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Objective: The objective of this study was to examine primary factors that may predict patients' failure to show at initial physical therapist evaluation in an orthopedic and sports outpatient setting., Methods: A retrospective analysis of patients' demographic data for physical therapist evaluations between January 2013 and April 2015 was performed. A binary logistic regression model was used to evaluate the odds of a no-show at evaluation. Demographic variables of age, employment status, days waited for the appointment, payer source, and distance traveled to the clinic were analyzed. Independent variables were considered significant if the 95% CIs of the odds ratios (ORs) did not include 1.0., Results: A total of 6971 patients were included in the final analysis, with 10% (n = 698) of the scheduled patients having a no-show event for their initial evaluation. The following factors increased the odds of patients having a no-show event: days to appointment (OR = 1.058; 95% CI = 1.042-1.074), unemployment status (OR = 1.96; 95% CI = 1.41-2.73), unknown employment status (OR = 3.22; 95% CI = 1.12-8.69), Medicaid insurance (OR = 4.87; 95% CI = 3.43-6.93), Medicare insurance (OR = 2.22; 95% CI = 1.10-4.49), unknown payer source (OR = 262.84; 95% CI = 188.72-366.08), and distance traveled 8 or more kilometers (OR = 1.31; 95% CI = 1.01-1.70). Female sex (OR = 0.73; 95% CI = 0.57-0.95) and age 40 years or older (OR = 0.44; 95% CI = 0.33-0.60) decreased the odds of a no-show event., Conclusions: Results from this study indicate there may be some demographic factors that are predictive of patients failing to attend their first physical therapist visit., Impact: Understanding the predictive factors and identifying potential opportunities for improvements in scheduling processes might help decrease the number of patients failing to show for their initial physical therapy appointment, with the ultimate goal of positively influencing patient outcomes., (© The Author(s) 2021. Published by Oxford University Press on behalf of the American Physical Therapy Association. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

A coupled hydrodynamic-biogeochemical modelling is developed to address main mechanisms that drive the particulate organic carbon (POC) deposition in the Gulf of Lions (NW-Mediterranean). Low-salinity water (LSW, salinity <37.5) lenses detached from the Rhone River plume under specific wind conditions tend to favour the biological productivity and provide a good opportunity for validating a planktonic ecosystem modelling. A specific calibration dedicated to river plume ecosystems is then proposed and validated using in situ measurements within such LSW lens (BIOPRHOFI cruise -- May 2006) and on the Gulf of Lions. During spring 2006, the POC deposition is maximal on the prodelta area and within the coastal area in the Gulf of Lions. Organic detritus mostly contribute to the total POC deposition (82-92%) whereas the contribution of living organisms (microphytoplankton) appears lower than 17%. Exploring both influences of terrestrial inputs from the Rhone River and planktonic ecosystems on the POC deposition on the shelf, we estimated that the contribution of terrestrial POM inputs to the total POC deposition is lower than 17% at the shelf scale during the study period, with maxima during peak discharges of the Rhone River. The main deposition area of terrestrial POC is found in the vicinity of the river mouth in agreement with sediment data. On the other hand, a remarkable influence of marine biological processes on the POC deposition is highlighted further on the shelf (from 60 to 80 m depth). A tight feedback between zooplankton and POM contents in the water column is proposed to explain the control of POC deposition by zooplankton: terrestrial POM inputs would favour the development of living organisms through photosynthesis and grazing processes increasing the retention of organic matter within the food web. By favouring the development of large-sized zooplankton, LSW lenses may have paradoxically a negative impact on the carbon deposition on the shelf. In the same way, peak discharges of the Rhone River finally increase the gradient of POC deposition between the prodelta and the offshore area in the Gulf of Lions. The biogenic elements from the Rhone River are then exported further offshore through advection of zooplankton communities on the Gulf of Lions shelf. [ABSTRACT FROM AUTHOR]

In situ oxygen microprofiles, sediment organic carbon content, and pore-water concentrations of nitrate, ammonium, iron, manganese, and sulfides obtained in sediments from the Rhône River prodelta and its adjacent continental shelf were used to constrain a numerical diagenetic model. Results showed that (1) the organic matter from the Rhône River is composed of a fraction of fresh material associated to high first-order degradation rate constants (11-33 yr-1); (2) the burial efficiency (burial/input ratio) in the Rhône prodelta (within 3 km of the river outlet) can be up to 80 %, and decreases to ~20 % on the adjacent continental shelf 10-15 km further offshore; (3) there is a large contribution of anoxic processes to total mineralization in sediments near the river mouth, certainly due to large inputs of fresh organic material combined with high sedimentation rates; (4) diagenetic by-products originally produced during anoxic organic matter mineralization are almost entirely precipitated (> 97 %) and buried in the sediment, which leads to (5) a low contribution of the re-oxidation of reduced products to total oxygen consumption. Consequently, total carbon mineralization rates as based on oxygen consumption rates and using Redfield stoichiometry can be largely underestimated in such River-dominated Ocean Margins (RiOMar) environments. [ABSTRACT FROM AUTHOR]

Low-salinity water (LSW, Salinity<37.5) lenses detached from the Rhone River plume under specific wind conditions tend to favour the biological productivity and potentially a transfer of energy to higher trophic levels on the Gulf of Lions (GoL). A field cruise conducted in May 2006 (BIOPRHOFI) followed some LSW lenses by using a lagrangian strategy. A thorough analysis of the available data set enabled to further improve our understanding of the LSW lenses' functioning and their potential influence on marine ecosystems. Through an innovative 3-D coupled hydrodynamic-biogeochemical modelling approach, a specific calibration dedicated to river plume ecosystems was then proposed and validated on field data. Exploring the role of ecosystems on the particulate organic carbon (POC) export and deposition on the shelf, a sensitivity analysis to the particulate organic matter inputs from the Rhone River was carried out from 1 April to 15 July 2006. Over such a typical end-of-spring period marked by moderate floods, the main deposition area of POC was identified alongshore between 0 and 50m depth on the GoL, extending the Rhone prodelta to the west towards the exit of the shelf. Moreover, the main deposition area of terrestrial POC was found on the prodelta region, which confirms recent results from sediment data. The averaged daily deposition of particulate organic carbon over the whole GoL is estimated by the model between 40 and 80 mgC/m², which is in the range of previous secular estimations. The role 20 of ecosystems on the POC export toward sediments or offshore areas was actually highlighted and feedbacks between ecosystems and particulate organic matters are proposed to explain paradoxical model results to the sensitivity test. In fact, the conversion of organic matter in living organisms would increase the retention of organic matter in the food web and this matter transfer along the food web could explain the 25 minor quantity of POC of marine origin observed in the shelf sediments. Thus, the effective carbon deposition on the shelf might be strongly dependent on the zooplankton presence in the GoL. Owing to their fertilizing ability in phosphorus, the LSW lenses could then have indirectly a negative impact on the carbon deposition on the shelf by favouring the development of large phytoplankton fuelling in turn zooplankton communities. The effective carbon deposition would then be delayed out of the GoL, unless a novel transfer of matter occurs toward higher trophic levels further in the open sea through small pelagic fishes. [ABSTRACT FROM AUTHOR]

We have implemented the brittle Bingham–Maxwell sea ice rheology (BBM) into SI3, the sea ice component of NEMO. After discussing the numerical aspects and requirements that are specific to the implementation of a brittle rheology in the Eulerian, finite-difference, Arakawa C-grid framework, we detail the approach we have used. This approach relies on the introduction of an additional set of prognostic stress tensor components, sea ice damage, and sea ice velocity vector, following a grid point arrangement that expands the C-grid into the Arakawa E-grid. The newly implemented BBM rheology is first assessed by means of a set of idealized SI3 simulations at different spatial resolutions. Then, sea ice deformation rates obtained from simulations of the Arctic at a 1/4 ° spatial resolution, performed with the coupled ocean–sea ice setup of NEMO, are assessed against satellite observations. For all these simulations, results obtained with the default current workhorse setup of SI3 are provided to serve as a reference. Our results show that using a brittle type of rheology, such as BBM, allows SI3 to simulate the highly localized deformation pattern of sea ice, as well as its scaling properties, from the scale of the model's computational grid up to the basin scale. [ABSTRACT FROM AUTHOR]

