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This study investigates the spatial variation of suspended sediment concentration (SSC) induced by Hangzhou Bay Bridge (HBB) in the coastal waters of the East China Sea. Based on Landsat Thematic Mapper (TM), Operational Land Imager (OLI) data and in-situ measurements, spectral characteristics of waters in Hangzhou Bay and SSC retrieved from near infrared single band have been analyzed. The results revealed significant difference of SSC in the water on two sides of HBB. SSC increases downstream of the bridge under conditions of low turbidity (SSC < 300 mg l −1 ) upstream water, while SSC decreases when high turbidity water (SSC > 400 mg l −1 ) upstream. This study shows that the interaction of bridge piers and currents has important influences on SSC distribution by inducing hydrodynamic factors and by changing suspended sediment transport. Remotely sensed data with high spatial resolution as TM and OLI can be applied to investigate SSC variations induced by a bridge in the bay area. [ABSTRACT FROM AUTHOR]

This study examines changes in the local oceanographic and atmospheric conditions over the southern Bay of Bengal and adjacent Indian Ocean waters after the 2004 Indian Ocean tsunami based on satellite remote sensing data and atmospheric reanalysis fields. After the tsunami that occurred on 26 December 2004, the accumulated rainfall had a notably increase (600 mm per month) in January of 2005 over deep waters to the southeast of Sri Lanka. This rainfall increase after the tsunami was accompanied with cooling in the sea surface temperature (SST) (up to −2 °C). Four-day averaged SST anomalies had a noticeable increase (1-4 °C) after the tsunami over the deep waters to the southwest of the epicenter. Series of ocean atmospheric and biological variables changed successively after the change of SST. The chain of causality between the tsunami and the changes in the local atmospheric conditions is suggested. [ABSTRACT FROM AUTHOR]

Abstract: It is well known that tropical cyclones can cause upwelling, decrease of sea surface temperature, increase of chlorophyll-a (Chl-a) concentration and enhancement of primary production. But little is known about the response of dissolved oxygen (DO) concentration to a typhoon in the open ocean. This paper investigates the impact of a typhoon on DO concentration and related ecological parameters using in situ and remote sensing data. The in situ data were collected 1week after the passage of the super-typhoon Nanmadol in the northern South China Sea in 2011. An increase in DO concentration, accompanied by a decrease in water temperature and an increase in salinity and Chl-a concentration, was measured at sampling stations close to the typhoon track. At these stations, maximum DO concentration was found at a depth of around 5m and maximum Chl-a concentration at depths between 50 and 75m. The layer of high DO concentration extends from the surface to a depth of 35m and the concentrations stay almost constant down to this depth. Due to the passage of the typhoon, also a large sea level anomaly (21.6cm) and a high value of Ekman pumping velocity (4.0×10−4 ms−1) are observed, indicating upwelling phenomenon. At the same time, also intrusion of Kuroshio waters in the form of a loop current into the South China Sea (SCS) was observed. We attribute the increase of DO concentration after the passage of the typhoon to three effects: (1) entrainment of oxygen from the air into the upper water layer and strong vertical mixing of the water body due to the typhoon winds, (2) upwelling of cold nutrient-rich water which stimulates photosynthesis of phytoplankton and thus the generation of oxygen, which also increases the DO concentration due to cold water since the solubility of oxygen increase with decreasing water temperature, and, possibly, (3) transport of DO enriched waters from the Western Pacific to the SCS via the intrusion of Kuroshio waters. [Copyright &y& Elsevier]

Temporal variations of chlorophyll a (Chl a) concentration before and after the Montara oil spill in August 2009 in the Timor Sea were analysed using MODIS-derived Chl a data. Time series data suggested a decrease in Chl a concentration following the oil spill, but an increase occurring in May 2010. A 4000 km2 patchy phytoplankton bloom with a high concentration of 13.8 mg m−3 occurred southeast of the platform, which coincided with the location the residual oil spill finally moved to. The Chl a was usually high in that area in May, but reached a peak in May 2010: the monthly Chl a for May 2010 was one and a half times higher than that of the average value for May between 2003 and 2009. The present study also analysed as many as 15 cases of major marine oil spills in the world and discussed their impacts on phytoplankton. The results suggested that the increase of Chl a may have relations with the oil spill incident. Natural seasonal variability is also an important factor for the formation of the phytoplankton bloom. [ABSTRACT FROM PUBLISHER]

