Vertical variations in physical and chemical conditions drive changes in marine zooplankton community composition. In turn, zooplankton communities play a critical role in regulating the transfer of organic matter produced in the surface ocean to deeper layers. Yet, the links between zooplankton community composition and the strength of vertical fluxes of particles remain elusive, especially on a global

Atlantic Water is a major contributor to the largest zonal variability in ocean properties and air-sea-ice interaction in the Nordic Seas and the European Arctic. Climate change has amplified warming and intensified extreme events, in both the ocean and the atmosphere, with severe implications for the marine environment. Here, we present our long-term (1999–2020) hydrographic observations from the

The sustainable development and environmental protection of the Arctic ecosystem is on the agenda globally. The Convention of Biological Diversity (CBD) and the UN Sustainable Development Goals call for conserving at least 10 per cent of coastal and marine areas globally. Management tools to achieve this goal include marine protected areas (MPAs) and “other effective area-based conservation measures”

Various environmental oceanic factors, such as ocean waves, affect seabird ecology; ocean waves are important, as most flying seabirds must land on ocean surfaces for foraging. However, the global ocean wave observation network is spatiotemporally poor compared to other parameters; fine-scale information on wave conditions is limited, and the influence of wave conditions on seabirds has not been quantitatively

Lanternfishes (Myctophidae) are among the most abundant, widespread, and diverse fish groups in the world ocean. They account for a significant part of oceanic fish biomass and play crucial roles in various ecosystem processes, including carbon sequestration and nutrient recycling. However, despite the increasing risks they face (e.g. global warming, plastic pollution, and exploitation of deep-sea

The Eastern Mediterranean Transient (EMT) was a major climatic event, as it affected profoundly and for a long time period, the circulation of the deep and intermediate layers, with important consequences on the distribution of oxygen and nutrients in the Ionian Sea and more generally, in the whole Eastern Mediterranean basin. In this paper, nutrient and oxygen data collected by the Hellenic Centre

A composite dataset of 27 moorings across the Chukchi Sea and Bering Strait in 2013–14, along with satellite sea ice concentration data, weather station data, and atmospheric reanalysis fields, are used to explore the relationship between the circulation, ice cover, and wind forcing. We find a clear relationship between northeasterly winds along the northwest coast of Alaska and reversed flow along

Seasonal variation in the acoustic presence of blue whale calls has been widely reported for feeding grounds worldwide, however variation over the submonthly scale (several days to <1 month) has been examined to a much lesser extent. This study combines passive acoustic, hydroacoustic, and in situ oceanographic observations collected at a mooring in the Corcovado Gulf, Northern Chilean Patagonia, from

The worldwide smallest cetacean, the vaquita (Phocoena sinus), is on the verge of extinction with fewer than 20 individuals left as of summer 2018. The main cause of mortality is bycatch by entanglement in illegal gillnets and environmental changes. Habitat disturbances have negatively impacted prey diversity, and therefore, the vaquita’s feeding success. We investigated the trophic niche of the vaquita

The present study investigates the advective pathways and transit times of virtual particles released in the Red Sea outflow area as a proxy for the poorly understood spreading of the Red Sea Overflow Water (RSOW) in the Arabian Sea. This work uses the Parcels toolbox, a Lagrangian framework, to simulate tens of thousands of trajectories under different initial conditions. Six different Lagrangian

The Svalbard shelf and Atlantic Arctic Ocean are a transition zone between northward flowing Atlantic Water and ice-covered waters of the Arctic. Effects of regional ocean warming, sea ice loss and greater influence of Atlantic Water or “Atlantification” on the state of ocean acidification, i.e. calcium carbonate (CaCO3) saturation (Ω) are yet to be fully understood. Anomalies in surface layer Ω for

The recruitment of many fish species is thought to be dependent on a match with the timing of spring phytoplankton biomass. This process is mediated by zooplankton dynamics. However, it remains unclear how phenological changes are coupled across trophic levels, and what mechanisms link variation in spring phytoplankton timing to changes in the phenology and abundance of important zooplankton prey species

Using the nitrogen chemical tracer N2* (an anomaly of [N2] in terms of the saturation ratio of dissolved nitrogen gas to dissolved argon gas in seawater), we quantitatively investigated the processes that affect the flux of oceanic nitrogen gas at the air-sea interface in the subarctic region of the Sea of Okhotsk (OK) and the North Pacific Ocean (NP): denitrification, air injection, and rapid cooling

