Rare Earth Element (REE) concentrations and Nd isotopic compositions (εNd) of five new seawater profiles scattered across the Rockall Trough (North-East Atlantic) were investigated in order: (1) to establish the seawater εNd distribution in the Rockall Trough, which is poorly known so far; (2) to identify the southward-flowing Wyville-Thompson Ridge Overflow Water (WTOW) originating from the Nordic

The Northeast U.S. continental Shelf (NES) extending from the Gulf of Maine to Cape Hatteras, is a dynamic region supporting some of the most commercially valuable fisheries in the world. This study aims to provide a systematic assessment of eight widely used, intermediate-to-high spatial resolution global ocean reanalysis products (CFSR, ECCO, ORAS, SODA, BRAN, GLORYS, GOFS3.0, and GOFS3.1) against

We investigated the characteristics of seasonal variations in sea surface salinity (SSS) in the subtropical North Pacific and North Atlantic oceans by analyzing observational datasets. As noted in previous studies, the seasonal variation in SSS markedly differs between the western and eastern parts of the basins. These contrasting seasonal variations in SSS have nonnegligible impacts on surface density

The Southern Ocean significantly contributes to primary production in the global ocean. In this study, size-fractionated primary production and chlorophyll a (Chl a), which are not well elucidated, were determined in the eastern Indian sector in the austral summer of 2018–2019. The Southern Antarctic Circumpolar Current Front, Southern Boundary of the Antarctic Circumpolar Current (SB), and Antarctic

In recent decades, southern elephant seals (SES) have become a species of particular importance in ocean data acquisition. The scientific community has taken advantage of technological advances coupled with suitable SES biological traits to record numerous variables in challenging environments and to study interactions between SES and oceanographic features. In the context of big dataset acquisition

Phytoplankton contribute approximately half of the Earth’s primary production, playing a crucial role in marine ecosystem functioning and global carbon cycling. However, our understanding of how ocean dynamics regulate the distribution of phytoplankton remains limited due to the scarcity of depth-resolved observations. Here, we compared the simultaneous measurements of two biogeochemical-Argo floats

Continental margins play a key role in the cycling of natural and anthropogenic trace metals (TMs) as pathways at the interface between landmasses and deep ocean basins but also as sinks. Knowledge of how short-lived forcings alter the export dynamics of TMs is essential for our understanding of their fate in that setting. Here we report time series of particulate metal fluxes in three submarine canyons

Marine heatwaves (MHWs) are period of extreme ocean temperatures that can last from a few days to several years. The increasing frequency and intensity of MHWs have devastating impacts on marine ecosystems. This study explores the characteristics of MHWs from 1982 to 2021 and their effects on chlorophyll (Chl) from 1998 to 2021 in the South China Sea (SCS), utilizing satellite data and reanalysis products

Abstract not available

The Barents Sea is presently undergoing rapid warming and the sea-ice edge and the productive zones are retreating northward at accelerating rates. Planktonic foraminifers and shelled pteropods are ubiquitous marine calcifiers that play an important role in the carbon budget and being particularly sensitive to ocean biogeochemical changes and ocean acidification. Their distribution at high latitudes

In the Southern Ocean, rapid environmental changes (warming, freshening, and poleward shifts of the physiological fronts) are underway. These changes affect the distribution, abundance, and life cycle of protists. However, the spatial distribution of protists is not well understood in the eastern Indian sector of the Southern Ocean. We, therefore, evaluated the effects of environmental factors at the

The Arctic Ocean is characterized by pronounced seasonality in the quantity and quality of organic matter exported from the surface ocean. While it is well established that changes in food availability can alter the abundance, biomass and function of benthic organisms, the impact on food web structure is not well studied. We used bulk carbon and nitrogen stable isotope analysis to assess the quantity

A chemotaxonomic approach (HPLC) was used to determine the phytoplankton composition for the Salish Sea (coastal NE Pacific Ocean). The method was applied to 721 samples collected between 2015 and 2019. Microscopy was used to build then verify the CHEMTAX matrix and CHEMTAX outputs. Statistical methods were used to describe the patterns of phytoplankton composition over space and time. HPLC produced

Biomass of Antarctic krill (Euphausia superba) in the eastern Indian sector of the Southern Ocean (80–150°E, corresponding to the longitudinal range of CCAMLR Division 58.4.1) in the austral summer of 2018–19 was estimated using data from a calibrated echosounder and biological sampling. This study was carried out as a part of the multidisciplinary ecosystem survey (KY1804) by Japanese research vessel