Abstract: Phytoplankton blooms appear in winter (Nov–Jan) in the southwest of Luzon Strait, South China Sea, which is an oligotrophic region in general. To understand dynamic features of the winter phytoplankton bloom southwest of Luzon Strait, this study analyzes seven years (2000–2006) of remote sensing data of Chlorophyll a, sea surface temperature, and ocean vector winds, along with in situ observations of dissolved oxygen, nutrients (nitrate, phosphate, and silicate), and physical oceanographic parameters mixed layer depth, Ekman pumping velocity, and entrainment velocity. The results demonstrate that the winter phytoplankton bloom in the southwest of Luzon Strait is primarily induced by both Ekman pumping-driven upwelling (observed at about 50m under sea surface) and upper mixed layer entrainment. The area of winter phytoplankton blooms is about 2.58×104 km2, based on Empirical Orthogonal Function analysis. The seasonal variability of the bloom is associated with monsoonal wind forcing. [ABSTRACT FROM AUTHOR]

Abstract: The effects of rainfall and wind speed on the dynamics of suspended sediment concentration (SSC), during the 2004 Indian Ocean tsunami, were analyzed using spatial statistical models. The results showed a positive effect of wind speed on SSC, and inconsistent effects (positive and negative) of rainfall on SSC. The effects of wind speed and rainfall on SSC weakened immediately around the tsunami, indicating tsunami-caused floods and earthquake-induced shaking may have suddenly disturbed the ocean–atmosphere interaction processes, and thus weakened the effects of wind speed and rainfall on SSC. Wind speed and rainfall increased markedly, and reached their maximum values immediately after the tsunami week. Rainfall at this particular week exceeded twice the average for the same period over the previous 4years. The tsunami-affected air–sea interactions may have increased both wind speed and rainfall immediately after the tsunami week, which directly lead to the variations in SSC. [Copyright &y& Elsevier]

Abstract: The Sumatra tsunami on 26 December, 2004 in the Indian Ocean was generated by one of the largest earthquakes of the past 100 years. The present study investigated spatial and temporal changes of suspended sediment concentration (SSC) in North-East Indian Ocean (NEIO) after the Sumatra tsunami used satellite remote sensing data. The nLw551 products of MODIS-aqua data (using as indexing SSC) were analyzed for 5 years (2002–2006). Result shows SSC notably increased (55.6–200%) in large river estuaries along coast of the Bay of Bengal (BOB) in a short time (4 weeks) after the tsunami, especially the northwest coast of Indonesia, southeast coast of Myanmar, as well as the north offshore of BOB. Those increases were mainly caused by the re-suspension function induced by the initial surge of the tsunami. Monthly analysis indicates increases (4.26%) of SSC of the entire North-East Indian Ocean area in 2005; especially in November 2005 when increase of SSC increased by about 6.19% compared with other years; those may mainly be caused by the destruction of coastal vegetation and modifying of estuaries or wetlands by the 2004 tsunami. The increases of SSC have different mechanism in different region and period after the tsunami. [Copyright &y& Elsevier]

