Significant seasonal variations in surface circulation are driven by the East Asian Monsoon in the South China Sea (SCS). Seasonal variations in copepod and hyperiid communities following the monsoon have been reported. The mechanisms controlling these monsoon-driven seasonal variations in hyperiid communities were analyzed using data from the central SCS (CSCS) during 2014–2015. Hyperiids mainly aggregated

The biological carbon pump is a critical component for uptake of carbon by the oceans. Most of this is mediated by gravitational sinking of particles and it is generally assumed that there is a positive relationship between sinking velocities and sizes of particles. Due to the difficulties inherent in measuring the sinking velocity of untouched and undamaged particles, the majority of studies have

River-dominated ocean margins (RiOMars), characterized by river plumes and abundant riverine nutrient inputs, are especially critical in determining the oceanic uptake of atmospheric CO2. Using a well validated three-dimensional, coupled physical-biogeochemical model, we examined the dynamics of the carbonate system in the Pearl River plume (PRP) during summer over a typical RiOMar in the northern

The surface circulation of the Ionian and Adriatic Seas is explored by the re-analysis of available datasets that estimate the mean monthly ocean state for the 60 years-long time period 1955-2015. Emphasis is given to the major recurrent and transitional events in the area. Two circulation indices are utilized for the quantification of the cyclonic or anticyclonic circulation modes and intensity, one

The Arctic Ocean is overwhelmingly forced by its lateral boundaries, and interacts with, the global system. For the development of nested conceptual models of the Arctic Ocean ecosystem we here choose the full pan-Arctic as our focal scale. Understanding the pan-Arctic scale, however, requires that we look at the underlying scales of its major components, by considering regionality, connectivity and

We combined time-series from a monitoring program and specific field observations in order to: 1) describe the characteristics of thin layers of phytoplankton (TLP) in the Galician Rías Baixas (NW Iberian Peninsula), 2) investigate the relationship between spatially-extended TLP (se-TLP) events and environmental variables, and 3) analyze the relationship between TLP occurrence and cell densities of

Subsurface-intensified anticyclones are ubiquitous in the ocean, yet their impact on the large-scale transport of heat, salt and chemical tracers is poorly understood. These submesoscale coherent vortices (SCVs) can trap and advect waters thousands of kilometers away from the formation region, providing a transport pathway that is unresolved by low-resolution Earth System Models. However, knowledge

Obtaining high resolution data on the physical and biological conditions in marine ecosystems is needed to better understand the impacts of environmental variability. The instrumentation of deep-diving, large marine predators has proven useful in sampling these conditions below the surface at fine spatio-temporal scales that would otherwise be extremely challenging. Data were retrieved from 94 grey

Picophytoplankton, the smallest phytoplankton (<3 micron), contribute significantly to primary production in the oligotrophic South China Sea. To improve our ability to predict picophytoplankton abundances in the South China Sea and infer the underlying mechanisms, we compared four machine learning algorithms to estimate the horizontal and vertical distributions of picophytoplankton abundances. The

A coupled circulation and sea ice model is used to examine the tidal impacts on the seasonal variability of circulation, hydrography and sea ice over the eastern Canadian shelf (ECS). The model performance is assessed using in-situ and satellite remote sensing observations. The tidal impacts have significant spatial variability, which are relatively small over the Labrador and Newfoundland Shelves

Due to the predicted future demand for critical metals, abyssal plains covered with polymetallic nodules are currently being prospected for deep-seabed mining. Deep-seabed mining will lead to significant sediment disturbance over large spatial scales and for extended periods of time. The environmental impact of a small-scale sediment disturbance was studied during the ‘DISturbance and reCOLonization’

The performance of two common approaches to data assimilation, an Ensemble Adjustment Kalman Filter (EAKF) and a 4-dimensional variational (4D-Var) method, is quantified in a popular community ocean model, the Regional Ocean Modeling Systems (ROMS). Two distinct circulation environments are considered: the California Current System (CCS), which is an eastern boundary upwelling regime, and the Indian

