The spatiotemporal distribution of sea ice in the cold Arctic region is of climatic and engineering significance. However, in terms of statistics, there remains a lack of quantitative mathematical descriptions of the annual periodic sea ice cycle for the entire Arctic and its regional seas. Using the semi-enclosed and seasonally ice-covered Kara Sea as a systematic case study, this quantitative study

We investigated diurnal-scale variations in the abundances of bacterioplankton, high and low nucleic acid (HNA, LNA) cells, and associated physico-chemical variables in a mangrove dominated estuary of the Indian Sundarbans, during pre-monsoon and monsoon conditions. Bacterioplankton abundance (BA) varying from 1.83 ± 0.47 to 0.34 ± 0.11 × 109 cells L−1 with lowest abundance during the monsoon, was

One interesting feature of the Portuguese man-of-war (Physalia physalis) is its dimorphism, with the existence of two distinct forms (left- and right-handed individuals). The worldwide distribution of this dimorphic wind-propelled siphonophore is a much discussed but poorly understood phenomenon. Here we investigate the most likely region of origin and routes of more than 3,500 individuals of this

The potentially toxic species Coolia monotis is widespread along the Mediterranean coasts. The Gulf of Gabès is one of the affected areas in the south-eastern part of the Mediterranean Sea. Coastal monitoring of such harmful species is needed for the management of Harmful Algal Blooms (HABs). Distribution patterns of C. monotis in relation to temperature and salinity were investigated at 24 monitoring

Mesoscale eddies are known to strongly influence oceanographic properties and biological responses. Since eddies can transport physical characteristics and biota, knowledge of their origin, pathways, and characteristics is important for understanding their potential impacts on ecosystems such as the Prince Edward Island (PEI) archipelago. Over a 26-year period (1993–2018), a total of 395 (724) cyclonic

Ammonia oxidation is an important part of the global nitrogen cycle. Ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) are important players in the ammoxidation process. In this study, 13 sediment samples from the Liaohe estuary were collected in the wet season. The abundances of 16S rRNA and amoA genes were detected by real-time fluorescence quantitative PCR. The diversity and community

The Yellow Sea Cold Water Mass (YSCWM) is a unique hydrological phenomenon in the central Yellow Sea, resulting in different macrobenthos community compositions inside and outside the YSCWM. However, this pattern in benthic microeukaryotes has never been identified by morphological methods and DNA sequencing. To determine whether microeukaryotes differ from macrobenthos in terms of regional geographical

This study uses ROMS (Regional Ocean Modeling System) with realistic forcing to analyse cross-shelf transport associated with the presence of mesoscale anticyclones as they interact with the western shelf of the Gulf of Mexico. Daily outputs from this validated 15-year numerical simulation were used to calculate the depth and time averaged cross-shelf volume transport through the 200 m isobath, used

The Bay of La Paz (BLPZ), located in the southwestern Gulf of California, is a region of significant biological productivity and strong environmental variability that remains to be understood. In particular, the spatial signature of different El Niño-Southern Oscillation (ENSO) conditions and their impact on the ecology of the bay remains puzzling because of contrasting field observations. In this

Phytoplankton size is a significant functional trait affecting many ecological processes and influencing the carbon fate and the trophic regimes of the ecosystems. In this study, we examined the effect of the lateral advection of nutrient-rich Messina Mixed Waters on the phytoplankton size structure and community composition in the euphotic layer of the Gulf of Augusta (Western Ionian Sea) in early

Time-series analysis of zooplankton species diversity, distribution, and abundance are essential for ecosystem assessment and fisheries management on continental shelves. This study analyzed two morphologically cryptic species of the calanoid copepod Pseudocalanus, P. moultoni and P. newmani, in zooplankton samples collected during May–June 1995–2012 over Georges Bank, NW Atlantic Ocean. Samples were

