen existing efforts of the CMS, providing the legal framework to expand capacity to implement

area-based management tools in international waters, extending or creating new ecologically connected networks of MPAs through critical habitats43. Provisions around environmental impact

assessments can increase transparency of activities and contribute to reducing impacts on migratory species in international waters, while mechanisms for shared research, capacity building,

and technology transfer offer opportunities for mutual benefit and learning between the two treaties43,44,45. The BBNJ treaty can also strengthen existing marine management efforts

implemented by regional fisheries management organizations (RFMOs). Several RFMOs exist with mandates and resolutions that include managing the impact of fishing on vulnerable marine

species, including the Western and Central Pacific Fisheries Commission and Inter-American Tropical Tuna Commission. Although these regulations can be hard to monitor and enforce46,47,48,

the BBNJ treaty may present a timely opportunity to mobilize greater political willingness and increase capacity within RFMOs to address these issues49. The BBNJ treaty can also provide a

common and consistent framework that supports an ecosystem-based approach to marine management across sectors, strengthening mechanisms already established by RFMOs and the CMS, promoting

coherence and coordination, as well as help to fill geographical gaps in coverage. PLANNING AHEAD: DATA NEEDS AND MANAGEMENT STRATEGIES Planning for climate-ready marine management and

conservation will require reliable projections and assessments of shifting human and species movements19. Investing in techniques that improve tracking human50,51 and biodiversity

activities52,53, such as machine learning, high-resolution satellite data, or new biologging tools, can highlight priority areas for focused biodiversity conservation efforts and improved

enforcement of fisheries management strategies. Enhanced real-time tracking of marine biodiversity that provides needed information on species distribution and habitat use can aid in

site-based biodiversity conservation and policy54,55. Equally as important is the need to increase monitoring of human activity at-sea, leveraging automatic tools such as onboard automated

identification systems (AIS) or using innovative remote-sensing strategies52, to anticipate overlaps between human activity and species habitat use. Notably, efforts to estimate human and

species footprints can be hindered by data biases in sampling efforts as well as barriers in information sharing. Transboundary conservation approaches can support the international exchange

of knowledge, technical expertise and conservation funding56. Bilateral agreements (e.g., Joint Norwegian-Russian Fisheries Commission57) or international online platforms (e.g., Migratory

Connectivity in the Oceans consortium; www.mico.eco) where data can be shared using open science principles58 can be built into ocean governance strategies and improve public availability of

data. Data accessibility is particularly critical in the case of highly migratory marine species, given that international coordination is essential for adequately managing species

throughout their range55. Further, MPAs are traditionally created with the assumption that biodiversity distribution and abundance remain static throughout time and space, thus these

strategies may not be equipped to adequately respond to climate-driven shifts in shifting distributions59. Climate-smart principles, such as utilizing a network of static, adaptive, and

dynamic conservation tools to more effectively and rapidly respond to shifts in species distributions and threats, as well as building climate change objectives into management targets and

indicators, should become more deeply integrated into spatial management initiatives60,61. In addition, marine spatial planning, a framework that considers the spatial and temporal

distribution of ocean activities, should also be multi-sectoral, moving away from single-sector management to integrated approaches that account for a wide range of human activities across

space and time62. Further, management plans, which are not typically developed for spatial management measures beyond MPAs, could be useful for designing and monitoring area-based management

strategies seeking to protect species on the move. Such tools could allow policy and management frameworks to adapt more quickly to meet the changing needs of species as they undergo

climate-driven habitat shifts. LIMITATIONS AND CONSIDERATIONS FOR FUTURE WORK Species distribution models, such as the methods underlining the data used in this study, are useful approaches

that can identify species’ shifts under climate change and inform conservation planning. While our results suggest that climate-driven habitat redistribution may not necessarily push study

species into completely new jurisdictional spaces or exit former ones, a similar methodology could be used with other species and in other locales to identify instances where species’

exposure to nationally instituted management regimes does significantly change. By assessing the specific movements of a few select species in a few locales, along with the policy

implications of these movements, generic guidance could be developed to foster the sort of international collaboration that is needed to sustainable manage and conserve these species in a

changing climate. Notably, while we chose to assess Hazen et al. 2. Climate-driven habitat projections given its large, cross-taxa repository of tagging data for Pacific predators, model