Bivalve shell fossils, cemented by authigenic carbonates, are widely spread in the Haima cold seep, Qiongdongnan Basin of the South China Sea (SCS). In this study, we examined an element profile of Gigantidas platifrons in the Haima cold seeps at a water depth of 1 381 m. Based on the scanning electron microscope (SEM) analyses, the prismatic layer and nacreous layer were identified, which are characterized by prismatic structure and stratified structure, respectively. In addition, the profile can be subdivided into two parts: altered and unaltered zones. Laser inductively coupled plasma mass spectrometry (LA-ICP-MS) mapping shows that the element concentrations of the altered zones were influenced by the authigenic carbonate rocks, whereas the element concentrations of unaltered zones remain stable. In-situ X-ray diffraction (XRD) analyses show that the mineral constituent of the nacreous layer is mainly composed of aragonite. Along with the growth profile, Mg/Ca ratios of unaltered zones have minor variations, ranging 0.72–0.97 mmol/mol (mean=0.87 mmol/mol), with estimated temperatures of 3.8–4.1 °C, indicating that the temperature of the surrounding seawater remains constant and agree with the measured data of 3.9 °C which was conducted by a conductivity-temperature-depth system (CTD). The minor variations of Ba/Ca ratios (0.01–0.06 mmol/mol; mean=0.04 mmol/mol) indicate a relatively stabilized salinity of the surrounding seawater. S/Ca ratios show large variations of 0.04–4.15 mmol/mol (mean=1.37 mmol/mol). S/Ca ratios have regular variations which generally correspond to the variations of the Mg/Ca ratios, highlighting that the S/Ca ratios of bivalve shells show the potential to reflect the growth rate of the Gigantides. However, further studies should be carried out on the understanding of the links between the S/Ca ratios and seepage intensity of cold-seep fluids. [ABSTRACT FROM AUTHOR]

New evidences provided that the tropical cyclone (TC) Linfa in 2015 induced looping path of Kuroshio invasion into the northeastern South China Sea (NESCS) through the northwestern Luzon Strait (LS), based on the in-situ measurements, satellite data and model output data. This TC-enhanced Kuroshio invasion with low nutrients and denser waters suppressed the TC "Wind Pump" induced upwelling and nutrients uptake, and therefore inhibited the Chlorophyll a concentration (Chl-a) increase from surface to ~50 m in the open ocean of the NESCS. The TC-induced Kuroshio invasion promoted the generation of the strong cyclonic eddy to its left side where weak Ekman Pumping Velocity was observed. This enhancing cyclonic eddy then dominated the nutrients uplift and increased the surface and subsurface (0–50 m) Chl-a through eddy pumping rather than Ekman Pumping. The TC-declined anti-cyclonic eddy, which shoaled the Mixed Layer Depth (MLD), benefited to the nutrient uptake through TC-induced upwelling and thereby increased the surface Chl-a and raised the Chl-a Maximum Layer (CML) to ~20 m over the southwestern LS. The temporal Chl-a variations were also influenced by TC intensities and biochemical processes. The air-sea heat budget analysis indicated that, the air-sea heat exchange contributed to nearly 80% of the sea surface cooling (SST cooling) over the northwestern LS with Kuroshio invasion, while eddy-induced upwelling dominated the SST cooling over the western LS, and the wind-driven upwelling (and mixing) controlled the SST cooling over the southwestern LS. These different formations of SST cooling then played important role in Chl-a variations. This study is the first case of TC "Wind Pump" induced Chl-a variations considering air-sea heat exchange, Kuroshio invasion and mesoscale eddies over LS, which would help to evaluate the influence of TCs over the other major heat transport arteries of the world ocean: The Gulf Stream area. Unlabelled Image • TC "Wind Pump" enhanced Kuroshio invasion which then inhibited the surface Chl-a. • Eddy-induced upwelling dominated Chl-a increase rather than wind-driven upwelling. • TC-enhanced Kuroshio invasion reduced a cyclonic eddy which right on its way. • TC-enhanced Kuroshio conduced to a cyclonic eddy generation in its left side. • Air-sea heat exchange dominated SST cooling which then inhibited Chl-a increase. [ABSTRACT FROM AUTHOR]

The water temperature at 100–300 m depth layer impact on bigeye tuna distribution has been studied from data collected by 15 fishery survey vessels, surveying every day, in the Equatorial Pacific Ocean from February to March and June to September 2010. The in situ ocean temperature measurements at four depths (100, 150, 200, and 300 m), satellite data and TAO/TRITON moored buoy data were also augmented in this study. The results reveal stereoscopic temperature factors for the prediction of tuna fishing ground: horizontal temperature gradient (HTG), vertical temperature gradient (VTG) in the 100–300 m layer. Maximal catches were observed where (1) vertically there has a strong subsurface temperature front in the 150–200 m layer, with horizontal temperature gradient up to near 0.020 °C/km; (2) there have vertical temperature gradient between −0.088 and −0.066 °C/m. Meanwhile, the monthly tuna fishery catches decrease with the synchronized reduction of 20 °C isotherm depth in the ocean. [ABSTRACT FROM AUTHOR]

