Turbulent mixing in the ocean exerts an important control on the rate and structure of the overturning circulation. However, the balance of processes underpinning this mixing is subject to significant uncertainties, limiting our understanding of the overturning\'s deep upwelling limb. Here, we investigate the hitherto primarily neglected role of tens of thousands of seamounts in sustaining deep-ocean upwelling. Dynamical theory indicates that seamounts may stir and mix deep waters by generating lee waves and topographic wake vortices. At low latitudes, stirring and mixing are predicted to be enhanced by a layered vortex regime in the wakes. Using three realistic regional simulations spanning equatorial to middle latitudes, we show that layered wake vortices and elevated mixing are widespread around seamounts. We identify scalings that relate mixing rate within seamount wakes to topographic and hydrographic parameters. We then apply such scalings to a global seamount dataset and an ocean climatology to show that seamount-generated mixing makes an important contribution to the upwelling of deep waters. Our work thus brings seamounts to the fore of the deep-ocean mixing problem and urges observational, theoretical, and modeling efforts toward incorporating the seamounts\' mixing effects in conceptual and numerical ocean circulation models.

Chirality, a fundamental property of matter, is often overlooked in the studies of marine organic matter cycles. Dihydroxypropanesulfonate (DHPS), a globally abundant organosulfur compound, serves as an ecologically important currency for nutrient and energy transfer from phytoplankton to bacteria in the ocean. However, the chirality of DHPS in nature and its transformation remain unclear. Here, we developed a novel approach using chiral phosphorus-reagent labeling to separate DHPS enantiomers. Our findings demonstrated that at least one enantiomer of DHPS is present in marine diatoms and coccolithophores, and that both enantiomers are widespread in marine environments. A novel chiral-selective DHPS catabolic pathway was identified in marine Roseobacteraceae strains, where HpsO and HpsP dehydrogenases at the gateway to DHPS catabolism act specifically on R-DHPS and S-DHPS, respectively. R-DHPS is also a substrate for the dehydrogenase HpsN. All three dehydrogenases generate stable hydrogen bonds between the chirality-center hydroxyls of DHPS and highly conserved residues, and HpsP also form coordinate-covalent bonds between the chirality-center hydroxyls and Zn2+, which determines the mechanistic basis of strict stereoselectivity. We further illustrated the role of enzymatic promiscuity in the evolution of DHPS metabolism in Roseobacteraceae and SAR11. This study provides the first evidence of chirality\'s involvement in phytoplankton-bacteria metabolic currencies, opening a new avenue for understanding the ocean organosulfur cycle.

Salmon lice, Lepeophtheirus salmonis (family Caligidae), are ectoparasites that have negatively impacted the salmon aquaculture industry and vulnerable wild salmon populations. Researchers have studied salmon lice to better understand their biology to develop effective control strategies. In this study, we updated the chromosome-level reference genome assembly of the Pacific subspecies of L. salmonis using Hi-C data. The previous version placed contigs/scaffolds using an Atlantic salmon louse genetic map. By utilizing Hi-C data from Pacific salmon lice, we were able to properly assign locations to contigs/scaffolds previously unplaced or misplaced. This resulted in a more accurate genome assembly and a more comprehensive characterization of the sex chromosome unique to females (W). We found evidence that the same ZW-ZZ mechanism is common in both Atlantic and Pacific subspecies of salmon lice using PCR assays. The W chromosome was approximately 800 kb in size, which is ∼30 times smaller than the Z chromosome (24 Mb). The W chromosome contained 61 annotated genes, including 32 protein-coding genes, 27 long noncoding RNA (lncRNA) genes, and 2 pseudogenes. Among these 61 genes, 39 genes shared homology to genes found on other chromosomes, while 20 were unique to the W chromosome. Two genes of interest on the W chromosome, prohibitin-2 and kinase suppressor of ras-2, were previously identified as potential sex-linked markers in the salmon louse. However, we prioritized the 20 unique genes on the W chromosome as sex-determining candidates. This information furthers our understanding of the biology of this ectoparasite and may help in the development of more effective management strategies.

