Jinzhou Bay Research Articles

Quantifying microplastics in sediments of Jinzhou Bay, China: Characterization and ecological risk with a focus on small sizes

Small-sized microplastics (MPs) pose greater ecological toxicity due to their larger surface area, which makes them more likely to act as carriers for other pollutants and to be ingested by aquatic organisms. However, traditional visual analysis often neglects small-sized MPs and their associated ecological risk. This study utilized Laser Direct Infrared (LDIR) spectroscopy and traditional visual analysis to examine MPs in 31 sediment samples from Jinzhou Bay, a typical semi-enclosed bay located at the economic center of Dalian, China. The results showed significant heterogeneity in MP distribution, with averages of 1192 and 2361 items/kg dry weight reported by visual analysis and LDIR spectroscopy, respectively. LDIR spectroscopy identified MPs as small as 10 μm, with the majority of MPs (89.21 %) within the 10–250 μm range, and a significant proportion (46.45 %) between 10 and 50 μm among them. However, visual analysis was limited to detecting MPs >50 μm, and significant portions were identified between 50 and 100 μm (49.36 %) and 100–250 μm (31.01 %), missing a substantial fraction of smaller MPs. The predominant polymers identified were polyamide (PA), polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and acrylonitrile butadiene styrene (ABS). LDIR spectroscopy demonstrated a strong positive correlation between MP abundance and clay content, a relationship not observed with traditional visual analysis. The Potential Ecological Risk Index (PERI) indicated that over 87 % of sites posed an extremely high risk according to LDIR spectroscopy, compared to 51 % by traditional visual analysis. These discrepancy underscores the underestimation of ecological risks by traditional methods, particularly for small-sized MPs. High-risk polymers such as polyvinyl chloride (PVC), ABS, and polyurethane (PUR) significantly influenced PERI values. These findings highlight the critical need for precise identification and thorough risk assessment of small-sized MPs in environmental studies and offer insights for understanding of MP vertical migration in aquatic environments, particularly in the context of co-settlement with sediments.

Bacterial community in the metal(loid)-contaminated marine vertical sediments of Jinzhou Bay: Impacts and adaptations

Metal(loid) discharge has led to severe coastal contamination; however, there remains a significant knowledge gap regarding its impact on sediment profiles and depth-resolved bacterial communities. In this study, geochemical measurements (pH, nutrient elements, total and bioavailable metal(loid) content) consistently revealed decreasing nitrogen, phosphorus, and metal(loid) levels with sediment depth, accompanied by reduced alpha diversity. Principal coordinate analysis indicated distinct community compositions with varying sediment depths, suggesting a geochemical influence on diversity. Ecological niche width expanded with depth, favoring specialists over generalists, but both groups decreased in abundance. Taxonomic shifts emerged, particularly in phyla and families, correlated with sediment depth. Microbe–microbe interactions displayed intricate dynamics, with keystone taxa varying by sediment layer. Zinc and arsenic emerged as key factors impacting community diversity and composition using random forest, network analysis, and Mantel tests. Functional predictions revealed shifts in potential phenotypes related to mobile elements, biofilm formation, pathogenicity, N/P/S cycles, and metal(loid) resistance along sediment profiles. Neutral and null models demonstrated a transition from deterministic to stochastic processes with sediment layers. This study provides insights into the interplay between sediment geochemistry and bacterial communities across sediment depths, illuminating the factors shaping these ecosystems.

Divergent adaptation strategies of abundant and rare bacteria to salinity stress and metal stress in polluted Jinzhou Bay

