Beach groynes are structures for erosion protection along sandy coasts near inlets and can reduce the coastal erosion substantially,but open groynes cannot stop erosion completely because sand can be removed from the ...Beach groynes are structures for erosion protection along sandy coasts near inlets and can reduce the coastal erosion substantially,but open groynes cannot stop erosion completely because sand can be removed from the groyne compartments by cross-shore processes.Beach groynes should be designed with sufficient bypassing of sand to minimise erosion.Regular beach maintenance is required to keep a sufficient beach width for recreational purposes.The effectiveness of groyne compartments can be significantly improved by using T-head groynes or by using a submerged sill or breakwater in between the groynes.An economic evaluation shows that the beach maintenance costs over 50 years may be substantially higher than the construction costs of a submerged breakwater.An important parameter to be studied is the longshore transport,which requires detailed information of the wave climate,preferably based on measured data(offshore buoys)in combination with deep water wave modelling.Various models have been used to determine the net longshore sand transport and coastline changes.The design of groynes to reduce coastal erosion is illustrated by three field cases(Atlantic coast near Soulac,France;Lagos coast,Nigeria and Black Sea coast,Romania).These example cases show that beach groynes are effective structures,but sufficient bypassing of longshore sand transport is essential to minimise erosion.Regular beach fills in the groyne compartments may be required at high-energy(exposed)coasts.A submerged or emerged breakwater can be built between the groynes to protect the beach in the groyne compartments against erosion by cross-shore processes.展开更多
With the increasing high-risk factors in a changing world,building a resilient marine economy is becoming increasingly essential for sustainable coastal governance.This study aimed to assess the resilience of marine e...With the increasing high-risk factors in a changing world,building a resilient marine economy is becoming increasingly essential for sustainable coastal governance.This study aimed to assess the resilience of marine ecological-economic systems(MEES)using a multi-level approach.Using Chinese coastal regions as an example,we first developed a conceptual framework to establish the indicators for measuring the resilience of MEES.Subsequently,the study introduced the projection pursuit model,coupling coordination model,and correlation network analysis to unpack the system complexities of resilience development at different levels.The results revealed that the resilience of MEES has expanded nearly twice over the last decade,which is largely attributed to the implementation of a national strategy for building maritime power.Spatial disparities in resilience have increasingly become obvious,with developed regions commonly achieving higher resilience levels while less developed regions present inadequate resilience growth because of a lack of robustness and recoverability.In addition,the coordination of the resilience dimensions has shifted from mild disorder to primary coordination.The resilience indicators related to technological inputs had higher network centralities and significantly affected the dynamics of MEES resilience.The study’s findings provide useful implications for guiding policy arrangements and planning practices in the Chinese coastal regions.展开更多
Humans have always engaged with their surroundings and the ecology in which they live.However,during the industrial age,this contact has been more intense and has had a substantial impact on environment and ecosystems...Humans have always engaged with their surroundings and the ecology in which they live.However,during the industrial age,this contact has been more intense and has had a substantial impact on environment and ecosystems.For example,overexploitation of natural resources,mining,pollution,and deforestation are all elements that negatively affect biodiversity and natural resources.Few studies have been conducted to evaluate the damage caused,despite the significant uncontrolled pressure from human activity.However,maintaining its environment is essential to the survival of coastal fishing.Goal:This study’s goal was to evaluate how human activity affected Tabounsou’s coastal ecology in order to suggest remedial actions for sustainable management.The following was the methodological approach used:executive consultation and archival analysis;stakeholder survey(locals,farmers,salt producers,fishers,and loggers);inventory of species;anthropogenic activity inventory;evaluation of how human activity affects aquatic life in the research region;suggestion and action for sustainable management;Outcome:Executive consultation indicated that the main issues are:construction projects that reduce the estuary’s surface area;agricultural practices such as woodcutting and salt farming;the rise in resource exploitation;noncompliance with fisheries laws;and the catching of young fish.Eighty-three percent of fisherman ditch their nets on the coast after using them,but only seventeen percent burn them.With a 75%frequency rate,the same survey indicates that most fisherman fish around the coast.In the Tabounsou area,according to loggers’survey,68%of the wood cut is Rhizophora,24%is Avicennia,and 8%is Laguncularia.Three fish stocks,representing nine families and nine species,were identified by the species inventory.At 18%and 15%,respectively,the actors most frequently capture the species Pseudotolithus elongatus and Arius parkii.According to a poll of 30 farmers,90%of them apply fertilizer to their soil,while only 10%do not.During the dry season,salt is grown.According to two actors,Bougna Toro Toro produces 100 kg of salt per day,followed by Khoumawadé,which produces 80 kg,and Toumbibougni,which produces 70 kg.展开更多
This study provides an in-depth exploration of seaweed biodiversity in Nigeria’s coastal waters, a largely unexplored area for marine resources. There is a dearth of sufficient data on seaweed biodiversity in Nigeria...This study provides an in-depth exploration of seaweed biodiversity in Nigeria’s coastal waters, a largely unexplored area for marine resources. There is a dearth of sufficient data on seaweed biodiversity in Nigeria. The research aimed to assess the diversity and distribution of seaweeds in this region. Seaweed samples were collected by hand, using scrapers, at low tide from four stations identified by local fisherfolk and commercial divers. These samples were analyzed in the laboratory for species identification. A total of 39 seaweed taxa were identified, with Rhodophyta (red algae) being the most abundant (74%), followed by Chlorophyta (green algae) (21%) and Heterokontophyta (brown algae) (5%). The highest biomass species included Grateloupia sp., Chaetomorpha antennina, Gracilaria sp., Ceratodictyon variabile, Cladophora sp., Gelidium pusillum, Ulva sp., Blidingia minima, and Caloglossa leprieurii. Species abundance was highest on breakwater rocks and on the bodies of anchored or sunken vessels, while sandy beaches exhibited lower abundance. The findings reveal significant potential for Nigeria’s seaweed in aquaculture, climate change mitigation, and biotechnology. The study recommends further molecular research, expansion of sampling areas, and the development of sustainable seaweed cultivation practices to support Nigeria’s blue economy.展开更多
The purpose of this study was to examine the knowledge,attitude,motivation and behavior of the community before and after the experiment,and also to determine the effect of the experiment on increasing knowledge,attit...The purpose of this study was to examine the knowledge,attitude,motivation and behavior of the community before and after the experiment,and also to determine the effect of the experiment on increasing knowledge,attitude,motivation,and behavior related to the construction of family toilets in coastal areas.The study was conducted in Pangkep and Maros Regencies.Atotal of 50 heads of families were selected as participants using the purposive sampling method.25 participants became the experimental group and 25 people became the control group.The research variables included knowledge,attitudes,motivation,and behavior of the community in building family toilets before and after the experiment.Data collection through tests,questionnaires,and observations to each participant.The research instruments were knowledge tests,questionnaires,and observations.Data analysis used descriptive and inferential statistical analysis,with the t-test.The results of the study showed that based on the experiment,knowledge had a significant effect with a correlation coefficient of 0.94,attitudes had an effect of 0.91,motivation was 0.756,and behavior was 0.865.It can be concluded that the construction of family toilets in the coastal areas of Pangkep and Maros Regencies,before the experiment,the knowledge,attitudes,motivation,and behavior of the community were in the low category,and after the experiment increased significantly to the high category. In addition, the results of the analysis showed that the experiment had a significant effect on increasing theknowledge, attitudes, motivation, and behavior of the community towards the construction of family toilets in coastal areas.展开更多
