Biogeochemical cycling in fjords underpins crucial environmental and economic functions including carbon sequestration and food security, and a fundamental understanding of the controls on these cycles is essential for sustainable management of fjords that are facing increasing climate and anthropogenic stressors. However, the interaction of external forcing and local geomorphology in fjords leads

Abstract not available

The Pacific Arctic region has experienced, and is projected to continue experiencing, rapid climate change. Large uncertainties exist in our understanding of the impact these physical changes have on the region’s ecology. This is, in part, due to the lack of long-term data. Here we investigate bivalve mollusc growth increment width chronologies (sclerochronologies) to develop a long-term biological

The North Pacific Ocean subtropical–subarctic gyre transition region is recognized as an important small pelagic fish nursery and feeding ground. To clarify the lower trophic level variability of the transition region pelagic ecosystem, we investigated the large-scale variation in copepod communities in relation to the oceanographic environment. We net sampled zooplankton in the upper 150 m from the

Internal tides are ubiquitously generated from disturbances between barotropic tides and bottom topography in stratified oceans. Incoherence is routinely considered as non-stationary phase discrepancy between internal and astronomical tides. Internal tides, especially incoherent constituents, contribute substantial energy to dissipation and turbulent mixing. Using ∼8-month near-full-depth moored current

Anthropogenic and/or climate-driven changes in zooplankton dynamics may serve as a bottom-up regulator of productivity of small pelagic fish. In the central Seto Inland Sea of Japan, the abundance of the recruit fish of Japanese anchovy (Engraulis japonicus) has markedly declined in the last decade under oligotrophication. However, the link between the reproductive success of anchovy and environmental

Although the Gulf of California is widely recognized as a region of high productivity and biodiversity, recent oceanographic and ecological changes have had a significant impact on its overall health. We review the relevant history of the economically important fishery based on large Humboldt (jumbo flying) squid (Dosidicus gigas) (>50 cm mantle-length and 10 kg body weight) that existed in the Guaymas

The variability of zooplankton populations is controlled by external and internal forcing, with the former being principally large-scale changes in circulation, and the latter being driven by in situ growth, competition, and predation. Assessing the relative importance of these forcings is challenging and requires analyses of multifaceted observational data. As part of the U.S. GLOBEC Georges Bank

The Antarctic Peninsula ecosystem is extremely sensitive to climatic variability and other anthropogenic perturbances ascribed to biomass extraction by fisheries. An Ecopath with Ecosim model calibrated for the 1996–2012 period was projected into the future (2100) under three different climate projections for environmental variables (sea ice extent, open water area and chlorophyll-a concentration)

Little is still known about the biology and ecology of many elasmobranchs which often inhibits species specific management measures from being implemented. The primary aim of this study was to improve the knowledge on the distribution and habitat use of the threatened and data deficient shagreen ray, Leucoraja fullonica, using fisheries dependent data. To model its distribution, we used Bayesian hierarchical

Adult fish abundance depends on survival of early life stages, which are susceptible -among other factors- to environmental variability. Ocean mesoscale events (i.e. eddies, costal upwelling, thermal fronts, cold filaments) can be mechanisms of enrichment, concentration, retention and dispersal in marine environments with effects on survival of marine species early life stages. The Pacific sardine

Harmful Algae Blooms pose an increasing threat to the public health and economic stability of Southern Chile, particularly to the aquaculture industries. This fieldwork performed during the PROFAN expedition from 12th to 22nd November 2019 extends the knowledge on the distribution of marine toxin-producing species in the difficult to access Última Esperanza Province in the Magallanes Region. Paralytic

The Kuroshio in different paths is considered to have different impacts on the generation, propagation and energetics of internal tides (ITs) originated from the Luzon Strait (LS). However, its influence on the incoherence of ITs remains unknown. Based on a regional model simultaneously simulating ITs and background circulations, this study examines the incoherence of the M2 and K1 ITs radiated from

Zooplankton biomass has been monitored on joint Norwegian-Russian surveys in late summer and autumn since the 1980s. We report here on zooplankton biomass in three size fractions (<1, 1–2, and > 2 mm in screen mesh opening) obtained with WP-2 plankton net (180 μm mesh size) hauled vertically over the water column from near bottom to the surface for the period 1989–2020. The number of samples (stations)

Based on 201 full depth profiles of temperature-salinity and velocity, we investigated the thickness, stratification and spatial variation of the bottom mixed layer in the South China Sea. The mean values of thickness and stratification N2 of the bottom mixed layer are about 154 m and 6.2 × 10-7 s−2, respectively, which is five times thicker and 100 times less stratified than the upper mixed layer