In this study, we used scale analysis of returning adults to examine the relationship between early marine growth, feeding conditions, and survival for southern Salish Sea Chinook salmon (Oncorhynchus tshawytscha). In total, we examined scales from 2,604 individuals over 7 outmigration years characterized by a range of survival conditions from 1976 to 2008. We observed a positive relationship between

Atlantic Water (AW) flowing along the western and northern Svalbard shelf-break extends the Atlantic domain into the Arctic and is the region’s major source of heat, nutrients and advected plankton. We investigated the inflow and recirculation of AW into four major troughs that cut into the Svalbard shelf, the Isfjorden, Kongsfjorden, Hinlopen and Kvitøya Troughs, and related the circulation patterns

Fatty acids (FA) have been used as diet biomarkers. They have proven to be a valuable method of defining food web relationships, trophic positioning, and the dietary behaviors of marine species. The endemic krill species of the Humboldt Current System (HCS), Euphausia mucronata, is the most abundant krill species over the continental shelf, usually associated with coastal upwelling zones. This study

The Northern California Current (NCC) is a complex, dynamic system experiencing distinctly different levels of upwelling and downwelling, ranging from intermittent upwelling in summer to downwelling in winter. In recent years, warm water anomalies along the Oregon coast have had significant effects on coastal plankton assemblages. To resolve some of the fine-scale responses to these conditions, we

In the Tropical Atlantic Ocean, we assessed the accuracy of a Lagrangian model (Ichthyop) forced with velocity fields from a hydrodynamical model (CROCO) and two different remote sensing products (GlobCurrent and OSCAR) using trajectories of oceanographic drifters. Additionally, we evaluated the possibility to expand the drifters data using trajectories of GPS-buoy equipped drifting Fish Aggregating

The phytoplankton and zooplankton biomass as well as nutrients in the southern region of Kuroshio Extension (KE) presents obvious decadal variability. Both local and remote links between biomass and physical properties are investigated by comparing satellite observations and the outputs from a biological-physical coupled model. The Regional Ocean Model System (ROMS) and Carbon, Silicate, and Nitrogen

Species distribution modelling (SDM) has been increasingly applied to Southern Ocean case studies over the past decades, to map the distribution of species and highlight environmental settings driving species distribution. Predictive models have been commonly used for conservation purposes and supporting the delineation of marine protected areas, but model predictions are rarely associated with extrapolation

The deep chlorophyll maximum (DCM), a critical layer in the ocean characterized by the highest biomass and productivity, determines marine productivity, biogeochemical cycling and carbon sequestration. However, a comprehensive understanding of microbial community structure and metabolic activities in this layer is lacking in several parts of the oceans. Here, we characterized the whole spectrum of

Coinciding with the marine heat wave in 2014 and a strong El Niño in 2016, blooms of the tropical-temperate pelagic colonial tunicate, Pyrosoma atlanticum, expanded into the Northern California Current (NCC). Given the high densities of P. atlanticum colonies observed in the NCC, and their potential for high grazing rates, we hypothesized that the species could have a substantial negative effect on

Image-based research in mesophotic and deep environments of the Mediterranean Sea has significantly increased during the past decades. So far, this research has been focused on the ecology of key structuring organisms such as scleractinians, antipatharians, gorgonians or large demosponges. However, the ecology of true soft corals has barely been studied and is still in a very preliminary stage. To

The northernmost commercial fisheries in the world take place in the northern Barents Sea up to around 80° N. This is an area where global warming is particularly intense and where large, previously ice-covered areas are now more accessible to fishing vessels. This raised questions whether existing conservation and management measures are adequate. In this paper, we discuss the process of developing

Biogenic silica (BSi), primarily derived from marine diatoms, is a major component of the oceanic silicon cycle. It links with the global carbon cycle through the silicate pump via photosynthesis and the so-called “ballast” effect in many areas of the world’s oceans, particularly in ocean margins. Here we examined the distribution and export of BSi based on a large data set collected from the upper

