Abstract Antarctic Intermediate Water (AAIW), occupying a broad region at intermediate depths in the Southern Hemisphere oceans, plays a crucial role in global heat and freshwater redistribution. However, its origin at the sea surface remains a subject of ongoing debate. A recently defined distance metric, which distinguishes similar water parcels, is applied to Argo data to trace the surface origins of the AAIW cores in each ocean basin. By examining the spatial distribution of distances to the AAIW cores, we identify that the Pacific and Atlantic AAIW cores primarily originate from localized surface regions, specifically near the Subantarctic Front in the southeast Pacific and the Falkland Plateau in the southwest Atlantic. Further investigation indicates that through subduction in the deep mixed layer, low-salinity water penetrates to intermediate depths in these regions. North of the subduction sites, water masses primarily circulate within the subtropical gyre in the South Pacific, whereas to the south, they are advected eastward by the Antarctic Circumpolar Current into the Atlantic Ocean. In the Indian Ocean, the AAIW core, distinguished by its relatively low oxygen concentration, originates both from eastward inflow carried by the Antarctic Circumpolar Current from the southeast Pacific and local surface sources near 90°E. Our findings confirm the reliability of the distance metric and emphasize the importance of localized physical processes in the penetration of AAIW into the ocean interior. Significance Statement Antarctic Intermediate Water (AAIW), found in Southern Hemisphere intermediate depths, is essential for global heat and freshwater distribution. Using a newly defined distance metric, it is found that AAIW originates primarily from the Subantarctic Front in the southeast Pacific and the Falkland Plateau in the southwest Atlantic, where low-salinity water subducts into deeper layers. In contrast, the Indian Ocean lacks this direct path, with its AAIW formed by the inflow of AAIW from the Atlantic via the Antarctic Circumpolar Current. These findings improve our understanding of AAIW origins and pathways within the ocean.

In this study, we reconstructed the North Atlantic Ocean temperature field by combining an interpretable deep learning framework with multi-source satellite data, including sea surface temperature (SST), sea surface height (SSH), sea level anomaly (SLA), sea surface wind field (SSW), and SST gradient (GRAD). The optimal model configuration achieved a root mean square error (RMSE) of 0.49 °C. This study extends the SHapley Additive exPlanations (SHAP) method to spatial, temporal, and vertical dimensions to systematically analyze the model’s error sources and feature contributions. The results show that the reconstruction error is concentrated in regions with large physical gradients, such as the thermocline and Gulf Stream, exhibiting a significant seasonal bias pattern. SHAP analysis reveals a clear vertical transition in feature importance that SST dominates at all depths with a relative contribution of 34.60%. The contributions of SSW and GRAD were mainly concentrated at the sea surface, whereas the contributions of SSH and SLA began to increase in the lower mixed layer and peaked in the thermocline, becoming crucial in connecting the surface and ocean interior. This study highlights the depth and spatial dependence of feature contributions, providing a physical basis for the future optimization of remote sensing-based ocean temperature reconstruction models.

Comprehensive review of the last 25 years regarding metals in the Atlantic coast of Patagonia.

The Southwestern Atlantic Ocean (SWAO) is a global biodiversity hotspot where the impact of plastic pollution on cetaceans remains poorly understood. This study evaluated debris ingestion in cetaceans stranded along the southern Brazilian coast from 2015 to 2020. Of the 884 individuals with analyzed gastrointestinal contents, representing 22 species, debris was found in 10.1% of cases, with coastal species being the most vulnerable. The endangered Franciscana dolphin (Pontoporia blainvillei) showed the highest ingestion rate (17.9%). Pathological analysis of a subsample (n=20) revealed that gross lesions in the digestive tract were rare and showed no apparent association with debris in these cases. In a subset of individuals with known causes of death, the most common findings were consistent with asphyxia caused by fishery interactions. This suggests that the high incidence of plastic ingestion warrants further investigation into chronic, sublethal impacts, such as toxic effects, that coexist alongside immediate threats, such as interactions with fisheries. Our findings provide an important baseline and underscore the need to assess plastic pollution within the context of multiple, simultaneous stressors to effectively protect vulnerable marine wildlife.

First confirmation of Caribbean ciguatoxins in fish samples from the South Atlantic coast of Brazil.