Arctic copepods are major grazers and vital food for planktivores in polar ecosystems but challenging to observe due to remoteness and seasonal sea ice coverage. Models offer higher spatio-temporal resolution, and individual-based models (IBMs) are useful since they incorporate individual variability which characterizes most copepod populations. Here, we present an IBM of the Arctic copepod Calanus

Sea ice is one of the most critical environmental drivers shaping primary production and fluxes of organic inputs to benthic communities in the Arctic Ocean. Fluctuations in organic inputs influence ecological relationships, trophic cascades, and energy fluxes. However, changes in sea-ice concentration (SIC) induced by global warming could lead to significant shifts in trophic interactions, ultimately

Phytoplankton size structure, a major determinant of trophic structure and biogeochemical functioning in pelagic ecosystems, can be described by the slope of the size-abundance spectrum (SAS). Previous observational studies reporting spatio-temporal changes in phytoplankton SAS slope have focused on particular open-ocean or coastal environments. Therefore, the overall variability in phytoplankton SAS

A pigment chemotaxonomic approach was used to find the distribution of phytoplankton groups over a wide extension of the oligotrophic tropical and subtropical Atlantic, Indian and Pacific oceans. The six sampling depths corresponded to percentages of surface irradiance, i.e. “isoirradiances”. Most of the 139 stations sampled presented a subsurface deep chlorophyll maximum (DCM). Only in 19 of the 818

Underwater gliders have advantages for typhoon observation. In recent years, the typhoon-resistant operation mode and cluster networking capabilities of such platforms have improved greatly; therefore, underwater gliders have received increasing attention for typhoon observation, no matter observing the salinity, density, or temperature of the seawater during the typhoon. However, there is a lack of

Exploring the biomass relationships among fish, zooplankton, and phytoplankton and the potential mechanisms that drive changes in their biomass are important for us to understand the structure and dynamics of aquatic ecosystems. In this study, we thus measured the biomass of planktivorous Pacific saury (Cololabis saira), zooplankton, and phytoplankton in the less-explored northwestern Pacific to illustrate

To investigate the cross-slope freshwater exchange in the Australian-Antarctic Basin between 80 and 150°E, the stable oxygen isotopic ratio (δ18O) was evaluated based on top-to-bottom hydrographic sections by R/V Kaiyo-Maru in 2018/2019 summer. The southern flank of the Antarctic Circumpolar Current (ACC) flows eastward in the north and the Antarctic Slope Current (ASC) flows westward along the continental

In-situ observations of the Sulu Sea internal solitary waves (ISWs) are too limited to reveal their variability. In this study, based on verified model reanalysis data, we study the variability of three basic dynamic parameters of ISWs, i.e., linear phase speed, nonlinear and dispersive coefficients, affected by the Sulu Sea circulations. Overall, the linear speed and dispersive coefficient of ISWs

Many marine fish species display a long larval drift between offshore spawning grounds and coastal nursery areas. This drift, whose efficiency drive the renewal of the population, critically depends on many environmental factors and on the spawning behaviour of species. Given the complexity to collect field data on fishes early life stages, modelling has proved to be one of the most valuable tool to

Physical–biological interactions in the ocean are known to be crucial for understanding ecosystem processes. This is particularly relevant in the highly dynamic coastal regions, where the biogeochemical processes associated with higher-frequency perturbations such as tidal waves play a key role in primary production. In this study, we examine the influence of the tide-topography interaction on the

While most of the U.S. Pacific coast is dominated by strong wind-driven upwelling in the spring and regular seasonal cycles of phytoplankton primary production, the Southern California Bight has weak intermittent wind-driven upwelling and low phytoplankton concentrations due to its irregular sheltered coastline. However, the Santa Barbara Channel (SBC), located in the northern Southern California Bight

Loss of sea ice alters habitat for organisms that function as energetic links in Arctic food webs. To address the impacts of such changes on lower trophic levels we focus on forage fish during the early life stages (polar cod: Boreogadus saida and saffron cod: Eleginus gracilis) and copepods (Calanus spp. and Pseudocalanus spp.) in the Chukchi Sea with differing reliance on sea ice environments. We

Abstract not available

It is widely recognized that ecosystems are influenced by both bottom-up (resource-driven) and top-down (predation-driven) controls. However, in the context of marine phytoplankton, there is often a strong emphasis on resource availability, with less attention given to the significant impact of top-down control on phytoplankton patterns. Studies in the Gulf of Cádiz have mainly focused on resource

