In this paper, a new type of breakwater structure of semi-elliptic breakwater was proposed, and a series of model tests were carried out on two different size semi-elliptic breakwater models. The aim of this study was to analyze the hydraulic characteristics of elliptic arc-shaped structural plane under wave action. The results provided a reference for the construction design of this new type breakwater. The influencing factors of wave force of semi-elliptic breakwater were determined byπtheorem, including wave steepness H/L, relative wave height H/D and scale parameter b/L. Based on the experimental data, the variation characteristics of wave forces on semi-elliptic breakwater with these three factors were analyzed and the stress characteristics of two semi-elliptic breakwater models were compared. The results showed that the wave force increased with the increase of H/D and decreased with the increase of H/L and b/L. The wave force in model 1 was larger, and the horizontal wave force was much larger than the vertical wave force. The wave force in Model 2 was smaller, and the horizontal wave force was close to the vertical wave force.

Due to the interference of human activities and the change of environment, the area of oyster reef in China keeps shrinking, which seriously affects the stability of marine ecosystem. To restore oyster reef, 440 mu of oyster reef was first established by oyster shell material in June 2021 in the intertidal zone of Yellow River Delta. Four months later, the development of oyster reef was investigated and analyzed. The results showed that the sinking depth of oyster reef varied between 15 and 20 cm, but the height of the whole oyster reef was above 1m; and the average oyster density on oyster reef was 0.216±0.128 ind/cm². The amount of oyster on the oyster shell was distinctly higher than that in bamboo rod and polyethylene rope. These results indicated that oyster shells are suitable for the attachment of oyster, and the reef based on oyster shells is suitable for oyster reef restoration in the intertidal zone of Yellow River Delta.

Based on the monitored information of seawater quality in the coastal areas of Hainan Province in 2020 and using principal components analysis, we identified the pollution factors dominating the change of seawater quality, characterized spatial-temporal distribution using N/P ratio and eutrophication index methods, and evaluated the nutrient structure and eutrophication level in the coastal areas around Hainan Island. The results showed that dissolved inorganic nitrogen and dissolved inorganic phosphorus are the main pollution factors in the coastal areas around Hainan Island in 2020, both are the highest in concentration in the normal water period. The pollution was mainly due to the terrestrial inputs. The concentrations of dissolved inorganic nitrogen and dissolved inorganic phosphorus in northern coastal areas were generally higher than those in southern coastal areas, especially in Haikou Bay and its adjacent sea areas, and Xinying Bay, where the pollution was mainly due to human activities and hydrodynamic forces. The highest concentrations of dissolved inorganic nitrogen and dissolved inorganic phosphorus appeared in Xiaohai of Wanning in the southern area where the pollution was mainly due to aquaculture activities and hydrodynamic forces. The coastal areas around Hainan Island is considered to be a potential eutrophic area with nitrogen limited, and the eutrophication level in the coastal areas around Hainan Island was generally low, only serious in regional areas, especially in Xiaohai of Wanning.

The neon flying squid Ommastrephes bartramii is a short-lived squid species. As an "ecological opportunist", its habitat is regulated by climatic and environmental factors. O. bartramii stocks are mostly distributed at the junction of the Kuroshio and Oyashio Currents. The environmental conditions within this area are complex and changeable. The marine environmental factors had an important impact on the biological characteristics of O. bartramii in the Northwest Pacific, which included population structure, age and growth, ingestion and migration during different life cycle stages. In addition, the abundance and spatial distribution of O. bartramii resources in the Northwest Pacific were very sensitive to the mesoscale marine environments and large-scale climate change, and responded rapidly to these changes. In this study, we suggested that the first step should clarify the complete life history process of squid to explore the response mechanism of O. bartramii to environmental change in the Northwest Pacific, and then examine the dynamic change characteristics of O. bartramii at various scales. One another important step is to accurately determine the suitable range of the key environmental factors that had been widely used for O. bartramii. Under the background of large-scale climate variability research, it was necessary to consider the impacts of various anomalous climatic events, and to quantify the marine dynamic environmental factors at small and medium-sized space-time scales. According to the results, a model suitable for the assessment and prediction of O. bartramii resources in the northwest Pacific should be established. Model outputs can provide a theoretical support for the rational development, efficient utilization and scientific management of O. bartramii resources.

As one of the economically important cephalopods with obvious diurnal vertical migration characteristics, the jumbo flying squid Dosidicus gigas abundance and habitat distribution are largely affected by the change of vertical water temperature in the habitat. In this study, the maximum entropy model was used to select the water temperature at the depths of the key water layers in each months according to the contribution rate, using the fisheries data of Dosidicus gigas off Peru from January to December during a period from 2006 to 2015 and the water temperature data at different water layers (0, 50, 100, 150, 200, 300, 400, 500, 750, 1000 m). According to the response curves of this squid to key water temperature factors, we further obtained the suitable temperature range at the key water layers in each months, analyzed the monthly variations in the water temperature factors at the key water layers, and identified the potential habitat distribution map in peak fishing season (September to February). The results showed that the water temperature factors at the key water layers in each months strongly affected the temporal and spatial distribution of squid habitat off Peru, especially the water temperature at the depths of 0, 50, 100, 150 m co ntributed the main impacts. The suitable water temperature range at the key water layers changed from month to month. The temporal and spatial distribution of the potential habitat of D. gigas was consistent with the movement of the longitudinal and latitudinal gravity centers of the fishing ground. Both moved southwestward with the month. Our findings suggested that the habitat of D. gigas off Peru sea was affected by the water temperature above the depths of 150 m, and the temporal and spatial distribution of the habitat could be well modeled using the vertical water temperature between 0 and 150 m.