projections should be cautiously interpreted given several limitations with this existing dataset. This study only used a single global climate model and a single RCP63 which limits our

ability to look at variability. We acknowledge that the RCP 8.5 climate scenario represents the extreme case, while RCP 4.5 is described by the Intergovernmental Panel on Climate Change as a

more moderate projection. Applying an ensemble modeling approach across multiple climate emission scenarios can help address model uncertainly in future work64. Further, the projections

used in this study includes sea surface temperature and chlorophyll, but not the direct prey species of the predators examined, which should better represent drivers of habitat shift. Future

models could be improved by using additional biotic and abiotic input variables. Further, the results of this study may be influenced by the track length and the North American coastal

deployments of many of the tagged animals in the dataset27. Our results depend on data from specific populations and life history stages as studied by the TOPP program27 and are not

necessarily applicable across all populations. It is also important to highlight that these models project potential suitable habitat based on oceanographic variables2, but do not

necessarily imply shifts in species distributions per se. Thus, results should be cautiously interpreted with this limitation in mind. Despite these limitations, our analysis provides a

methodological approach for using climate-driven habitat projections to assess species’ jurisdictional redistribution and highlights potential governance implications to consider. Research

could apply this approach using habitat projections that incorporate newer tagging data and updated climate models as well as consider differences in habitat use based on life history stage,

such as those related to reproduction. Future work can also be conducted to distinguish and expand on management considerations associated with highly migratory marine species which are

commercially exploited, versus those that are predominately species of conservation concern. In additional, vulnerability can vary significantly based on life history stage, thus

understanding species behavior across redistributed areas of core habitat is a key component in assessing changes in species risk. Importantly, not at all ocean spaces pose the same level of

threat for marine species, thus truly understanding governance challenges and opportunities from an international collaboration standpoint requires a deeper understanding of individual

species-level risks and country-level policies. Species-specific protection priorities may differ significantly depending on the life history of individual taxa, as well as habitat

specificity and scale65,66,67,68,69. Such considerations highlight the need to understand specific population-level life history characteristics and regional geopolitical nuances more

deeply. This study uses data from this Pacific case study to illustrate an analytical approach for further research, rather than intending to provide a detailed and robust modeling or policy

analysis. Future efforts should build off this work to assess threats and policies at both the species and country-level, consider international and regional organizations and agreements

across a range of individual species, and use updated, state-of-the-art climate models and species predictions to identify more specific gaps and opportunities for climate-ready conservation

and policy priorities. CONCLUSION Our results contribute to a growing body of literature that seeks to understand how to better manage highly migratory marine species in a changing climate.

We demonstrate the feasibility of using climate-driven habitat projections to assess changes across geopolitical boundaries and discuss how resulting shifts may provoke new management

challenges. Within our Pacific case study, we found that climate change may redistribute species core habitat across jurisdictional borders of Northeast Pacific nations by the end of the

century, with the greatest gains projected within the U.S. and in ABNJ. Governance strategies that rely on man-made boundaries are likely to be less effective for these highly migratory

species, underscoring the importance of strong international cooperation to ensure the sustainable management of migratory marine species in changing climate. Future research unpacking risk

exposure, adaptive capacity, and vulnerability at the species, country, and international level is needed to better identify discrete areas for increased conservation attention and

collaborative management efforts. METHODS SPECIES SELECTION The study region of Block et al. 27 and Hazen et al. 2 encompassed the entire northeast Pacific Ocean (10°N to 60°N, 110°W to

180°W), predicting changes in habitat suitability of fifteen species on a broader, basin-wide scale. As our analysis required a finer-scale geographical comparison (e.g., comparing across

ocean governance boundaries such as EEZs), we limited our analyses to species whose habitats we felt confident that the Hazen et al. 2. Models reproduced well within smaller, coastal areas.