The Luzon Strait (LS) is a key region for estimating carbon sources and sinks in the South China Sea (SCS) and is highly influenced by the Kuroshio Current (KC) and typhoons. Understanding the variations in the sea surface partial pressure of carbon dioxide (pCO2-sw) under the combined effects of typhoons and KC in this region is crucial for estimating local and regional changes in ocean carbon flux. Based on valuable in situ pCO2-sw and remote sensing data, this study aimed to reveal the temporal variations and the physical mechanisms of pCO2-sw variations under the comprehensive effects of both typhoons and Kuroshio Intrusion (KI) in the LS. One week after the passage of the tropical cyclone (TC) Nanmadol, the concentration in the pCO2-sw and the influencing mechanisms varied in three different regions (W1–W3) on Transect A (120°E). In the region dominated by SCS waters (W1), the average pCO2-sw increased by 5.1 μatm after TC, which was mainly due to the TC "Wind Pump" inducing strong vertical mixing, which brought dissolved inorganic carbon (DIC)-rich deeper water up to the surface. In the region affected by KC (W2 and W3), pCO2-sw decreased after the TC (−8.2 μatm and −1.8 μatm, respectively) with TC-enhanced KI because the invasion of lower pCO2-sw of Kuroshio waters inhibited the TC-induced upwelling. More significant TC-induced upwelling (W3) would alleviate the decrease in pCO2-sw caused by the TC-enhanced KI. This study is a rare case providing a better understanding of the variations in pCO2-sw under TC-enhanced KI, which provides support for regional climate change prediction and carbon flux estimation in the western boundary current regions. [ABSTRACT FROM AUTHOR]

Most previous studies confirmed that marine phytoplankton biomass can increased dramatically and then formed blooms along the typhoon track after typhoon passage. However, many events of no significant responses to typhoons were neglected. In order to figure out the most important factor for bloom formation, a coupled physical-biogeochemical model was used to study the biogeochemical phytoplankton responses to all 79 typhoon events that affected the South China Sea (SCS) during 2000–2009. The major factors investigated included typhoon intensity and translation speed, Chlorophyll a concentration (Chl-a) and vertical nitrate transport in the euphotic zone before and after typhoon passage. The results revealed that phytoplankton blooms were triggered after 43 typhoon events, but no significant blooms were found after 36 other typhoons. Of the 43 typhoon events that triggered blooms, 24 were in the open ocean and 19 were on the coast. Subsurface blooms were detected after five typhoon events that did not trigger surface blooms. Over half of the typhoons that affect the oligotrophic SCS can trigger phytoplankton blooms, and contribute to the marine primary productivity. The mechanism of the above results were surveyed, we found that (1) an increased nitrate concentration is the basic and key precondition for phytoplankton blooming in the oligotrophic SCS; (2) typhoon intensity, and translation speed control the upward flux of nitrates together, and translation speed has more effect than intensity; (3) uplifted nitrates could trigger phytoplankton bloom, and Chl-a levels reached a peak 3 days later than nitrate levels; (4) mesoscale eddies and the nutricline depth before a typhoon’s arrival also affects bloom genesis; and (5) the composition of phytoplankton functional groups in the coast was adjusted by typhoon, which have more complex mechanism of bloom formation than that in the open ocean. In summary, the physical driving force that modulates blooms is vertical nutrient transportation in the SCS. [ABSTRACT FROM AUTHOR]