The Bay of Marseille (BoM), located in the northwestern Mediterranean Sea, is affected by various hydrodynamic processes (e.g., Rhône River intrusion and upwelling events) that result in a highly complex local carbonate system. In any complex environment, the use of models is advantageous since it allows us to identify the different environmental forcings, thereby facilitating a better understanding. By combining approaches from two biogeochemical ocean models and improving the formulation of total alkalinity, we develop a more realistic representation of the carbonate system variables at high temporal resolution, which enables us to study air–sea CO 2 fluxes and seawater p CO 2 variations more reliably. We apply this new formulation to two particular scenarios that are typical for the BoM: (i) summer upwelling and (ii) Rhône River intrusion events. In both scenarios, our model was able to correctly reproduce the observed patterns of p CO 2 variability. Summer upwelling events are typically associated with a p CO 2 decrease that mainly results from decreasing near-surface temperatures. Furthermore, Rhône River intrusion events are typically associated with a p CO 2 decrease, although, in this case, the p CO 2 decrease results from a decrease in salinity and an overall increase in total alkalinity. While we were able to correctly represent the daily range of air–sea CO 2 fluxes, the present configuration of Eco3M_MIX-CarbOx does not allow us to correctly reproduce the annual cycle of air–sea CO 2 fluxes observed in the area. This pattern directly impacts our estimates of the overall yearly air–sea CO 2 flux as, even if the model clearly identifies the bay as a CO 2 sink, its magnitude was underestimated, which may be an indication of the limitations inherent in dimensionless models for representing air–sea CO 2 fluxes. [ABSTRACT FROM AUTHOR]

Marine sediments are among the largest carbon reservoirs on the planet and play a key role in the global cycling of organic matter. Bottom fisheries are the most widespread anthropogenic physical disturbance to seabed habitats, prompting NGOs and governments to act on regulating mobile bottom-contacting fishing gear. However, the scientific evidence of the effects of bottom trawling on sediment biogeochemistry is highly diverse and presents contrasting results. Here we present a global harmonized dataset of 71 independent studies that assess the effects of demersal fisheries on sedimentological (i.e. grain size, porosity) and biogeochemical (i.e. organic carbon, phytopigments, nutrient fluxes) properties: the Demersal fishery Impacts on Sedimentary Organic Matter (DISOM) database (Paradis, 2023; 10.3929/ethz-b-000634336). We identify considerable gaps, namely in the geographical extension of the data; coverage of environmental predictors (i.e. seasons); fishing descriptors such as the availability of true controls, quantification of fishing effort, and distribution of fishing gear types; and biogeochemical variables that study the remineralization of organic matter. Future studies should address these data gaps to enhance the comprehensiveness of the dataset. With this harmonized database, we aim to allow researchers to explore the effects of demersal fisheries in variable environmental settings to disentangle the effects of this disturbance and provide efficient management strategies. [ABSTRACT FROM AUTHOR]

The Gulf of Lion, Northwestern Mediterranean Sea, is one of few oceanic regions where deep convection occurs. We investigate the restratification following a convection event using measurements from an ocean glider equipped with turbulence microstructure sensors. This unique combination of instruments provides a high‐resolution description of the mixed layer with regard to turbulence, stratification and chlorophyll. We observe a rapid restratification process that proceeds over a timescale of days to one week. We find that restratification exerts a leading order control on surface mixed layer turbulence variability, as abrupt changes in turbulence dissipation rates are associated with the formation of near‐surface stratification. The near‐surface formation of stratification occurs through both the diurnal variability in surface buoyancy fluxes and through lateral advective processes. We conclude that daily near‐surface processes that influence stratification control mixed layer turbulence levels, and thus the phytoplankton response in the critical transition period to spring bloom. Plain Language Summary: During winter in the Gulf of Lion, Northwestern Mediterranean Sea, a unique alignment of ocean conditions allow strong winds to cool the ocean surface enough to cause mixing of the surface waters to great depths in a process known as deep convection. When this event ceases, the water column tends to restore its original configuration, with light waters above dense waters. We capture the onset of this process, known as restratification, in high‐resolution observational detail together with measurements of ocean turbulence levels, collected with an autonomous ocean vehicle. The onset of restratification after convection takes place on a timescale of days to one week, and strongly influences turbulence variations within the surface waters. We conclude that this restratification has two main contributors, the near‐surface stratification that forms due to the daily variation of surface buoyancy fluxes, and the lateral exchange of denser waters from the surroundings. With sufficient light and nutrients after convection, this near‐surface stratification together with the absence of turbulent mixing allow phytoplankton to grow. Key Points: Autonomous glider‐based turbulence measurements have captured restratification in a deep convection regionThe onset of restratification occurs rapidly, over a timescale of days to one weekNear‐surface restratification is a primary control on mixed layer turbulence and phytoplankton growth [ABSTRACT FROM AUTHOR]

Aims & Objectives: The purpose of this study was to identify patient characteristics associated with engagement and completion of physical therapy (PT) following total knee arthroplasty (TKA) and examine the relationship between number of PT sessions attended and outcomes during the first 12 weeks after surgery. Methods: Patients underwent unilateral primary TKA by a single surgeon and were advised to complete 17 PT sessions over 6 weeks at a hospital-affiliated facility. Analyses examined predictors of PT engagement (attendance of ≥2 sessions) and completion (attendance of 17 ± 1 sessions) within 6 weeks and associations between number of PT sessions attended and changes in range of motion (ROM) and Knee Injury and Osteoarthritis Outcome Score (KOOS) values. Results: Patients living <40 km were more likely to be engaged in PT than those living ≥40 km from the clinic (P <.0001). Among patients who completed PT within 6 weeks, 95.0%, 85.1%, and 56.4% achieved flexion of, respectively, ≥90°, ≥100°, and ≥110°. Among engaged patients, the active flexion thresholds of ≥90°, ≥100°, and ≥110° were achieved by, respectively, 94.4%, 82.5%, and 58.1% by 6 weeks and by 96.7%, 92.1%, and 84.2% by 12 weeks. Improvement in KOOS Symptoms (P =.029), Function in daily living (P =.030) and quality of life (P =.031) linearly decreased as number of PT sessions increased. Conclusions: These results raise the question of whether patients who meet satisfactory outcomes before completing 6 weeks of prescribed PT and those who attend more PT sessions than prescribed may be over-utilizing healthcare resources without additional benefit. [ABSTRACT FROM AUTHOR]

Advances in coastal modeling and computation provide the opportunity to examine non-hydrostatic and compressible fluid effects at very small scales, but the cost of these new capabilities and the accuracy of these models versus trusted non-hydrostatic codes has yet to be determined. Here the Coastal and Regional Ocean COmmunity model (CROCO, v1.2) and the National Center for Atmospheric Research large-eddy simulation (NCAR-LES) model are compared, with a focus on their simulation accuracy and computational efficiency. These models differ significantly in numerics and capabilities, so they are run on common classic problems of surface-forced, boundary-layer turbulence. In terms of accuracy, we compare turbulence statistics, including the effect of the explicit subgrid-scale (SGS) parameterization, the effect of the second (dilatational) viscosity, and the sensitivity to the speed of sound, which is used as part of the CROCO compressible turbulence formulation. To gauge how far CROCO is from the NCAR-LES, we first compare the NCAR-LES with two other non-hydrostatic Boussinesq approximation LES codes (PALM and Oceananigans), defining the notion and magnitude of accuracy for the LES and CROCO comparison. To judge efficiency of CROCO, strong and weak scaling simulation sets vary different problem sizes and workloads per processor, respectively. Additionally, the effects of 2D decomposition of CROCO and NCAR-LES and supercomputer settings are tested. In summary, the accuracy comparison between CROCO and the NCAR-LES is similar to the NCAR-LES compared to other LES codes. However, the additional capabilities of CROCO (e.g., nesting, non-uniform grid, and realism of ocean configuration in general) and its weakly compressible formulation come with roughly an order of magnitude of additional costs, despite efforts to reduce them by adjusting the second viscosity and speed of sound as far as accuracy allows. However, a new variant of the non-hydrostatic CROCO formulation is currently undergoing prototype testing and should enable faster simulations by releasing the stability constrain by the free surface. Overall, when the additional features of CROCO are needed (nesting, complex topography, etc.) additional costs are justified, while in idealized settings (a rectangular domain with periodic boundary conditions) the NCAR-LES is faster in arriving at nearly the same result. [ABSTRACT FROM AUTHOR]