First, to avoid unrealistic model extrapolation beyond a species’ observed movements, we geographically constrained Hazen et al. 2. Climate-driven habitat projections to the domains of the

original tagging data, using species-specific bounding boxes from Welch et al. 20. These areas were created by drawing a minimum bounding polygon around each of the species’ original tagging

data from Block et al. 27. Next, the original tagging data (deployments occurring during 2000-2009) for each species was visually compared to habitat projections during a similar period

(2001–2010) to check if habitat hotspots were correctly replicated. This was assessed by looking for strong overlap between model-predicted core habitat hotspots and areas of aggregated raw

tagging data. Model outputs from four species overlapped nearly identically with the raw tagging data and were deemed sufficient for further analysis. These species included shortfin mako

shark (_Isurus oxyrinchus_), California sea lion (_Zalophus californianus_), northern elephant seal (_Mirounga angustirostris_), and sooty shearwater (_Ardenna grisea_). Importantly, many

species-specific tagging information in the TOPP dataset are impacted by biological life history traits such as age, sex, or annual cycles. Our results reported herein, utilizing models from

Hazen et al. 2, are based on specific geographies or life history stages and are not necessarily generalizable to entire populations (e.g. future modelers could sort data sets by sex,

maturity and or ontogeny to see how they are influenced). See Block et al. 27. For dataset details. PREDICTED CORE HABITATS We assessed the predicted core habitat for these four species from

2001 to 2100 at a monthly, 1o resolution throughout their species-specific bounding box domain using habitat suitability predictions and core habitat thresholds outputs generated in the

original models from Hazen et al. 2, which used variables of sea surface temperature and chlorophyll. We recognize that not all habitats are used similarly by species. Still, identifying

core habitat allows an _a priori_ selection of the most important habitats for assessment. Species-specific core habitat was determined by calculating the top quantile of model outputs each

month from 2001 to 2010 (a time period classified as the “historical period”). These monthly values were averaged together over the 10 years, calculating a core habitat threshold for each

month, with values above this top quantile threshold considered core habitat. For each year over the entire model output (2001–2100), individual grid cells were re-coded to indicate the

presence (1) or absence (0) of core habitat based on this threshold. The total monthly core habitat area was calculated by summing across the entire bounding box domain for each year-month

combination. OVERLAP WITH JURISDICTIONAL AREAS We calculated the monthly overlap between species core habitats and jurisdictional areas in the northeast Pacific Ocean, including areas beyond

and within national jurisdictions. Areas within national jurisdiction included Pacific coast portions of the EEZs of the United States (including the western continental region, Alaska,

Hawaii, and Johnston Atoll), Canada, and Mexico. First, for each species, the shapefiles of these regions were cropped to the individual bounding box. Next, each month-year threshold raster

output was overlaid with each shapefile. The total number of grid cells containing a “1” within each jurisdictional area was counted. This value represented the “size” of the species’ core

habitat during a given month-year combination within each jurisdictional area. It was divided by the size of the total core habitat (e.g., the total number of grid cells across all

jurisdictional spaces within the bounding box) and multiplied by 100 to calculate the percentage of core habitat within each jurisdictional area. This process was repeated for each

jurisdictional area and each year-month model combination across all four species. Deviations from the average monthly proportion of core habitat within each jurisdictional area over time

was calculated for each species. First, the percent of total core habitat within each jurisdictional area during the historical period (e.g., 2001–2010) was calculated by averaging results

across this 10-year period for each month. Then, for each year-month combination from 2001 to 2100, the percentage of core habitat within each jurisdictional area was subtracted from the

percentage during the averaged historical period at its corresponding monthly period. This deviation from the average monthly proportion of core habitat within each EEZ was averaged within

5-year bins. DATA AVAILABILITY The modeling data underlining this research are from Hazen et al. 2. The spatial analysis of this data (in terms of proportion within and beyond national

jurisdictions) are available from the corresponding author upon reasonable request. REFERENCES * Doney, S. C. et al. Climate change impacts on marine ecosystems. _Annu. Rev. Mar. Sci._ 4,

11–37 (2012). Article  Google Scholar  * Hazen, E. L. et al. Predicted habitat shifts of Pacific top predators in a changing climate. _Nat. Clim. Change_ 3, 234–238 (2013). Article  Google

Scholar  * Poloczanska, E. S. et al. Responses of marine organisms to climate change across oceans. _Front. Mar. Sci_. 3, 62 (2016). * Chaudhary, C., Richardson, A. J., Schoeman, D. S. &

Costello, M. J. Global warming is causing a more pronounced dip in marine species richness around the equator. _Proc. Natl. Acad. Sci. USA_ 118, e2015094118 (2021). Article  CAS  Google

Scholar  * Pinsky, M. L., Selden, R. L. & Kitchel, Z. J. Climate-driven shifts in marine species ranges: Scaling from organisms to communities. _Annu. Rev. Mar. Sci._ 12, 153–179 (2020).