The influence of plate tectonics on microbial distributions remains poorly understood. Here, we demonstrate that the global biogeography of hydrothermal vent-endemic chemoautotrophic microbiota is structured by the tectonic history of the global major oceans. These microbiota, particularly anaerobic ones, are significantly more abundant in early-origin Pacific, Arctic, and Mediterranean oceans, whereas they are notably scarce in late-formed Atlantic and Indian Oceans. This pattern was attributed to the timing of ocean formation and its interplay with global redox evolution. Fully oxygenated conditions in the Phanerozoic during the formation of the latter two oceans imposed a dual-dispersal barrier among oceans: toxicity of molecular oxygen to anaerobes and depletion of energy sources (especially reduced chemicals) for aerobes, but such a barrier didn't exist before the Phanerozoic, when the former three oceans started. These results integrate microbial biogeography into a geodynamic framework, revealing that even microbial life is subject to planetary-scale geological constraints.

Simulating 135 years of post-hatchling sea turtle dispersal in a dynamic North Atlantic Ocean

High temporal resolution vessel transects reveal systematic patterns of floating marine debris in the Baía de Todos os Santos, South Atlantic.

Bioaccumulation of trace elements by Leach's storm-petrels (Hydrobates leucorhous) in the North and South Atlantic Ocean during the non-breeding period.

Pteropods are promising proxy archives for paleoceanographic reconstructions but remain underexplored. Previous oxygen isotope analyses indicated that Heliconoides inflatus calcifies at shallow depths (50–75 m), suggesting its potential to record surface-ocean conditions. Here, we evaluate for the first time the applicability of Li/Mg thermometry in pteropod shells, a temperature proxy widely used in coral studies. We show that, in addition to recording environmental variability through shell carbon and oxygen isotopic composition, H. inflatus shells record upper-water temperature conditions, with Li/Mg ratios showing a robust relationship with ambient temperatures at sampling locations. Li/Mg ratios decrease exponentially with increasing temperature, enabling temperature reconstructions with an average precision of ± 1–2 °C. Pteropod shells (species H. inflatus, formerly known as Limacina inflata) were collected along a latitudinal transect in the Atlantic Ocean (31° N to 38° S), spanning a surface-water temperature gradient of approximately 15 °C. The global distribution and abundance of this annual species in sediments makes it a suitable alternative for paleo-surface temperature reconstruction. The utility of pteropod shells extends further to seasonal paleotemperature reconstruction, as seasonal temperature variability is captured in the elemental ratios from the embryonic to later (adult) sections of the shell. These results, in combination with a basin-scale distribution, make the Li/Mg thermometer in pteropods an exciting new tool in paleoceanography and further cement this group as new proxy archives.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-026-55990-z.

ABSTRACTMigration patterns in birds are shaped by ecological and physiological constraints that differ between sexes, seasons and among breeding regions, resulting in complex temporal and spatial strategies. Understanding this variation is crucial for revealing how individuals optimise their annual cycles. As very little is known about the individual migratory behaviour of pied avocets (Recurvirostra avosetta), this study investigated how spatiotemporal migration patterns of avocets breeding in northern Europe vary seasonally, sexually, and spatially. We captured 122 adults on their nests in three countries using walk‐in traps and equipped them with lightweight (6–9 g) solar‐powered GPS loggers. Avocets spent an extended post‐breeding period (on average until early November) in the Wadden Sea before commencing autumn migration. While most individuals followed the East Atlantic Flyway, four deviated via an inland route across the Alps to Italian wintering sites. On average, avocets travelled 1503 ± 996 km within 13.3 ± 19.8 days, resulting in a mean migration speed of 470.8 ± 554.0 km day−1. The main wintering range was concentrated in France and Portugal, with the Tejo Estuary being the most frequently used site. Migration tactics differed between seasons and sexes: autumn migration lasted longer and involved fewer but extended stopovers, whereas spring migration was faster, with more but shorter stopovers. Females migrated significantly further (1928 km vs. 1277 km in males) and wintered at more southern latitudes, while males remained longer in the Wadden Sea in autumn and tended to arrive at breeding sites earlier in spring. Avocets breeding in the Wadden Sea tended to winter further south than those from the Baltic Sea (Poland), most of which first moved to the Wadden Sea before continuing migration. Our findings highlight the central role of the Wadden Sea as a key fuelling area in the annual cycle of pied avocets from northern Europe.