Pteropods are a group of cosmopolitan holoplanktic gastropods that produce an aragonite shell and play an important role in both marine ecosystems and geochemical cycles. In addition to being affected by anthropogenic impacts that include warming and changes in carbonate system parameters, the Mediterranean Sea is considered to be understudied concerning pteropods dynamics and abundances. This work aims to document the modern spatial and temporal distributions of pteropods populations in the Northwestern and Central Mediterranean Sea (Gulf of Lions and Strait of Sicily), respectively. We present data from two sediment-trap records that cover the timeframe between early 1996 and early 2004 for the Gulf of Lions and late 2013 to late 2014 for the Sicily Strait. A total of 843 pteropod shells and 18 different species were identified. Limacina inflata, Creseis virgula and Creseis clava were the most abundant species in the Gulf of Lions, while in the Sicily Strait, C. conica replaced C. clava as the most abundant species. These taxons represented around 70% of the total individuals identified in both sites. Overall, our results suggest a greater pteropod abundance in the Gulf of Lions than in the Sicily Strait, most likely due to enhanced food conditions. In the Gulf of Lions, maximum fluxes occurred in autumn (32.5% of the annual pteropod fluxes registered in October), while in the Sicily Strait peak fluxes occurred in winter (30.5% of the annual pteropod fluxes registered in January). Comparison of temporal changes pteropod fluxes with satellite sea surface temperature (SST), and chlorophyll-a concentration suggest a possible positive effect of high algal accumulation and cool water conditions in the Strait of Sicily on the main pteropod groups. In turn, no clear relationships between pteropod groups, SST and chlorophyll-a were identified in the Gulf of Lions, highlighting the effect of salinity and carbonate system parameters. Overall, and despite the limitations associated with the use of sediment traps for pteropod population monitoring, the consistency of our results with the literature supports the use of sediment traps as useful tools for documenting the diversity and temporal distribution of pteropods. [ABSTRACT FROM AUTHOR]

This study focuses on fishing activity, specifically the extraction of marine resources in the Algerian coastal and offshore zones. This sector is expected to meet several objectives and contribute to Algeria's food security. Seafood is a significant source of protein and is highly favoured by Algeria's coastal communities. However, with limited data available describing the biomass that could be exploited, the pressure could eventually increase on a common stock that is shared by all users and is already regarded as poorly studied. Against this backdrop, this work considers the estimation of the marine footprint, which is the ratio between the demand of each fished species, known as the required primary production, and the available biomass in terms of primary production of Algerian fishing waters. The latter is derived from the literature, relying on studies covering the considered area. The main study findings outline a marine footprint ratio that does not exceed 1%, demonstrating a sustainable fishing activity. However, the obtained results, i.e., low marine footprint percentage, may imply that the available marine biomass in the Algerian fishing zones is not fully exploited. [ABSTRACT FROM AUTHOR]

Devil firefish Pterois miles is an invasive alien species which has severely impacted biodiversity and ecological processes in invaded areas of the Mediterranean. In recent years, its presence has been documented in several countries of the Adriatic Sea. Based on the negative ecological and socio-economic impacts in other areas of the Mediterranean Sea, the potential invasiveness of devil firefish was analyzed for the coastal areas of the three eastern Adriatic countries (Albania, Croatia and Montenegro) using the Aquatic Species Invasiveness Screening Kit. Generally, based on the average value of the Basic Risk Assessment and the threshold used, the outcomes suggest that this species will be highly invasive in the eastern Adriatic countries. In addition, the results have shown that the most affected sector is represented by the local species populations and relative characteristics, while commercial sectors represent the least affected sector. However, considering that the negative impact of non-native species is not seen directly, the governments of these countries should address this issue as soon as possible. [ABSTRACT FROM AUTHOR]

Bivalves can concentrate biological and chemical pollutants, causing foodborne outbreaks whose occurrence is increasing, due to climatic and anthropic factors that are difficult to reverse, hence the need for improved surveillance. This study aimed to evaluate the hygienic qualities of bivalves sampled along the production and distribution chain in Sicily and collect useful data for consumer safety. Bacteriological and molecular analyses were performed on 254 samples of bivalves for the detection of enteropathogenic Vibrio, Arcobacter spp., Aeromonas spp., Salmonella spp., and beta-glucuronidase-positive Escherichia coli. A total of 96 out of 254 samples, collected in the production areas, were processed for algal biotoxins and heavy metals detection. Bacterial and algal contaminations were also assessed for 21 samples of water from aquaculture implants. Vibrio spp., Arcobacter spp., Aeromonas hydrophila, Salmonella spp., and Escherichia coli were detected in 106/254, 79/254, 12/254, 16/254, and 95/254 molluscs, respectively. A total of 10/96 bivalves tested positive for algal biotoxins, and metals were under the legal limit. V. alginolyticus, A. butzleri, and E. coli were detected in 5, 3, and 3 water samples, respectively. Alexandrium minutum, Dinophysis acuminata, Lingulodinium polyedra, and Pseudonitzschia spp. were detected in water samples collected with the biotoxin-containing molluscs. Traces of yessotoxins were detected in molluscs from water samples containing the corresponding producing algae. Despite the strict regulation by the European Commission over shellfish supply chain monitoring, our analyses highlighted the need for efficiency improvement. [ABSTRACT FROM AUTHOR]

We present a study on the ocean surface currents reconstruction by merging Level-4 (L4, gap-free) altimeter-derived geostrophic currents and satellite sea surface temperature. Building upon past studies on the multi-variate reconstruction of geostrophic currents from satellite observations, we regionalized and optimized an algorithm to improve the altimeter-derived surface circulation estimates in the North Atlantic Ocean. A ten-year-long time series (2010–2019) is presented and validated by means of in situ observations. The newly optimized algorithm allowed us to improve the currents estimate along the main axis of the Gulf Stream and in correspondence of well-known upwelling areas in the North Eastern Atlantic, with percentage improvements of around 15% compared to standard operational altimetry products. [ABSTRACT FROM AUTHOR]

The South China Sea throughflow (SCSTF) connects the South China Sea (SCS) with neighboring seas and oceans, transferring surface water of the global thermohaline circulation between the Pacific and Indian oceans. A configuration of the SYMPHONIE ocean model at high resolution (4 km) and including an explicit representation of tides is implemented over this region, and a simulation is analyzed over 2010–2018. Comparisons with in situ and satellite data and other available simulations at coarser resolution show the good performance of the model and the relevance of the high resolution for reproducing the spatial and temporal variability of the characteristics of surface dynamics and water masses over the SCS. The added value of an online computation of each term of the water, heat, and salt SCS budgets (surface, lateral oceanic and river fluxes, and internal variations) is also quantitatively demonstrated: important discards are obtained with offline computation, with relative biases of ∼40% for lateral oceanic inflows and outflows. The SCS water volume budget, including the SCSTF, is analyzed at climatological and seasonal scales. The SCS receives on average a 4.5 Sv yearly water volume input, mainly from the Luzon Strait. It laterally releases this water to neighboring seas, mainly to the Sulu Sea through Mindoro Strait (49 %), to the East China Sea via Taiwan Strait (28 %), and to the Java Sea through Karimata Strait (22 %). The seasonal variability of this water volume budget is driven by lateral interocean exchanges. Surface interocean exchanges, especially at Luzon Strait, are all driven by monsoon winds that favor winter southwestward flows and summer northeastward surface flows. Exchanges through Luzon Strait deep layers show a stable sandwiched structure with vertically alternating inflows and outflows. Last, differences in flux estimates induced by the use of a high-resolution model vs. a low-resolution model are quantified. [ABSTRACT FROM AUTHOR]

The brown meagre (Sciaena umbra) is an endangered species, which requires specific protection measures to ensure its conservation. These measures need to be informed by high-quality scientific knowledge on their space use patterns. Here, we used acoustic telemetry to assess its seasonal movement patterns and habitat use within a marine protected area (MPA). Our results suggested that S. umbra is a highly sedentary species (home range < 1.0 km2) and, therefore, the MPA is extensive enough to protect the local population. Their population was discretely distributed in two main areas within the MPA, which was likely a result of habitat segregation and density-dependent movements. The temporal variability of their movements further uncovered when and where spawning occurs (mainly, but probably not only, in the fully protected area in June) and indicated that spillover of this species is limited but still possible. Overall, we highlight the importance of MPAs in the recovery of S. umbra, we advocate the need to perpetuate the current national fishing bans and extend it to other countries in the Mediterranean region, and we emphasize that considering the fine-scale movements of S. umbra in future management actions is key to achieving a successful recovery of their populations. [ABSTRACT FROM AUTHOR]