Article  Google Scholar  * IPCC. _Special Report on the Ocean and Cryosphere in a Changing Climate —_. 775 https://www.ipcc.ch/srocc/ (2019). * Perry, A. L., Low, P. J., Ellis, J. R. &

Reynolds, J. D. Climate change and distribution shifts in marine fishes. _Science_ 308, 1912–1915 (2005). Article  CAS  Google Scholar  * Poloczanska, E. S. et al. Global imprint of climate

change on marine life. _Nat. Clim. Change_ 3, 919–925 (2013). Article  Google Scholar  * Hindell, M. A. et al. Tracking of marine predators to protect Southern Ocean ecosystems. _Nature_

580, 87–92 (2020). Article  CAS  Google Scholar  * Pinsky, M. L., Worm, B., Fogarty, M. J., Sarmiento, J. L. & Levin, S. A. Marine taxa track local climate velocities. _Science_ 341,

1239–1242 (2013). Article  CAS  Google Scholar  * Laidre, K. L. et al. Quantifying the sensitivity of Arctic marine mammals to climate‐induced habitat change. _Ecol. Appl._ 18, S97–S125

(2008). Article  Google Scholar  * Jenkins, M. Prospects for biodiversity. _Science_ 302, 1175–1177 (2003). Article  CAS  Google Scholar  * Poloczanska, E. S. et al. Climate change and

Australian marine life. _Oceanogr. Mar. Biol._ 45, 407 (2007). Google Scholar  * Pecl, G. T. et al. Biodiversity redistribution under climate change: Impacts on ecosystems and human

well-being. _Science_ 355, eaai9214 (2017). Article  Google Scholar  * Madin, E. M. P. et al. Socio-economic and management implications of range-shifting species in marine systems. _Glob.

Environ. Change_ 22, 137–146 (2012). Article  Google Scholar  * Sumaila, U. R., Cheung, W. W. L., Lam, V. W. Y., Pauly, D. & Herrick, S. Climate change impacts on the biophysics and

economics of world fisheries. _Nat. Clim. Change_ 1, 449–456 (2011). Article  Google Scholar  * Buisson, L., Thuiller, W., Lek, S., Lim, P. & Grenouillet, G. Climate change hastens the

turnover of stream fish assemblages. _Glob. Change Biol._ 14, 2232–2248 (2008). Article  Google Scholar  * Basen, T., Ros, A., Chucholl, C., Oexle, S. & Brinker, A. Who will be where:

Climate driven redistribution of fish habitat in southern Germany |. _PLOS Clim. PLOS Clim._ 1, e0000006 (2022). Article  Google Scholar  * Pinsky, M. L. et al. Preparing ocean governance

for species on the move. _Science_ 360, 1189–1191 (2018). Article  CAS  Google Scholar  * Welch, H. et al. Impacts of marine heatwaves on top predator distributions are variable but

predictable. _Nat. Commun._ 14, 5188 (2023). Article  CAS  Google Scholar  * Harrison, A. L. et al. The political biogeography of migratory marine predators. _Nat. Ecol. Evolut._ 2,

1571–1578 (2018). Article  Google Scholar  * Beal, M. et al. Global political responsibility for the conservation of albatrosses and large petrels. _Sci. Adv._ 7, eabd7225 (2021). Article 

Google Scholar  * Oremus, K. L. et al. Governance challenges for tropical nations losing fish species due to climate change. _Nat. Sustain_ 3, 277–280 (2020). Article  Google Scholar  *

Enuka, C. Challenges of international environmental cooperation. _Global J. Human Soc.-Sci._ XVIII, 7–15 (2018). * Lascelles, B. et al. Migratory marine species: Their status, threats and

conservation management needs. _Aquat. Conserv. Mar. Freshw. Ecosyst._ 24, 111–127 (2014). Article  Google Scholar  * Dunn, D. C. et al. The importance of migratory connectivity for global

ocean policy. _Proc. R. Soc. B: Biol. Sci._ 286, 20191472 (2019). * Block, B. A. et al. Tracking apex marine predator movements in a dynamic ocean. _Nature_ 475, 86–90 (2011). Article  CAS 