ABSTRACT This article examines Kamala Harris’ 2020–2024 presidential trajectory as a site where multiracial, diasporic identity confronts white supremacist nostalgia in contemporary US politics. Its central thesis argues that Harris’ transoceanic hybridity, rooted in Black Atlantic and South Asian Indian Ocean histories, both destabilizes hegemonic narratives of national belonging and reveals the structural limits placed on hybrid, gendered bodies within presidential politics. Drawing on Critical Mixed Race Studies and Diaspora Theory, the article investigates how Harris’ multi-ethnoracial identity was mobilized, scrutinized, and contested in media, campaign discourse, and political attacks, particularly in contrast to Donald Trump’s masculinist, frontier-based imaginaries of power. Methodologically, the study employs qualitative critical discourse analysis of key campaign texts, including the September 2024 presidential debate, Trump’s victory speech, and Harris’ concession speech, alongside close readings of Harris’ memoir. The analysis demonstrates how hybridity operates as a politically ambivalent force that can challenge exclusionary racial logics while remaining vulnerable to containment within dominant structures of power.

ABSTRACTMarine ecosystems are undergoing rapid transformation under climate change, yet the responses of many marine invertebrates remain vastly understudied. In particular, for many benthic gastropods there is a striking imbalance between their traditional appreciation by shell collectors—and, consequently, their consistent representation in Natural History Collections—and the limited attention they receive in ecological and conservation studies. Focusing on the northeastern Atlantic and the Mediterranean, the cowries Luria lurida, Naria spurca, Zonaria pyrum and the frog‐shell Talisman scrobilator are emblematic examples of this knowledge gap, despite being frequently mentioned as species of conservation concern. Using long‐term occurrence records spanning more than a century, we modelled past and present distributions of these species and explored their potential responses to future climate scenarios through a multi‐temporal Species Distribution Modelling framework. Our results show that intermediate climatic conditions—both in time (2050–2060 vs. 2090–2100) and scenario intensity (moderate SSP2‐4.5 versus high‐emission SSP5‐8.5)—may represent a critical transition phase, leading to habitat contractions without compensatory gains in newly emerging suitable areas. The Mediterranean Sea is expected to increasingly function as a cul‐de‐sac, with the dominant circulation patterns strongly limiting outward movements towards cooler regions for species relying on planktic larvae for dispersal. Furthermore, incorporating larval sensitivity to reduced pH suggests that large areas of the Atlantic Ocean may actually result unsuitable for larval persistence, substantially reducing the habitat effectively available for completion of the full life cycle; this highlights the need to account for connectivity, life‐history constraints and juvenile‐stage sensitivity when assessing climate‐driven range shifts in shelled organisms with planktic larvae.

Marine heatwaves (MHWs) are intensifying with climate change, driving significant alterations in marine ecosystems, especially those dominated by macroalgae. This study assesses the stress response and recovery capacity of two geographically and environmentally distinct populations of the agarophyte Gelidium corneum under simulated MHWs. One population originated from the inner Southern Bay of Biscay (Cantabrian Sea, non-upwelling area) and the other from northern Portugal (Atlantic Ocean, upwelling-influenced). MHWs were simulated using three intensities, control (20°C), low (22°C) and high (24°C), and two durations, short (7 days) and long (21 days), each followed by a 7-day recovery period. Stress responses were evaluated through growth rates, tissue damage, and photophysiological parameters (Fv/Fm, photosynthesis and respiration). Results revealed population-specific thermal responses. Short, intense MHWs induced reversible photophysiological stress in both populations, indicating a general sensitivity of the photosynthetic apparatus to abrupt temperature increases. In contrast, prolonged MHWs triggered divergent responses: warm-adapted individuals from the Cantabrian Sea displayed photosynthetic plasticity and resilience, while cold-adapted individuals from the Atlantic population suffered a sustained reduced performance, particularly under high-intensity events. These findings highlight the role of local thermal adaptation in shaping macroalgal responses to future ocean warming scenarios.

Dolphin morbillivirus (DMV) epizootics have recurrently occurred in the western Mediterranean Sea since the first reported outbreak in 1990-1992. In August-November 2025, 5 stranded striped dolphins Stenella coeruleoalba were diagnosed with systemic DMV infection in the Spanish Mediterranean Sea. Dolphins were thin, and 4 of them had typical viral lesions of bronchiolointerstitial pneumonia, lymphoid depletion, and encephalitis. RT-PCR for DMV was positive in at least 2 organs in all dolphins, and viral antigen was detected by immunohistochemistry in 4 dolphins. Four dolphins died due to morbillivirus infection, while the other DMV-infected dolphin died from cranial trauma and tension pneumothorax. The viral genome recovered from the sample of one dolphin has higher identity to delphinid 2016-2017 Italian DMV sequences and to a fin whale strain from Denmark in 2016, and is approximately 1% distant from strains of previous epizootics in the Mediterranean Sea. The exact source of the infection is unknown, but direct contact with infected striped dolphins from other areas of the Mediterranean or a new DMV incursion from the Atlantic Ocean are possible.

