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Southern Ocean ecosystems are under pressure from resource exploitation and climate change1,2. Mitigation requires the identification and protection of Areas of Ecological Significance (AESs), which have so far not been determined at the ocean-basin scale. Here, using assemblage-level tracking of marine predators, we identify AESs for this globally important region and assess current threats and protection levels. Integration of more than 4,000 tracks from 17 bird and mammal species reveals AESs around sub-Antarctic islands in the Atlantic and Indian Oceans and over the Antarctic continental shelf. Fishing pressure is disproportionately concentrated inside AESs, and climate change over the next century is predicted to impose pressure on these areas, particularly around the Antarctic continent. At present, 7.1% of the ocean south of 40°S is under formal protection, including 29% of the total AESs. The establishment and regular revision of networks of protection that encompass AESs are needed to provide long-term mitigation of growing pressures on Southern Ocean ecosystems.

The Retrospective Analysis of Antarctic Tracking Data (RAATD) is a Scientific Committee for Antarctic Research project led jointly by the Expert Groups on Birds and Marine Mammals and Antarctic Biodiversity Informatics, and endorsed by the Commission for the Conservation of Antarctic Marine Living Resources. RAATD consolidated tracking data for multiple species of Antarctic meso- and top-predators to identify Areas of Ecological Significance. These datasets and accompanying syntheses provide a greater understanding of fundamental ecosystem processes in the Southern Ocean, support modelling of predator distributions under future climate scenarios and create inputs that can be incorporated into decision making processes by management authorities. In this data paper, we present the compiled tracking data from research groups that have worked in the Antarctic since the 1990s. The data are publicly available through biodiversity.aq and the Ocean Biogeographic Information System. The archive includes tracking data from over 70 contributors across 12 national Antarctic programs, and includes data from 17 predator species, 4060 individual animals, and over 2.9 million observed locations.

The North Sea is one of the most industrialised marine regions globally. We integrated cetacean-dedicated aerial surveys (2015–2022) with environmental covariates and ship positions from the Automatic Identification System (AIS) to investigate the disturbance radius and duration on harbour porpoise distribution. This study is based on 81,511 km of line-transect survey effort, during which 6511 harbour porpoise groups (8597 individuals) were sighted. Several proxies for ship disturbance were compared, identifying those best explaining the observed distribution. Better model performance was achieved by integrating maritime traffic, with frequent traffic representing the most significant disturbance to harbour porpoise distribution. Porpoises avoided areas frequented by numerous vessels up to distances of 9 km. The number of ships and average approach distance over time improved model performance, while reasons for the lower performance of predicted ship sound levels remain unclear. This study demonstrates the short-term effects of maritime traffic on harbour porpoise distribution. [Display omitted] • Cetacean survey data (2015–2022) in the North Sea were combined with vessel positions. • Effects of vessel presence on harbour porpoise distribution were investigated. • Spatial avoidance was detected, particularly in areas with heavy or frequent traffic. • Best predictors were the number of vessels and average approach distance over time. • This broad-scale study shows short-term effects over 9 km on porpoise distribution. [ABSTRACT FROM AUTHOR]

There is no clear recommendation for wound closure material in foot and ankle surgery. Thus, we hypothesized that there was no difference in clinical outcomes among 3 suture materials, namely, absorbable sutures, nonabsorbable sutures, and metallic staples. This study compared the 3 materials for wound closure in foot and ankle surgery. In this prospective randomized study, 124 patients were randomly divided into the nonabsorbable suture group, absorbable suture group, and staple group. ASEPSIS score, Hollander Wound Evaluation Scale, and numerical rating scale (regarding pain and satisfaction) were collected at first dressing changes, suture removal, and 6 weeks after surgery. Suture time and incision length were recorded. No significant differences were detected for the ASEPSIS and Hollander Wound Evaluation Scale scores. There was significantly more pain after 6 weeks in the nonabsorbable suture group. The closure time (13 s/cm) with staples was significantly lower in the nonabsorbable suture group than in the other groups. Regardless of wound closure material, male sex and obesity appeared to be associated with a higher risk for the occurrence of wound complications. The 3 suture materials showed no significant differences regarding the frequency of wound complications. Staples and absorbable sutures should therefore be considered in the repertoire of suture materials used in foot and ankle surgery. [ABSTRACT FROM AUTHOR]