Intensive phytoplankton blooms, which mainly consist of diatoms, take place in the northern Bering and Chukchi Seas from spring to summer. Little is known, however, about the diatoms contributing to new production in these waters during summer when the water column is often stratified. In this study, using a 13C, 15N dual isotope tracer technique plus scanning electron microscopy, we assessed the diatom

A peculiar water mass forms as a result of stirring and mixing between water originating from the Kuroshio and Oyashio currents in the Transition Domain, which is a boundary region between the subtropical and subarctic gyres extending zonally at approximately 40°N in the western North Pacific west of the dateline. The domain is important not only for oceanographic processes such as the inter-gyre exchange

This study aimed to understand the effects of nonlinear internal waves (NLIWs) on nutrient-involved biogeochemical processes and the consequences in the continental margin off Dongsha Atoll (DA) in the northern South China Sea (NSCS). Shipboard and mooring observations were conducted to determine hydrological and biogeochemical conditions mainly from two transects covering the DA-associated upper slope

The Indian Ocean, the third largest among the world’s oceans, is experiencing unprecedented changes in sea surface temperature (SST). We present temporal and spatial dynamics of phytoplankton and their response to warming in the Indian Ocean (∼25°N to 30°S) during 1998–2019 using remote sensing data. Our study revealed that the area of the Indian Ocean Warm Pool (IOWP), defined as waters with SST values

Long-chain n-alkanes are measured in sediment cores (Cores U1341C and UMK-3A) collected from the Bering Sea to evaluate the paleoclimatic utility of n-alkanes in high northern latitude marine sediments. The variations in concentration and molecular composition of long-chain n-alkanes since the end of the last glacial period (the past 18 kyr) have been reconstructed. Sedimentary records of molecular

The salinity measured by SBE 41CP and SBE 61 conductivity-temperature-depth (CTD) sensors on deep floats was evaluated by comparison with shipboard CTD casts at deployment, after temperature and pressure were verified as unlikely to be biased. Salinity biases with a negative pressure dependency, expressed as ΔS = ΔSoffset + ap × pressure and ap < 0, were identified statistically even in the first profiles

Ship-based time-series observations provide crucial data for understanding marine ecosystems, improving decision making in ocean and coastal management. However, only a few time series survive for more than a decade. RADIALES is one of the longest multidisciplinary programs in operation in the northern and northwestern coast of Spain. In the last 30 years, this program collected monthly data on physical

The Atlantic Water (AW) Layer in the Arctic Subpolar gyre sTate Estimate Release 1 (ASTE R1), a data-constrained, regional, medium-resolution coupled ocean-sea ice model, is analyzed for the period 2004–2017 in combination with available hydrographic data. The study, focusing on AW defined as the waters between two bounding isopycnals, examines the time-average, mean seasonal cycle and interannual

This paper examines the seasonal variability of surface ocean pCO2 and pH in the northern Indian Ocean. It aims to identify their controlling factors using a high-resolution, regional ocean-ecosystem model simulation and available surface ocean carbon observations. The seasonal variability of pCO2 and pH of the northern Indian Ocean is attributed to the changes in surface temperature (T), dissolved

Characterising ocean temperature variability and extremes is fundamental for understanding the thermal bounds in which marine ecosystems have adapted. While there is growing evidence of how marine heatwaves threaten marine ecosystems, prolonged periods of extremely cold ocean temperatures, marine cold-spells, have received less global attention. We synthesize the literature on cold ocean temperature

The present study has examined the long-term variability of water mass properties and its relation to sea ice production (SIP) in the northwestern Bering Sea shelf using hydrographic and satellite data, and output from atmospheric reanalysis. As per our analysis of hydrographic data in the summer seasons, significant variability in bottom water temperature and salinity was noted. The temperature in

Data from a four-mooring array deployed across the shelf and slope of Mackenzie Canyon, from 2016 to 2018, are used to characterize wind-driven upwelling and downwelling events and investigate their impact on the transport of water masses. We distinguish between coastal upwelling/downwelling forced by the along-coast wind stress, and canyon upwelling/downwelling associated with the wind stress curl

Acoustic meso- and bathypelagic studies are scarce in the Bay of Biscay but increasing over the last years. This study provides a description of seasonal and bathymetric variation in the distribution of the main scattering layers. We combine acoustics and hydrographic information from four surveys carried out in 2015 in the southern Bay of Biscay. Water mass properties as well as mixing processes studied