Several cyclonic (CE) and anticyclonic (ACE) eddies form in the Bay of Bengal (BoB) and they expect to contain different proportion of nutrients due to divergence and convergence of waters respectively and may have impact on phytoplankton composition. In order to test this hypothesis, one CE and two ACE (north ACE (ACEN) and south ACE (ACES)) were sampled in the BoB during spring intermonsoon. Higher

Radiolarians are planktonic protozoon that play an important role in marine ecosystem and paleoenvironmental construction. The South China Sea (SCS) and Malacca Strait (MLS), strongly influenced by the East Asian monsoon, are the key gateway between the Pacific and Indian Oceans. However, few studies of radiolarians in the water column are performed during winter and spring in the SCS and MLS due to

The coastal zone is a hotspot of biodiversity and anthropogenic activities. Its conservation is of major concern. To test whether different types of environmental disturbance have an impact on marine fishes, in this three-year study we have compared otolith shapes of Oblada melanura juveniles. One type of disturbance was the type of site: recreational harbours, waterway mouths, or preserved from identified

Based on mooring observations carried out in the southern Yellow Sea during late summer 2017, this study focuses on the characteristics of the internal tide-induced turbulent mixing and the influences on the vertical transport of nitrates. We observe clear semidiurnal pycnocline displacements with an amplitude of ~3.5 m during 25 h. The baroclinic velocity and velocity shear are mainly controlled by

The values of δ13C and δ15N in POM and nutrient concentrations were investigated in the surface water of Jiaozhou Bay during spring, summer and autumn. Results showed that eutrophic conditions were generally the highest in the northeastern bay during the three seasons. It suggested the sewage from urban rivers were the major pollution source in the northeastern Jiaozhou Bay. The δ13C value of POM was

Morphological evolution in tidally influenced estuarine channel networks has strong influence on the redistribution of fluvial discharge and tidal motion. Based on channel bathymetry and hydrological data observed in 2002 and 2016, this study investigated the influence of morphological evolution on subtidal flow division in the Yangtze River Delta. Experiments using a 2D hydrodynamic model revealed

The Nam Dinh Coast is a constituent part of the dynamic coastline, belonging to the Red River Delta. It is bounded to the north and south by the Red and Day Rivers, with Ninh Co and So Rivers located in the middle. This coast has been undergoing severe erosion during the last hundred years. Over this period, vital agricultural area along the coastline has vanished into the sea and families have been

A support vector machine (SVM) regression algorithm was developed for estimating the chlorophyll-a concentration (Cchla) in the turbid estuarine waters of the Pearl River estuary (PRE) based on visible infrared imaging radiometer suite (VIIRS) ocean color data. The proposed SVM algorithm outperformed the OC3 algorithm in the turbid waters. The temporal variation and spatial distribution of SVM-based

The performance of seven wind resources in simulating the significant wave height (Hs) for the Bohai, Yellow, and East China Seas (BYES) was evaluated with a numerical wave model (Simulating WAves Nearshore, SWAN) for the year 2016. The model outputs were carefully compared with coastal oceanic station data and altimeter observations. Most wind fields can deliver good wave simulations in our study

The present study demonstrates the usability of Satellite-Derived Bathymetry (SDB) to understand the geomorphological changes that have occurred in a coastal region located along Puducherry, India, where a beach restoration project was taken up in 2017 to arrest the shoreline erosion that is prevalent due to installation of hard structures. In the study, multi-temporal bathymetry data is generated

Determining the availability of suspension load, i.e. suspended particulate matter (SPM), in shallow marine tidal systems is necessary to estimate whether coastal lowlands may experience vertical accretion rates that keep pace with global sea level rise. In particular anthropogenic marshland areas are affected by limitations of SPM accumulation due to artificial structures such as dikes and revetments

Simultaneous time series of current velocity profiles are used to characterize flow structures over intermediate-depth coral ecosystems in the eastern Gulf of Mexico. Understanding of temporal variability and spatial coherence in flow is necessary to establish connectivity among these ecosystems. Time series were collected at Pulley Ridge (the westernmost site), Northern Dry Tortugas, and Southern