The cycling of dissolved organic matter in the productive west Antarctic Peninsula (WAP) region is not well understood. For this study, dissolved organic carbon (DOC) and nitrogen (DON) concentrations and other biogeochemical measurements were collected along the WAP shelf during austral summer 2017. Concentrations of both DOC and DON in the upper ocean were lower than in lower latitudes (38.13–48

A fully-coupled atmospheric-ocean model was developed by coupling WRF (Weather Research and Forecasting Model) with FVCOM (the unstructured-grid, Finite-Volume Community Ocean Model) through the Earth System Model Framework (ESMF). The coupled WRF-FVCOM is configured with either hydrostatic or non-hydrostatic oceanic dynamics and can run with wave-current interactions. We applied this model to simulate

Although juvenile anguillid eels live in freshwater/estuarine habitats, and marine eels live in diverse ocean environments ranging from shallow-to-deep continental shelf areas and around islands to deep-benthic habitats and deeper meso- and bathy- pelagic zones, the larvae (leptocephali) of all species mix together in the ocean surface layer. All types of eel habitats are present in the western South

The Labrador Sea is known for strong surface heat losses and deep ocean ventilation in the wintertime as well as high biological productivity and carbon export associated with extensive spring blooms. Using satellite-derived estimates of chlorophyll-a and net primary productivity, this study documents that the Labrador Sea has recently become more productive, evident in the form of more intense and

Young-of-the-year (0-group) fish in the Barents Sea have been investigated in an annual joint Norwegian-Russian pelagic trawl survey in autumn, using a standardized procedure since 1980. We use a conceptual framework of ‘upstream’ spawning areas and ‘downstream’ nursery areas, recorded as 0-group distribution in the Barents Sea, to address spatial (geographical) and temporal (1980–2017) variation in

The Indian Ocean Dipole (IOD) is a basin-wide ocean–atmosphere phenomenon that has profound impacts on the global climate, land, and ocean. The Dipole Mode Index (DMI), which is defined as the difference of the sea surface temperature (SST) anomaly in the east IOD zone and the west IOD zone has long been used to characterize and quantify the strength of IOD events. In this study, we propose biological

The Pacific sardine fishery is the most important in terms of catch volume in Mexico. Due to their trophic position, small pelagic fishes respond rapidly and abruptly to ocean climate variability at interannual (ENSO) and decadal time scales (PDO), which is why their response to climate change is expected. The present study applied the Rapid Vulnerability Assessment (RVA) designed for Natural Protected

A very severe storm in the Antarctic belt is analysed that sent a very large swell throughout the South-Pacific Ocean. The reasons for the storm were a deep depression passing over an anomalous warm sea area, with consequent increased intensity, more active wind input, gustiness, with also dynamical generation. Wind and wave model results are verified with scatterometer and altimeter data. We follow

The conservation status of the long-lived Greenland shark (Somniosus microcephalus) is unknown, and methods for non-invasively estimating local or regional abundances are wanted. Using a multifrequency split beam echosounder during long line fishery for Greenland sharks, we demonstrate how individual sharks can be identified and separated with high accuracy from the acoustic backscattering at three

With increase in the Arctic warming, fjords in the region are undergoing significant decline in sea-ice, increase in glacier retreat, and changes in primary productivity. Warm and saline Atlantic water (AW) advected from the open ocean is attributed as one of the primary reasons for these changes. Vertical mixing of the subsurface AW with the cold surface Arctic water positively feeds many of these

Globally, marine communities are experiencing gradual warming and extreme heatwaves causing species to shift in geographic range. As a result, the biological assemblages outside tropical latitudes are being reorganized or “tropicalized” as warm-affinity species become increasingly dominant and cool water species recede, with impacts on our economies, food supply, and health. In the Gulf of California

Particulate organic matter (POM) forms the base of the pelagic food web, but is a complex category of material that undergoes substantial changes in quantity and quality across different time scales. As the primary consumers of POM, zooplankton are influenced by these fluctuations, resulting in shifts in the food web pathways that contribute to the production of higher trophic levels. We measured POM

The Arabian Sea and the Bay of Bengal are cul-de-sacs of the northern Indian Ocean, and they contain more than half of the world's Oxygen Minimum Zones (OMZs). The current study reviews the vast and advancing literature on the oceanographic settings that lead to distinct OMZs in the Arabian Sea and the Bay of Bengal and links them with the copepods thriving there, their status, and likely adaptations

A long-term information baseline is necessary to identify the seasonal and interannual variability of diatom production driven by environmental dynamics. This motivated our compiling hydrographic data and concurrent diatom fluxes at the Alfonso Basin sub-zone. The diatom data time series spanned from February 2008 to September 2012. These data were analyzed along with primary productivity and chlorophyll-a