At the land–sea interface, the benthic carbon cycle is strongly influenced by the export of terrigenous particulate material across the river–ocean continuum. Episodic flood events delivering massive sedimentary materials can occur, but their short-term impact on carbon cycling is poorly understood. In this paper, we use a coupled data–model approach to estimate the temporal variations in sediment–water fluxes, biogeochemical pathways and their reaction rates during these abrupt phenomena. We studied one episodic depositional event in the vicinity of the Rhône River mouth (NW Mediterranean Sea) during the fall–winter of 2021/22. The distributions of dissolved inorganic carbon (DIC), sulfate (SO42-) and methane (CH4) were measured in sediment porewaters collected every 2 weeks before and after the deposition of a 25 cm sediment layer during the main winter flood event. Significant changes in the distribution of DIC, SO42- and CH4 concentrations were observed in the sediment porewaters. The use of an early diagenetic model (FESDIA) to calculate biogeochemical reaction rates and fluxes revealed that this type of flood event can increase the total organic carbon mineralization rate in the sediment by 75 % a few days after deposition. In this period, sulfate reduction is the main process contributing to the increase in total mineralization relative to non-flood deposition. The model predicts a short-term decrease in the DIC flux out of the sediment from 100 to 55 mmolm-2d-1 after the deposition of the new sediment layer with a longer-term increase by 4 %, therefore implying an initial internal storage of DIC in the newly deposited layer and a slow release over relaxation of the system. Furthermore, examination of the stoichiometric ratios of DIC and SO42- as well as model output over this 5-month window shows a decoupling between the two modes of sulfate reduction following the deposition – organoclastic sulfate reduction (OSR) intensified in the newly deposited layer below the sediment surface, whereas anaerobic oxidation of methane (AOM) intensified at depth below the former buried surface. The bifurcation depth of sulfate reduction pathways, i.e., the sulfate–methane transition zone (SMTZ), is shifted deeper by 25 cm in the sediment column following the flood deposition. Our findings highlight the significance of short-term transient biogeochemical processes at the seafloor and provide new insights into the benthic carbon cycle in the coastal ocean. [ABSTRACT FROM AUTHOR]

Total alkalinity (AT) and dissolved inorganic carbon (CT) in the oceans are important properties with respect to understanding the ocean carbon cycle and its link to global change (ocean carbon sinks and sources, ocean acidification) and ultimately finding carbon-based solutions or mitigation procedures (marine carbon removal). We present a database of more than 44 400 AT and CT observations along with basic ancillary data (spatiotemporal location, depth, temperature and salinity) from various ocean regions obtained, mainly in the framework of French projects, since 1993. This includes both surface and water column data acquired in the open ocean, coastal zones and in the Mediterranean Sea and either from time series or dedicated one-off cruises. Most AT and CT data in this synthesis were measured from discrete samples using the same closed-cell potentiometric titration calibrated with Certified Reference Material, with an overall accuracy of ±4 µ mol kg -1 for both AT and CT. The data are provided in two separate datasets – for the Global Ocean and the Mediterranean Sea (10.17882/95414, Metzl et al., 2023), respectively – that offer a direct use for regional or global purposes, e.g., AT –salinity relationships, long-term CT estimates, and constraint and validation of diagnostic CT and AT reconstructed fields or ocean carbon and coupled climate–carbon models simulations as well as data derived from Biogeochemical-Argo (BGC-Argo) floats. When associated with other properties, these data can also be used to calculate pH, the fugacity of CO 2 (f CO 2) and other carbon system properties to derive ocean acidification rates or air–sea CO 2 fluxes. [ABSTRACT FROM AUTHOR]

The ocean is the main heat reservoir in Earth's climate system, absorbing most of the top-of-the-atmosphere excess radiation. As the climate warms, anomalously warm and fresh ocean waters in the densest layers formed near Antarctica spread northward through the abyssal ocean, while successions of warming and cooling events are seen in the deep-ocean layers formed near Greenland. The abyssal warming and freshening expands the ocean volume and raises sea level. While temperature and salinity characteristics and large-scale circulation of upper 2000 m ocean waters are well monitored, the present ocean observing network is limited by sparse sampling of the deep ocean below 2000 m. Recently developed autonomous robotic platforms, Deep Argo floats, collect profiles from the surface to the seafloor. These instruments supplement satellite, Core Argo float, and ship-based observations to measure heat and freshwater content in the full ocean volume and close the sea level budget. Here, the value of Deep Argo and planned strategy to implement the global array are described. Additional objectives of Deep Argo may include dissolved oxygen measurements, and testing of ocean mixing and optical scattering sensors. The development of an emerging ocean bathymetry dataset using Deep Argo measurements is also described. [ABSTRACT FROM AUTHOR]

We have developed a physics ensemble of Weather Research and Forecasting (WRF) model simulations for the Middle East, Mediterranean and North Africa (MEMNA) regions. These simulations use different configurations for the cumulus, microphysics, surface layer, planetary boundary layer, and land surface schemes and are forced by the Community Earth System Model (CESM) General Circulation Model for the historical period 1979-1993. We have also created a complementary ensemble in which the WRF model is fully-coupled to the Regional Ocean Modelling System (ROMS) that simulates the dynamics of the entire Mediterranean Sea. Analysis of our ensembles reveals that the simulated precipitation and near surface temperature (T2) fields in WRF are largely influenced by the cumulus and the land surface schemes during the summer and winter seasons, respectively. The coupling of Weather Research and Forecasting to Regional Ocean Modelling System yields Mediterranean sea surface temperatures that are directly correlated with T2 and have higher spatial resolution than the global model. Meanwhile no significant difference is found between the atmospheric fields from the coupled and uncoupled runs because the Community Earth System Model sea surface temperatures over the Mediterranean, that are used for surface forcing in the uncoupled runs, are already in close agreement with both Regional Ocean Modelling System and observations. We conclude that our high-resolution coupled atmosphere-ocean modelling system is capable of producing climate data of good quality, and we identify those combinations of physics schemes that result in an acceptable level of bias that facilitates their use in future studies. [ABSTRACT FROM AUTHOR]

Sustained time-series measurements are crucial to understand changes in oceanic carbonate chemistry. In the North Western Mediterranean Sea, the temporal evolution of the carbonate system is here investigated based on two 10-year time-series (between January 2010 and December 2019) of monthly carbonate parameters measurements at two sampling sites in the Ligurian Sea (ANTARES and DYFAMED). At seasonal timescale, the seawater partial pressure of CO2 (pCO2) within the mixed layer is mostly driven by temperature at both sites, and biological processes as stated by the observed relationships between total inorganic carbon (CT), nitrate and temperature. This study suggests also that mixing and water masses advection could play a role in modulating the CT content. At decadal timescale, significant changes in ocean chemistry are observed with increasing trends in CT (+3.2 ± 0.9 µmol.kg-1.a-1 - ANTARES; +1.6 ± 0.8 µmol.kg-1.a-1 - DYFAMED), associated with increasing pCO2 trends and decreasing trends in pH. The magnitude of the increasing trend in CT at DYFAMED is consistent with the increase in atmospheric pCO2 and the anthropogenic carbon transport of water originating from the Atlantic Ocean, while the higher trends observed at the ANTARES site could be related to the hydrological variability induced by the variability of the Northern Current. [ABSTRACT FROM AUTHOR]

Deep convection plays a key role in the circulation, thermodynamics, and biogeochemical cycles in the Mediterranean Sea, which is considered to be a hotspot of biodiversity and climate change. In the framework of the DEWEX (Dense Water Experiment) project, the seasonal and annual budgets of dissolved inorganic carbon in the deep-convection area of the northwestern Mediterranean Sea are investigated over the period September 2012–September 2013 using a 3D coupled physical–biogeochemical–chemical modeling approach. At the annual scale, we estimate that the northwestern Mediterranean Sea's deep-convection region was a moderate sink of 0.5 mol C m -2 yr -1 of CO 2 for the atmosphere. The model results show the reduction of oceanic CO 2 uptake during deep convection and its increase during the abrupt spring phytoplankton bloom following the deep-convection events. We highlight the major roles in the annual dissolved inorganic carbon budget of both the biogeochemical and physical fluxes, which amount to -3.7 and 3.3 mol C m -2 yr -1 , respectively, and are 1 order of magnitude higher than the air–sea CO 2 flux. The upper layer (from the surface to 150 m depth) of the northwestern deep-convection region gained dissolved inorganic carbon through vertical physical transport and, to a lesser extent, oceanic CO 2 uptake, and it lost dissolved inorganic carbon through lateral transport and biogeochemical fluxes. The region, covering 2.5 % of the Mediterranean, acted as a source of dissolved inorganic carbon for the surface and intermediate water masses of the Balearic Sea and southwestern Mediterranean Sea and could represent up to 22 % and 11 %, respectively, of the CO 2 exchanges with the Atlantic Ocean at the Strait of Gibraltar. [ABSTRACT FROM AUTHOR]