To dampen periodic off-levelling motions within an inertial platform while undergoing horizontal accelerations of the same period and to achieve a levelling accuracy of a few tens of arcseconds with that system, an internally damped inertial platform for a marine scalar gravity system was the developed. Methods for attenuating horizontal acceleration and reducing off-levelling error by a satisfactory gyro-levelling loop, which are fundamental to the internally damped inertial platform, were designed and implemented. In addition, phase delays are introduced by the levelling loop. The resulting off-levelling gravity errors were analyzed and modeled. A series of tests on a motion simulator were performed in laboratory for a variety of simulated sea conditions. We found that the motion of the platform is a function of the amplitude and period of the simulated ship motions and ranges between 10 and 40 arcseconds. In addition, the phase lag between platform motion and ship motion is not constant but ranges 180°–270°, depending on the period and amplitude of the motion. Then, the platform, on which a gravimeter was mounted, was installed on the R/V Shiyan 2 to conduct a gravity survey in the South China Sea. Despite rough sea conditions, it was shown that in short periods of 2–30 s, the off-levelling angle was less than 30 arcseconds, and the phase lagged the horizontal acceleration by 230°–260°. From a repeated survey line and intersecting survey points, the estimated errors of gravity measurements were between 1.3 and 1.7 mGal. The marine measurements results were compared with those of satellite altimetry data and show a mean value of 0.5 mGal in a standard deviation of 1.5 mGal. [ABSTRACT FROM AUTHOR]

A new gravity sensor based on electromagnetic damping for the JMGrav marine gravimeter is presented. The new gravity sensor considered the advanced construction methods of the electromagnetic damping system of the gravimeter. The design features of the new system are discussed and the research survey data in the South China Sea are shown. Numerical simulations are applied to model the magnetic and mechanical characteristics of the system using finite element analysis and to evaluate the force distribution and the resulting damping effects. The performance characteristics of the system were tested on a motion simulator in laboratory, and the gravimeter was subjected to vertical accelerations of up to 100 Gal in 1–1 000 s. It was found that the amplitude reduction of vertical accelerations in 3–15 s is 30–45 dB, with a time lag of 2–5 s, while the effect on gravity in period greater than 600 s is less than 0.5 dB, with a time lag of less than 100 s. The accelerations cause discrepancies of approximately only 1 mGal between the static value and the mean dynamic value. The sea tests were conducted in September 2020. Gravity measurements were taken with a JMGrav marine gravimeter onboard the R/V Dongfanghong 3, and the effective survey line exceeded 2 000 km. Completely irregular accelerations with peaks up to 100 Gal yielded a reduction of approximately 40 dB in amplitude. The survey data were evaluated using ocean gravity field models and grid line tests. The results show that the accuracy of the gravity measurements is better than 2 mGal. [ABSTRACT FROM AUTHOR]

This study analyzes the pH of surface-sediment porewater (i.e. 2–3 cm below the water-sediment interface), and concentrations of CaCO 3 and organic carbon (OC) in 1192 sediment cores from the northern South China Sea, in water depths ranging from 137 to 3702 m. This is the first study in the literature to analyze the large-scale spatial variability of deep-water surface-sediment pH over a large ocean basin. The data showed strong spatial variations in pH. The lowest pH values (<7.3) were observed south of Hainan Island, an area that is affected by summer upwelling and freshwater runoff from the Pearl and Red Rivers. Moderately low pH values (generally 7.3–7.5) occurred in two other areas: a submarine canyon, where sediments originated partly from the Pearl River and correspond to a paleo-delta front during the last glacial period; and southwest of Taiwan Island, where waters are affected by the northern branch of the Kuroshio intrusion current (KIC) and runoff from Taiwan rivers. The surface sediments with the highest pH (⩾7.5, and up to 8.3) were located in a fourth area, which corresponded to the western branch of the KIC where sediments have been intensively eroded by bottom currents. The pH of surface-sediment porewater was significantly linearly related to water depth, bottom-water temperature, and CaCO 3 concentration ( p < 0.05 for the whole sampling area). This study shows that the pH of surface-sediment porewater can be sensitive to characteristics of the overlying water column, and suggests that it will respond to global warming as changes in surface-ocean temperature and pH progressively reach deeper waters. [ABSTRACT FROM AUTHOR]