Understanding how abundant (AT) and rare (RT) taxa adapt to diverse environmental stresses is vital for assessing ecological processes, yet remains understudied. We collected sediment samples from Liaoning Province, China, representing rivers (upstream of wastewater outlet), estuaries (wastewater outlets), and Jinzhou Bay (downstream of wastewater outlets), to comprehensively evaluate AT and RT adaptation strategies to both natural stressors (salinity stress) and anthropogenic stressors (metal stress). Generally, RT displayed higher α- and β-diversities and taxonomic groups compared to AT. Metal and salinity stresses induced distinct α-diversity responses in AT and RT, while β-diversity remained consistent. Both subcommunities were dominated by Woeseia genus. Metal stress emerged as the primary driver of diversity and compositional discrepancies in AT and RT. Notably, AT responded more sensitively to salinity stress than RT. Stress increased topological parameters in the biotic network of AT subcommunities while decreasing values in RT subcommunities, concurrently loosening interactions of AT with other taxa and strengthening interactions of RT with others in biotic networks. RT generally exhibited greater diversity of metal resistance genes compared to AT. Greater numbers of genes related to salinity tolerance was observed for the RT than for AT. Compared to AT, RT demonstrated higher diversity of metal resistance genes and a greater abundance of genes associated with salinity tolerance. Additionally, deterministic processes governed AT community assembly, reinforced by salinity stress. However, the opposite trend was observed in the RT, where the importance of stochastic process gradually increased with metal stresses. The study is centered on exploring the adaptation strategies of both AT and RT to environmental stress. It underscores the importance of future research incorporating diverse ecosystems and a range of environmental stressors to draw broader and more reliable conclusions. This comprehensive approach is essential for gaining a thorough understanding of the adaptive mechanisms employed by these microorganisms.

Holocene marine deposits in the Bohai Sea: Depocenters, sediment sources, and oceanic and tectonic influences

The Bohai Sea is a semi-enclosed shallow shelf sea that has undergone a unique sediment source-to-sink process in the past. Despite this, our knowledge about the sediment budget, existence of depocenters and the factors controlling depocenter formation during the Holocene remains limited. This paper aims to address these gaps by estimating the Holocene marine deposit thickness and sediment budget in the Bohai Sea using high-resolution subbottom profiles. The results reveal that the mean thickness of Holocene marine deposits is approximately 7.8 m and a maximum thickness of 28 m was found in Jinzhou Bay. The Highstand System Tracts (HST) have a mean thickness of approximately 5.4 m and a maximum thickness of 25 m observed in the Jinzhou Bay. On the other hand, the Transgressive System Tracts (TST) have a mean thickness of approximately 2.5 m and a maximum thickness of 7 m in the north of the Laizhou Bay. The total accumulation in the Bohai Sea is estimated to be ∼713.97 × 109 tons, consisting of 489.28 × 109 tons from the HST and 224.69 × 109 tons from the TST. Three deposit centers were identified and estimated to be approximately 299 × 109 tons, accounting for approximately 42 % of the total Bohai Sea sediments. The development of Holocene marine deposit centers was mainly influenced by the Tanlu Fault zone and water circulations. Based on preliminary estimates, it is suggested that roughly half of the sediments dispersed from the estuaries are preserved on the Bohai Sea shelf since the maximum flooding (∼7000 cal yr BP). This research provides valuable insights for the post-glacial sedimentary and geomorphic evolution of the Bohai Sea.

Diversity, functional potential, and assembly of bacterial communities in metal(loid)-contaminated sediments from a coastal industrial basin

A comprehensive understanding of ecological processes related to bacterial communities in these ecosystems is critical for improving the sustainability of estuarine-coastal ecosystem functions. However, the community composition, functional potential, and assembly mechanisms of bacterial community in metal(loid)-contaminated estuarine-coastal habitats remain poorly understood, especially along lotic systems extending from rivers to estuaries and to bays. Here, we collected sediment samples associated with sewage outlets from rivers (upstream/midstream of sewage outlet), estuaries (sewage outlets), and Jinzhou Bay (downstream of sewage outlets) within Liaoning Province, China in order to evaluate the relationships between microbiome and metal(loid) contamination. Sewage discharge markedly increased the concentrations of metal(loid)s in sediments, including of As, Fe, Co, Pb, Cd, and Zn. Significant discrepancies in alpha diversity and community composition were observed among the sampling sites. The above dynamics were primarily caused by salinity and metal(loid) concentrations (i.e., of As, Zn, Cd, and Pb). Furthermore, metal(loid) stress significantly increased abundances of metal(loid)-resistant genes, but decreased abundances of denitrification genes. Dechloromonas, Hydrogenophaga, Thiobacillus, and Leptothrix were denitrifying bacteria present within sediments of this estuarine-coastal ecosystem. Moreover, the stochastic processes dominated the community assembly in estuary offshore sites, while deterministic processes dominated river community assembly mechanisms. Salinity and total nitrogen concentration, rather than metal(loid) concentrations, governed the assembly processes in these sites. Overall, these elucidate mechanisms involved in constructing community diversities, functional potential, and assembly.