UNASSIGNED: Surfing is an increasingly popular sport with a high propensity for both traumatic and atraumatic injuries.
UNASSIGNED: To analyze the trends, etiologies, and diagnoses of lower extremity orthopaedic-related surfing injuries presenting to United States (US) emergency departments (EDs) within a 21-year study period.
UNASSIGNED: Descriptive epidemiology study.
UNASSIGNED: The National Electronic Injury Surveillance System database was queried for data on lower extremity surfing injuries presenting to US EDs from January 1 to December 31, 2022. Data collected included year, injury mechanism, injury location, diagnosis, and disposition. The raw data were used to calculate national estimates (NEs) based on each hospital\'s assigned statistical sample weight. Linear regressions were performed to analyze annual trends.
UNASSIGNED: A total of 776 lower extremity surfing injuries were included (NE = 49,218 injuries). The mean age of the patients was 29.4 ± 13.6 years. The most common injured areas were the foot (NE = 17,411; 35.4%), lower leg (NE = 8673, 17.6%), and knee (NE = 8139; 16.5%). The most common mechanism of injury was impact with board (NE = 17,144; 34.8%), and the most common fracture locations were the lower leg (NE = 1195; 29.5%), ankle (NE = 1594; 24.5%), and foot (NE = 1495; 23.0%). There were statistically significant decreases in weighted estimates for lower extremity surfing injuries by 108 per year (P < .001), for lacerations by 76 per year (P < .001), and for sprains by 18 per year (P = .01). Impact-with-board injuries decreased by 59 injuries per year (P < .001) and constituted 63.5% of lacerations and 12.1% of fractures. Only 3.9% of patients were admitted for hospitalization.
UNASSIGNED: There was a decreasing trend in lower extremity surfing injuries presenting to US EDs during the 21-year study period.

UNESCO\'s Intergovernmental Oceanographic Commission launched the United Nations Decade of Ocean Science for Sustainable Development in 2021 to boost global and sustainable Ocean governance. The initiative resulted from historical and political dynamics at the global and lower political scales, with maritime environmental and economic concerns becoming more prominent in 2010. The Ocean Decade\'s pillars include science and research, sustainability, conservation, and bridging gaps for a global Ocean-Climate-Biodiversity nexus. The Sustainable Development Goals recognized the importance of oceans and marine resources, and the Ocean was officially perceived as a determining factor of Climate Change at CoP 21 in 2015. Portugal has built integrated and far-reaching policies for ocean governance, including significant involvement with an international perspective since the Lisbon World Exhibition in 1998. In addition, the national government established a Ministry of the Sea in 2015 to re-develop relations with its maritime space. This article analyzes and compares the discourse of the United Nations\' Sustainable Development Goals reports and the Portuguese government programs (2005-2022) to explore the prominent trends in Portuguese Ocean governance discourse and how global and national perspectives interact. Through this case study, the research aims to develop insights into the multiscalar impacts of promoting global and sustainable Ocean governance and its interaction with national perspectives.

Understanding the characteristics and structure of populations is fundamental to comprehending ecosystem processes and evolutionary adaptations. While the study of animal and plant populations has spanned a few centuries, microbial populations have been under scientific scrutiny for a considerably shorter period. In the ocean, analyzing the genetic composition of microbial populations and their adaptations to multiple niches can yield important insights into ecosystem function and the microbiome\'s response to global change. However, microbial populations have remained elusive to the scientific community due to the challenges associated with isolating microorganisms in the laboratory. Today, advancements in large-scale metagenomics and metatranscriptomics facilitate the investigation of populations from many uncultured microbial species directly from their habitats. The knowledge acquired thus far reveals substantial genetic diversity among various microbial species, showcasing distinct patterns of population differentiation and adaptations, and highlighting the significant role of selection in structuring populations. In the coming years, population genomics is expected to significantly increase our understanding of the architecture and functioning of the ocean microbiome, providing insights into its vulnerability or resilience in the face of ongoing global change. Video Abstract.

Parmales (Bolidophyceae) is a minor eukaryotic phytoplankton group, sister to diatoms, which exists as two distinct forms of unicellular organisms: silicified cells and naked flagellates. Since their discovery, many field studies on Parmales have been performed; however, their global distribution has not yet been examined in detail. We herein compiled more than 3,000 marine DNA metabarcoding datasets targeting the V4 region of the 18S rRNA gene from the EukBank database. By linking this large dataset with the latest morphological and genetic information, we provide updated estimates on the diversity and distribution of Parmales in the global ocean at a fine taxonomic resolution. Parmalean amplicon sequence variants (ASVs) were detected in nearly 90% of the samples analyzed. However, the relative abundance of parmaleans in the eukaryotic community was less than 0.2% on average, and the estimated true richness of parmalean ASVs was approximately 316 ASVs, confirming their low abundance and diversity. A phylogenetic ana-lysis divided these algae into four clades, and three known morphotypes of silicified cells were classified into three different clades. The abundance of Parmales is generally high in the poles and decreases towards the tropics, and individual clades/subclades show further distinctions in their distribution. Collectively, the present results suggest clade/subclade-specific adaptation to different ecological niches.