Energetics of the abyssal ocean account greatly for the redistribution and dissipation of global oceanic energy. In this study, we characterize the intraseasonal fluctuations in the deep South China Sea (SCS) and evaluate the relevant energy budget using observations and numerical simulations. The results indicate substantial geographical inhomogeneity in the intraseasonal energy reservoir. The high-energy

Abstract not available

Marine Heatwaves (MHW) and Cold Spells (MCS) in the Mediterranean Sea have been extracted from an SST dataset from which the annual warming trend had been removed. The number of events per year (max 6) and their intensity resulted stable, indicating that the increasing occurrence of actual MHW in the last decades is mainly due to the warming rate. The extent (daily mean around 10% of the basin surface)

Fish recruitment variability results from a complex mix of biological and physical processes, and their interactions, acting in the early life stages. In this study, we aim to investigate the environmental factors driving the recruitment success of blue whiting (Micromesistius poutassou) in the NW Mediterranean through reconstruction of early life history traits derived from otoliths microstructure

Multiple publications over the past decades argue that the Gulf of California is a region with high biological diversity and productivity. However, ecosystem resilience to climate disturbances and anthropogenic stressors in the Gulf of California remains poorly explored. One method to assess ecosystem resilience based on ecological indicators is the analysis of continuous records of critical environmental

The sessile benthic fauna on ferromanganese (Fe-Mn) crusts is poorly known, with many groups of invertebrates still barely examined. Collections made during Yuzhmorgeologiya expeditions on RV Gelendzhik in October 2016 (YMG 6–16) and October 2020 (YMG 6–19) to the Magellan Seamounts, tropical western Pacific, have yielded two new species and a new genus of cheilostome bryozoans. These are Allantocallopora

Until recently, high-resolution global modeling of tides has been done separately from high-resolution global modeling of the atmospherically-forced oceanic general circulation. Here we review the emerging class of high-resolution global models that are simultaneously forced by both atmospheric fields and the astronomical tidal potential. Such models simulate barotropic (surface) tides, internal tides

Planktonic protists are an essential component of marine pelagic ecosystems where they mediate important trophic and biogeochemical functions. Although these functions are largely influenced by their taxonomic affiliation, the composition and spatial variability of planktonic protist communities remain poorly characterized in vast areas of the ocean. Here, we investigated the diversity of these communities

The sloping sides of ocean basins are of particular interest for their potential importance for considerable turbulence generation via internal wave breaking and associated water circulation. The difference with the ocean interior may be manifest in a 10–100 m relatively thin layer above the seafloor. We set up an observational study with high-resolution stand-alone instrumentation attached to a custom-made

Chub mackerel is one of the most important fisheries target species worldwide. These fish have large fluctuations in biomass, the mechanism of which remains unclear. This study developed a bioenergetics individual-based model for chub mackerel distributed in the Northwest Pacific and evaluated the dominant environmental factors that affect their early life history. The parameters in the bioenergetics

Climatic variability exerts enormous pressures on the structure and function of open ocean ecosystems. Although the responses of primary producers and top predators to these pressures are being increasingly well-documented, little is known about how midtrophic communities respond to oceanographic and climatic variability. We address this knowledge gap through a study of the effects of El Niño Southern

Organic matter is known to influence community composition and metabolism of marine prokaryotes. However, few studies have addressed this linkage in the deep ocean. We studied the relationship between fluorescent dissolved organic matter and prokaryotic community composition in meso- and bathypelagic water masses along a surface productivity gradient crossing the subtropical and tropical Atlantic Ocean

The North Equatorial Current (NEC) and western boundary currents (WBCs) of the Kuroshio Current (KC) and the Mindanao Current (MC) characterize the circulation pattern and water mass transports in the tropical western North Pacific. We utilized the validated three-dimensional and time-dependent China Sea Multi-scale Ocean Modeling System to investigate the variability of the WBCs and the physical processes

The pelagic tunicates, gelatinous zooplankton that include salps, doliolids, and appendicularians, are filter feeding grazers thought to produce a significant amount of particulate organic carbon (POC) detritus. However, traditional sampling methods (i.e., nets), have historically underestimated their abundance, yielding an overall underappreciation of their global biomass and contribution to ocean

The benthic community in the Chilean Patagonia is as rich and highly diverse as the spatial variation of its habitats and food sources. Environmental stress from glacier melt and river discharge are known drivers of benthic community dynamics. Here, we analyze longitudinal patterns of soft-bottom benthic communities across transects of glacier-marine environments and how these habitats may respond

