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 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

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 comparison

In many mid-latitude coastal waters during winter months, in addition to temperature, the large change in biogeochemical processes often influence and complex 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 December

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 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

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 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

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

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

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

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

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

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

Accurate representation of wind stress is important for modelling and predictions of marine environmental conditions, particularly under extreme weather events. The effect of sea state on the wind stress is usually parameterized by relating the equivalent sea surface roughness to the wave age or wave steepness. In this study, we present a new parameterization for the dependence of sea surface roughness

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)

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

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 variations of these parameters are determined mainly by

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

Estuaries of large Siberian rivers, Yenisei and Ob, play a pivotal role in transformation and sedimentation of the suspended matter from the riverine runoff. The mesozooplankton community is one of the key players in estuarine functioning. Most of the studies in the Yenisei region were performed at the end of the productive season (August–September) and concentrated on the structure of zooplankton

The franciscana (Pontoporia blainvillei) is a coastal dolphin endemic to the south-western Atlantic Ocean. Incidental captures in fishing gillnets are the greatest conservation concern for this species. The present study examines the biophysical interactions between the franciscana prey composition and the marine environment. The feeding regime of franciscana was investigated from stomach contents

Cross-shore and alongshore velocities were measured over five high tide cycles in the swash and inner surf zones of a dissipative beach (significant wave height between 0.5 and 1.65 m; water levels between 0 and 0.87 m) using acoustic and electromagnetic current meters. Measurements are used to determine the importance of alongshore motions relative to cross-shore motions for bed shear stress; a parameter

In the western Pacific Ocean, the Kuroshio cross-shelf intrusion and the shelf circulation are vital components of the coastal environment. However, the key dynamic factors driving them remained unclear. Our model and theoretical analysis show that wind stress over the open Pacific Ocean east of Japan drives a net equatorward water flux of 2.2 Sv, and this flux sets up a south-north sea surface drop

Coastal lagoons and marshes are among the most fluctuating and productive ecosystems in the world, which provide a wide range of ecosystem. The objective of this work was to evaluate the factors and processes that condition the hydrogeochemical dynamics in salt marshes associated with the development of small coastal lagoons located at the southern end of the outer estuary of the Rio de la Plata, where

Several problems related with coastal flooding depend on tidal levels, rise in sea level induced by meteorological effects and their nonlinear interaction. The latter is particularly meaningful in coastal lagoons and estuaries since it is strongly dependent on shallow water processes. This work aims to understand the role of tide-surge interaction in local inundation patterns of Ria de Aveiro lagoon

Normal incidence echo data (bottom reflection) can provide acoustic reflectivity estimates for seabed classification and predicting sediment properties with the use of seabed sediment models. However, the accuracy of normal-incident reflection coefficients significantly affects the geoacoustic inversion result. In this study, a multi-core platform with an acoustic recording system, which can perform

Suspended cohesive sediments form aggregates or ‘flocs’ and are often closely associated with carbon, nutrients, pathogens and pollutants, which makes understanding their composition, transport and fate highly desirable. Accurate prediction of floc behaviour requires the quantification of 3-dimensional (3D) properties (size, shape and internal structure) that span several scales (i.e. nanometre [nm]

An analysis is presented of hydrographic and nutrient data collected over three years for the Kangaroo Island upwelling region, Lincoln Shelf, South Australia, to determine the signature of upwelled water, depth of upwelling and the source water mass being brought onto the shelf. Strong upwelling seasons were recorded during the 2007–2008 and 2009–2010 summers, while the summer of 2008–2009 had only

In situ thermohaline variables measured monthly or bimonthly in the shallow northern Adriatic at prescribed stations between 1979 and 2017 were correlated with the local (river runoff, precipitation, net heat flux) and remote atmospheric (various hemispheric and regional indices) and oceanic (the Adriatic-Ionian Bimodal Oscillating System, BiOS) drivers acting on monthly to annual timescales. The highest

Large freshwater pulses to coastal ecosystems change local hydrologic regimes and alter biogeochemical processes. The Mississippi Bight coastal ecosystem, located in the northern Gulf of Mexico shelf, is influenced by extensive freshwater inputs: the Mississippi River (MSR) and several smaller rivers to the east. Under river flood conditions, MSR waters flow through the Bonnet Carré Spillway (BCS)

The Tōhoku earthquake and tsunami that struck on 11 March 2011 caused 22 fuel tanks around Kesennuma Bay in northern Japan to collapse. A sediment-contact-type fluorescence spectroscopy system was developed to observe the coastal distribution of polycyclic aromatic hydrocarbons (PAHs) deposited on the seafloor. A fluorescence maximum value of a sediment sample collected at Kesennuma Bay was considered

Organic-rich sediments of the southernmost Chilean Pacific coast and its fjord system constitute an important component of the global marine carbon budget. Sediment records from Trampa and Caribe bays and Churruca fjord in the western Magellan fjord system have been analyzed with the goal of understanding the factors controlling carbon accumulation and its regional fluctuation throughout the Holocene

Post-war marine munition dumpsites do exist and are acknowledged by authorities, but their real extent and their effect onto the environment are mostly unknown. Military historic reconstruction and ocean current data (from in-situ measurements and modelled data) indicate that the German dumpsite in the Baltic Sea ‘Kolberger Heide’ is an active environment with a huge content of discarded munition material

Bacterial pathogens in coastal sediments may pose a health risk to users of beaches. Although recent work shows that beach sands harbor both indicator bacteria and potential pathogens, it is not known how deep within beach sands the organisms may persist nor if they may be exposed during natural physical processes. In this study, sand cores of approximately 1 m depth were collected at three sites across

In situ observations and a coupled bio-physical model were used to study the germination, initiation, and development of the Gulf of Maine (GOM) Alexandrium fundyense bloom in 2006. Hydrographic measurements and comparisons with GOM climatology indicate that 2006 was a year with normal coastal water temperature, salinity, current and river runoff conditions. A. fundyense cyst abundance in bottom sediments

Two-hundred and twenty seven satellite-tracked drifters were deployed in the Gulf of Maine (GoM) from 1988 to 2007, primarily during spring and summer. The archive of tracks includes over 100,000 kilometers logged thus far. Statistics such as transit times, mean velocities, response to wind events, and preferred pathways are compiled for various areas of the coastal GoM. We compare Lagrangian flow

Field observations of flow and sediment transport in a tributary channel through intertidal mudflats indicate that suspended sediment was closely linked to advection and dispersion of a tidal salinity front. During calm weather when tidal forcing was dominant, high concentrations of suspended sediment advected up the mudflat channel in the narrow region between salty water from San Francisco Bay and