Oceanic net primary production forms the foundation of marine ecosystems. Understanding the impact of climate change on primary production is therefore critical and we rely on Earth System Models to project future changes. Stemming from their use of different physical dynamics and biogeochemical processes, these models yield a large spread in long-term projections of change on both the global and regional

Abstract not available

We investigated the geographic variations of micronektonic fish communities along the transects in the subtropical North Pacific (23° N, 138° E–120° W) and California Current (30–45° N, 123–125° W) during August–October 2017 in relation to environmental factors, including primary productivity and nitrogen fixation. Throughout the cruise, 102 species across 31 families were collected at a depth of 0–500 m

Mesopelagic fishes may contribute substantially to marine carbon transport by consuming organic carbon near the surface at night and releasing it in the mesopelagic zone during the day. However, the magnitude and uncertainties associated with this transport are not well understood; fish-mediated carbon flux estimates range from less than 1 % to greater than 30 % of biologically-driven carbon export

A current critical issue in climate change studies is how temperature changes and shifts on different spatial and temporal scales can affect organisms in terms of trends, variability and frequency of extremes. In this paper, we analysed marine temperature data on different temporal and spatial scales. We related the sea surface temperature data from the Helgoland Roads Time Series, one of the most

Understanding bio-physical relationships for areas of high biodiversity in marine systems can illuminate potential impacts of environmental change on concentrations of marine life. A biodiversity hotspot of singular significance in the North Pacific Ocean is Unimak Pass, Alaska, where millions of seabirds, hundreds of cetaceans, and thousands of pinnipeds concentrate each summer to forage on rich zooplankton

Maps of surface water fugacity of CO2 (fCO2) over eastern Fram Strait, south-western Nansen Basin, and the north-western Barents Sea (73–84°N, 5–46°E) from September 1997 to December 2020 were made and used to investigate seasonal and temporal trends. The mapping utilized a neural network technique, the self-organizing map (SOM), that was trained with different combinations of satellite/observational/model

Internal waves are commonly observed in oceans and lakes where high stratification exists. In the present study in the Strait of Gibraltar, we analyse internal soliton signals recorded in different locations in their eastward propagation from their release point (Camarinal Sill) to the continental slope of the northwestern Alboran Sea. Moreover, the effect of subinertial forcing on the release of solitons

Hydrographic and bio-optical measurements were conducted along a south–north transect on the northwestern Barents Sea shelf from early spring to late summer in 2021. Strong climate change manifestations observed in this region are rapidly changing the marine environment. These rare observations cover the seasonal evolution from well-mixed and sea ice-covered winter conditions, through sea ice retreat

The Eastern Arabian Sea Shelf i.e. Western Indian Continental Shelf (WICS) – a known biogeochemical hotspot is characterized by monsoonal upwelling, seasonal O2 deficiency, extremely high N2O build-up and sulphidic events. The frequency and duration of the sulphidic events have increased over the last two decades, but their impact on the pelagic N cycling, N budget, and N2O dynamics is poorly constrained

Underpinning primary food chains, atmospheric carbon cycling, and vital ecosystem functions are diatoms, a class of microalgae found ubiquitously in aquatic environments around the globe (Armbrust, 2009; Nelson et al., 1995). As with most organisms on earth climate change threatens their survival and distribution, therefore their ability to adapt to environmental drivers through phenotypic plasticity

Mesoscale ocean fronts play a significant role in marine fisheries, ecosystems, and climate change, and a front detection algorithm appropriate for satellite Earth observation use is a fundamental tool to observe and monitor long-term frontal activities. Since various ecological processes usually work on different spatiotemporal scales, it is vital to separate the fronts at different scales from the

Newly ventilated winter water (NVWW) is a cold, salty, nutrient-rich water mass that is critical for supporting the ecosystem of the western Arctic Ocean. In this study, NVWW formation is documented using timeseries from an 8-mooring array deployed from 2008 to 2009 across the shelf and slope in the western Beaufort Sea near 150°W. The saltiest (densest) class of the winter water (salinity > 32.6)

The A20 line is a meridional hydrographic section located at 52°W that cuts through the western North Atlantic Subtropical Gyre (NASG). It encloses the main paths of the Atlantic Meridional Overturning Circulation (AMOC). Using data from three A20 hydrographic cruises carried out in 1997, 2003 and 2012 together with Acoustic Doppler Current Profiler data and the velocities from an inverse box model