Deepening the knowledge on Antarctic coastal plankton and its links with environmental conditions is essential to understand the role of these organisms in the carbon and energy flow, and to detect and predict impacts of climate change. This study addresses for the first time the seasonal succession (February 2016 to April 2017) of the phytoplanktonic and protozoan communities of Scotia Bay (Laurie

The Sea of Okhotsk is a marginal sea of the western North Pacific Ocean and a key region for the seawater circulation of the North Pacific. In winter, a large amount of sea ice forms over the northern shelf and off the eastern Sakhalin coast. The sea ice is transported to the southern part of the sea by the fresh and cold East Sakhalin Current (ESC). Microalgae are the main players in the primary production

Using satellite altimetry and wind stress data, the spatially coherent decadal variabilities in current intensity and current path during 1993–2018 were investigated for a western boundary current system, namely, the Kuroshio from the east of Luzon Island to the south of Japan and the Kuroshio Extension (KE). Analyses based on Hovmöller diagrams showing decadal variabilities along the entire current

The ocean vertical circulation has been historically underappreciated compared to the lateral circulation, largely due to the poor availability of the ocean vertical-velocity information. With the advent of high-performance ocean models, especially those constrained by the most available observations, it is now possible and incentive to dig into the vertical branch of ocean circulation. In this study

The large-scale distribution of thaliaceans in relation to environmental variables was investigated over 4500 km in the transition region of the North Pacific (36°N–43.6° N, 141.5° E–164.5° W) in the summer of 2016–2019. Three main patterns occurred in the thaliacean bloom formations with specific and annual variabilities. Thalia democratica, the most dominant thaliacean species in this region, formed

The size, type and abundance of planktonic organisms influence the efficiency with which carbon is transferred through the lower trophic levels, ultimately affecting dynamics at the higher trophic levels of the marine food web. In temperate shelf sea, such as the waters south-west of the UK, the plankton growing season span from early spring to autumn. While the plankton spring bloom has been extensively

Conservation strategies, such as the establishment of Marine Protected Areas (MPAs), aim to safeguard biodiversity and to promote resilience of ecosystems by increasing their capacity to maintain key functions and processes following disturbance. However, the extent to which ecosystems in MPAs exhibit resilience remains debated. To address this question, we evaluated changes in reef fish species and

Particulate adenosine-5′-triphosphate (P-ATP) and particulate carbon (PC) concentrations were measured on approximately monthly intervals throughout the upper water column (0–1000 m) over a 30-yr (1989–2018) period at Station ALOHA to track the seasonal-to-decadal variability in total microbial biomass and the dynamics of living-to-nonliving particulate organic matter pools. On selected cruises, samples

We present the first observational-based assessment of the seasonal circulation and volume transport driven by the Bransfield Current (BC), a surface-intensified coastal jet which flows northeastward along the southern slope of the South Shetland Islands (SSI) in the Bransfield Strait (BS). To this aim, we construct a seasonal climatology based on an extensive dataset of direct velocity measurements

Many ocean fronts are known to feature enhanced primary and secondary production and elevated biodiversity. The confluence of water masses on strong fronts promotes concentration of plankters (phytoplankton and small zooplankton) contributing to creation of oases in the oceanic desert for marine habitants, from small pelagic fish and turtles to seabirds and apex (top) predators. This article is a concise

The biogeographic transition from boreal to Arctic marine communities entails a strong taxonomic and functional turnover. Communities living in these areas are being strongly affected by climate warming with rapid reorganizations and change in ecosystem functioning. We assess the megabenthic species composition and functional character in a transition zone around Svalbard. The relationships between

The organic carbon resulting from photosynthesis in the upper ocean is transferred downward through the passive sinking of organic particles, physical mixing of particulate and dissolved organic carbon as well as active flux transported by zooplanktonic and micronektonic migrants. Several meso- and bathypelagic organisms feed in shallower layers during the nighttime and respire, defecate, excrete and

The phytoplankton absorption cross-section is a fundamental quantity in biogeochemical ocean models that alters the underwater spectral light field and the photosynthetic response of phytoplankton. Phytoplankton taxa are characterized by absorption spectra with defined absorption bands in the visible region of the light spectrum that govern the capability of different taxa of phytoplankton to exploit

Understanding scales and drivers of ecological variability is essential to a full understanding of ecosystem functioning. At remote deep-sea hydrothermal vents, infra-annual dynamics remain poorly described. This study aims to characterise the factors that drive the dynamics of a vent faunal assemblage dominated by Bathymodiolus azoricus mussels from infra-daily to monthly time steps. We analysed a