Chromophoric dissolved organic matter (CDOM) significantly contributes to the non-water absorption budget in the Mediterranean Sea. The absorption coefficient of CDOM, aCDOM(λ) , is measurable in situ and can be retrieved remotely, although ocean-colour algorithms do not distinguish it from the absorption of detritus. These observations can be used as indicators for the concentration of other relevant biogeochemical variables in the ocean, e.g. dissolved organic carbon. However, our ability to model the biogeochemical processes that determine CDOM concentrations is still limited. Here we propose a novel parameterization of the CDOM cycle that accounts for the interplay between the light- and nutrient-dependent dynamics of local CDOM production and degradation, as well as its vertical transport. The parameterization is included in a one-dimensional (1D) configuration of the Biogeochemical Flux Model (BFM), which is here coupled to the General Ocean Turbulence Model (GOTM) through the Framework for Aquatic Biogeochemical Models (FABM). Here the BFM is augmented with a bio-optical component that resolves spectrally the underwater light transmission. We run this new GOTM-(FABM)-BFM configuration to simulate the seasonal aCDOM(λ) cycle at the deep-water site of the Bouée pour l'acquisition de Séries Optiques à Long Terme (BOUSSOLE) project in the northwestern Mediterranean Sea. Our results show that accounting for both nutrient and light dependence of CDOM production improves the simulation of the seasonal and vertical dynamics of aCDOM(λ) , including a subsurface maximum that forms in spring and progressively intensifies in summer. Furthermore, the model consistently reproduces the higher-than-average concentrations of CDOM per unit chlorophyll concentration observed at BOUSSOLE. The configuration, outputs, and sensitivity analyses from this 1D model application will be instrumental for future applications of BFM to the entire Mediterranean Sea in a three-dimensional configuration. [ABSTRACT FROM AUTHOR]

Many current biogeochemical models rely on an autotrophic versus heterotrophic food web representation. However, in recent years, an increasing number of studies have begun to challenge this approach. Several authors have highlighted the importance of protists capable of combining photoautotrophic and heterotrophic nutrition in a single cell. These mixotrophic protists are known to play an important role in the carbon cycle. Here, we present a new biogeochemical model that represents the food web using variable stoichiometry. It contains the classic compartments such as zooplankton, phytoplankton, and heterotrophic bacteria and a newly added compartment to represent two types of mixotrophic protists: non-constitutive mixotrophs (NCMs) and constitutive mixotrophs (CMs). We demonstrate that the model correctly reproduces the characteristics of NCMs and CMs and proceed to study the impact of light and nutrient limitation on planktonic ecosystem structure in a highly dynamic Mediterranean coastal area, namely the Bay of Marseille (BoM, France), paying special attention to the dynamics of mixotrophic protists in these limiting conditions. In addition, we investigate the carbon, nitrogen, and phosphorus fluxes associated with mixotrophic protists and showed the following: (i) the portion of the ecosystem in terms of the percentage of carbon biomass occupied by NCMs decreases when resources (nutrient and prey concentrations) decrease, although their mixotrophy allows them to maintain a carbon biomass almost as significant as the copepod one (129.8 and 148.7 mmolCm-3 , respectively), as photosynthesis increases as a food source, and (ii) the portion of the ecosystem in terms of the percentage of carbon biomass occupied by CM increases when nutrient concentrations decrease due to their capability to ingest prey to supplement their N and P needs. In addition to providing new insights regarding the conditions that lead to the emergence of mixotrophs in the BoM, this work provides a new tool to perform long-term studies and predictions of mixotroph dynamics in coastal environments under different environmental forcings. [ABSTRACT FROM AUTHOR]

A numerical stochastic wave model was developed in this study based on the quasi-coherent theoretical framework proposed by Smit and Janssen in 2013. Subsequently, the model was implemented to reproduce and cross-confirm the findings of the quasi-coherent (QC) spectral wave modeling approach. The process included simulations of experiments conducted by Vincent and Briggs regarding waves propagating over a submerged shoal. The results of the simulations agree with the expected results of the QC theory, which can account for the spatial coherence of inhomogeneous wave fields and capture wave interference more accurately than conventional spectral wave models. In addition, extra insight was gained about aspects of the overall numerical implementation of the QC theory. [ABSTRACT FROM AUTHOR]

Offshore anthropogenic activities such as the installation of Offshore Renewable Energy (ORE) developments and sediment extraction for marine aggregates have been shown to disrupt current flow, wave propagation, and sediment transport pathways, leading to potential environmental instability. Due to the complexity of the interconnected sediment transport pathways in the south-western Irish Sea combined with an increase in planned anthropogenic activities, the assessment of this risk is imperative for the development of a robust marine spatial plan. Subsequently, this study uses two-dimensional morphological modelling to build upon previous studies to assess the dependency of Arklow Bank's local sediment transport regime on external sediment sources. Additionally, scenario modelling is used to identify vulnerable areas of this offshore linear sand bank to wind and wave-forcing and to examine the nature of this impact. A sediment budget is estimated for Arklow Bank, whereby seven source and nine sink pathways are identified. New evidence to support the exchange of sediment between offshore sand banks and offshore independent sand wave fields is also provided. The areas of the bank most vulnerable to changes in external sediment sources and the addition of wind- and wave-induced flow are analogous. These high vulnerability zones (HVZs) align with regions of residual cross-flow under pure current conditions. The restriction of sediment sources off the southern extent of Arklow Bank impacts erosion and accretion patterns in the mid- and northern sections of the bank after just one lunar month of simulation. Where tidal current is the primary driver of sand bank morphodynamics, wind- and wave-induced flow is shown to temporarily alter sediment distribution patterns. Wind and wave-induced flow can both accelerate and decelerate the east-west fluctuation of the upper slopes of the bank, yet the nature of this impact is inconsistent due to the misalignment of the directionality of these two forces. The methods and new knowledge derived from this study are directly applicable to tidally-dominated environments outside the Irish Sea. [ABSTRACT FROM AUTHOR]

The new generation of regional ocean models can provide the evolution of both the slow and fast components of pressure, consequently opening original opportunities to evaluate the acoustic signal generated by ocean slower dynamical processes. This capacity is evaluated in the case of surface waves, with a focus on the hydro-acoustic precursors and on the acoustic modes induced by supersonic surface wave groups. The consistency with theory confirms that such models are adapted to answer recent interrogations by Wunsch [(2022). J. Acoust. Soc. Am. 152(4), 2160–2168] about evaluating the noise of ocean processes. [ABSTRACT FROM AUTHOR]

The Rhodes Gyre is a cyclonic persistent feature of the general circulation of the Levantine Basin in the eastern Mediterranean Sea. Although it is located in the most oligotrophic basin of the Mediterranean Sea, it is a relatively high primary production area due to strong winter nutrient supply associated with the formation of Levantine Intermediate Water. In this study, a 3D coupled hydrodynamic–biogeochemical model (SYMPHONIE/Eco3M-S) was used to characterize the seasonal and interannual variability of the Rhodes Gyre's ecosystem and to estimate an annual organic carbon budget over the 2013–2020 period. Comparisons of model outputs with satellite data and compiled in situ data from cruises and Biogeochemical-Argo floats revealed the ability of the model to reconstruct the main seasonal and spatial biogeochemical dynamics of the Levantine Basin. The model results indicated that during the winter mixing period, phytoplankton first progressively grow sustained by nutrient supply. Then, short episodes of convection driven by heat loss and wind events, favoring nutrient injections, organic carbon export, and inducing light limitation on primary production, alternate with short episodes of phytoplankton growth. The estimate of the annual organic carbon budget indicated that the Rhodes Gyre is an autotrophic area, with a positive net community production in the upper layer (0–150 m) amounting to 31.2 ± 6.9 gCm-2yr-1. Net community production in the upper layer is almost balanced over the 7-year period by physical transfers, (1) via downward export (16.8 ± 6.2 gCm-2yr-1) and (2) through lateral transport towards the surrounding regions (14.1 ± 2.1 gCm-2yr-1). The intermediate layer (150–400 m) also appears to be a source of organic carbon for the surrounding Levantine Sea (7.5 ± 2.8 gCm-2yr-1) mostly through the subduction of Levantine Intermediate Water following winter mixing. The Rhodes Gyre shows high interannual variability with enhanced primary production, net community production, and exports during years marked by intense heat losses and deep mixed layers. However, annual primary production appears to be only partially driven by winter vertical mixing. Based on our results, we can speculate that future increase of temperature and stratification could strongly impact the carbon fluxes in this region. [ABSTRACT FROM AUTHOR]