Purpose: The efficacy of routine antibiotic prophylaxis for prevention of surgical site infection (SSI) after elective inguinal hernia repair with a mesh patch remains uncertain. The authors of a recent Cochrane meta-analysis based on 17 randomized trials were unable to draw a definitive conclusion on this subject. The purpose of this study was to determine the effectiveness of prophylactic antibiotics for prevention of SSI after elective inguinal hernia repair with mesh and the risk factors for SSI. Methods: All low-risk patients who underwent elective inguinal hernia repair with mesh at our institution between 2010 and 2015 were enrolled in this study, with the exception of patients with recurrent hernias or immunosuppressive diseases. All patients received a single intravenous (i.v.) injection of cefuroxime (1.5 g) within 2 h prior to surgery at the discretion of the surgeon. SSI was defined using criteria of the Centers for Disease Control and Prevention. The variables which could influence the rate of SSI were analyzed by multivariate analysis to determine the independent risk factors for SSI. Results: Among the 605 patients who underwent elective inguinal hernia repair with mesh during the study period, 553 were eligible for enrolment in the study. Of these, 331 received a single dose of cefuroxime preoperatively. The overall SSI rate was 5.4 %; 9.4 % of those patients who did not receive preoperative antibiotic prophylaxis developed SSI versus 2.8 % of those who did receive prophylaxis ( P = 0.001). All infections were superficial. Factors independently associated with SSI were advanced age, smoking and preoperative stay. Conclusions: The incidence of SSI among low-risk patients who did and did not receive preoperative antibiotic prophylaxis after elective inguinal hernia repair with mesh differed significantly, particularly among patients of advanced age, smokers and patients with a prolonged preoperative stay in the hospital. [ABSTRACT FROM AUTHOR]

Hydrodynamic responses of the northern South China Sea (nSCS) to Typhoon Linfa in 2009 are examined using observations and model results. A shelf circulation model based on the Regional Ocean Modelling System (ROMS-nSCS) is used in quantifying the important physical processes affecting the storm-induced changes in circulation and hydrography in the upper ocean during Linfa. The ROMS-nSCS is forced by atmospheric forcing taken from the Climate Forecast System Reanalysis (CFSR). A parametric vortex is inserted into the CFSR atmospheric forcing to improve winds and sea-level air pressures associated with Linfa. The lateral open boundary condition of ROMS-nSCS is specified based on the global ocean circulation reanalysis produced by the Hybrid Coordinate Ocean Model (HYCOM). The simulated upper ocean circulation produced by ROMS-nSCS is characterized by strong wind-driven currents over the area affected directly by Linfa and intense near-inertial oscillations (NIOs) in the wake of Linfa. The simulated cooling in the wake of the storm is biased to the right of the storm track and agrees well with satellite-derived analysis data. The simulated NIOs also have significant rightward biases. The rotary spectral analysis of model currents demonstrates that the peak frequency f p of NIOs is about 9% greater than the local inertial frequency, which can be explained mostly by the vorticity of the background circulation. Analysis of model results also reveal that different dynamics are responsible for storm-induced cooling at different stages of Linfa. In the early development stage of Linfa, the cooling in the wake of the storm is affected mostly by the storm-induced advection in the vertical. In the mature stage of Linfa, the cooling in the wake of the storm is dominated by the joint effect of the storm-induced mixing and advection. Storm-induced warming occurs outside the wake of Linfa, due to downwelling generated by the storm. • Storm-induced changes in circulation and temperature during Typhoon Linfa were studied. • Both storm-induced upwelling and vertical mixing play important roles for cooling in the wake of Linfa. • Storm-induced cooling and near-inertial oscillations during Linfa are affected by background flow. [ABSTRACT FROM AUTHOR]