The Malvinas Islands Shelf (MIS) encompasses one of the most productive portions of the southwestern Atlantic. Large phytoplankton blooms, which constitute the base of the marine food web, emerge from the northern sector of the MIS and extend hundreds of kilometers northward along the Patagonian shelfbreak. The physical processes contributing to MIS fertilization are poorly understood. Here we use

To understand and characterize the Pacific chub mackerel (Scomber japonicus) spatiotemporal distribution in the northern Peruvian Current System, this study characterized the ecological niche using the minimum volume ellipsoid (MVE) approach considering two meteorological conditions jointly: El Niño (EN) and La Niña (LN). For this purpose, the species presence records collected by the Peruvian onboard

Climate change is warming the ocean and impacting lower trophic level (LTL) organisms. Marine ecosystem models can provide estimates of how these changes will propagate to larger animals and impact societal services such as fisheries, but at present these estimates vary widely. A better understanding of what drives this inter-model variation will improve our ability to project fisheries and other ecosystem

It is known that the wind stress coefficient on sea surface is a key parameter in modeling ocean waves and depends on the wave condition at the same time, while an ocean wave condition is affected not only by the wind speed over the sea surface but also on the water depth in general. Investigating the effect of water depth on wind stress coefficient is thus of great importance for an accurate wave

Strong temperature fronts are commonly formed in the coastal northern South China Sea (NSCS) by mixing of the nearshore mesotrophic cold waters with the offshore oligotrophic warm waters. To understand community response to the rapid environmental change across the frontal system, a field survey was conducted during March 2019 focusing on the spatial and vertical variations of plankton size structure

A large-scale stomach sampling program was carried out in 2015 where 27.627 stomachs from 70 fish species (including two genera) were collected and analysed. This provided a baseline for further trophic investigations in the Barents Sea. Here, we focus on spatial and seasonal variations in fish diet and feeding intensity, and how the trophic structure of fish communities varies between seasons. Principal

Egg surveys are used worldwide for the estimation of spawning stock biomass (SSB) of small pelagic fish species, requiring detailed knowledge about their reproductive biology. In the present study, we revisit the current conceptual framework of teleost fecundity types using Northeast Atlantic (NEA) mackerel (Scomber scombrus) as case study due to conflicting views across different assessment methods

The isoscape of particulate organic matters (POM) in the euphotic zone at the shelf of the East China Sea (ECS) is affected by hydrological interactions and biological activities. Based on the stable carbon and nitrogen isotope values (δ13C and δ15N) and C:N ratio of POM (0.7 to 50 μm) in the euphotic zone of the ECS from 2008 to 2018 with a total of 113 samples, we inferred their resources and then

Most global analysis on the role of copepods in food web efficiency or carbon sequestration ignore the harpacticoid or poecilostomatoid copepods that are under-estimated in traditional zooplankton surveys and under-studied with respect to their ecology and behavior. Nevertheless, when small-mesh-size nets are used these groups appear to dominate zooplankton abundance and sometimes even biomass from

Analysis of observed iron (Fe) and nutrient data from the East Kamchatka Current (EKC) in the western Bering Sea, including the Kamchatka Basin, northeastern shelf slope, and Gulf of Anadyr, in the summers of 2014 and 2018 was conducted. The results indicate the location of the edge of high-nutrient and low-chlorophyll water (Fe-limited subarctic Pacific water), which expands into the EKC area. The

Seasonal and interannual variabilities of surface and subsurface chlorophyll (Chl) in the eastern equatorial Indian Ocean (IO) and Bay of Bengal were examined based on vertical Chl inferred from satellite data. Four biotic zones were identified by Empirical orthogonal function analysis, which represented different types of mixed layer processes. The areas south of Sri Lanka indicated the most significant

Biological production in the oceanic zone (i.e. waters beyond the continental shelves) is typically spatially patchy and strongly seasonal. In response, seabirds have adapted to move rapidly within and between ocean basins, making them important pelagic consumers. Studies in the Pacific, Southern and Indian Oceans have shown that seabirds are relatively abundant in major frontal systems, with species

Modes of variability in ocean wave conditions are coupled to atmospheric circulation changes due to exchange of energy and momentum at the interface. Here, we explored for the South Atlantic Ocean the relations between three main climate oscillations (El Niño–Southern Oscillation [ENSO], Southern Annular Mode [SAM], and Pacific Decadal Oscillation [PDO]), four wave parameters (significant wave height