Wildlife tourism can have adverse effects on the behaviours and movements of animals, with implications for the health and fitness of individuals and populations. We used acoustic-tracking to show that food-based attractants used in shark-tourism increases activity (15%) and burst behaviours (60%) in yellowtail kingfish (Seriola lalandi, n  = 18). Increased activity was restricted to periods when kingfish were on the same side of the island group as berleying tourism vessels, but decreased after operators left the site. Despite the raised activity and frequency of burst swimming events, the physiological condition of kingfish (n  = 39, 6 tagged, and 33 untagged) measured using bioelectrical impedance analysis remained consistent with kingfish from control sites not exposed to tourism. This suggests that kingfish were able to compensate raised energy expenditure by feeding on bait and berley used by operators or through natural foraging. We highlight that the effects of provisioning from wildlife tourism can extend beyond changes in behaviours and movements and can additionally influence the energetic condition of non-focal animals through increased activity. However, supplemental food-sources provided through wildlife tourism may be sufficient to compensate for the increased energy expenditure and lessen the effects of tourism on individual fitness and health. [ABSTRACT FROM AUTHOR]

Declines in individuals' growth in exploited fish species are generally attributed to evolutionary consequences of size‐selective fishing or to plastic responses due to constraints set by changing environmental conditions dampening individuals' growth. However, other processes such as growth compensation and non‐directional selection can occur and their importance on the overall phenotypic response of exploited populations has largely been ignored. Using otolith growth data collected in European anchovy and sardine of the Bay of Biscay (18 cohorts from 2000 to 2018), we parameterized the breeder's equation to determine whether declines in size‐at‐age in these species were due to an adaptive response (i.e. related to directional or non‐directional selection differentials within parental cohorts) or a plastic response (i.e. related to changes in environmental). We found that growth at age‐0 in anchovy declined between parents and their offspring when biomass increased and the selective disappearance of large individuals was high in parents. Therefore, an adaptive response probably occurred in years with high fishing effort and the large increase in biomass after the collapse of this stock maintained this adaptive response subsequently. In sardine offspring, higher growth at age‐0 was associated with increasing biomass between parents and offspring, suggesting a plastic response to a bottom‐up process (i.e. a change in food quantity or quality). Parental cohorts in which selection favoured individuals with high growth compensation produced offspring high catch up growth rates, which may explain the smaller decline in growth in sardine relative to anchovy. Finally, on non‐directional selection differentials were not significantly related to the changes in growth at age‐0 and growth compensation at age‐1 in both species. Although anchovy and sardine have similar ecologies, the mechanisms underlying the declines in their growth are clearly different. The consequences of the exploitation of natural populations could be long lasting if density‐dependent processes follow adaptive changes. [ABSTRACT FROM AUTHOR]

Nowadays, overexploitation and climate change are among the major threats to fish production all over the world. In this study, we focused our attention on the Adriatic Sea (AS), a shallow semi-enclosed sub-basin showing the highest exploitation level and warming trend over the last decades within the Mediterranean Sea. We investigated the life history traits and population dynamics of the cold-water species whiting (Merlangius merlangus, Gadidae) 30 years apart, which is one of the main commercial species in the Northern AS. The AS represents its southern limit of distribution, in accordance with the thermal preference of this cold-water species. Fish samples were collected monthly using a commercial bottom trawl within the periods 1990–1991 and 2020–2021. The historical comparison highlighted a recent reduction in large specimens (>25 cm total length, TL), which was not associated with trunked age structures, therefore indicating a decrease in growth performance over a period of 30 years (L∞90–91 = 29.5 cm TL; L∞20–21 = 22.8 cm TL). The current size at first sexual maturity was achieved within the first year of life, at around 16 cm TL for males and 17 cm TL for females. In the AS, whiting spawns in batches from December to March, showing a reproductive investment (gonadosomatic index) one order of magnitude higher in females than in males. Potential fecundity (F) ranged from 46,144 to 424,298, with it being heavily dependent on fish size. We hypothesize that the decreased growth performance might be related to a metabolic constraint, possibly related to the increased temperature and its consequences. Moreover, considering the detrimental effects of size reduction on reproductive potential, these findings suggest a potential endangerment situation for the long-term maintenance of whiting and cold-related species in the AS, which should be accounted for in setting management strategies. [ABSTRACT FROM AUTHOR]

The effectiveness of a Marine Protected Area (MPA) is strongly related to its zoning design, management, and surveillance, and fish communities are considered indicators of conservation effects. Posidonia oceanica beds and fish assemblages were studied here to evaluate the fishing impacts and the effectiveness of the Marine Protected Areas (MPAs) of Santa Maria di Castellabate (SMC) and Costa degli Infreschi e della Masseta (CIM) in the South Tyrrhenian Sea, Italy. P. oceanica characteristics were estimated counting and collecting shoots, while fish communities were investigated by visual census. Multivariate analyses were performed to detect differences in fish assemblages among the MPA protection levels and seagrass characteristics. Significant differences in fish communities were observed between the depth and protection levels. The latter are probably due to the zoning design at SMC, which does not allow a spillover effect, and to fishing activities, as showed by the ABC curve results. Trophic analyses suggested the use of longlines at SMC, due to the dominance of planktivorous fish species, and of trammel nets at CIM, due to the great heterogeneity of the fish trophic groups. Shoot density and leaf length were significantly correlated with fish communities. CCA analyses showed omnivorous species, mostly belonging to the Sparidae family, correlated with the highest shoot densities, with their feeding habits mostly directed to crustaceans, while macro- and microinvertivores, mainly belonging to the Serranidae and Labridae families, correlated with the highest leaf lengths, where they sough shelter and feed. In conclusion, the data suggest that a zoning redesign at SMC and an increase in the surveillance of fishing activities at CIM might enhance the effectiveness of these MPAs, highlighting the role of fish community studies in identifying MPA efficiency issues and providing trustful guidelines for their management. [ABSTRACT FROM AUTHOR]

Marine microplastics can be colonized by biofouling microbial organisms, leading to a decrease in microplastics' buoyancy. The sinking of biofouled microplastics could therefore represent a novel carbon export pathway within the ocean carbon cycle. Here, we model how microplastics are biofouled by diatoms, their consequent vertical motion due to buoyancy changes, and the interactions between particle‐attached diatoms and carbon pools within the water column. We initialize our Lagrangian framework with biogeochemical data from NEMO‐MEDUSA‐2.0 and estimate the amount of organic carbon exported below 100 m depth starting from different surface concentrations of 1‐mm microplastics. We focus on the Mediterranean Sea that is characterized by some of the world's highest microplastics concentrations and is a hotspot for biogeochemical changes induced by rising atmospheric carbon dioxide levels. Our results show that the carbon export caused by sinking biofouled microplastics is proportional to the concentration of microplastics in the sea surface layer, at least at modeled concentrations. We estimate that, while current concentrations of microplastics can modify the natural biological carbon export by < 1%, future concentrations projected under business‐as‐usual pollution scenarios may lead to carbon exports up to 5% larger than the baseline (1998–2012) by 2050. Areas characterized by high primary productivity, that is, the Western and Central Mediterranean, are those where microplastics‐mediated carbon export results to be the highest. While highlighting the potential and quantitatively limited occurrence of this phenomenon in the Mediterranean Sea, our results call for further investigation of a microplastics‐related carbon export pathway in the global ocean. [ABSTRACT FROM AUTHOR]