Google Scholar  * Dunne, J. P. et al. GFDL’s ESM2 global coupled climate–carbon earth system models. Part I: Physical formulation and baseline simulation characteristics. _J. Clim._ 25,

6646–6665 (2012). Article  Google Scholar  * Palacios-Abrantes, J. et al. Timing and magnitude of climate-driven range shifts in transboundary fish stocks challenge their management. _Glob.

Change Biol._ 28, 2312–2326 (2022). Article  CAS  Google Scholar  * Roberson, L. A. et al. Multinational coordination required for conservation of over 90% of marine species. _Glob. Change

Biol._ 27, 6206–6216 (2021). Article  Google Scholar  * Mason, N., Ward, M., Watson, J. E. M., Venter, O. & Runting, R. K. Global opportunities and challenges for transboundary

conservation. _Nat. Ecol. Evol._ 4, 694–701 (2020). Article  Google Scholar  * UNEP-WCMC. _National and Regional Networks of Marine Protected Areas: A Review of Progress_. (2008). * Enright,

S. R., Meneses-Orellana, R. & Keith, I. The Eastern Tropical Pacific Marine Corridor (CMAR): The Emergence of a Voluntary Regional Cooperation Mechanism for the Conservation and

Sustainable Use of Marine Biodiversity Within a Fragmented Regional Ocean Governance Landscape. _Front. Marine Sci._ 8, (2021). * Vásárhelyi, C. & Thomas, V. G. Reflecting ecological

criteria in laws supporting the Baja to Bering Sea marine protected areas network case study. _Environ. Sci. Policy_ 11, 394–407 (2008). Article  Google Scholar  * Arafeh-Dalmau, N.,

Torres-Moye, G., Seingier, G., Montaño-Moctezuma, G. & Micheli, F. Marine spatial planning in a transboundary context: Linking Baja California with California’s Network of Marine

Protected Areas. _Front. Mar. Sci._ 4, 150 (2017). Article  Google Scholar  * Jiang, R. & Guo, P. Sustainable management of marine protected areas in the high seas: From regional

treaties to a global new agreement on biodiversity in areas beyond national jurisdiction. _Sustainability_ 15, 11575 (2023). Article  Google Scholar  * Wright, G., Rochette, J., Druel, E.

& Gjerde, K. M. The long and winding road continues: Towards a new agreement on high seas governance. _IDDRI, Paris, France_ (2016). * Nasby-Lucas, N. et al. Movements of electronically

tagged shortfin mako sharks (Isurus oxyrinchus) in the eastern North Pacific Ocean. _Anim. Biotelemetry_ 7, 12 (2019). Article  Google Scholar  * Gray, C. A. & Kennelly, S. J. Bycatches

of endangered, threatened and protected species in marine fisheries. _Rev. Fish. Biol. Fish._ 28, 521–541 (2018). Article  Google Scholar  * White, T. D. et al. Predicted hotspots of overlap

between highly migratory fishes and industrial fishing fleets in the northeast Pacific. _Sci. Adv._ 5, eaau3761 (2019). * Queiroz, N. et al. Global spatial risk assessment of sharks under

the footprint of fisheries. _Nature_ 572, 461–466 (2019). Article  CAS  Google Scholar  * Žydelis, R., Small, C. & French, G. The incidental catch of seabirds in gillnet fisheries: A

global review. _Biol. Conserv._ 162, 76–88 (2013). * Kachelriess, D. et al. _The BBNJ Agreement and the Convention on the Conservation of Migratory Species of Wild Animals_

https://highseasalliance.org/wp-content/uploads/2024/02/BBNJ-Agreement-and-CMS.pdf (2024). * Ardron, J. A., Rayfuse, R., Gjerde, K. & Warner, R. The sustainable use and conservation of

biodiversity in ABNJ: What can be achieved using existing international agreements? _Mar. Policy_ 49, 98–108 (2014). Article  Google Scholar  * Vierros, M. K. & Harden-Davies, H.