Understanding ecosystem drivers of fish stock performance is essential to improving conservation and management. We used a hypothesis-driven approach to identify potential ecosystem indicators and developed a retrospective analysis using regression models of steelhead trout marine survival in Puget Sound, an urban estuary in Washington State, USA, over a 30-year time series. Indicators related to predator

Internal solitary waves (ISWs) were observed by mooring data in the South China Sea in August and September 2014. Normally the arrival pattern of ISWs is relatively regular and the ISW amplitudes have a positive correlation with the magnitude of semidiurnal tidal currents near the Luzon Strait. However, the ISW amplitudes observed in the second spring tide of September are significantly large when

In this study the mesoscale and submesoscale features in the South China Sea (SCS) are characterized based on a submesoscale-permitting numerical simulation (MITgcm llc4320) with nominal horizontal grid spacing of 1/48° (~2.2 km in the SCS). The simulation includes tidal forcing, which is particularly crucial in the SCS where tides play a key role in many aspects of regional dynamics. Evaluation against

Krill are a key component of pelagic food webs where they are vital to the transfer of energy from phytoplankton to higher trophic levels. Krill have a high lipid content compared to other zooplankton and form dense aggregations, making them an important prey source for higher trophic level fish, seabirds, and marine mammals. The two dominant euphausiid species in the northern California Current (NCC)

Long-term mechanistic research and monitoring provides integral science support for ecosystem-based management (EBM) of resources, activities and services. Decades of oceanographic and ecological research by Bill Peterson and colleagues along the Newport Hydrographic Line (NH Line) provides essential context for understanding and managing Pacific salmon Oncorhynchus spp. and other marine resources

The long-term (almost 20 years) hydrographic and primary production data collected by the U.S. Antarctic Marine Living Resources (AMLR) program during the austral summer near Elephant Island and the South Shetland Islands were combined with satellite observations to assess interannual variability in environmental conditions and production of the northern Antarctic Peninsula (NAP). Correlation analyses

Isopods are a highly diversified group of deep-sea fauna, with a wide variety of shapes which must reflect a similar great variety of adaptations to the deep environments. The deep Mediterranean, however, has a low diversity of isopods related to its oligotrophy, the thermal stability of deep-water masses (~12.8 °C below 150–200 m) and rather homogeneous geomorphology. The main factor defining isopod

Gelatinous zooplankton (GZ), here understood as pelagic cnidarians and ctenophores, are an important component of marine ecosystems. Their diversity and distribution reflect local hydrological settings especially well, thus allowing the development of biotic indices for studying climate-mediated changes in the world’s oceans. The effects of global warming are most pronounced in the Arctic Ocean and

We analyzed an 11-year data set of length measurements for Euphausia pacifica, resolved by developmental stages ranging from early furcilia through adults, to characterize temporal variability in size distributions in relation to environmental and climate forcing in coastal waters of the northern California Current. Our analysis reveals that coastal size distributions of this linchpin species are related

Large-scale geostrophic flow across an oceanographic section can be computed from in situ density profiles and satellite-borne sea level anomaly measurements at the section endpoints. Here, uncertainties are estimated and compared for observations that span the North Atlantic Current. Out of multi-year mooring records from two sites, Porcupine Abyssal Plain and Central Irminger Sea, 16 months from

The West Antarctic Peninsula (WAP) region encompasses numerous fjords known to be hotspots of benthic biodiversity and biomass. These ecosystems are undergoing rapid climate warming and oceanographic change; consequent glacial melt and retreat may dramatically alter benthic communities and ecosystem functions in WAP fjords. In addition, there is extreme variability in seasonal productivity and phytodetrital

The abyssal seafloor of the Clarion Clipperton Zone (CCZ) in the central Pacific has the largest known deposits of polymetallic nodules and associated benthic faunal communities with high biodiversity. The environmental factors that structure these communities, both at regional and local scales, are not well understood. In this study, seabed image surveys were used to assess distribution patterns in