Arsenic(As)pollution in coastal wetlands has been receiving growing attention.However,the exact mechanism of As mobility driven by tidal action is still not completely understood.The results reveal that lower total As...Arsenic(As)pollution in coastal wetlands has been receiving growing attention.However,the exact mechanism of As mobility driven by tidal action is still not completely understood.The results reveal that lower total As concentrations in solution were observed in the flood-ebb treatment(FE),with the highest concentration being 7.1μg/L,and As(V)was the predominant species.However,elevated levels of total As in solution were found in the flooded treatment(FL),with a maximum value of 14.5μg/L after 30 days,and As(III)was the predominant form.The results of dissolved organicmatter(DOM)suggest that in the early to mid-stages of the incubation,fulvic acid-like substances might be utilized by microorganisms as electron donors or shuttle bodies,facilitating the reductive release of As/Fe from sediments.Both flood-ebb and flooded treatments promoted the transformation of crystalline iron hydrous oxides-bound As into residual forms.However,prolonged flooded conditions more readily facilitated the formation of specific adsorption forms of As and the reduction of crystalline iron hydrous oxides-bound As,increasing As mobility.In addition,the flood-ebb tides have been found to increase the diversity ofmicrobial populations.The main microbial genera in the flood-ebb treatment included Salinimicrobium,Erythrobacter,Yangia,Sulfitobacter,and Marinobacter.Bacillus,Psychrobacter,and Yangia showed a significant correlation with As(V).In flooded treatment,Bacillus,Pseudomonas,and Geothermobacter played a major role in the reduction and release of As.This study significantly contributes to the current understanding of how As behaves in diverse natural environments.展开更多
Chlorophyll a(Chl a)is a key photosynthetic pigment and an essential indicator of phytoplankton biomass.Accurate Chl a measurements are crucial for understanding marine biogeochemical processes.China launched the Chin...Chlorophyll a(Chl a)is a key photosynthetic pigment and an essential indicator of phytoplankton biomass.Accurate Chl a measurements are crucial for understanding marine biogeochemical processes.China launched the Chinese Ocean Color and Temperature Scanner(COCTS)aboard the HY-1D satellite in 2020,yet its Chl a products require further validation in complex coastal waters.This study assesses HY-1D Chl a products in the Bohai and Yellow Seas,two optically complex coastal regions,using in situ data collected during multiple cruises.Additionally,we compare HY-1D Chl a products with those from the Moderate Resolution Imaging Spectroradiometer(MODIS)and the Visible Infrared Imaging Radiometer Suite(VIIRS).We observed that although Chl a products from HY-1D are generally consistent with those from the MODIS and VIIRS in spatial distribution,there are still significant errors when compared with in situ data.Therefore,we developed a new blended algorithm to improve the accuracy of HY-1D Chl a products.The algorithm distinguishes between turbid and relatively clean waters using a classification index based on the ratio of remote sensing reflectance(R_(rs)(λ)).After the initial classification,we developed targeted algorithms based on the optical properties of different water bodies.The new model shows a significant improvement,reducing the mean absolute percentage error(MAPE)from 43.1%to 24.3%.Additionally,merging Chl a data from HY-1D,MODIS,and VIIRS maintains good accuracy,with HY-1D Chl a products significantly enhancing data coverage and robustness.This research provides important support for producing high-quality HY-1D Chl a products for coastal waters.展开更多
Coasts are subject to multiple natural hazards,which are increasing nowadays.Coastal flooding and erosion are some of the most common hazards affecting coastlines.Being aware of the vulnerability of coasts is importan...Coasts are subject to multiple natural hazards,which are increasing nowadays.Coastal flooding and erosion are some of the most common hazards affecting coastlines.Being aware of the vulnerability of coasts is important to achieve integrated coastal management.The coastal vulnerability index(CVI)is a common index used to assess coastal vulnerability because it is easily calculated.However,given that its calculation includes numerous manual steps,it requires considerable time,which is often unavailable,to produce accurate and utilizable results.In this work,we developed a ModelBuilder model by using the tools provided by ArcGIS Pro(ESRI).Through this model,we automatized most of the steps involved in CVI calculation.We applied the ModelBuilder model in the northern Peloponnese,for which the CVI has already been calculated in three other works.We were thus able to assess the effectiveness of our ModelBuilder model.Our results demonstrated that through the ModelBuilder,most of the processes could effectively be automatized without problems,and our results are consistent with the findings of previous works in our study area.展开更多
PM_(2.5) and black carbon(BC)are important air pollutants impacting radiation balance,air quality,health,and ecosystems.Ozone(O_(3))levels are increasing despite decreases in other pollutants,posing a challenge for po...PM_(2.5) and black carbon(BC)are important air pollutants impacting radiation balance,air quality,health,and ecosystems.Ozone(O_(3))levels are increasing despite decreases in other pollutants,posing a challenge for pollution control,especially in coastal cities like Zhoushan,where the monsoonal climate can exacerbate PM_(2.5) and ozone pollution.This study conducted continuous online measurements of major atmospheric pollutants in Zhoushan,Zhejiang Province,in 2020.The results indicate that the highest contribution from local air masses in Zhoushan is observed in spring,accounting for 17.7%,while the greatest average contribution from northern Zhejiang Province,Jiangsu Province,and Shanghai occurs in winter,at 18.5%.Pollutant concentrationswere seasonally variable,with PM_(2.5),BC,and sulfur dioxide concentrations 56.6%,36%,and 58.2%higher in the cold season compared to the warm season.The O_(3) in spring is approximately 50%higher than that in summer.Ship emissions significantly contributed to BC,nitrogen oxides(NO_(x)),and carbon monoxide in Zhoushan.In spring,PM_(2.5) sources included photochemical processes and northern air mass transport,while in winter,PM_(2.5) was due to regional transport.The inhibitory effect of PM_(2.5) on O_(3) formation in the Zhoushan area is relatively weak.Reducing NO_(x) emissions may increase O_(3),emphasizing the need for volatile organic compounds monitoring and regional control measures to improve air quality and ensure sustainable development in Zhoushan.展开更多
Coastal Bangladesh is highly vulnerable to various impacts of climate change,including rising temperatures,unpredictable precipitation,cyclones,droughts,and saltwater intrusion.These factors collectively threaten agri...Coastal Bangladesh is highly vulnerable to various impacts of climate change,including rising temperatures,unpredictable precipitation,cyclones,droughts,and saltwater intrusion.These factors collectively threaten agricultural productivity and food security.This study examines the relationship between farmers’perceptions and observable climatic trends,with a focus on the sustainability of food systems and the promotion of adaptable farming techniques in Bagerhat District,Bangladesh.A mixed-methods strategy was employed,incorporating household surveys(a total of 110 purposively selected farmers),focus group discussions,key informant interviews,and climatic data analysis.The Mann-Kendall test,Sen’s slope estimator,precipitation concentration index(PCI),and standardized rainfall anomaly index(SRAI)were employed to analyze climate trends from 1991 to 2020.The findings showed that more than 70.00%of respondents indicated that summers were becoming warmer,over 50.00%reported that winters were becoming colder,and 63.00%stated that yearly precipitation was decreasing.Farmers reported an increase in flood occurrences and a decline in the predictability of precipitation.Between 2011 and 2019,the output of most rice varieties decreased,with the exception of high-yielding Aman rice and hybrid Boro rice.The results also showed that 60.00%of respondents reported experiencing salinity intrusion,and 57.00%attributed significant yield losses to salinity.Planting salt-tolerant rice varieties(such as BRRI Dhan 67 and Binadhan-10),practicing homestead vegetable cultivation,and moderately integrating shrimp aquaculture were also common adaptive measures.To improve long-term food security in coastal Bangladesh,we suggest growing more salt-tolerant crop varieties,promoting vertical and homestead gardening,enhancing seed systems that are resilient to climate change,and educating farmers on the use of climate-smart farming methods.This study highlights the importance of aligning farmers’perceptions with observed climatic data to design effective adaptation strategies.The findings of this study can guide policy-makers and development practitioners in strengthening climate-resilient agriculture and ensuring long-term food security in coastal Bangladesh.展开更多
Saltmarsh is one of the blue carbon ecosystems for the highest carbon burial efficiency.However,the buried carbon in saltmarsh may still be exported to coastal water through porewater exchange,a process that has often...Saltmarsh is one of the blue carbon ecosystems for the highest carbon burial efficiency.However,the buried carbon in saltmarsh may still be exported to coastal water through porewater exchange,a process that has often been overlooked in previous studies.A typical tidal creek of the Dongtan saltmarsh wetland in Chongming Island,Shanghai,China,was studied.The224Ra and223Ra activities were measured and the hydrological parameters such as water flow were determined,from which the porewater exchange rate in the tidal creek was estimated to be 1.78±1.73 cm/d.Meanwhile,the carbon concentrations in porewater were determined,based on which the fluxes of dissolved inorganic carbon(DIC),dissolved organic carbon(DOC),CH_(4),and CO_(2)exported from porewater exchange were derived to be 60±17,6.6±4.0,0.082±0.079,and 16±11 mmol/(m^(2)·d),respectively.In addition,analysis on different species of carbon in the creek water showed that,the fluxes of DIC,DOC,CH_(4),and CO_(2)exported laterally from tidal creek to coastal sea were 58±14,7.6±2.3,0.0011±0.00063,and 1.5±0.68 mmol/(m^(2)·d),respectively,indicating that the porewater exchange-derived carbon fluxes accounted for a large portion of the lateral carbon outwelling,and even much higher than those in CH_(4)and CO_(2)fluxes.Furthermore,the carbon exported from porewater exchange accounted for 50%of the carbon burial in the tidal creek system,of which DIC accounted for 73%of the total carbon flux transported by porewater exchange.Therefore,this study indicated that the porewater exchange-derived carbon fluxes to the tidal creek water may cause an overestimation in the carbon sequestration capacity of saltmarsh wetlands,and revealed the importance of porewater exchange for the carbon cycle of tidal creek system of saltmarsh wetlands.展开更多