Here, we present the draft genome sequences of three Croceitalea sp. strains containing microbial rhodopsins, isolated from the Japanese coastal sea surface microlayer, which is exposed to intense sunlight. This study will contribute to the understanding of the genus Croceitalea and the diversity of microbial rhodopsins.

UNASSIGNED: The Antarctic Penguin Biogeography Project is an effort to collate all known information about the distribution and abundance of Antarctic penguins through time and to make such data available to the scientific and management community. The core data product involves a series of structured tables with information on known breeding sites and surveys conducted at those sites from the earliest days of Antarctic exploration through to the present. This database, which is continuously updated as new information becomes available, provides a unified and comprehensive repository of information on Antarctic penguin biogeography that contributes to a growing suite of applications of value to the Antarctic community. One such application is the Mapping Application for Antarctic Penguins and Projected Dynamics (MAPPPD; www.penguinmap.com), a browser-based search and visualisation tool designed primarily for policy-makers and other non-specialists, and mapppdr, an R package developed to assist the Antarctic science community. This dataset contains records of Pygoscelisadeliae, Pygoscelisantarctica, Pygoscelispapua, Eudypteschrysolophus, Aptenodytespatagonicus and Aptenodytesforsteri annual nest, adult and/or chick counts conducted during field expeditions or collected using remote sensing imagery, that were subsequently gathered by the Antarctic Penguin Biogeography Project from published and unpublished sources, at all known Antarctic penguin breeding colonies south of 60 S from 01-11-1892 to 12-02-2022-02-12.
UNASSIGNED: This dataset collates together all publicly available breeding colony abundance data (1979-2022) for Antarctic penguins in a single database with standardised notation and format. Colony locations have been adjusted as necessary using satellite imagery and each colony has been assigned a unique four-digit alphanumeric code to avoid confusion. These data include information previously published in a variety of print and online formats as well as additional survey data not previously published. Previously unpublished data derive primarily from recent surveys collected under the auspices of the Antarctic Site Inventory, Penguin Watch or by the Lynch Lab at Stony Brook University.

BACKGROUND: The ice-free season (typically late-June to early-October) is crucial for anadromous species of fish in the Arctic, including Arctic Char (Salvelinus alpinus), which must acquire adequate resources for growth, reproduction, and survival during a brief period of feeding in the marine environment. Arctic Char is an important food fish for Inuit communities across the Arctic. Understanding drivers and patterns of migration in the marine environment is thus essential for conservation and management of the species.
METHODS: We used passive acoustic telemetry to characterize migration patterns of 51 individual anadromous Arctic Char during the ice-free season in the marine environment of Coronation Gulf (Nunavut, Canada; 2019-2022). Based on recent genetic evidence, some tagged individuals were likely Dolly Varden (Salvelinus malma malma), a closely related species to Arctic Char. Using local Getis G* and network analysis, we described movement patterns and identified high-use locations in the marine environment. We also related freshwater overwintering location to migration timing and movement pattern.
RESULTS: Comparing groups of fish that overwintered in distinct locations, we found: (i) limited evidence that marine movements were associated with overwintering location; (ii) minor differences in use of marine space; and, (iii) timing of freshwater return differed significantly between overwintering groups, and was related to length and difficulty of the migratory pathway in freshwater. Results from both network analysis and local Getis G* revealed that, regardless of overwintering location, coastal locations were highly used by fish.
CONCLUSIONS: Overwintering locations, and the migratory routes to access overwintering locations, affect the timing of freshwater return. Preference of fish for coastal marine locations is likely due to abundance of forage and patterns in break-up of sea ice. Similarities in marine space use and movement patterns present challenges for managing this and other mixed stock fisheries of anadromous Salvelinus spp. Absences or periods of time when fish were not detected prevented comprehensive assessment of movement patterns. Local Getis G*, a local indicator of spatial association, is a helpful tool in identifying locations associated with absences in acoustic telemetry arrays, and is a complementary method to network analysis.