Due to ongoing climate change, a new Arctic Ocean ecosystem is emerging. Within the framework of the Nansen Legacy project, we investigated the community composition of the large zooplankton and its seasonal development along a latitudinal gradient in the northern Barents Sea. Total biomass was maximal in summer and early winter, and minimal in spring, with copepods contributing considerably in all

Sub-Arctic seafloor communities rely on seasonal phytoplankton blooms for food, revealing a tight benthic-pelagic coupling. To maximize resource availability for offspring, organisms such as snow crabs, sea stars, and sea cucumbers synchronize their reproductive and feeding behaviours with spring blooms. Due to climate change, spring blooms are occurring earlier in sub-Arctic regions, leading to a

Mesozooplankton have been widely used as a bioindicator of marine ecosystems due to their key position in ocean food webs, rapid response to environmental changes, and ubiquity. Here, we show mesozooplankton biomass values in the Canary Current System from 1971 to 2021 in three different areas in relation to mesoscale activity: (1) scarcely affected by mesoscales structures (North of the Canary Islands)

Observational data (ADCP and CTD) were collected from two areas on either side of the Tiwi Islands and Coburg Peninsula. Tides dominated the ocean dynamics in both areas, with contributions from solar radiation, nighttime convective cooling, surface wind mixing, and benthic frictional mixing. Despite the same dominating forcing factors, the dynamics and envrionments differed between the east and west

1. Marine ecosystem models have been used to project the impacts of climate-induced changes in temperature and oxygen on biodiversity mainly through changes in species spatial distributions and primary production. However, fish populations may also respond to climatic pressures via physiological changes, leading to modifications in their life history that could either mitigate or worsen the consequences

Over the past four decades, the understanding of Mediterranean oceanography has evolved considerably. From a purely stationary view, there has been a shift to a concept that considers the Mediterranean as a highly dynamic sea in which ocean-typical processes occur on smaller spatial and temporal scales. The recent discovery of the mechanism called BiOS (Adriatic-Ionian Bimodal Oscillating System) has

Abstract not available

Obtaining a long-term perspective on the evolution of the ocean is hindered by a lack of sub-surface observations. Ocean reanalyses, which merge fields from an ocean model with observations using complex data assimilation techniques, provide a dynamically consistent estimate of the ocean in time and space. Recently developed ocean reanalyses, several with resolutions finer than 10 km, provide a three-dimensional

Climate change related alterations in the Arctic have influences on the marine ecosystems, in particular on phytoplankton bloom dynamics. Since phytoplankton blooms are the main provider of carbon sources to the microbial loop, the bacterial and archaeal community are affected by the changes as well. Warmer water and less sea ice can lead to an earlier onset of phytoplankton blooms and consequently

Predictive dynamical models for marine ecosystems are used for a variety of needs. Due to the sparse measurements and limited understanding of the myriad of ocean processes, there is however significant uncertainty. There is model uncertainty in the parameter values, functional forms with diverse parameterizations, and level of complexity needed, and thus in the state variable fields. We develop a

The Bering Strait is the sole gateway and an oceanographic bottleneck for the seasonally warm and comparatively fresh and nutrient-rich Pacific waters to flow into the Arctic, melting ice, lowering salinity, and feeding bird, mammal, and fish populations. The Diomede Islands split this small strait into two main channels, both with northward flow (in the annual mean). The eastern channel, in U.S. waters

The dynamics of fluid flows give rise to robust, persistent circulation features that underpin the flow and exert strong control over the advection of water masses, either enhancing it or suppressing it, collectively known as lagrangian coherent structures. Lagrangian approaches and metrics have been shown to be better suited than eulerian ones at locating and delineating such structures and capturing

The generation and subsequent evolution of nonlinear internal waves (NLIWs) in the Strait of Georgia (British Columbia, Canada) is investigated with both remote sensing images and a three-dimensional regional non-hydrostatic numerical simulation. Many satellite images depict clear snapshots of two successive NLIWs propagating northward about 1 h or 4 km apart during the flood tides. In the model results

The ocean region around Tasmania forms an interface between major ocean basins and represents a significant global ocean hotspot due to a rate of warming higher than the global average. Nearshore Tasmanian waters are of central importance for shallow-water ecosystems and a range of human activities, including recreation, aquaculture and fisheries which have become increasingly impacted by warming in

Southern Ocean organisms are uniquely adapted to the extreme environmental conditions that characterise this region, making them especially vulnerable to climate change. Alterations to the physical environment have already been linked to alterations in the structure and functioning of entire ecosystems, and ecological disruptions are expected to continue to occur. Although our understanding of the