Capacity building and technology transfer for improving governance of marine areas both beyond and within national jurisdiction. _Mar. Policy_ 122, 104158 (2020). Article  Google Scholar  *

Ewell, C., Hocevar, J., Mitchell, E., Snowden, S. & Jacquet, J. An evaluation of Regional Fisheries Management Organization at-sea compliance monitoring and observer programs. _Mar.

Policy_ 115, 103842 (2020). Article  Google Scholar  * Hannesson, R. Rights based fishing on the high seas: Is it possible? _Mar. Policy_ 35, 667–674 (2011). Article  Google Scholar  *

Elliott, B., Tarzia, M. & Read, A. J. Cetacean bycatch management in regional fisheries management organizations: Current progress, gaps, and looking ahead. _Front. Marine Sci._ 9,

(2023). * Haas, B., Haward, M., McGee, J. & Fleming, A. Regional fisheries management organizations and the new biodiversity agreement: Challenge or opportunity? _Fish Fish_ 22, 226–231

(2021). Article  Google Scholar  * Crespo, G. O. et al. The environmental niche of the global high seas pelagic longline fleet. _Sci. Adv._ 4, 3681–3689 (2018). Article  Google Scholar  *

Park, J. et al. Tracking elusive and shifting identities of the global fishing fleet. _Sci. Adv._ 9, eabp8200 (2023). Article  Google Scholar  * Weimerskirch, H. et al. Ocean sentinel

albatrosses locate illegal vessels and provide the first estimate of the extent of nondeclared fishing. _Proc. Natl. Acad. Sci. USA_ 117, 3006–3014 (2020). Article  CAS  Google Scholar  *

Crear, D. P., Curtis, T. H., Durkee, S. J. & Carlson, J. K. Highly migratory species predictive spatial modeling (PRiSM): an analytical framework for assessing the performance of spatial

fisheries management. _Mar. Biol._ 168, 148 (2021). Article  Google Scholar  * Davies, T. E. et al. Tracking data and the conservation of the high seas: Opportunities and challenges. _J.

Appl. Ecol._ 58, 2703–2710 (2021). Article  Google Scholar  * Hays, G. C. et al. Translating marine animal tracking data into conservation policy and management. _Trends Ecol. Evolution_ 34,

459–473 (2019). Article  Google Scholar  * Wolf, S. et al. Transboundary seabird conservation in an important North American marine ecoregion. _Envir. Conserv._ 33, 294–305 (2006). Article

  Google Scholar  * Hammer, M. & Hoel, A. H. The development of scientific cooperation under the Norway–Russia Fisheries Regime in the Barents Sea. _Arct. Rev. Law Politics_ 3, 244–274

(2012). Google Scholar  * Tanhua, T. et al. Ocean FAIR data services. _Front. Marine Sci._ 6, (2019). * Abrahms, B., DiPietro, D., Graffis, A. & Hollander, A. Managing biodiversity under

climate change: challenges, frameworks, and tools for adaptation. _Biodivers. Conserv_ 26, 2277–2293 (2017). Article  Google Scholar  * Holsman, K. K. et al. Towards climate resiliency in

fisheries management. _ICES J. Mar. Sci._ 76, 1368–1378 (2019). Google Scholar  * Tittensor, D. P. et al. Integrating climate adaptation and biodiversity conservation in the global ocean.

_Sci. Adv._ 5, eaay9969 (2019). Article  Google Scholar  * Foley, M. M. et al. Guiding ecological principles for marine spatial planning. _Mar. Policy_ 34, 955–966 (2010). Article  Google

Scholar  * Burgess, M. G., Becker, S. L., Langendorf, R. E., Fredston, A. & Brooks, C. M. _Climate Change Scenarios in Fisheries and Aquatic Conservation Research_. https://osf.io/nwxae,

https://doi.org/10.31235/osf.io/nwxae (2022). * Blair, M. E., Le, M. D. & Xu, M. Species distribution modeling to inform transboundary species conservation and management under climate

change: promise and pitfalls. _Front. Biogeogr._ 14, e54662 (2022). * Shaffer, S. A. et al. Migratory shearwaters integrate oceanic resources across the Pacific Ocean in an endless summer.