Fishery resources along China’s coasts have been declining. Could those decline be alleviated by deploying artificial reefs (ARs) in suitable areas? This study investigates effects of a big project conducted in December 2007 that deployed ARs in the southwestern part of Daya Bay. The ARs cover a total dimension of 966.10 × 2850.60 m 2 and surface area of 91,500 m 2 . This study analyzed the spatial and temporal variations of ecological factors, including Chlorophyll a concentrations (Chl-a), nutrients, attaching organisms and nekton resources, on and around the ARs using both satellite (Moderate Resolution Imaging Spectroradiometer, MODIS) and in situ data. Results showed that the potential affected area of ARs in Daya Bay reached a distance of 4.9 km in the water depth of 12.0–15.2 m. In the study area, Chl-a level reached 2.93 mg m −2 during the post-AR period (2008–2012), that was higher than the pre-AR period (2002–2007) (2.37 mg m −2 ). Nekton biomass increased by 4.66–16.22 times compared with that in the pre-AR survey, and the species diversity increased by 15%–23%. This parallel trend suggested that ARs might have contribution to the increase in nekton biomass. Long-term observations shall be conducted to understand the response of phytoplankton to ARs. [ABSTRACT FROM AUTHOR]

Identifying the spatial distribution of species and their relationship with environmental factors is crucial for conservation and management efforts. In Pakistan, jellyfish are economically significant and serves as an important fishery resource. This study utilized both in-situ and satellite data to investigate the relationship between fish catch and sea surface temperature (SST) gradient magnitude (GM). Notably, an unusually high subsurface Chlorophyll a (Chl-a) level (∼1.5 mg/m3) was observed, significantly higher than surrounding waters (∼0.5 mgm−3). Additionally, on October 27 at station 6, a high SST GM of 0.097 °C km−1 was recorded alongside an elevated subsurface Chl-a of 1.24 mg/m3. Low salinity levels (<36.2 psμ) were detected in areas with strong frontal activity, while higher levels (>36.7 psμ) were observed in the surrounding regions. Moreover, a high wind stress curl (>0.4 N/m3) was noted in regions with strong SST fronts along coastal and offshore areas of Balochistan and Sindh. A strong correlation (R2 = 0.987) was identified between annual fish catch and catch per unit effort (CPUE). The study revealed a significant fish catch (>200 kg) along the Balochistan coast and the Indus River estuary, with the exception of one offshore catch station. Results also indicated a strong correlated (R2 = 0.73, p < 0.001) between SST GM and fish catch in the upper layer (<50 m depth). By establishing a GM threshold at 0.06 °C km−1, there was an 80% likelihood of achieving a high catch within the upper 50 m layer. These findings enhance our understanding of how SST fronts influence the spatial distribution of jellyfish and improve our ability to forecast jellyfish fishing grounds in the northern Arabian Sea. • This study used in-situ and satellite data to examine the relationship between fish catch and SST gradient magnitude. • Strong correlation (R2 =0.73, p < 0.001) between SST gradient magnitude and catch in upper 50 m. • A threshold of 0.06 °C km⁻1 resulted in 80% likelihood of achieving a high catch within the upper 50 m depth. [ABSTRACT FROM AUTHOR]

High spatial resolution bathymetric maps of coral reefs can show the details of terrain. However, most satellite-based imagery with a spatial resolution < 10 m has only three visible bands and one near-infrared (NIR) band. When in situ bathymetric data are unavailable, it is difficult to map bathymetry from high spatial resolution imagery with spectral matching or empirical models for clear or turbid waters. In this study, we developed a downscaled bathymetric mapping approach (DBMA) that uses the water depth estimated from multitemporal Landsat-8 data to calibrate the empirical model for high spatial resolution imagery (e.g., Sentinel-2A/B, GaoFen-1/2, ZiYuan-3, and WorldView-2) in the absence of in situ bathymetric data. Our results show that DBMA provides high accuracy for depth ranging from 0 to 12 m for clear waters (0 m to 5 m for turbid waters), with a root mean squared error (RMSE) smaller than 2 m. Relative to empirical models (calibrated with in situ data), DBMA underestimates water depth more for depth >12 m for clear waters (5 m for turbid waters) while slightly overestimates more for depth < 4 m for clear waters (3 m for turbid waters). Nevertheless, DBMA performs better than the empirical models for depth between 4 m and 12 m for clear waters (3 m and 5 m for turbid waters). Furthermore, the good performance of DBMA is also demonstrated by the finding that the scaling effect on the DBMA is limited. DBMA presents a reliable solution to obtain high spatial resolution bathymetric maps without leaving out small regions in the absence of in situ data. [ABSTRACT FROM AUTHOR]