Over the last 3 decades, satellite altimetry has observed sea surface height variations, providing a regular monitoring of the surface ocean circulation. Altimetry measurements have an intrinsic signal-to-noise ratio that limits the spatial scales of the currents that can be captured. However, the recent progress made on both altimetry sensors and data processing allows us to observe smaller geophysical signals, offering new perspectives in coastal areas where these structures are important. In this methodological study, we assess the ability of three altimeter missions with three different technologies to capture the Northern Current (northwestern Mediterranean Sea) and its variability, namely Jason-2 (Ku-band low-resolution-mode altimeter, launched in 2008), SARAL/AltiKa (Ka-band low-resolution-mode altimeter, launched in 2013) and Sentinel-3A (synthetic aperture radar altimeter, launched in 2016). Therefore, we use a high-resolution regional model as a reference. We focus along the French coast of Provence, where we first show that the model is very close to the observations of high-frequency radars and gliders in terms of surface current estimates. In the model, the Northern Current is observed 15–20 km from the coast on average, with a mean core velocity of 0.39 m s -1. Its signature in terms of sea level consists of a drop whose mean value at 6.14 ∘ E is 6.9 cm, extending over 20 km. These variations show a clear seasonal pattern, but high-frequency signals are also present most of the time. In comparison, in 1 Hz altimetry data, the mean sea level drop associated with the Northern Current is overestimated by 3.0 cm for Jason-2, but this overestimation is significantly less with SARAL/AltiKa and Sentinel-3A (0.3 and 1.4 cm respectively). In terms of corresponding sea level variability, Jason-2 and SARAL altimetry estimates are larger than the model reference (+1.3 and +1 cm respectively), whereas Sentinel-3A shows closer values (-0.4 cm). When we derive geostrophic surface currents from the satellite sea level variations without any data filtering, in comparison to the model, the standard deviations of the velocity values are also very different from one mission to the other (3.7 times too large for Jason-2 but 2.4 and 2.9 times too large for SARAL and Sentinel-3A respectively). When low-pass filtering altimetry sea level data with different cutoff wavelengths, the best agreement between the model and the altimetry distributions of velocity values are obtained with a 60, 30 and 40–50 km cutoff wavelength for Jason-2, SARAL and Sentinel-3A data respectively. This study shows that using a high-resolution model as a reference for altimetry data allows us not only to illustrate how the advances in the performances of altimeters and in the data processing improve the observation of coastal currents but also to quantify the corresponding gain. [ABSTRACT FROM AUTHOR]

The South Vietnam upwelling (SVU) develops off the Vietnamese coast (South China Sea, SCS) during the southwest summer monsoon over four main areas: the northern coastal upwelling (NCU), the southern coastal upwelling (SCU), the offshore upwelling (OFU) and the shelf off the Mekong River mouth (MKU). An ensemble of 10 simulations with perturbed initial conditions were run with the fine-resolution SYMPHONIE model (1 km inshore) to investigate the daily to intraseasonal variability of the SVU and the influence of the ocean intrinsic variability (OIV) during the strong SVU of summer 2018. The intraseasonal variability is similar for the SCU, MKU and OFU, driven to the first order by the wind variability. The MKU and SCU are induced by stable ocean dynamics (the northeastward then eastward boundary current) and have very little chaotic variability. The OIV has a stronger influence on OFU. In July, OFU mainly develops along the northern flank of the eastward jet. The influence of the OIV is strongest and related to the chaotic variability of the meridional position of the jet. In August, this position is stable and OFU develops mainly in the area of positive wind curl and cyclonic eddies north of the jet. The influence of the OIV, weaker than in July, is related to the organization of this mesoscale circulation. The NCU shows a behavior different from that observed in the other areas. In the heart of summer, a large-scale circulation formed by the eastward jet and eddy dipole is well established with an alongshore current preventing the NCU development. In early and late summer, this circulation is weaker, allowing a mesoscale circulation of strongly chaotic nature to develop in the NCU area. During those periods, the OIV influence on the NCU is very strong and related to the organization of this mesoscale circulation: the NCU is favored (annihilated) by offshore-oriented (alongshore) structures. [ABSTRACT FROM AUTHOR]

The seasonally dependent Antarctic sea ice concentration (SIC) budget is well observed and synthesizes many important air–sea–ice interaction processes. However, it is rarely well simulated in Earth system models, and means to tune the former are not well understood. In this study, we investigate the sensitivity of 18 key NEMO4.0-SI 3 (Nucleus for European Modelling of the Ocean coupled with the Sea Ice Modelling Integrated Initiative) model parameters on modelled SIC and sea ice volume (SIV) budgets in the Southern Ocean based on a total of 449 model runs and two global sensitivity analysis methods. We found that the simulated SIC and SIV budgets are sensitive to ice strength, the thermal conductivity of snow, the number of ice categories, two parameters related to lateral melting, ice–ocean drag coefficient and air–ice drag coefficient. An optimized ice–ocean drag coefficient and air–ice drag coefficient can reduce the root-mean-square error between simulated and observed SIC budgets by about 10 %. This implies that a more accurate calculation of ice velocity is the key to optimizing the SIC budget simulation, which is unlikely to be achieved perfectly by simply tuning the model parameters in the presence of biased atmospheric forcing. Nevertheless, 10 combinations of NEMO4.0-SI 3 model parameters were recommended, as they could yield better sea ice extent and SIC budgets than when using the standard values. [ABSTRACT FROM AUTHOR]

This study aimed to describe the interannual variability of dense shelf water cascading and open ocean convection in the Gulf of Lions (NW Mediterranean) based on long-term temperature and current records and its impact on particle fluxes and associated metals. These observations highlight the predominant role of the rare intense events of dense shelf water cascading (1999/2000, 2005/2006, 2012/2013) in the basinward export of particles, which are mainly brought by rivers. Measurements of particulate trace metals in 2012 indicate that the monitored intense cascading event may be responsible for a significant fraction (~15%) of the annual input to the shelf. To this first process is added the effect of somehow more recurrent deep convection events (2005, 2009–2013) that remobilize the deep sediments, receptacle of coastal inputs, and disperse them rapidly at the scale of the northern Mediterranean basin, and gradually over the entire western basin. Coastal and oceanic dense water formations are key physical processes in the Mediterranean margins, whose reduction in intensity and recurrence has already been observed and also anticipate in climate scenarios that will likely change the dispersion pathways of chemical particles in this region. [ABSTRACT FROM AUTHOR]

This paper presents a collection of environmental, geophysical, and other marine-related data for marine ecological models and ecological-niche models. It consists of 2132 raster data for 58 distinct parameters at regional and global scales in the ESRI-GRID ASCII format. Most data originally belonged to open data owned by the authors of this article but residing on heterogeneous repositories with different formats and resolutions. Other data were specifically created for the present publication. The collection includes 565 data with global scale range; 154 at 0.5° resolution and 411 at 0.1° resolution; 196 data with annual temporal aggregation over ~10 key years between 1950 and 2100; 369 data with monthly aggregation at 0.1° resolution from January 2017 to ~May 2021 continuously. Data were also cut out on 8 European marine regions. The collection also includes forecasts for different future scenarios such as the Representative Concentration Pathways 2.6 (63 data), 4.5 (162 data), and 8.5 (162 data), and the A2 scenario of the Intergovernmental Panel on Climate Change (180 data). Measurement(s) habitat similarity • Time Series Analysis • Principal Component Technology Type(s) Habitat Representativeness Score • Cross-Correlation • Principal Component Analysis Factor Type(s) Sea-bottom and sea-surface dissolved oxygen, salinity, and temperature • Sea net primary production • Sea ice concentration • Average, minimum, maximum sea depth • Average, minimum, maximum elevation • Distance of a square marine area from land and its fraction covered by water • Indication of the belonging Large Marine Ecosystem (LME), Exclusive Economic Zone (EEZ), Marine Ecoregions of the World (MEOW), Major Ocean Basins, and Marine Protected Area (MPA) • Number of islands • Water area that lies within the shelf, slope, and abyssal zones • Tidal range extension • Coral density • Estuary and seamount presence • Carbon dioxide flux at soil • Air surface temperature • Precipitation • Difference between air surface temperature and sea surface temperature • World population density • Sediment thickness • Atmospheric concentration of methane and nitrous oxide • Earth heat flow • Distance from crust plates • Earthquake density, depth, magnitude • Groundwater resources Sample Characteristic - Environment climate system Sample Characteristic - Location Oceans and Seas • Adriatic Sea • Aegean Sea • Baltic Sea • Bay of Biscay • Black Sea • Mediterranean Sea, Eastern Basin • North Sea • Mediterranean Sea, Western Basin [ABSTRACT FROM AUTHOR]