_Proc. Natl Acad. Sci. USA_ 103, 12799–12802 (2006). Article  CAS  Google Scholar  * Robinson, R. A. et al. Travelling through a warming world: Climate change and migratory species.

_Endanger. Species Res._ 7, 87–99 (2009). Article  Google Scholar  * Silber, G. K. et al. Projecting marine mammal distribution in a changing climate. _Front. Marine Sci._ 4, (2017). *

Jones, M. C. & Cheung, W. W. L. Using fuzzy logic to determine the vulnerability of marine species to climate change. _Glob. Change Biol._ 24, e719–e731 (2018). Article  Google Scholar 

* Blondin, H. et al. Land-dependent marine species face climate-driven impacts on land and at sea. _Mar. Ecol. Prog. Ser._ 699, 181–198 (2022). Article  Google Scholar  Download references

ACKNOWLEDGEMENTS We would like to thank members of the Marine Ecology and Conservation Lab at Stanford University for feedback during study conception and design. We also acknowledge the

many scientific teams, partners, and working group leaders that contributed to the TOPP dataset that made this work possible. Funding was provided through Stanford University’s Emmett

Interdisciplinary Program in Environment and Resources, as well as Stanford University’s Hopkins Marine Station. AUTHOR INFORMATION AUTHORS AND AFFILIATIONS * Emmett Interdisciplinary

Program in Environment and Resources, Stanford University, Stanford, CA, USA Bianca S. Santos * Southwest Fisheries Science Center, National Oceanographic and Atmospheric Administration,

Monterey, CA, USA Elliott L. Hazen, Heather Welch & Nerea Lezama-Ochoa * Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA Elliott L. Hazen, Heather

Welch & Nerea Lezama-Ochoa * Hopkins Marine Station, Department of Oceans, Stanford University, Stanford, CA, USA Barbara A. Block & Larry B. Crowder * Department of Ecology and

Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA Daniel P. Costa * Department of Biological Sciences, San José State University, San Jose, CA, USA Scott A.

Shaffer Authors * Bianca S. Santos View author publications You can also search for this author inPubMed Google Scholar * Elliott L. Hazen View author publications You can also search for

this author inPubMed Google Scholar * Heather Welch View author publications You can also search for this author inPubMed Google Scholar * Nerea Lezama-Ochoa View author publications You can

also search for this author inPubMed Google Scholar * Barbara A. Block View author publications You can also search for this author inPubMed Google Scholar * Daniel P. Costa View author

publications You can also search for this author inPubMed Google Scholar * Scott A. Shaffer View author publications You can also search for this author inPubMed Google Scholar * Larry B.

Crowder View author publications You can also search for this author inPubMed Google Scholar CONTRIBUTIONS B.S. led the study design and data analysis. E.H., H.W., N.L. and L.C assisted in

conceptualizing research aims and data consultation. B.S. wrote the manuscript, with edits and revisions from E.H., H.W., N.L., B.B, D.C., S.S., and L.C. CORRESPONDING AUTHOR Correspondence

to Bianca S. Santos. ETHICS DECLARATIONS COMPETING INTERESTS L.C. serves on the journals' editorial board. ADDITIONAL INFORMATION PUBLISHER’S NOTE Springer Nature remains neutral with

regard to jurisdictional claims in published maps and institutional affiliations. SUPPLEMENTARY INFORMATION SUPPLEMENTAL MATERIALS RIGHTS AND PERMISSIONS OPEN ACCESS This article is licensed

under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give

appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in

this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative

Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a

copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Santos, B.S., Hazen, E.L., Welch, H. _et al._ Beyond

boundaries: governance considerations for climate-driven habitat shifts of highly migratory marine species across jurisdictions. _npj Ocean Sustain_ 3, 22 (2024).

https://doi.org/10.1038/s44183-024-00059-5 Download citation * Received: 21 March 2023 * Accepted: 21 March 2024 * Published: 09 April 2024 * DOI: https://doi.org/10.1038/s44183-024-00059-5

SHARE THIS ARTICLE Anyone you share the following link with will be able to read this content: Get shareable link Sorry, a shareable link is not currently available for this article. Copy to

clipboard Provided by the Springer Nature SharedIt content-sharing initiative