Invasive species are recognised as a major driver of global biodiversity loss. In marine ecosystems, blooms of non-native jellyfish species are widely perceived to be increasing globally, with impacts on food webs, ecosystem services, biogeochemical cycles, and coastal livelihoods. Pelagia noctiluca (Forsskål, 1775) is a jellyfish native to the Mediterranean Sea and the northeastern Atlantic Ocean, but has been increasingly associated with recurrent bloom events in non-native regions, which cause adverse ecological and socio-economic impacts. Here, we use an ensemble species distribution modelling framework implemented in the biomod2 package in R to assess the global habitat suitability of P. noctiluca, and to evaluate its present-day and future invasion potential across non-native marine ecosystems. Based on species occurrence records and eight environmental variables, our results indicate that P. noctiluca exhibits high habitat suitability in temperate and subtropical coastal waters, driven primarily by salinity, primary productivity, and sea surface temperature. Ultimately, by projecting a substantial future habitat contraction, our findings strongly contradict the general perception that jellyfish blooms and distribution will universally increase under global climate change.

Long-distance migrations allow animals to exploit seasonal prey opportunities and track favorable oceanographic conditions. The basking shark (Cetorhinus maximus) is a large, filter-feeding elasmobranch commonly observed in temperate shelf habitats, though it is known to seasonally occupy warmer, lower-latitude regions. In the Northwest Atlantic Ocean, basking sharks migrate from summer habitats on the continental shelf of the northeastern United States and Canada to the tropical waters of the Caribbean and South America during winter. However, the functional role of these large-scale movements is poorly understood, and their overwintering behavior during migration remains enigmatic. Here, we use pop-up satellite archival transmitting (PSAT) tags to measure basking shark vertical habitat use during this migration. Based on daily summaries of time-at-depth and time-at-temperature, we find that sharks exhibited two main behaviors: shallow epipelagic occupancy on or near the continental shelf and movements throughout the mesopelagic in offshore waters. While offshore, vertical habitat use was characterized by a strong diel vertical migration (DVM) that overlapped with primary and secondary deep scattering layers, particularly in the southern Sargasso Sea. However, DVM behavior was widespread throughout the Sargasso Sea, where most tagged individuals overwintered, and continued into the Caribbean and during trans-equatorial movements. Our results suggest basking sharks likely forage throughout these large-scale migrations, rather than relying primarily on energy stores as has been suggested for other highly migratory shark species. We also suggest that basking sharks may regularly target prey biomass in a deeper, often non-migratory prey layer below the primary deep scattering layer. These findings highlight the potential ecological importance of mesopelagic prey for basking sharks during migration and contribute to growing recognition of the ecosystem services supported by deep-pelagic food webs within and beyond the primary deep scattering layer.

Since 1989, the Department of Anatomical Sciences at the State University of New York at Stony Brook has given out the Norman Creel Prize For Outstanding Student Research in Anatomical Sciences, named for a late professor in the department whose 1990 obituary hailed him as "one of the major ambassadors linking Europe and the United States." However, documents obtained from German archives show that while working in Germany the 1960s and 1970s, Norman Creel collaborated in research with Sophie Ehrhardt, a German anthropologist who contributed to the Nazi genocide of the Romani people. Their work used data derived from coercive Nazi research on Romani populations, yielding a 1977 abstract publication in connection with a US anthropological conference. The discovery of these documents provides an example of the postwar use of data from research conducted on human beings during the Nazi period and shows how the long shadow of Nazi science reaches across the Atlantic Ocean to the United States, including in the field of anatomical sciences. Creel's work with an unrepentant former Nazi race scientist like Ehrhardt, the unethical nature of that work and the indignity that it inflicted on victims, survivors, and their families raise serious concerns about an academic award being named in his honor.

Optical tracing of dissolved organic matter in the South Atlantic Ocean: linking water masses and biogeochemical processes

Saint Peter and Saint Paul Archipelago as a key stopover for yellowfin tunas from the Gulf of Guinea.