Temporal Changes in Genetic Diversity of Fenneropenaeus chinensis Populations from Jinzhou Bay: Implications for Management

Temporal Changes in Genetic Diversity of Fenneropenaeus chinensis Populations from Jinzhou Bay: Implications for Management

Temporal and spatial effects of large airport construction and operation on the local thermal environment.

New construction has resulted in impervious surfaces increasingly replacing natural landscapes, altering surface radiation, thermal properties, and humidity in urban areas. Based on Landsat-8 data, the temporal and spatial impacts of the construction of Dalian Jinzhouwan Airport and Beijing Daxing Airport on the thermal environment were studied. The local thermal gradient (LTG) of the airport before and after construction is compared. The results showed that after the completion of the airport, the LTG value of Daxing Airport increased by 0.033 and that of Jinzhou Bay Airport increased by 0.009. After the airport operation, LTG values increase again. Daxing Airport added another 0.053, and Jinzhou Bay Airport added another 0.127. Two land classification models (land use type, LUT; local climate zone, LCZ) were used to explore the relationship between land use type and LTG. The results show that the increase of alloy buildings after the completion of the airport has a great influence on the thermal environment of the two study areas. The operation of airports will further enhance this effect. Our study can provide a reference for the influence of large-scale traffic construction on the urban thermal environment.

Monitoring and Predicting the Subsidence of Dalian Jinzhou Bay International Airport, China by Integrating InSAR Observation and Terzaghi Consolidation Theory

Dalian Jinzhou Bay International Airport (DJBIA) is an offshore artificial island airport, where the reclaimed land is prone to uneven land subsidence due to filling consolidation and construction. Monitoring and predicting the subsidence are essential to assist the subsequent subsidence control and ensure the operational safety of DJBIA. However, the accurate monitoring and prediction of reclaimed subsidence for such a wide area under construction are hard and challenging. This paper utilized the Small Baseline Subset Synthetic Aperture Radar (SBAS-InSAR) technology based on Sentinel-1 images from 2017 to 2021 to obtain the subsidence over the land reclamation area of the DJBIA, in which the results from ascending and descending orbit data were compared to verify the reliability of the results. The SBAS-InSAR results reveal that uneven subsidence is continuously occurring, especially on the runway, terminal, and building area of the airport, with the maximum subsidence rate exceeding 100 mm/year. It was found that there is a strong correlation between the subsidence rate and backfilling time. This study provides important information on the reclaimed subsidence for DJBIA and demonstrates a novel method for reclaimed subsidence monitoring and prediction by integrating the advanced InSAR technology and Terzaghi Consolidation Theory modeling. Moreover, based on the Terzaghi consolidation theory and the corresponding geological parameters of the airport, predicted subsidence curves in this area are derived. The comparison between predicted curves and the actual subsidence revealed by InSAR in 2017–2021 is highly consistent, with a similar trend and falling in a range of ±25 mm/year, which verifies that the subsidence in this area conforms to Terzaghi Consolidation Theory. Therefore, it can be predicted that in the future, the subsidence rate of the new reclamation area in this region will reach about 80 mm/year ± 25 mm/year, and the subsidence rate will gradually slow down with the accumulation of reclamation time. The subsidence rate will slow down to about 30 mm/year ± 25 mm/year after 10 years.

Genetic identification of Chinese shrimp Fenneropenaeus chinensis post-release in Jinzhou Bay: Implications for management of stock enhancement

The Chinese shrimp (Fenneropenaeus chinensis), one of the important fishery resources in North China, has sharply declined. Artificial propagation and release of F. chinensis have been developed in recent decades in order to supplement wild stocks and improve economic profit. For investigation of the effects of stock enhancement in Jinzhou Bay, we traced this program by sampling 574 female shrimp after spawning and recaptured 293 individuals post-release. Among recaptured individuals, 21 were identified as being hatchery-raised via mtDNA control region and six microsatellite markers identification, accounting for 7.2%, indicating that the hatchery-released juvenile shrimps could survive in the natural environment and contribute to F. chinensis population replenishment in the wild. To address genetic impacts from stock enhancement, we compared the genetic variations between spawners used for enhancement release and local recaptured individuals. High genetic diversities were maintained in F. chinensis stocks, but local recaptured individual stock seemed to exhibit lower genetic diversity. Deviation from Hardy–Weinberg equilibrium and positive values in the inbreeding coefficient in all microsatellite loci and stocks indicated that homogenization and inbreeding may have occurred. More appropriate strategies to restore F. chinensis populations should be discussed for future fishery management.