The solubility feature of redox electrolyte is a key factor to influence the performance of salt removal in redox flow electrode capacitive deionization. Herein, a novel redox flow desalination using ionic liquid (IL) as the eco-friendly solvent is proposed, i.e., 1-ethyl-3-methylimidazolium acetate. The high salt removal rate of 4.82 μg·min−1·cm−2 was obtained at the current density of 11 mA·cm−2. The low energy consumption of 254.12 kJ·mol−1 was achievable in IL, compared with 466.3 kJ·mol−1 in aqueous solution and 317.86 kJ·mol−1 ethanol. In addition, a long-term test with 11 cycles was conducted, and the real seawater was desalinated to a freshwater standard in batch mode. This work is significant for development of low-energy consumption in redox flow desalination via the usage of novel ionic liquids as solvent. An ionic liquid redox flow desalination device is proposed with the excellent solubility of redox couples, low energy consumption, high removal rate, long-term stability, and environment friendliness. [Display omitted] • A novel redox desalination system using ionic liquid (IL) as the eco-friendly solvent is proposed. • The energy consumption in IL-based FCDI system is significantly reduced. • Ionic liquid showed environmental friendliness and excellent stability as FCDI solvent. • Seawater is desalinated to freshwater. [ABSTRACT FROM AUTHOR]

• Couping brine desalination with Li+ extraction from spent LiFePO 4. • The residual energy of spent LiFePO 4 enables the regeneration of redox species. • Continuous desalination over 24 h yields freshwater. • 70.46 % lithium recovery is achievable from spent LiFePO 4. • Economic analysis compared with conventional battery recycling methods. Electrochemical redox flow desalination is an emerging method to obtain freshwater; however, the costly requirement for continuously supplying and regenerating redox species limits their practical applications. Recycling of spent lithium-ion batteries is a growing challenge for their sustainable utilization. Existing battery recycling methods often involve massive secondary pollution. Here, we demonstrate a redox flow system to couple redox flow desalination with lithium recovery from spent lithium-ion batteries. The spontaneous reaction between a battery cathode material (LiFePO 4) and ferricyanide enables the continuous regeneration of the redox species required for desalination. Several critical operating parameters are optimized, including current density, the concentrations of redox species, salt concentrations of brine, and the amounts of added LiFePO 4. With the addition of 0.5920 g of spent LiFePO 4 in five consecutive batches, the system can operate over 24 h, achieving 70.46 % lithium recovery in the form of LiCl aqueous solution at the concentration of 6.716 g·L−1. Simultaneously, the brine (25 mL, 10000 ppm NaCl) was desalinated to freshwater. Detailed cost analysis shows that this redox flow system could generate a revenue of ¥ 13.66 per kg of processed spent lithium-ion batteries with low energy consumption (0.77 MJ kg−1) and few greenhouse gas emissions indicating excellent economic and environmental benefits over existing lithium-ion battery recycling technologies, such as pyrometallurgical and hydrometallurgical methods. This work opens a new approach to holistically addressing water and energy challenges to achieve sustainable development. [Display omitted] [ABSTRACT FROM AUTHOR]

We investigated the impact of the Ningbo North Dyke (NND) built in 2012–2014 in the coastal waterway of East China Sea on local suspended sediment concentration (SSC). Several multi-spectral satellite images acquired by the Landsat Thematic Mapper (TM)/Operational Land Imager (OLI) in 2008–2017 were used. We analyzed the change of SSC and spectral curves of study area around small NND (the NND's total length less than 1 km) using a prior model proposed in our previous study. We found that SSC near NND in the Meishan Waterway decreased after the NND construction by 200–300 mg/l, so that clean blue water is now observed in the Meishan Waterway, apparently thanks to stable dynamic environment in presence of NND. Our results reveal the impact of a small coastal dyke with length less than 1 km on the movement and distribution of SSC from a remote-sensing perspective. [ABSTRACT FROM AUTHOR]