Copepod species assemblage and biomass were studied during a weekly time series done during an anomalously warm and low sea surface Chlorophyll-a concentration period 2014–2015, compared with 2002–2018, at Cabo Pulmo National Park, Gulf of California, Mexico. Forty-nine copepod species accounted for 64% of the total zooplankton abundance. Three small copepods (Oncaea venusta 12.6%, Paracalanus parvus

Tropical estuaries may release large amounts of carbon dioxide to the atmosphere, but remain understudied relative to temperate systems. Here, we investigate hydrological drivers of pCO2 along ~22 km of an aquatic continuum from the mountain river to the coastal ocean, including highly modified aquaculture and urban zones (Perancak Estuary, Ijo Gading River, Bali, Indonesia). We report seasonal spatial

The seasonal and interannual variability of chlorophyll a was studied between 2008 and 2016 in two coastal bays located in the northeastern limit of the Iberia/Canary upwelling ecosystem. The work aims (i) to understand if small latitudinal distances and/or coastline orientation can promote different chlorophyll a seasonal cycles; and (ii) to investigate if different meteorological and oceanographic

Seasonal nutrient dynamics regulated by hydrological and biological variables in the southern Yellow Sea (SYS) were studied based on the datasets collected during four cruises: spring (April 28-May 10, 2014), summer (August 17-September 22, 2015), autumn (November 7–17, 2014) and winter (January 13-February 1, 2016). In the present study, by dividing the study area into three distinct current-dominated

A coupled ocean-wave model was used to investigate residence times of the water masses on the Gulf of Lion shelf and their export routes during autumn 2010 and winter 2010–2011. Particular attention is paid to the Cap de Creus region and submarine canyon, a key site for the export of water from the Gulf of Lion shelf. First, model results were compared to numerous observations taken during the same

The dramatic marine environmental change seen today can be difficult to fully document and interpret without adequate, spatially and temporally comprehensive, baseline datasets of hydrographic properties. Here we present isotope data measured in water samples collected during a nine-day research cruise in October 2016 throughout the Gulf of Maine, a rapidly changing region of the world's oceans. A

In many mid-latitude coastal waters during winter months, in addition to temperature, the large change in biogeochemical processes often influence and complicate the surface partial pressure of CO2 (pCO2). Based on the hydrological and carbonate parameters in seven cruises, this study analysed the evolution process and explored the control mechanism of the surface pCO2 in Jiaozhou Bay, China, from

The multiple and complex N sources in coastal upwelling areas make it difficult to understand the behaviour of the N cycle. Stable N and O isotopes (δ15N and δ18O) of nitrate (NO3−) from coastal upwelling off eastern Hainan Island in the South China Sea (SCS) identified the main NO3− sources and the processes that control NO3− distribution in the area. Our results revealed that upwelling occurred in

To understand the modern sedimentation and land-sea interaction processes in the Sunda Shelf, we evaluated the rare earth element (REE) compositions, the total organic carbon (TOC) contents, grain sizes, and detrital minerals of 39 surface sediments, collected from the western Sunda Shelf. All of the sampled sediments are characterised by a higher content of light REEs (LREEs) relative to the content

Several anticyclonic (ACE) and cyclonic (CE) eddies constitute the circulation in the Bay of Bengal (BoB) and are associated with the downwelling and upwelling processes leading to oligotrophic and eutrophic conditions respectively. In this study, the nitrogen (N2) fixation rates and controlling factors are estimated through deck incubation experiments in the BoB using enriched N2 gas dissolution method

The present study addresses the copepods size structure in different phases of a cold-core eddy based on a 17 day time-series measurement (21st February to 8th March 2016) from a coastal site in the western Bay of Bengal during the Spring Intermonsoon (SIM). Copepod size measured using FlowCAM and microscope was converted into biovolumes. Based on the salinity and temperature in discrete depth layers