The distribution of organisms is related to both environmental factors and interactions between organisms. However, such associations between organisms across an abyssal megafaunal community have not previously been investigated at landscape scale because of a lack of positional data on specimens over such scales. We quantified spatial distributions and investigated interspecific associations in benthic

This study examines temporal variations of 234Th-based particle export based on time-series observations conducted from 2004 to 2014 at the South-East Asian Time-series Study (SEATS) site in the basin area of the Northern South China Sea. It shows significant variability in particle export at both seasonal and interannual time scales. A significant feature of our data as observed by prior studies is

The Yellow Sea Warm Current (YSWC), which carries warm, saline water into the Yellow Sea (YS), exhibits a typical northward (upwind) flow during winter. Observations have shown that the path of the YSWC has shifted to the west from the deep trough, and it has been suggested that continental shelf waves (CSWs) may play an important role in this westward shift. However, the source of southward propagating

The dynamic of the thermohaline structure of the upper ocean, which depends on ocean–atmosphere interactions, drives most near surface oceanic processes, including the control of gases and heat fluxes, and nutrient availability in the photic layer. The thermohaline structure of the southwestern tropical Atlantic (SWTA), a key region for diagnosing variation of the Atlantic Meridional Overturning Circulation

Dissolved oxygen concentrations in the ocean are declining on a global scale. However, the impact of climate change on oxygen in shelf seas is not well understood. We investigate potential future changes in oxygen on the northwest European continental shelf under a business as usual greenhouse gas emissions scenario (Representative Concentration Pathway RCP8.5). Regions of the European shelf are thermally

The deep sea is characterized by a wide range of landscapes, including complex features where topography and currents interact to form highly heterogeneous habitats. In addition to a complex topography, hydrothermal vent environments are characterized by strong environmental gradients that structure the spatial distribution of biological communities. The role of vent fluid temperature and chemical

Data from a five-mooring array extending from the inner shelf to the continental slope in the vicinity of Mackenzie Canyon, Beaufort Sea are analyzed to elucidate the components of the boundary current system and their variability. The array, part of the Marine Arctic Ecosystem Study (MARES), was deployed from October 2016 to September 2017. Four distinct currents were identified: an eastward-directed

The 2010 Deepwater Horizon oil spill in the Gulf of Mexico demonstrated that oil in the water column may be transported from surface waters to the sediments via marine snow. Interactions between oil droplets and mineral particles have been intensively studied since the middle of the twentieth century, but interactions between oil and organic particles, such as phytoplankton, fecal pellets, and other

Isfjorden, a broad Arctic fjord in western Spitsbergen, has shown significant changes in hydrography and inflow of Atlantic Water (AW) the last decades that only recently have been observed in the Arctic Ocean north of Svalbard. Variability and trends in this fjord’s climate and circulation are therefore analysed from observational and reanalysis data during 1987 to 2017. Isfjorden experienced a shift

Bathymetric gradients in the deep sea are known to affect key benthic community characteristics such as diversity. However, most studies investigate large-scale bathymetric variation, while habitat heterogeneity related to modest bathymetric variation has generally been overlooked because of limitations to sampling technology. We investigate the role of modest bathymetric variation (~10 m water depth

The Gulf of Alaska experienced extreme temperatures during 2014–2019, including the four warmest years ever observed. The goal of this study is to evaluate the ecological consequences of that warming event, across multiple trophic levels and taxa. We tested for evidence that observed sea surface temperature (SST) anomalies were outside the envelope of natural climate variability in order to evaluate

Reduction in summer sea ice coverage has recently been observed in the western Arctic Ocean. Changes in the coverage and timing of sea ice retreat are expected to have a great impact on the marine ecosystem. In this study, we evaluated inter-annual changes in the spatial distribution of zooplankton communities in the western Arctic Ocean, during the summers of 2008, 2010, 2012–2017. A total of 339