Heavy metals uptake and translocation of typical wetland plants and their ecological effects on the coastal soil of a contaminated bay in Northeast China

Heavy metal pollution in coastal zone is a global environment problem concerning the international society. As an eco-friendly and economical method, phytoremediation is a promising strategy for improving heavy metal pollution in coastal soil. In order to alleviate the ecological risk of heavy metal pollution in Jinzhou Bay, a typical and important heavy industrial area in China, three local wetland plants (Scirpus validus, Typha orientalis and Phragmites australis) were selected and planted in the field. The plants showed strong tolerance of high concentrations of heavy metals. Stressed by the heavy metals, the root weight of S. validus and P. australis increased 114.74% and 49.91%, respectively. The concentrations of heavy metals (Cd, Cr, Cu, Ni, Pb, Zn, As, Hg) accumulated in the plant roots were 4–60 times higher than that in plant shoots. The SEM analysis found that abundant heavy metals were adhered to the root surface closely. Bioconcentration factor of heavy metals on the plant roots were 0.08–0.89 (except Cr, Ni), while the translocation factor from roots to above ground of plants were 0.02–0.27. Furthermore, the wetland plants improved the regional ecological environment quality. The concentrations of heavy metals in the rhizosphere soil decreased significantly. Compared with the bulk soil, the potential ecological risk index in the rhizosphere soil reduced 26.51%–69.14%. Moreover, the microbial diversity in rhizosphere soil increased significantly, and the abundances of Proteobacteria and Bacteroidetes also increased in rhizosphere soil. Pearson correlations indicated that Hg, As, Ni and Cr were negatively correlated with Proteobacteria (p < 0.05), and Cu was significantly negative correlated with Bacteroidetes (p < 0.05). The results support that using suitable local plants is a promising approach for repairing heavy metal contaminated costal soil, not only because it can improve the regional ecological environment quality, but also because it can enhance the landscape value of coastal zone.

Sound velocity characteristics of unconsolidated sediment based on high-resolution sub-bottom profiles in Jinzhou Bay, Bohai Sea of China

Accurate inversion of sound velocity in a Holocene stratum and a Quaternary stratum was achieved based on rich high-resolution sub-bottom profiles and boreholes in the Jinzhou Bay, Bohai Sea of China. The average value of the sound velocity is 1540.2 m/s in the Holocene stratum and 1764.7 m/s in the Quaternary stratum. The fitting analysis shows that there is an obvious positive linear correlation between the sound velocity and the burial depth of the stratum, with a gradient of 4.5 s−1. The method involving the solution of over-determined equations was innovatively put forward to explore the sound velocity characteristics of different types of sediments. The eigenvalues of the sound velocities of seven types of sediments and weathered rock in the study area are solved: the sound velocities of mud, muddy sand, muddy silty clay, muddy clay, silty clay, clay, silty sand, and strongly weathered rock are 1513.7 m/s, 1484.3 m/s, 1532.0 m/s, 1511.3 m/s, 1693.9 m/s, 1602.7 m/s, 1599.4 m/s, and 2137.7 m/s, respectively. And statistical analysis shows that the sound velocity of the sediment in the study area has obvious quadratic correlations with the void ratio and compressibility.

Trend and Cause Analysis of Seawater Quality in Jinzhou Bay

According to the water quality monitoring data of Jinzhou Bay in July 2018, September 2018 and September 2019, the change trend of seawater quality in Jinzhou Bay is analysed. The results showed that the degree of eutrophication increased with time. The excessive emission of active phosphate is the main reason for this phenomenon. In recent years, large-scale dredging and land reclamation have been carried out in Jinzhou Bay, which has effectively removed the polluted sediment and effectively controlled and improved the heavy metal pollution in Jinzhou Bay. Therefore, it is necessary to strictly control the discharge of polluted oil into the sea.