Estuarine fronts are the boundaries between different water masses at river mouths and play important roles in trapping suspended particles. Investigating the response of estuarine fronts to climate and sea-level changes during the Holocene could elucidate the evolution of complex hydro- and sediment-dynamic processes at river mouths. To assess the estuarine frontal dynamics of the Changjiang (Yangtze)

In the past several decades, anthropogenic changes throughout drainage basins have threatened physical, hydrological and ecological river-to-ocean continuum balances. Dams are one of these anthropogenic influences that can seriously affect sediment fluxes to the ocean. Here, we investigate the formation and dispersion of a high-concentration mud suspension (HCMS) at a river mouth due to a tailing dam

This work examines the seasonal thermohaline variability in the Gulf of Cádiz (SW Iberian Peninsula) based on 2009–2020 repeated hydrographic observations. Subsurface water types are assorted within the mixing triangle formed by Mediterranean and Eastern North Atlantic Central Waters (ENACW). A sharp interface between 400-500 m depth separates the saline Mediterranean Overflow Waters (MOW) from the

A survey along the coast of India (~1100 km stretch) between Benaulim (Goa) in the west coast and Thoothukudi (Tamil Nadu) in the east coast was conducted during summer 2014, to evaluate the mesozooplankton community structure. Zooplankton community was dominated by holoplanktonic forms representing 93.7% of the total zooplankton, while meroplanktonic forms constituted 6.3%. Zooplankton was generally

The rates of water exchange between coastal reef systems and the surrounding ocean are key physical drivers of water quality and reef ecosystems. It is generally assumed that water exiting a reef system through reef channels is predominantly replaced by ‘new’ water from offshore. However, exiting water may also recirculate back into the reef system reducing the rate of exchange between the reef and

Tidal sand ridges are large-scale bottom features that occur on continental shelves with strong tidal currents and abundance of sand. These ridges have longshore spacings of several kilometres, heights of tens of metres, they evolve on centennial time scales and their crests are cyclonically rotated with respect to the direction of the dominant tidal currents. The coupled Delft3D-SWAN numerical model

Past major changes in sea level have had a significant influence on global- and shelf sea tidal dynamics. Some of these changes are preserved in sedimentary records from the shelf seas, and so appropriate proxy data have the potential to constrain tidal model outputs over the recent geological past. Tidal models which simulate the evolution of tide-dependent parameters over geological timescales are

The radial sand ridges found off the coast of Jiangsu (China) are major morphological features in the southern Yellow Sea and undergo rapid changes in morphology. Despite extensive observational and modeling efforts, the physical processes controlling sediment transport and associated morphological evolution over the ridges remain not well understood. Here we analyzed data collected from systematic

Accurate representation of wind stress is important for modelling and predictions of marine environmental conditions. The effect of sea state on wind stress is usually parameterized by relating the equivalent sea surface roughness to the wave age or wave steepness. In this study, a new parameterization is presented for the dependences of sea surface roughness on the wind speed and sea state based on

Flocculation has a great influence on the biogeochemical cycle by altering the particle size, density and settling velocity of suspended particulate matter (SPM) from coastal to shelf sea areas. However, the flocculation process in the shelf sea areas of China has not been systematically studied. In this study, the influencing mechanism of the North Yellow Sea cold water mass (NYSCWM) on the distribution

In order to examine the role of eddies on total and size-fractionated primary production, two cyclonic (CE), one anticyclonic (ACE) and no-eddy (NE) regions were sampled in the BoB during pre-summer monsoon (June 2019). The upper ocean is strongly stratified due to freshwater discharge from major rivers. Low (high) nutrients concentrations were noticed in the ACE (CE) regions due to convergence (divergence)

Chlorophyll-a concentrations were recorded in three oceanographic surveys (GOMEX-4, GOMEX-5, GOMEX-6) during 2015–2018 throughout the Yucatan shelf, southeast Gulf of Mexico (GoM). Such campaigns encompassed the warm-phase, cold-phase, and neutral-phase of El Niño-Southern Oscillation (ENSO), respectively, as well as a progressively increasing upwelling intensification scenario. We undertook the analysis