Articular cartilage is a mechanically highly challenged material with very limited regenerative ability. In contrast to elastic cartilage, articular cartilage is exposed to recurring partial dehydration owing to ongoing compression but maintains its functionality over decades. To extend our current understanding of the material properties of articular cartilage, specifically the interaction between the fluid and solid phase, we here analyze the reversibility of tissue dehydration. We perform an artificial dehydration that extends beyond naturally occurring levels and quantify material recovery as a function of the ionic strength of the rehydration buffer. Mechanical (indentation, compression, shear, and friction) measurements are used to evaluate the influence of de- and rehydration on the viscoelastic properties of cartilage. The structure and composition of native and de/rehydrated cartilage are analyzed using histology, scanning electron microscopy, and atomic force microscopy along with a 1,9-dimethylmethylene blue (DMMB) assay. A broad range of mechanical and structural properties of cartilage can be restored after de- and rehydration provided that a physiological salt solution is used for rehydration. We detect only minor alterations in the microarchitecture of rehydrated cartilage in the superficial zone and find that these alterations do not interfere with the viscoelastic and tribological properties of the tissue. Statement of Significance We here demonstrate the sturdiness of articular cartilage towards changes in fluid content and show that articular cartilage recovers a broad range of its material properties after dehydration. We analyze the reversibility of tissue dehydration to extend our current understanding of how the material properties of cartilage are established, focusing on the interaction between the fluid and solid phase. Our findings suggest that the high resilience of the tissue minimizes the risk of irreversible material failure and thus compensates, at least in part, its poor regenerative abilities. Tissue engineering approaches should thus not only reproduce the correct tissue mechanics but also its pronounced sturdiness to guarantee a similar longevity. [ABSTRACT FROM AUTHOR]

The article discusses a research programme which is part of a long-term study led by the Laboratory for Polar Ecology on the at-sea distribution of seabirds and marine mammals in the Arctic and Antarctic polar regions. Topics include the objective of improving the knowledge on distribution and densities of higher tropic levels due to influencing environmental factors. Also mentioned is integration of programme data into a time series since 1973 to detect changes in the animal distribution.

The colonization of a new habitat affords an important advantage to the successful pioneer species because competitors, predators and parasites are likely to be out of step. Here, we report the first retrieval and molecular characterization of a cryo-benthic community of isopod crustaceans that live at depths of 80-150m on the underside of a floating shelf-ice tongue at the Drescher Inlet (Riiser-Larsen Ice Shelf), Eastern Weddell Sea. The specimens were retrieved with a sampler mounted on a remotely operated vehicle (ROV) when video transsects were carried out. The molecular analysis of mitochondrial and nuclear genes of four specimens spanning the size range of individuals collected confirmed that (1) all belonged to a single species and that (2) this species has previously been identified in benthic communities in the Eastern Weddell Sea as Antarcturus cf. spinacoronatus. The molecular phylogeny shows that the cryo-benthic A. cf. spinacoronatus are deeply nested in a family of isopods characterized by increasing complexity of morphological and behavioural adaptations to the acquisition of detrital and planktonic food particles. This demonstrates that the floating shelf-ice was likely colonized from the seafloor and not vice versa and that the filter-feeding life style of A. cf. spinacoronatus formed a predisposition playing a key role in the colonization of the new habitat. Density estimates of A. spinacoronatus under the floating shelf ice (25 adults and 190 juveniles per square meter) are significantly higher than on the seafloor, suggesting that the transition to the new habitat devoid of any macrofaunal competition or predation provides a major advantage to the species. [ABSTRACT FROM AUTHOR]