Our understanding about the atmospheric dimethyl sulfide (DMS) and its influence to sea-to-air flux calculation in the Southern Ocean is still limited due to insufficient investigations. Herein, high-resolution shipboard underway simultaneous surface seawater and atmospheric DMS measurements were conducted in the Southern Ocean from February 23 to March 31, 2018. A larger variation of DMS levels was

Species of the family Sternoptychidae (hatchetfishes) occur worldwide and play critical roles by sequestering carbon, recycling nutrients, and acting as a key trophic link between epipelagic primary consumers and higher trophic levels in marine ecosystems. Nevertheless, basic knowledge on their ecology is still lacking and their functional ecology remains understudied with respect to composition, organization

Chaetognaths (arrow worms) are important components of zooplankton communities in terms of abundance, biomass and contribution to carbon export. Though traditionally considered strict carnivores, recent studies have identified “omnivorous” chaetognaths. These may feed on non-animal materials, including algae, detritus or sediments. The feeding strategies of the Arctic species Eukrohnia hamata and Parasagitta

We present a lower trophic level pelagic ecosystem model that allows the investigation of the role of hydrography, bacterial remineralization and detritus consumption on the strength of carbon export and its attenuation. We apply the model to investigate the controls on the carbon export at the Bermuda Atlantic Time-Series Study site (BATS) and the European Station for Time series in the Ocean, Canary

Formulation of the wind energy input into waves in developing sea is a very important but rather difficult problem in physical oceanography. The complex flow condition within the air-sea boundary layer including wave breaking is known to be the most important factor governing the wind energy input. However, the existing theoretical and empirical models are not always satisfactory or of limited generality

Marine growth and survival of juvenile Pacific salmon (Oncorhynchus spp.) have been linked to marine temperatures and feeding conditions during their first few months at sea. Therefore, understanding what salmon consume under varying environmental conditions is important to understanding how their growth and survival are affected by climate change. Here, we examined how warm/cool-phase variation in

The East African Coastal Current (EACC) is the dominant oceanographic influence along the coastlines of Tanzania and Kenya yet formal descriptions of the biogeochemical characteristics of these waters remain fragmented or poorly defined. Whilst the region remains undersampled, and information for many parameters is limited or even absent, the region is not understudied and complex patterns, due in

An important decrease in small pelagic fish condition and size has been observed in the most productive ecosystem of the Mediterranean Sea, the Gulf of Lions, since 2008, leading to an important fishery crisis. Previous studies suggested bottom-up control to be the most probable cause for these changes. Here, we investigate whether an environmental change might have caused such a situation. In the

This study provides the first comprehensive description of the Gulf of Cadiz (SW Spain) marine zooplankton community. To do this we compiled information from a number of surveys and monitoring programs carried out in the area over the last 14 years. Using this time-series of quarterly (3 times per year) resolution, we describe their general composition, spatio-temporal variability and relationship

Over the last decades, the western Arctic Ocean has undergone unprecedented environmental changes. However, long-term in situ observations of marine phytoplankton are still rare and therefore insufficient to fully characterize their evolutionary trends. This study investigated the diatom fluxes and composition in sediment trap material collected from the Northwind Ridge, western Arctic Ocean, from

This is the first study presents the patterns and environmental controls of benthic biomass size spectra, carbon demand, and production along the entire bathymetric gradient from the shelf to the abyssal depths in the transition zone between the northern North-Atlantic and the central Arctic Ocean. The material was collected at 17 stations (76-5561 m) in the eastern Fram Strait, in the vicinity of

Manipulative laboratory studies provide strong evidence that phytoplankton primary production (PP), stoichiometry, and taxonomic composition affect marine copepod production (CP), which is the biomass-dominant zooplankton group. However, field observations investigating the simultaneous effects of prey stoichiometric quality, PP, and phytoplankton and copepod taxonomic composition on CP remain relatively