Morphological evolution of large river deltas is highly vulnerable to extreme storm events due to insufficient sediment supply. As an abandoned delta lobe, the coasts along the northern Yellow River Delta (YRD) and Gudong Oil Field have recently suffered serious erosion due to extreme storm events and become increasingly vulnerable. In this study, a well validated and tested Delft 3D module by the

Coral reefs are ecosystems highly vulnerable to changes in seawater carbonate chemistry, including those related to the ocean acidification and global warming. Brazilian coral reefs contains the major area of reefs coverage in the Southwestern (SW) Atlantic Ocean, however, studies aimed at investigating the controls of seawater carbonate chemistry in coral reefs are still overlooked in Brazil. This

In this work, we present results of the first long-term oceanographic study of the mussel farm area in the brackish oligotrophic coastal waters off Sevastopol (Crimea, Black Sea). The long-term seasonal and annual variations of the thermohaline and main hydrochemical characteristics, their trends and probability distributions are reported. The significant trends are related to the regional climate

ADCP profiles near the sea bed, at a 130 m depth continental shelf, were used to estimate the mean veering of the velocity vectors using a complex correlation coefficient. An analytic expression for the veering vertical gradient (∂θ/∂z) as function of turbulent Ekman layer thickness (δE) was developed and, using constant eddy viscosity assumptions, sea bottom stress and additional turbulent boundary

The Iguape River estuary – located on the southern coast of São Paulo state (Brazil) – presents geomorphological records of the complex processes operating during the Late Holocene. Dating the top deposits of coastal (fluvial, transition and marine deposits) low terraces, contributes to the understanding of the erosive-depositional events resulting from autogenic and allogenic processes. Optically

It has been historically documented that deep, nutrient-rich, offshore slope waters that enter the Gulf of Maine through the Northeast Channel are the principal source of nutrients to the region. Silicate (Si(OH)4) and nitrate (NO3) in particular are potentially limiting nutrients for phytoplankton production. We examine here the extent to which nutrient variability in the region may be caused by internal

Riverine supply of largely terrestrial carbon is important to the carbon cycle chemistry of the oceans. Along a river-ocean continuum, sedimentary organic matter composition and distribution can provide insights to the balance of terrestrial input and in situ production of an estuary. In the Yangtze River estuary (YRE), this balance is especially important to understand as human impacts and climate

We examined the effect of mesoscale oceanographic conditions on the seasonal abundance and distribution patterns of chaetognaths, a major component of the zooplankton community in the northern Gulf of Mexico, with data collected in late spring (May/June) and summer (July) from 2015 to 2017. Overall, 13 chaetognath species from six genera were observed in the samples. Significant pairwise associations

To effectively manage anthropogenic stressors causing widespread and pervasive habitat change, resource managers and policy makers require advice on priority stressors to optimally target conservation and restoration outcomes. This is difficult in soft sediment ecosystems affected by multiple stressors operating across centuries with possible legacy interactions. Using tools from the emerging discipline

Downwelling-favorable winds modify the front structure of river plumes and are important for cross-shelf mass transport. To understand the adjustment process of river plume fronts in response to downwelling-favorable wind events, a series of generic numerical experiments were conducted. The adjustment of river plume fronts underwent three stages: destratification and restratification during the wind

Inter-relationships between physical ocean-atmosphere processes over the eastern Agulhas Bank are explored using data assimilation by the Hybrid Coordinate Ocean Model (HYCOM), which provides daily fields and time series off the south coast of South Africa (33.75–34.5S, 24.0–26.5E) in the period 2009–2017. Our objectives are: i) to describe and understand the sharp gradients over the shelf, ii) to

Salinization stands among the most prominent environmental hazards of the largest delta on Earth, the Bengal delta. It has significant impacts on the local societies and the economy. Using an unprecedented collection of in situ river salinity records over the Bengal delta, extending from the Hooghly estuary in the west to the Meghna estuary in the east, we report a sudden salinization of the central