Shrimp farming is a major global aquaculture activity;however,its social and ecological impacts raise sustainability concerns.While previous research has focused on isolated social or environmental aspects of sustaina...Shrimp farming is a major global aquaculture activity;however,its social and ecological impacts raise sustainability concerns.While previous research has focused on isolated social or environmental aspects of sustainability in shrimp farming,integrated assessments of these factors using a social-ecological systems(SES)approach are rare.A framework for assessing the sustainability of shrimp farming-comprising a set of social and ecological indicators-is developed and conceptualized in this study for the first time,using an integrated,interdisciplinary,and empirical SES approach.We first identified key social and ecological indicators and developed a conceptual framework based on SES approach,then surveyed 90 shrimp farms across 3 coastal regions(including Satkhira,Bagerhat,and Cox’s Bazar districts)in Bangladesh.Nearly all farmers in Satkhira(97%)and all in Bagerhat(100%)expressed dissatisfaction with the decreasing pattern of shrimp production and profitability over the last decade.In contrast,nearly all respondents in Cox’s Bazar(97%)reported satisfaction with increasing shrimp production.Except in Cox’s Bazar,equity in labor payment remained a concern for the social sustainability of the shrimp farming system.The changing pattern of shrimp production and profitability,which does not ensure equity,poses a threat to the sustainability of shrimp farming.Most of the surveyed farmers recognized the mutual benefits of mangrove forests and shrimp farming(97%in Satkhira and 77%in Cox’s Bazar),which suggests potential for the development of policy on integrated mangrove-shrimp farming with community-based management.This research could help assess the sustainability of the shrimp farming system and contribute to achieving Sustainable Development Goals 2(zero hunger)and 8(decent work and economic growth).By examining existing practices and developing a novel framework,this study highlights informed decision-making and guides methodological discussion on assessing the sustainability of shrimp farming using the SES approach in coastal regions and different aquaculture systems worldwide.展开更多
Marine biological activity has long been recognized to impact the atmospheric chemistry of coastal areas.In this work,we monitored the seasonal variation of carbonyl compounds in the coastal city of Qingdao,located in...Marine biological activity has long been recognized to impact the atmospheric chemistry of coastal areas.In this work,we monitored the seasonal variation of carbonyl compounds in the coastal city of Qingdao,located in the north of China’s coastline and the south of Jiaodong Peninsula,with the vast hinterland in the west.The mean total concentration of the 15 carbonyls varied significantly between seasons,with the highest observed in autumn(10.2±6.2 ppbv),followed by spring(9.0±3.0 ppbv),winter(6.4±4.0 ppbv)and summer(3.4±1.4 ppbv).Using bivariate analysis,the agricultural emissions from inland areas were responsible for the high levels of carbonyls in the autumn.In summer,clean and humid sea winds helped reduce the concentration of carbonyls,but they also brought air masses from vegetation,and marine organisms,which contributed to high levels of carbonyls in the spring of coastal areas.The observation-based chemistry box model found that the forma-tion of formaldehyde and acetaldehyde was primarily controlled by the RO+O2 reaction,and alkenes oxidation was the main contributing factor.Based on the OH radical loss rate(LOH)and ozone formation potential(OFP)calculation,we found that autumn and spring seasons have significantly higher values of LOH and OFP than winter and summer due to the presence of high concentrations of carbonyl compounds.Therefore,it is believed that these carbonyl compounds primarily originate from agricultural activities,and marine air influences the atmospheric chemistry of the coastal areas.展开更多
Land-sea coordination is a crucial strategy for ensuring the sustainable and rapid development of coastal cities.Assessing the level of land-sea coordination is vital for understanding the degree of coordination and i...Land-sea coordination is a crucial strategy for ensuring the sustainable and rapid development of coastal cities.Assessing the level of land-sea coordination is vital for understanding the degree of coordination and identifying imbalances within land-sea systems.However,empirical research in this area remains scarce,necessitating further investigation.Using coastline,land use,and socio-economic data for the Taizhou coastal zone of China across seven time periods from 1990 to 2021,this study analyzed the spatiotemporal characteristics of coastal zone development intensity,developed a comprehensive evaluation model for land-sea coordination,and examined its evolutionary dynamics.The results indicated a substantial rise in development intensity within the Taizhou coastal zone,accompanied by significant alterations in coastline morphology and structure.These changes included a marked reduction in the extent of natural coastline and a corresponding expansion of artificial coastline.The intensity of coastal land use also increased,primarily driven by the expansion of built-up areas and aquaculture ponds.The development level of land-sea systems,as well as the overall coordination of the Taizhou land-sea system,demonstrated a consistent upward trend,advancing from basic to intermediate coordination.These findings provide actionable insights for enhancing land-sea coordination strategies to support the sustainable development of coastal cities.展开更多
Protoporphyrin Ⅸ(PPⅨ), a basic porphyrin system found in nature, all “porphyrin-type”tetrapyrroles with a biological function are biosynthetically derived thereof. PPⅨ is a metalloprosthetic group of numerous pro...Protoporphyrin Ⅸ(PPⅨ), a basic porphyrin system found in nature, all “porphyrin-type”tetrapyrroles with a biological function are biosynthetically derived thereof. PPⅨ is a metalloprosthetic group of numerous proteins involved in diverse metabolic and respiratory processes across all domains of life, and is thus considered essential for respiring organisms. Determining the biotic and abiotic factors that influence marine microbial growth and community structure is critical for understanding global biogeochemical cycles. Here,we present vertical profiles of intracellular PPⅨ and four derivative products(Chlorophylla/b and Pheophytin-a/b) from two coastal sediment cores, alongside ancillary geochemical and 16S rRNA microbial community data. Our findings indicated that PPⅨ is present in the natural sediment environment and displays a decreasing trend with depth, revealing a significant positive correlation with both organic matter and microbial abundance. Cooccurrence networks revealed that the environmental distribution of PPⅨ was positively correlated with the microbial porphyrin producer(high genetic completeness), but negatively correlated with auxotrophs(absence or low genetic completeness). It emphasized the critical role of PPⅨ as a biological molecule involved in key physiological processes. These results suggest that PPⅨ is a prominent component of the shared extracellular metabolite pool, especially in anoxic marine sediments where it exists at physiologically relevant concentrations for microbial metabolism. This study highlighted the significance of PPⅨ in microbial ecology and its potential impact on biogeochemical cycles in marine sedimentary environments.展开更多
This paper provides an overview of the recent advancements in magnetic structured triboelectric nanogenerators(MSTENGs)and their potential for energy harvesting and sensing in coastal bridge infrastructure.This paper ...This paper provides an overview of the recent advancements in magnetic structured triboelectric nanogenerators(MSTENGs)and their potential for energy harvesting and sensing in coastal bridge infrastructure.This paper begins with a brief discussion on the fundamental physics modes of triboelectric nanogenerators(TENGs),triboelectric series,and factors affecting TENG power generation and transmission,providing a foundation for the subsequent sections.The review focuses on the different types of MSTENGs and their applications in coastal infrastructure.Specifically,it covers magnetic spherical TENG networks,magnet-assisted TENGs,MSTENGs for bridges,and magnetic multilayer structures based on TENGs.The advantages and limitations of each type of MSTENG are discussed in detail,highlighting their respective suitability for different coastal bridge infrastructure applications.In addition,the paper addresses the challenges and provides insights into the future of MSTENGs.These include the need for improved durability and sustainability of MSTENGs in harsh coastal environments,increasing their power-output levels to fulfll high energy needs,and the requirement for collaborative efforts between academia,industry,and government institutions to optimize MSTENG performance.展开更多