Scleractinian cold-water corals (CWCs) are among the main habitat engineers of the deep Mediterranean Sea, hosting a high diversity of species and playing a significant ecological role. In the last two decades, many new living scleractinian CWC sites throughout the Mediterranean Basin have been recorded and their distribution has been updated. In the summer of 2018, new scleractinian CWC assemblages

Inspired by the pioneering work of Dr. Bill Peterson who demonstrated the utility of ocean indicators at predicting survival of coho and chinook salmon in the Columbia River, we investigated whether the phenology of primary productivity could explain variable marine survival of Fraser River sockeye salmon. Building on a study that had found a strong correlation between satellite-derived spring chlorophyll

Principles of the spatio-temporal statistics are used to investigate the characteristics of short-term/range extreme sea waves and related sea-state parameters under cyclone winds (northern hemisphere). We base our analysis upon consistent stereo-imaging observations of the 3D (2D space + time) sea surface elevation field, and spectral wave model results in the Northwestern Pacific during tropical

To protect the range of habitats, species, and ecosystem functions in the Clarion Clipperton Zone (CCZ), a region of interest for deep-sea polymetallic nodule mining in the Pacific, nine Areas of Particular Environmental Interest (APEIs) have been designated by the International Seabed Authority (ISA). The APEIs are remote, rarely visited and poorly understood. Here we present and synthesise all available

Impacts of the exceptionally high temperature and salinity on species composition, abundance, biomass and diversity of zooplankton communities were examined in the central Arabian (Persian) Gulf in late winter and summer of 2010 and 2011. Remarkably diverse zooplankton assemblages were characterized with small calanoids (Paracalanus aculeatus and Temora longicornis), cyclopoids (Oithona nana and Oithona

We focus on the characterization of thermohaline fronts in the Western Mediterranean, with a particular focus on the North Balearic Front (NBF), separating the Atlantic Waters that spread into the Algerian Basin from the saltier and colder waters of the Liguro-Provençal area. We use a simple gradient-based method of front detection applied to a 20-year (from June 1993 to June 2013) reanalysis of the

In the last decades, among the marine biogeochemical models, there have been an increasing number of marine Plankton Functional Type (PFT) models. Since the precursor NPZD models, the general trend has been towards the development of models that are more and more complex, either by the number of variables they include and/or by the level of detail they consider. In this respect, flexible-stoichiometry

The northern Bering Sea (NBS) and southern Chukchi Sea (SCS) contain several water masses with different characteristics that have been conventionally classified using temperature and salinity data. However, recent warming and sea ice decline can change these water properties, which suggests that classifying water masses using temperature–salinity diagrams could be problematic for this region. We used

Continuous measurements from the OSNAP (Overturning in the Subpolar North Atlantic Program) array yield the first estimates of trans-basin heat and salinity transports in the subpolar latitudes. For the period from August 2014 to May 2018, there is a poleward heat transport of 0.50 ± 0.05 PW and a poleward salinity transport of 12.5 ± 1.0 Sv across the OSNAP section. Based on the mass and salt budget

Although considerable work has been done in the Chukchi Sea during summer, much less has been done during other seasons. This has limited our ability to fully understand seasonal cycles and transformations of the Chukchi Sea zooplankton, particularly the key copepod species Calanus glacialis. Abundance and distributions of large zooplankton and of all life stages of C. glacialis in the northeastern

The Santa Barbara Channel, CA (SBC) is a biodiverse marine ecosystem fueled largely by phytoplankton productivity, and the composition of the phytoplankton community influences the magnitude and fates of this productivity. Here, we create a 22-year monthly time series of phytoplankton biomarker pigment concentrations in the SBC by combining 12 years of high performance liquid chromatography phytoplankton

The inflow of Alaska Coastal Water (ACW) acts as a source of heat and freshwater for the Arctic Ocean, and contributes to ecosystem succession as well as phytoplankton change. To explore the mechanisms and patterns of the phytoplankton composition in response to the ACW, diagnostic pigments and environmental parameters were analyzed along three similar transects from shelf to basin in the Arctic Ocean

In the Oyashio region, remarkable climatic signals are observed in biogeochemical parameters such as phosphate (PO4) concentration and debate continues regarding possible causes. Using a regional ice–ocean coupled model with a simple biogeochemical cycle, this study investigated the mechanisms controlling interannual–decadal variations in surface PO4 in the Oyashio region and their relationships to