Modeling trace metal partitioning and speciation at the sediment-water interface using a chemical equilibrium model

Isotherm adsorption experiments for Pb, Cd and Zn were carried out with coastal sediments from China under oxic sediment-water conditions. The conditional equilibrium constants (Kads) determined from the adsorption isotherms were found to be most strongly correlated with Mn oxides (MnOx) for Pb and Cd, and with particulate organic carbon (POC) for Zn. MnOx and POC were then used as the surrogate metal-binding phases in a sediment-water chemical equilibrium model (SCEM). The apparent equilibrium constants (βsed, Me⁎) of the SCEM were determined to be 109.56±0.41 for Pb (n = 9), 105.25±0.34 for Zn (n = 7), and 106.51±0.29 for Cd (n = 7). The SCEM was then used to predict the free metal ion activities ({Me2+}) in seawaters of Jinzhou Bay, China. The SCEM-predicted {Me2+} compared well with the measured ones for Pb and Zn in seawater. However, the predicted {Cd2+} was higher than measured, which may reflect a detoxification mechanism of marine organisms in Jinzhou Bay seawater. Overall, a model of this kind can be highly useful for predicting {Men+} in the overlying waters based on the surface sediment chemistry, and can contribute to the development of sediment quality guidelines by linking them with the corresponding water quality criteria.

Distribution and assessment of heavy metals in surface sediments from the Bohai Sea of China

In this study, we analyzed heavy metals in 404 surface sediment samples from the Bohai Sea to measure contamination status and distribution. We found Zn levels to be the highest, whereas Hg concentrations were the lowest of measured heavy metals. We found that the samples containing the most heavy metals were those collected from Fuzhou Bay, Jinzhou Bay, central Bohai Sea mud area, and the Yellow River Delta. Further analyses suggest that these heavy metals in surface sediments in the Jinzhou Bay and Fuzhou Bay pose a serious ecological risk, with substantial Cd and Hg accumulation in the Jinzhou Bay and Yellow River Delta regions being indicative of intense human activities.

Tendency and Causes Analysis of Marine Water Quality of Jinzhou Bay

Based on the two monitoring data of Jinzhou Bay in July 2008, September 2013 and September 2016, this article analysis the temporal trends of marine water quality of Jinzhou Bay. The average concentration of COD, inorganic nitrogen and phosphate is between 1.09mg/L~1.45mg/L, 0.42mg/L~0.711mg/L and 0.006mg/L~0.03mg/L, respectively. The concentration of inorganic nitrogen showed a downward trend while the concentration of phosphate showed an increased trend. Meanwhile, the concentration of COD had no significant change. Results showed that the inorganic nitrogen concentration and phosphate concentration have good correlation with eutrophication index and Eutrophication parameters（E）showing a clear upward trend. The emission of active phosphates and inorganic nitrogen from land-based pollutants are the main cause of this phenomenon.

Benthic trace metal fluxes in a heavily contaminated bay in China: Does the sediment become a source of metals to the water column?

Over three different seasons, seawater, porewater and sediment samples were collected from Jinzhou Bay, a previously heavily contaminated bay, to quantitatively assess the benthic flux of trace metals after a reduction in fluvial/sewage discharge for almost three decades. The spatial distribution patterns of trace metals in seawater, surface sediment, as well as the vertical distribution patterns of metals in porewater and solid phases in short sediment cores were reported. Metal concentrations in seawater and sediment all showed much higher Cd and Zn concentrations inside the Jinzhou Bay compared to the rest of Bohai Sea area. Zn, Ni, Pb and Co all had average benthic fluxes coming out of the sediments to the water column, contributing about 0.5%, 0.3%, 1.4% and 14% to their current standing stock in Jinzhou Bay. Seasonal difference was also identified in seawater and porewater, as well as in the benthic fluxes. In general, benthic fluxes and porewater concentrations all tended to be higher in summer, implying a close relationship between benthic flux and the temperature-dependent organic matter degradation process at the sediment-water interface.Currently, there are clearly still other sources, possibly fluvial/sewage discharge, as the main source of trace metals in Jinzhou Bay waters. For Cd and Cu, concentrations in the water column remain high on an annual basis indicating that sediment still acts as a sink. Conversely, for Pb, Zn, Co, and Ni, the sediment is beginning to act as a source to the water column. Although this may not yet be significant, it will become more and more important with time, and can last for hundreds to thousands of years.