Motivated by the wide applications of empirical global ocean tide models in Earth science,particularly in shallow waters and coastal regions,we proposed an updated global ocean tide model representing all major diurna...Motivated by the wide applications of empirical global ocean tide models in Earth science,particularly in shallow waters and coastal regions,we proposed an updated global ocean tide model representing all major diurnal and semidiurnal tidal constituents.We integrated the development technique of the Technical University of Denmark(DTU10)model and calculated the residual tides using the intermediary FES2012 model.We utilized all available Topex/Poseidon,Jason-1,Ocean Surface Topography Mission(OSTM)/Jason-2 primary and tandem missions to develop the new model.To reduce the discrepancies between the model and in situ measurements estimated S2 tide constituent,the ERA-Interim model was selected for dry tropospheric correction of altimetry data.The newly developed model with an improved spatial resolution from 1/8°×1/8°to 1/16°×1/16°was assessed and compared against contemporary global ocean tide models using in situ measurements in coastal regions,continental shelf waters,marginal seas,and deep waters.The results demonstrate improvements in shallow waters and coastal regions,particularly in representative coastal re-gions such as the Northwest European Shelf and East Asian Marginal Seas.Moreover,the model performs well in simulating S_(2) and K_(2) tides with root mean square differences of 0.355 and 0.234 cm,respectively,against in situ measurements in deep waters world-wide.Compared with that of DTU10,the root sum square of the new model for the eight main tidal constituents decrease by 8.4%to 0.997 cm.展开更多
Antarctic coastal polynyas play a vital role in atmosphere-ocean interactions and local ecosystems.This study investigates the interannual variability of springtime coastal polynyas over the Ross Sea based on satellit...Antarctic coastal polynyas play a vital role in atmosphere-ocean interactions and local ecosystems.This study investigates the interannual variability of springtime coastal polynyas over the Ross Sea based on satellite-retrieved sea-ice concentration(SIC)data from 1992 to 2021.Firstly,the springtime coastal polynya areas display large interannual variability as well as a positive trend of about 2000 km^(2)(10 yr)^(-1) over the 30 years.Secondly,based on composite analysis,in spring,we find that a deepened Amundsen Sea Low(ASL)induces stronger meridional winds over the eastern Ross Sea,leading to stronger sea-ice advection and expansion of coastal polynya areas.This is accompanied by more solar radiation absorption in early summer(about 16 W m^(2)),resulting in upper-ocean warming(~0.4℃)and significant sea-ice loss in late summer(~50%SIC).Additionally,the physical processes are validated by 500-year piControl simulations of a state-of-the-art Earth system model.Based on the same composite analysis,the results show that the sea-ice decline is consistent with the deepening of the ASL and the increase of the meridional sea-ice advection of the preceding spring,which is highly consistent with that of observations.This further confirms the circulations-polynyas-sea-ice physical linkages.Since the springtime ASL is strongly modulated by the tropical Pacific variability and the stratospheric polar vortex,changes in the polynya areas of the Ross Sea can be traced back to remote regions.展开更多
Texture analysis methods offer substantial advantages and potential in examining macro-topographic features of dunes.Despite these advantages,comprehensive approaches that integrate digital elevation model(DEM)with qu...Texture analysis methods offer substantial advantages and potential in examining macro-topographic features of dunes.Despite these advantages,comprehensive approaches that integrate digital elevation model(DEM)with quantitative texture features have not been fully developed.This study introduced an automatic classification framework for dunes that combines texture and topographic features and validated it through a typical coastal aeolian landform,namely,dunes in the Namib Desert.A three-stage approach was outlined:(1)segmentation of dune units was conducted using digital terrain analysis;(2)six texture features(angular second moment,contrast,correlation,variance,entropy,and inverse difference moment)were extracted from the gray-level co-occurrence matrix(GLCM)and subsequently quantified;and(3)texture–topographic indices were integrated into the random forest(RF)model for classification.The results show that the RF model fused with texture features can accurately identify dune morphological characteristics;through accuracy evaluation and remote sensing image verification,the overall accuracy reaches 78.0%(kappa coefficient=0.72),outperforming traditional spectral-based methods.In addition,spatial analysis reveals that coastal dunes exhibit complex texture patterns,with texture homogeneity being closely linked to dune-type transitions.Specifically,homogeneous textures correspond to simple and stable forms such as barchans,while heterogeneous textures are associated with complex or composite dunes.The complexity,periodicity,and directionality of texture features are highly consistent with the spatial distribution of dunes.Validation using high-resolution remote sensing imagery(Sentinel-2)further confirms that the method effectively clusters similar dunes and distinguishes different dune types.Additionally,the dune classification results have a good correspondence with changes in near-surface wind regimes.Overall,the findings suggest that texture features derived from DEM can accurately capture the dynamic characteristics of dune morphology,offering a novel approach for automatic dune classification.Compared with traditional methods,the developed approach facilitates large-scale and high-precision dune mapping while reducing the workload of manual interpretation,thus advancing research on aeolian geomorphology.展开更多
Enhanced weathering(EW)of ultramafi c rocks from the Muslim Bagh Ophiolite,Pakistan,has been studied in laboratory experiments to explore carbon sequestration as a climate change mitigation strategy for coastal and op...Enhanced weathering(EW)of ultramafi c rocks from the Muslim Bagh Ophiolite,Pakistan,has been studied in laboratory experiments to explore carbon sequestration as a climate change mitigation strategy for coastal and open sea environments.The research focused on a cost-eff ective ex situ experiment to examine the eff ects of EW reaction pathways arising from the interactions among rock powder,seawater and CO_(2).The experimental fi ltrates from diff erent milled peridotite samples exhibit a decrease in the Mg/Ca ratio as the specifi c surface area increases,which accelerates reaction rates.This suggests that the leached Mg from the original rock may have been consumed in the formation of brucite,serpentine and carbonates during EW.Similar reaction pathways are also responsible for the chemical alterations observed in amphibolite,albeit to varying degrees.On the other hand,the experimental residues showed an increase in loss on ignition compared to the original rock,indicating that EW has facilitated the incorporation of H 2 O and CO_(2) into secondary mineral structures through various reaction pathways,leading to the formation of brucite,serpentine and carbonates.Thermal gravimetric analysis of the experimental residues confi rms the presence of these minerals based on their decomposition temperatures.Additionally,XRD analysis identifi ed a range of carbonates in the residues of both peridotite and amphibolite samples,validating the occurrence of carbonation reactions.SEM images reveal textural changes in both samples,supporting the formation of secondary minerals through EW,consistent with observations from the petrographic study of untreated samples.Control experiments on CO_(2) absorption in seawater showed a decrease in pH,highlighting ocean acidifi cation from increased CO_(2) emissions.However,when rock powder was added to the seawater-CO_(2) mixture,the pH increased.This suggests that the EW of ultramafi c rock powders can sequester CO_(2) while raising seawater pH through the formation of secondary minerals.This research could serve as an analog for EW applications,considering the worldwide abundance of ultramafi c rocks and the availability of coastal and open ocean environments.However,further research is required to understand the behavior of other elements and their impacts on ocean chemistry in EW processes before applying CO_(2) sequestration strategies.展开更多
文摘Beach groynes are structures for erosion protection along sandy coasts near inlets and can reduce the coastal erosion substantially,but open groynes cannot stop erosion completely because sand can be removed from the groyne compartments by cross-shore processes.Beach groynes should be designed with sufficient bypassing of sand to minimise erosion.Regular beach maintenance is required to keep a sufficient beach width for recreational purposes.The effectiveness of groyne compartments can be significantly improved by using T-head groynes or by using a submerged sill or breakwater in between the groynes.An economic evaluation shows that the beach maintenance costs over 50 years may be substantially higher than the construction costs of a submerged breakwater.An important parameter to be studied is the longshore transport,which requires detailed information of the wave climate,preferably based on measured data(offshore buoys)in combination with deep water wave modelling.Various models have been used to determine the net longshore sand transport and coastline changes.The design of groynes to reduce coastal erosion is illustrated by three field cases(Atlantic coast near Soulac,France;Lagos coast,Nigeria and Black Sea coast,Romania).These example cases show that beach groynes are effective structures,but sufficient bypassing of longshore sand transport is essential to minimise erosion.Regular beach fills in the groyne compartments may be required at high-energy(exposed)coasts.A submerged or emerged breakwater can be built between the groynes to protect the beach in the groyne compartments against erosion by cross-shore processes.