Few coastal ecosystems remain untouched by direct human activities, and none are unimpacted by anthropogenic climate change. These drivers interact with and exacerbate each other in complex ways, yielding a mosaic of ecological consequences that range from adaptive responses, such as geographic range shifts and changes in phenology, to severe impacts, such as mass mortalities, ecological regime shifts and loss of biodiversity. Identifying the role of climate change in these phenomena requires corroborating evidence from multiple lines of evidence, including laboratory experiments, field observations, numerical models and palaeorecords. Yet few studies can confidently quantify the magnitude of the effect attributable solely to climate change, because climate change seldom acts alone in coastal ecosystems. Projections of future risk are further complicated by scenario uncertainty - that is, our lack of knowledge about the degree to which humanity will mitigate greenhouse-gas emissions, or will make changes to the other ways we impact coastal ecosystems. Irrespective, ocean warming would be impossible to reverse before the end of the century, and sea levels are likely to continue to rise for centuries and remain elevated for millennia. Therefore, future risks to coastal ecosystems from climate change are projected to mirror the impacts already observed, with severity escalating with cumulative emissions. Promising avenues for progress beyond such qualitative assessments include collaborative modelling initiatives, such as model intercomparison projects, and the use of a broader range of knowledge systems. But we can reduce risks to coastal ecosystems by rapidly reducing emissions of greenhouse gases, by restoring damaged habitats, by regulating non-climate stressors using climate-smart conservation actions, and by implementing inclusive coastalzone management approaches, especially those involving nature-based solutions. [ABSTRACT FROM AUTHOR]

The Mediterranean Sea hosts a great Nudibranchia diversity and has proved to be particularly intriguing in the case of the family Onchidorididae, a group of dorid nudibranchs that lately increased its diversity with the addition of one recently described Mediterranean species. The Onchidorididae family has a troubled systematic history to date, characterized by uncertainties and genera that are considered valid or not, according to the different authors. This confused taxonomy reflects the lack of a broad and comprehensive view on the phylogenetic relationships occurring between Onchidorididae members, an incorrect interpretation of the diagnostic morphological characters, and a poor knowledge of important biological aspects characterizing the different genera included in the family. To shed some light on the systematics of Onchidorididae, an integrative taxonomic revision was carried out involving morphological, ecological, and molecular analyses on an updated dataset. Mediterranean specimens and species were added to the dataset of the already known Onchidorididae and a new species from the Adriatic Sea (Central Mediterranean Sea) is described here. Furthermore, historical controversies are clarified due to the discovery of new important synapomorphies useful to define genera belonging to the Onchidorididae family and to describe a new genus. Finally, the taxonomic status of all the known Onchidorididae species is investigated and discussed, filling the gap of knowledge on neglected species. [ABSTRACT FROM AUTHOR]

The present study aims to determine fish assemblages spreading between 0 and 40 m depth on the northern coasts of Cyprus. During the study, Underwater Observations (UO) have been conducted in 54 locations and photographed the fish species. The hourly imaging figures of the recorded species were determined by using the Time-Transect Method (TTM). Also, dominance Analysis (DA) and Incidence Frequency Analysis (IFA) of the identified species were performed. As a result, 72 different fish species belonging to 26 families were found to occur in the studied area. After the evaluation of identified species, 56 of them were determined as native species of the Mediterranean and 14 of them as Indo-Pacific origin. Additionally, we provide two new records (Dasyatis chrysonota and Gobius fallax) from Cyprus. [ABSTRACT FROM AUTHOR]

Population genetic analysis of variation at five neutral microsatellite loci for Mediterranean mussels (Mytilus galloprovincialis) from 18 sites along the eastern Adriatic Sea revealed little or no spatial variation. In contrast, seascape genetics analysis revealed a pronounced locus‐specific gradient in allelic and genotypic frequencies across the study region. At a sixth locus, MGE7, the frequencies of two alleles, MGE7243 and MGE7249, were strongly associated, negatively and positively, respectively, with a single environmental variable – minimum salinity (minSAL). The frequency of the MGE7243/243 homozygous genotype was strongly negatively associated with minSAL, whereas the frequencies of the MGE7246/249 and the MGE7249/249 genotypes were strongly positively correlated with minSAL. Interpretation of these pronounced gradients is confounded by the fact that minSAL and another environmental variable, maximum sea surface temperature (maxSST), are highly correlated (R = −.911) and are therefore not necessarily acting independently. BLAST searches of the MGE7 locus against M. galloprovincialis whole genome shotgun sequence returned an alignment with contig mg10_S01094 (accession UYJE01010330.1) and 7 predicted M. galloprovincialis proteins VDI82194.1 ‐ VDI82200.1. Conserved domain searches revealed a similar structure to the transcriptional regulator Msx2‐interacting protein. The BLASTp search also returned significant alignments to Msx2‐interacting proteins in Mytilus coruscus, Crassostrea virginica, and Haliotis rubra. The existence of the MGE7 gradient highlights the role that environmental variation may play in retarding gene flow among wild M. galloprovincialis populations, and also how the success of collection of young mussels (spat) from one site and their transfer to another site (the farm) may be influenced by a single factor such as minSAL or maxSST on a localized scale. [ABSTRACT FROM AUTHOR]

Episodic events of flood deposit in coastal environments are characterized by deposition of large quantities of sediment containing reactive organic matter within short periods of time. While steady-state modelling is common in sediment biogeochemical modelling, the inclusion of these events in current early diagenesis models has yet to be demonstrated. We adapted an existing model of early diagenetic processes to include the ability to mimic an immediate organic carbon deposition. The new model version (FESDIA) written in Fortran and R programming language was able to reproduce the basic trends from field sediment porewater data affected by the November 2008 flood event in the Rhône River prodelta. Simulation experiments on two end-member scenarios of sediment characteristics dictated by field observation (1–high thickness deposit, with low TOC (total organic carbon) and 2–low thickness, with high TOC), reveal contrasting evolutions of post-depositional profiles. A first-order approximation of the differences between subsequent profiles was used to characterize the timing of recovery (i.e. relaxation time) from this alteration. Our results indicate a longer relaxation time of approximately 4 months for SO42- and 5 months for DIC (dissolved inorganic carbon) in the first scenario, and less than 3 months for the second scenario which agreed with timescale observed in the field. A sensitivity analysis across a spectrum of these end-member cases for the organic carbon content (described as the enrichment factor α) and for sediment thickness indicates that the relaxation time for oxygen, sulfate, and DIC decreases with increasing organic enrichment for a sediment deposition that is less than 5 cm. However, for larger deposits (>14 cm), the relaxation time for oxygen, sulfate, and DIC increases with α. This can be related to the depth-dependent availability of oxidant and the diffusion of species. This study emphasizes the significance of these sediment characteristics in determining the sediment's short-term response in the presence of an episodic event. Furthermore, the model described here provides a useful tool to better understand the magnitude and dynamics of flooding event on biogeochemical reactions on the seafloor. [ABSTRACT FROM AUTHOR]

The subsurface oxygen maximum (SOM) is observed in oligotrophic oceans and is associated with different physical and biological processes. This study characterizes the SOM in the Mediterranean Sea at the basin scale and investigates its driving mechanisms by analysing the output of the 1/24 ∘ resolution biogeochemical reanalysis provided by the Copernicus Marine Service for the 1999–2019 time period. We validated the model-derived oxygen concentration in the epipelagic layer at different spatial and temporal scales, including novel process comparisons with estimates from in situ observations. Moreover, using Biogeochemical Argo (BGC-Argo) float observations, we estimated the model uncertainty in reproducing the SOM concentration and depth in summer (13 mmol O 2 m -3 and 13 m, respectively). The western and eastern Mediterranean Sea depicts different SOM signatures in summer, with higher oxygen values and shallower depths in the western Mediterranean. The concentrations and depths (in the ranges of 230–250 mmol O 2 m -3 and 30–100 m, respectively) are in agreement with the estimations from the literature and show mesoscale variability patterns. The western Mediterranean also shows a stronger biological activity, specifically oxygen production and consumption, along the whole epipelagic layer and higher oxygen concentrations at the surface throughout the year, but heavy undersaturated waters are associated with winter deep convection in the northwestern Mediterranean Sea. A 1-year analysis conducted on selected areas that are representative of the heterogeneity of summer SOM highlighted that the SOM can actually be sustained by biological production (as in northwestern Mediterranean areas), or it can be a residual of the confinement of spring production (as in the central Ionian area) and vertical motions influence its depth (as in the Levantine subduction area). [ABSTRACT FROM AUTHOR]