Mercury and methylmercury bioaccumulation in a contaminated bay

The bioaccumulation and the main source of total Hg (THg) and methylmercury (MMHg) in the deposit-feeding polychaete Neanthes japonica collected in Jinzhou Bay, China, were investigated. Compared with the historical data, THg bioaccumulation in polychaetes collected in sediment of Jinzhou Bay was distinctly higher due to higher sediment THg concentration, but MMHg bioaccumulation was significantly lower. THg accumulation in polychaetes mainly derived from its accumulation in sediment. However, MMHg bioaccumulation in polychaetes did not correlate with Hg concentration in sediment. Besides sediment ingestion, MMHg accumulation in polychaetes may partially source from the process of in vivo transformation. The in vivo Hg methylation may take place in polychaetes, according to the excellent correlation between MMHg concentration and THg and inorganic Hg concentration in polychaetes. The biochemical characters in polychaete body, the oxidation-reduction environment and the microbial activity in polychaete gut may be beneficial to in vivo Hg methylation.

Tendency and Causes Analysis of Marine Water Quality of Jinzhou Bay

Based on the three monitoring data of Jinzhou Bay in July 2008, September 2013 and September 2016, this article analysed the temporal trends of marine water quality of Jinzhou Bay. Results showed that Eutrophication parameters (E) is showing a clear upward trend. The emission of active phosphates from land-based pollutants is the main cause of this phenomenon. Large-scale dredging and land reclamation of Jinzhou Bay in recent years resulted in effective removal of contaminated sediment. Heavy metal pollution has been effectively controlled and improved of Jinzhou Bay. For non-persistent pollutant oils from ships must be strictly control to discharge into the sea.

Comprehensive large-scale investigation and assessment of trace metal in the coastal sediments of Bohai Sea

The Bohai Sea is characterized as a semi-closed sea with limited water exchange ability, which has been regarded as one of the most contaminated regions in China and has attracted public attention over the past decades. In recent years, the rapid industrialization and urbanization around the coastal region has resulted in a severe pollution pressure in the Bohai Sea. Although efforts from official government and scientific experts have been made to protect and restore the marine ecosystem, satisfactory achievements were not gained. Moreover, partial coastal areas in the Bohai Sea seemingly remain heavily polluted. In this study, we focused on five coastal regions around the Bohai Sea to study the spatial distribution pattern of trace elements in the sediments and their ecological risk. A total of 108 sediment samples were analyzed to determine the contamination degree of trace elements (Cu, Cd, As, Pb, Zn, Cr, and Hg). Contamination factor (CF), pollution load index (PLI), geoaccumulation index (Igeo), and potential ecological risk index (PERI) were utilized to assess the pollution extent of these metals. Spatial distribution patterns revealed that the sedimentary environments of coastal Bohai were in good condition, except Jinzhou Bay, according to the Marine Sediment Quality of China. The concentrations of Hg and Cd were considerably higher than the average upper crust value and presented high potential ecological risk and considerable potential ecological risk, respectively. The overall environment quality of the coastal Bohai Sea does not seem to pose an extremely serious threat in terms of metal pollution. Thus, the government should continue implementing pollution control programs in the Bohai Sea.

Land-ocean-human interactions in intensively developing coastal zone: Demonstration of case studies

Land-Ocean-Human (L-O-H) interactions in intensively developing coastal zones are demonstrated using four case studies in the western Bohai Sea, China. Three aspects of L-O-H interactions are discussed: 1. Coastlines are the result of Land-Ocean (L-O) interactions, but human activities have changed many coastlines from natural to artificial. In recent years, sea reclamation projects have moved the land and its coastline towards the sea, leading to hydrodynamic changes and affecting both the topography and sediment-erosion dynamics in western Bohai Bay (case study 1). 2. Estuaries are key areas for L-O interactions; river sediments, together with ocean power, shape the topography of the estuarine delta, while river nutrients impact offshore biological productivity. However, due to irrigation and reservoir construction up-stream, runoff and sediments have decreased resulting in increased coastal erosion in the Yellow River Delta (case study 2). Rivers carry industrial and agricultural point and non-point source pollution into the sea, causing marine pollution in Jinzhou Bay (case study 3). 4. Sea-level rise caused by global climate change enhances the role of the ocean. At a local scale, in Binhai New Area, sea-level change is also influenced by vertical land movement along with some land subsidence caused by over-exploitation of groundwater. Rising sea levels exacerbate storm surges and floods, and increase the risk of socio-economic and ecological impacts (case study 4). Because of rapid economic growth in Chinese coastal areas, L-O-H interactions have become the most significant factors changing natural and artificial environments. If the coastal zone is to be developed sustainably, human activities must be regulated.