基金supported by the National Social Science Foundation of China[Grant No.25CJY091].
文摘With the increasing high-risk factors in a changing world,building a resilient marine economy is becoming increasingly essential for sustainable coastal governance.This study aimed to assess the resilience of marine ecological-economic systems(MEES)using a multi-level approach.Using Chinese coastal regions as an example,we first developed a conceptual framework to establish the indicators for measuring the resilience of MEES.Subsequently,the study introduced the projection pursuit model,coupling coordination model,and correlation network analysis to unpack the system complexities of resilience development at different levels.The results revealed that the resilience of MEES has expanded nearly twice over the last decade,which is largely attributed to the implementation of a national strategy for building maritime power.Spatial disparities in resilience have increasingly become obvious,with developed regions commonly achieving higher resilience levels while less developed regions present inadequate resilience growth because of a lack of robustness and recoverability.In addition,the coordination of the resilience dimensions has shifted from mild disorder to primary coordination.The resilience indicators related to technological inputs had higher network centralities and significantly affected the dynamics of MEES resilience.The study’s findings provide useful implications for guiding policy arrangements and planning practices in the Chinese coastal regions.
文摘Humans have always engaged with their surroundings and the ecology in which they live.However,during the industrial age,this contact has been more intense and has had a substantial impact on environment and ecosystems.For example,overexploitation of natural resources,mining,pollution,and deforestation are all elements that negatively affect biodiversity and natural resources.Few studies have been conducted to evaluate the damage caused,despite the significant uncontrolled pressure from human activity.However,maintaining its environment is essential to the survival of coastal fishing.Goal:This study’s goal was to evaluate how human activity affected Tabounsou’s coastal ecology in order to suggest remedial actions for sustainable management.The following was the methodological approach used:executive consultation and archival analysis;stakeholder survey(locals,farmers,salt producers,fishers,and loggers);inventory of species;anthropogenic activity inventory;evaluation of how human activity affects aquatic life in the research region;suggestion and action for sustainable management;Outcome:Executive consultation indicated that the main issues are:construction projects that reduce the estuary’s surface area;agricultural practices such as woodcutting and salt farming;the rise in resource exploitation;noncompliance with fisheries laws;and the catching of young fish.Eighty-three percent of fisherman ditch their nets on the coast after using them,but only seventeen percent burn them.With a 75%frequency rate,the same survey indicates that most fisherman fish around the coast.In the Tabounsou area,according to loggers’survey,68%of the wood cut is Rhizophora,24%is Avicennia,and 8%is Laguncularia.Three fish stocks,representing nine families and nine species,were identified by the species inventory.At 18%and 15%,respectively,the actors most frequently capture the species Pseudotolithus elongatus and Arius parkii.According to a poll of 30 farmers,90%of them apply fertilizer to their soil,while only 10%do not.During the dry season,salt is grown.According to two actors,Bougna Toro Toro produces 100 kg of salt per day,followed by Khoumawadé,which produces 80 kg,and Toumbibougni,which produces 70 kg.
文摘This study provides an in-depth exploration of seaweed biodiversity in Nigeria’s coastal waters, a largely unexplored area for marine resources. There is a dearth of sufficient data on seaweed biodiversity in Nigeria. The research aimed to assess the diversity and distribution of seaweeds in this region. Seaweed samples were collected by hand, using scrapers, at low tide from four stations identified by local fisherfolk and commercial divers. These samples were analyzed in the laboratory for species identification. A total of 39 seaweed taxa were identified, with Rhodophyta (red algae) being the most abundant (74%), followed by Chlorophyta (green algae) (21%) and Heterokontophyta (brown algae) (5%). The highest biomass species included Grateloupia sp., Chaetomorpha antennina, Gracilaria sp., Ceratodictyon variabile, Cladophora sp., Gelidium pusillum, Ulva sp., Blidingia minima, and Caloglossa leprieurii. Species abundance was highest on breakwater rocks and on the bodies of anchored or sunken vessels, while sandy beaches exhibited lower abundance. The findings reveal significant potential for Nigeria’s seaweed in aquaculture, climate change mitigation, and biotechnology. The study recommends further molecular research, expansion of sampling areas, and the development of sustainable seaweed cultivation practices to support Nigeria’s blue economy.
文摘The purpose of this study was to examine the knowledge,attitude,motivation and behavior of the community before and after the experiment,and also to determine the effect of the experiment on increasing knowledge,attitude,motivation,and behavior related to the construction of family toilets in coastal areas.The study was conducted in Pangkep and Maros Regencies.Atotal of 50 heads of families were selected as participants using the purposive sampling method.25 participants became the experimental group and 25 people became the control group.The research variables included knowledge,attitudes,motivation,and behavior of the community in building family toilets before and after the experiment.Data collection through tests,questionnaires,and observations to each participant.The research instruments were knowledge tests,questionnaires,and observations.Data analysis used descriptive and inferential statistical analysis,with the t-test.The results of the study showed that based on the experiment,knowledge had a significant effect with a correlation coefficient of 0.94,attitudes had an effect of 0.91,motivation was 0.756,and behavior was 0.865.It can be concluded that the construction of family toilets in the coastal areas of Pangkep and Maros Regencies,before the experiment,the knowledge,attitudes,motivation,and behavior of the community were in the low category,and after the experiment increased significantly to the high category. In addition, the results of the analysis showed that the experiment had a significant effect on increasing theknowledge, attitudes, motivation, and behavior of the community towards the construction of family toilets in coastal areas.
基金supported by the National Natural Science Foundation of China(No.41977283)the Qing Lan Project of Jiangsu Province of China.
文摘Arsenic(As)pollution in coastal wetlands has been receiving growing attention.However,the exact mechanism of As mobility driven by tidal action is still not completely understood.The results reveal that lower total As concentrations in solution were observed in the flood-ebb treatment(FE),with the highest concentration being 7.1μg/L,and As(V)was the predominant species.However,elevated levels of total As in solution were found in the flooded treatment(FL),with a maximum value of 14.5μg/L after 30 days,and As(III)was the predominant form.The results of dissolved organicmatter(DOM)suggest that in the early to mid-stages of the incubation,fulvic acid-like substances might be utilized by microorganisms as electron donors or shuttle bodies,facilitating the reductive release of As/Fe from sediments.Both flood-ebb and flooded treatments promoted the transformation of crystalline iron hydrous oxides-bound As into residual forms.However,prolonged flooded conditions more readily facilitated the formation of specific adsorption forms of As and the reduction of crystalline iron hydrous oxides-bound As,increasing As mobility.In addition,the flood-ebb tides have been found to increase the diversity ofmicrobial populations.The main microbial genera in the flood-ebb treatment included Salinimicrobium,Erythrobacter,Yangia,Sulfitobacter,and Marinobacter.Bacillus,Psychrobacter,and Yangia showed a significant correlation with As(V).In flooded treatment,Bacillus,Pseudomonas,and Geothermobacter played a major role in the reduction and release of As.This study significantly contributes to the current understanding of how As behaves in diverse natural environments.
基金The National Key Research and Development Program of China under contract No.2021YFB3901304the National Natural Science Foundation of China under contract No.42842176181,42476173,and 42176179the Natural Science Foundation of Jiangsu Province under contract No.BK20211289.
文摘Chlorophyll a(Chl a)is a key photosynthetic pigment and an essential indicator of phytoplankton biomass.Accurate Chl a measurements are crucial for understanding marine biogeochemical processes.China launched the Chinese Ocean Color and Temperature Scanner(COCTS)aboard the HY-1D satellite in 2020,yet its Chl a products require further validation in complex coastal waters.This study assesses HY-1D Chl a products in the Bohai and Yellow Seas,two optically complex coastal regions,using in situ data collected during multiple cruises.Additionally,we compare HY-1D Chl a products with those from the Moderate Resolution Imaging Spectroradiometer(MODIS)and the Visible Infrared Imaging Radiometer Suite(VIIRS).We observed that although Chl a products from HY-1D are generally consistent with those from the MODIS and VIIRS in spatial distribution,there are still significant errors when compared with in situ data.Therefore,we developed a new blended algorithm to improve the accuracy of HY-1D Chl a products.The algorithm distinguishes between turbid and relatively clean waters using a classification index based on the ratio of remote sensing reflectance(R_(rs)(λ)).After the initial classification,we developed targeted algorithms based on the optical properties of different water bodies.The new model shows a significant improvement,reducing the mean absolute percentage error(MAPE)from 43.1%to 24.3%.Additionally,merging Chl a data from HY-1D,MODIS,and VIIRS maintains good accuracy,with HY-1D Chl a products significantly enhancing data coverage and robustness.This research provides important support for producing high-quality HY-1D Chl a products for coastal waters.
文摘Coasts are subject to multiple natural hazards,which are increasing nowadays.Coastal flooding and erosion are some of the most common hazards affecting coastlines.Being aware of the vulnerability of coasts is important to achieve integrated coastal management.The coastal vulnerability index(CVI)is a common index used to assess coastal vulnerability because it is easily calculated.However,given that its calculation includes numerous manual steps,it requires considerable time,which is often unavailable,to produce accurate and utilizable results.In this work,we developed a ModelBuilder model by using the tools provided by ArcGIS Pro(ESRI).Through this model,we automatized most of the steps involved in CVI calculation.We applied the ModelBuilder model in the northern Peloponnese,for which the CVI has already been calculated in three other works.We were thus able to assess the effectiveness of our ModelBuilder model.Our results demonstrated that through the ModelBuilder,most of the processes could effectively be automatized without problems,and our results are consistent with the findings of previous works in our study area.
基金supported by Zhejiang Province Science Fund for Distinguished Young Scholars(No.LR24D050001)the Joint Funds of Zhejiang Provincial Natural Science Foundation of China(No.LZJMZ23D050002)+3 种基金the National Natural Science Foundation of China(No.42175116)the Scientific Research Foundation for Guilin University of Technology(No.GUTQDJJ2023046)supported by Guangxi Engineering Research Center of Comprehensive Treatment for Agricultural Non-Point Source Pollutionthe Modern Industry College of Ecology and Environmental Protection,Guilin University of Technology.
文摘PM_(2.5) and black carbon(BC)are important air pollutants impacting radiation balance,air quality,health,and ecosystems.Ozone(O_(3))levels are increasing despite decreases in other pollutants,posing a challenge for pollution control,especially in coastal cities like Zhoushan,where the monsoonal climate can exacerbate PM_(2.5) and ozone pollution.This study conducted continuous online measurements of major atmospheric pollutants in Zhoushan,Zhejiang Province,in 2020.The results indicate that the highest contribution from local air masses in Zhoushan is observed in spring,accounting for 17.7%,while the greatest average contribution from northern Zhejiang Province,Jiangsu Province,and Shanghai occurs in winter,at 18.5%.Pollutant concentrationswere seasonally variable,with PM_(2.5),BC,and sulfur dioxide concentrations 56.6%,36%,and 58.2%higher in the cold season compared to the warm season.The O_(3) in spring is approximately 50%higher than that in summer.Ship emissions significantly contributed to BC,nitrogen oxides(NO_(x)),and carbon monoxide in Zhoushan.In spring,PM_(2.5) sources included photochemical processes and northern air mass transport,while in winter,PM_(2.5) was due to regional transport.The inhibitory effect of PM_(2.5) on O_(3) formation in the Zhoushan area is relatively weak.Reducing NO_(x) emissions may increase O_(3),emphasizing the need for volatile organic compounds monitoring and regional control measures to improve air quality and ensure sustainable development in Zhoushan.
基金supported by the Research Grant of Military Institute of Science and Technology,Bangladesh。
文摘Coastal Bangladesh is highly vulnerable to various impacts of climate change,including rising temperatures,unpredictable precipitation,cyclones,droughts,and saltwater intrusion.These factors collectively threaten agricultural productivity and food security.This study examines the relationship between farmers’perceptions and observable climatic trends,with a focus on the sustainability of food systems and the promotion of adaptable farming techniques in Bagerhat District,Bangladesh.A mixed-methods strategy was employed,incorporating household surveys(a total of 110 purposively selected farmers),focus group discussions,key informant interviews,and climatic data analysis.The Mann-Kendall test,Sen’s slope estimator,precipitation concentration index(PCI),and standardized rainfall anomaly index(SRAI)were employed to analyze climate trends from 1991 to 2020.The findings showed that more than 70.00%of respondents indicated that summers were becoming warmer,over 50.00%reported that winters were becoming colder,and 63.00%stated that yearly precipitation was decreasing.Farmers reported an increase in flood occurrences and a decline in the predictability of precipitation.Between 2011 and 2019,the output of most rice varieties decreased,with the exception of high-yielding Aman rice and hybrid Boro rice.The results also showed that 60.00%of respondents reported experiencing salinity intrusion,and 57.00%attributed significant yield losses to salinity.Planting salt-tolerant rice varieties(such as BRRI Dhan 67 and Binadhan-10),practicing homestead vegetable cultivation,and moderately integrating shrimp aquaculture were also common adaptive measures.To improve long-term food security in coastal Bangladesh,we suggest growing more salt-tolerant crop varieties,promoting vertical and homestead gardening,enhancing seed systems that are resilient to climate change,and educating farmers on the use of climate-smart farming methods.This study highlights the importance of aligning farmers’perceptions with observed climatic data to design effective adaptation strategies.The findings of this study can guide policy-makers and development practitioners in strengthening climate-resilient agriculture and ensuring long-term food security in coastal Bangladesh.
基金Supported by the National Key R&D Program of China(No.2022YFE0209300)the National Natural Science Foundation of China(Nos.42106043,42141016)。
文摘Saltmarsh is one of the blue carbon ecosystems for the highest carbon burial efficiency.However,the buried carbon in saltmarsh may still be exported to coastal water through porewater exchange,a process that has often been overlooked in previous studies.A typical tidal creek of the Dongtan saltmarsh wetland in Chongming Island,Shanghai,China,was studied.The224Ra and223Ra activities were measured and the hydrological parameters such as water flow were determined,from which the porewater exchange rate in the tidal creek was estimated to be 1.78±1.73 cm/d.Meanwhile,the carbon concentrations in porewater were determined,based on which the fluxes of dissolved inorganic carbon(DIC),dissolved organic carbon(DOC),CH_(4),and CO_(2)exported from porewater exchange were derived to be 60±17,6.6±4.0,0.082±0.079,and 16±11 mmol/(m^(2)·d),respectively.In addition,analysis on different species of carbon in the creek water showed that,the fluxes of DIC,DOC,CH_(4),and CO_(2)exported laterally from tidal creek to coastal sea were 58±14,7.6±2.3,0.0011±0.00063,and 1.5±0.68 mmol/(m^(2)·d),respectively,indicating that the porewater exchange-derived carbon fluxes accounted for a large portion of the lateral carbon outwelling,and even much higher than those in CH_(4)and CO_(2)fluxes.Furthermore,the carbon exported from porewater exchange accounted for 50%of the carbon burial in the tidal creek system,of which DIC accounted for 73%of the total carbon flux transported by porewater exchange.Therefore,this study indicated that the porewater exchange-derived carbon fluxes to the tidal creek water may cause an overestimation in the carbon sequestration capacity of saltmarsh wetlands,and revealed the importance of porewater exchange for the carbon cycle of tidal creek system of saltmarsh wetlands.
基金Prime Minister Fellowship, Government of the People’s Republic of Bangladesh, for providing a PhD fellowship to Kazi Atiah TAIYEBIGraduate Research and Travel Awards (GRATA) under the School of Social&Environmental Sustainability, University of Glasgow, for supporting the field work in Bangladesh。
文摘Shrimp farming is a major global aquaculture activity;however,its social and ecological impacts raise sustainability concerns.While previous research has focused on isolated social or environmental aspects of sustainability in shrimp farming,integrated assessments of these factors using a social-ecological systems(SES)approach are rare.A framework for assessing the sustainability of shrimp farming-comprising a set of social and ecological indicators-is developed and conceptualized in this study for the first time,using an integrated,interdisciplinary,and empirical SES approach.We first identified key social and ecological indicators and developed a conceptual framework based on SES approach,then surveyed 90 shrimp farms across 3 coastal regions(including Satkhira,Bagerhat,and Cox’s Bazar districts)in Bangladesh.Nearly all farmers in Satkhira(97%)and all in Bagerhat(100%)expressed dissatisfaction with the decreasing pattern of shrimp production and profitability over the last decade.In contrast,nearly all respondents in Cox’s Bazar(97%)reported satisfaction with increasing shrimp production.Except in Cox’s Bazar,equity in labor payment remained a concern for the social sustainability of the shrimp farming system.The changing pattern of shrimp production and profitability,which does not ensure equity,poses a threat to the sustainability of shrimp farming.Most of the surveyed farmers recognized the mutual benefits of mangrove forests and shrimp farming(97%in Satkhira and 77%in Cox’s Bazar),which suggests potential for the development of policy on integrated mangrove-shrimp farming with community-based management.This research could help assess the sustainability of the shrimp farming system and contribute to achieving Sustainable Development Goals 2(zero hunger)and 8(decent work and economic growth).By examining existing practices and developing a novel framework,this study highlights informed decision-making and guides methodological discussion on assessing the sustainability of shrimp farming using the SES approach in coastal regions and different aquaculture systems worldwide.
基金supported by the National Natural Science Foundation of China(Nos.21976106,42005092,and 42105111)the Natural Science Foundation of Shandong Province(Nos.ZR2020QD058 and ZR2021QD144)+1 种基金the Introduction and Cultivation Plan for Young Innovative Talents of Colleges and Universities by the Education Department of Shandong Province(No.142,2019)。
文摘Marine biological activity has long been recognized to impact the atmospheric chemistry of coastal areas.In this work,we monitored the seasonal variation of carbonyl compounds in the coastal city of Qingdao,located in the north of China’s coastline and the south of Jiaodong Peninsula,with the vast hinterland in the west.The mean total concentration of the 15 carbonyls varied significantly between seasons,with the highest observed in autumn(10.2±6.2 ppbv),followed by spring(9.0±3.0 ppbv),winter(6.4±4.0 ppbv)and summer(3.4±1.4 ppbv).Using bivariate analysis,the agricultural emissions from inland areas were responsible for the high levels of carbonyls in the autumn.In summer,clean and humid sea winds helped reduce the concentration of carbonyls,but they also brought air masses from vegetation,and marine organisms,which contributed to high levels of carbonyls in the spring of coastal areas.The observation-based chemistry box model found that the forma-tion of formaldehyde and acetaldehyde was primarily controlled by the RO+O2 reaction,and alkenes oxidation was the main contributing factor.Based on the OH radical loss rate(LOH)and ozone formation potential(OFP)calculation,we found that autumn and spring seasons have significantly higher values of LOH and OFP than winter and summer due to the presence of high concentrations of carbonyl compounds.Therefore,it is believed that these carbonyl compounds primarily originate from agricultural activities,and marine air influences the atmospheric chemistry of the coastal areas.
基金Under the auspices of National Natural Science Fundation(No.42276234,41976209,42206236)。
文摘Land-sea coordination is a crucial strategy for ensuring the sustainable and rapid development of coastal cities.Assessing the level of land-sea coordination is vital for understanding the degree of coordination and identifying imbalances within land-sea systems.However,empirical research in this area remains scarce,necessitating further investigation.Using coastline,land use,and socio-economic data for the Taizhou coastal zone of China across seven time periods from 1990 to 2021,this study analyzed the spatiotemporal characteristics of coastal zone development intensity,developed a comprehensive evaluation model for land-sea coordination,and examined its evolutionary dynamics.The results indicated a substantial rise in development intensity within the Taizhou coastal zone,accompanied by significant alterations in coastline morphology and structure.These changes included a marked reduction in the extent of natural coastline and a corresponding expansion of artificial coastline.The intensity of coastal land use also increased,primarily driven by the expansion of built-up areas and aquaculture ponds.The development level of land-sea systems,as well as the overall coordination of the Taizhou land-sea system,demonstrated a consistent upward trend,advancing from basic to intermediate coordination.These findings provide actionable insights for enhancing land-sea coordination strategies to support the sustainable development of coastal cities.
基金supported by the Doctoral Research Initiation Fund Project of Hebei Normal University(No.L2025B19)PhD Fellowship of the State Key Laboratory of Marine Environmental Science at Xiamen University.
文摘Protoporphyrin Ⅸ(PPⅨ), a basic porphyrin system found in nature, all “porphyrin-type”tetrapyrroles with a biological function are biosynthetically derived thereof. PPⅨ is a metalloprosthetic group of numerous proteins involved in diverse metabolic and respiratory processes across all domains of life, and is thus considered essential for respiring organisms. Determining the biotic and abiotic factors that influence marine microbial growth and community structure is critical for understanding global biogeochemical cycles. Here,we present vertical profiles of intracellular PPⅨ and four derivative products(Chlorophylla/b and Pheophytin-a/b) from two coastal sediment cores, alongside ancillary geochemical and 16S rRNA microbial community data. Our findings indicated that PPⅨ is present in the natural sediment environment and displays a decreasing trend with depth, revealing a significant positive correlation with both organic matter and microbial abundance. Cooccurrence networks revealed that the environmental distribution of PPⅨ was positively correlated with the microbial porphyrin producer(high genetic completeness), but negatively correlated with auxotrophs(absence or low genetic completeness). It emphasized the critical role of PPⅨ as a biological molecule involved in key physiological processes. These results suggest that PPⅨ is a prominent component of the shared extracellular metabolite pool, especially in anoxic marine sediments where it exists at physiologically relevant concentrations for microbial metabolism. This study highlighted the significance of PPⅨ in microbial ecology and its potential impact on biogeochemical cycles in marine sedimentary environments.
文摘This paper provides an overview of the recent advancements in magnetic structured triboelectric nanogenerators(MSTENGs)and their potential for energy harvesting and sensing in coastal bridge infrastructure.This paper begins with a brief discussion on the fundamental physics modes of triboelectric nanogenerators(TENGs),triboelectric series,and factors affecting TENG power generation and transmission,providing a foundation for the subsequent sections.The review focuses on the different types of MSTENGs and their applications in coastal infrastructure.Specifically,it covers magnetic spherical TENG networks,magnet-assisted TENGs,MSTENGs for bridges,and magnetic multilayer structures based on TENGs.The advantages and limitations of each type of MSTENG are discussed in detail,highlighting their respective suitability for different coastal bridge infrastructure applications.In addition,the paper addresses the challenges and provides insights into the future of MSTENGs.These include the need for improved durability and sustainability of MSTENGs in harsh coastal environments,increasing their power-output levels to fulfll high energy needs,and the requirement for collaborative efforts between academia,industry,and government institutions to optimize MSTENG performance.
基金supported by the open funding of the Technology Innovation Center for South China Sea Re-mote Sensing,Surveying and Mapping Collaborative Ap-plication,Ministry of Natural Resources,P.R.China(No.RSSMCA-2024-B001)the National Natural Science Foundation of China(Nos.T2261149752 and 42476172).
文摘Motivated by the wide applications of empirical global ocean tide models in Earth science,particularly in shallow waters and coastal regions,we proposed an updated global ocean tide model representing all major diurnal and semidiurnal tidal constituents.We integrated the development technique of the Technical University of Denmark(DTU10)model and calculated the residual tides using the intermediary FES2012 model.We utilized all available Topex/Poseidon,Jason-1,Ocean Surface Topography Mission(OSTM)/Jason-2 primary and tandem missions to develop the new model.To reduce the discrepancies between the model and in situ measurements estimated S2 tide constituent,the ERA-Interim model was selected for dry tropospheric correction of altimetry data.The newly developed model with an improved spatial resolution from 1/8°×1/8°to 1/16°×1/16°was assessed and compared against contemporary global ocean tide models using in situ measurements in coastal regions,continental shelf waters,marginal seas,and deep waters.The results demonstrate improvements in shallow waters and coastal regions,particularly in representative coastal re-gions such as the Northwest European Shelf and East Asian Marginal Seas.Moreover,the model performs well in simulating S_(2) and K_(2) tides with root mean square differences of 0.355 and 0.234 cm,respectively,against in situ measurements in deep waters world-wide.Compared with that of DTU10,the root sum square of the new model for the eight main tidal constituents decrease by 8.4%to 0.997 cm.
基金supported by the National Key R&D Program of China(Grant No.2021YFC2802504)the National Outstanding Youth Grant(Grant No.41925027)+1 种基金the National Natural Science Foundation of China(Grant No.42206251)the Innovation Group Project of the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(Grant No.311021008).
文摘Antarctic coastal polynyas play a vital role in atmosphere-ocean interactions and local ecosystems.This study investigates the interannual variability of springtime coastal polynyas over the Ross Sea based on satellite-retrieved sea-ice concentration(SIC)data from 1992 to 2021.Firstly,the springtime coastal polynya areas display large interannual variability as well as a positive trend of about 2000 km^(2)(10 yr)^(-1) over the 30 years.Secondly,based on composite analysis,in spring,we find that a deepened Amundsen Sea Low(ASL)induces stronger meridional winds over the eastern Ross Sea,leading to stronger sea-ice advection and expansion of coastal polynya areas.This is accompanied by more solar radiation absorption in early summer(about 16 W m^(2)),resulting in upper-ocean warming(~0.4℃)and significant sea-ice loss in late summer(~50%SIC).Additionally,the physical processes are validated by 500-year piControl simulations of a state-of-the-art Earth system model.Based on the same composite analysis,the results show that the sea-ice decline is consistent with the deepening of the ASL and the increase of the meridional sea-ice advection of the preceding spring,which is highly consistent with that of observations.This further confirms the circulations-polynyas-sea-ice physical linkages.Since the springtime ASL is strongly modulated by the tropical Pacific variability and the stratospheric polar vortex,changes in the polynya areas of the Ross Sea can be traced back to remote regions.
基金supported by the National Natural Science Foundation of China(42271421).
文摘Texture analysis methods offer substantial advantages and potential in examining macro-topographic features of dunes.Despite these advantages,comprehensive approaches that integrate digital elevation model(DEM)with quantitative texture features have not been fully developed.This study introduced an automatic classification framework for dunes that combines texture and topographic features and validated it through a typical coastal aeolian landform,namely,dunes in the Namib Desert.A three-stage approach was outlined:(1)segmentation of dune units was conducted using digital terrain analysis;(2)six texture features(angular second moment,contrast,correlation,variance,entropy,and inverse difference moment)were extracted from the gray-level co-occurrence matrix(GLCM)and subsequently quantified;and(3)texture–topographic indices were integrated into the random forest(RF)model for classification.The results show that the RF model fused with texture features can accurately identify dune morphological characteristics;through accuracy evaluation and remote sensing image verification,the overall accuracy reaches 78.0%(kappa coefficient=0.72),outperforming traditional spectral-based methods.In addition,spatial analysis reveals that coastal dunes exhibit complex texture patterns,with texture homogeneity being closely linked to dune-type transitions.Specifically,homogeneous textures correspond to simple and stable forms such as barchans,while heterogeneous textures are associated with complex or composite dunes.The complexity,periodicity,and directionality of texture features are highly consistent with the spatial distribution of dunes.Validation using high-resolution remote sensing imagery(Sentinel-2)further confirms that the method effectively clusters similar dunes and distinguishes different dune types.Additionally,the dune classification results have a good correspondence with changes in near-surface wind regimes.Overall,the findings suggest that texture features derived from DEM can accurately capture the dynamic characteristics of dune morphology,offering a novel approach for automatic dune classification.Compared with traditional methods,the developed approach facilitates large-scale and high-precision dune mapping while reducing the workload of manual interpretation,thus advancing research on aeolian geomorphology.
基金supported by internal grant from Sultan Qaboos University(IG/DVC/ESRC/21/01).
文摘Enhanced weathering(EW)of ultramafi c rocks from the Muslim Bagh Ophiolite,Pakistan,has been studied in laboratory experiments to explore carbon sequestration as a climate change mitigation strategy for coastal and open sea environments.The research focused on a cost-eff ective ex situ experiment to examine the eff ects of EW reaction pathways arising from the interactions among rock powder,seawater and CO_(2).The experimental fi ltrates from diff erent milled peridotite samples exhibit a decrease in the Mg/Ca ratio as the specifi c surface area increases,which accelerates reaction rates.This suggests that the leached Mg from the original rock may have been consumed in the formation of brucite,serpentine and carbonates during EW.Similar reaction pathways are also responsible for the chemical alterations observed in amphibolite,albeit to varying degrees.On the other hand,the experimental residues showed an increase in loss on ignition compared to the original rock,indicating that EW has facilitated the incorporation of H 2 O and CO_(2) into secondary mineral structures through various reaction pathways,leading to the formation of brucite,serpentine and carbonates.Thermal gravimetric analysis of the experimental residues confi rms the presence of these minerals based on their decomposition temperatures.Additionally,XRD analysis identifi ed a range of carbonates in the residues of both peridotite and amphibolite samples,validating the occurrence of carbonation reactions.SEM images reveal textural changes in both samples,supporting the formation of secondary minerals through EW,consistent with observations from the petrographic study of untreated samples.Control experiments on CO_(2) absorption in seawater showed a decrease in pH,highlighting ocean acidifi cation from increased CO_(2) emissions.However,when rock powder was added to the seawater-CO_(2) mixture,the pH increased.This suggests that the EW of ultramafi c rock powders can sequester CO_(2) while raising seawater pH through the formation of secondary minerals.This research could serve as an analog for EW applications,considering the worldwide abundance of ultramafi c rocks and the availability of coastal and open ocean environments.However,further research is required to understand the behavior of other elements and their impacts on ocean chemistry in EW processes before applying CO_(2) sequestration strategies.