Heavy metal pollution seriously affects the ecological environment and human health. In order to scientifically manage the heavy metal pollution, it is necessary to explore the law of heavy metal migration and transformation in the river basin and predict the whereabouts of heavy metal migration. In this study, the migration and transformation processes of heavy metals in the basin and the main influencing factors were summarized. The literature on the migration and transformation model of heavy metals in the basin was analyzed, the existing models, the research progresses and application of each model were summarized, and the future research direction of the model was prospected. The results showed that the heavy metals simulated by basin heavy metal models were limited and the simulation processes were mainly concentrated between surface water and soil. Future development directions of heavy metal watershed models include adding Tl, Co and other heavy metal simulation modules, improving the migration processes of heavy metals in groundwater and between organisms, and increasing the function of dynamic change of external environment such as land use type and soil physical and chemical properties.

High-quality marine management talents are an important guarantee for the development of marine programs, while improving the level of marine management disciplines construction is the fundamental way to cultivate talents. However, there are still some gaps in the research on the disciplinary orientation, development status and evaluation system of marine management disciplines in China. Therefore, the disciplinary orientation of marine management disciplines was clarified in this paper and the construction status of marine management disciplines in China was briefly sorted out. Then, the marine management disciplines evaluation system was initially constructed, including 4 primary indicators and 13 secondary indicators, and the index weight was determined by the analytic hierarchy process. Finally, based on systematic and scientific induction analysis, several suggestions for improving the construction of marine management disciplines in China’s universities have been put forward, to provide theoretical support and practical guidance for the construction of marine management discipline.

Reclamation, as a way to broaden the land space for development, plays a positive role in social and economic development, whereas it will lead serious threat to marine ecological environment. From strong support to strict management and control, China has paid more and more attention to the ecological problems caused by reclamation. However, the one-size-fits-all policy had made a large number of reclamation projects which became historical problems to be solved. This paper reviewed the case of Yue island project in Wanning city, Hainan province and analyzed the causes of historical and problematic reclamation, mainly including: (1) imperfect, conflicting and insufficient laws, regulations policies and systems; (2) government’s ineffective supervision, failure to enforce the law and act of substituting punishment for custody; and (3) weak legal consciousness, insufficient social responsibility consciousness, weak awareness of the ocean in the society. Based on the cause analysis, relevant countermeasures and suggestions for prior prevention, in-process supervision and post-processing were put forward, in order to help solve the historical problems of reclamation properly.

Using the random point process method, this paper made a statistical analysis of the large wave process in the northern Yellow Sea with an effective wave heights of 2.5 m ~ 4.0 m in 30 years (1988-2017), and obtained the statistical laws of cold air cyclone waves and cold wave waves in the northern Yellow Sea from November to next April, and estimated the number of large wave processes in this period. Using the compound extreme value distribution, the represent value of wave heights for 100A and 50A return periods in this period was calculated. The results showed that the large wave process with an effective wave height of 2.5 ~ 4.0 m in the northern Yellow Sea from November to next April was a homogeneous Poisson process, and the extreme wave heights of 100 year return period was about 8.0 m. The research results can provide reference for the research of wave disaster and the engineering design of offshore buildings in the northern Yellow Sea.

The concentration of nutrients such as nitrogen and phosphorus in water, sulfide content in sediment and dissolved oxygen content in water may be the limiting factors for aquaculture capacity in baiting type offshore cage aquaculture. However, studies on nitrogen, phosphorus, sulfide content in sediment and other limiting factors are all based on the perspective of meeting environmental standards. From the perspective of aquaculture itself, the content of dissolved oxygen is often the key factor to control aquaculture density and limit aquaculture capacity. For this purpose, A dimension analysis model of dissolved oxygen was established and the aquaculture capacity of Trachinotus ovatus was calculated as an example in Houshui bay offshore cage aquaculture in this paper. The results showed that the theoretical cage culture capacity of Trachinotus ovatus was about 22500 tons. Compared with the existing fish production, it can be seen that the aquaculture capacity has reached saturation in Houshui bay offshore cage aquaculture. According to the results of the aquaculture capacity and the proportion of current cage culture specifications, the estimated number of cages with a circumference of 40 m and 60 m were about 2127 and 435, respectively, and the total number was about 2562 which could be judged that the number of cage culture in Houshui bay has also reached saturation, and it was not suitable to be further developed. Due to the limitations of each method, the aquaculture capacity should not be exceeded in practice, and the number of cage culture could be comprehensively considered according to the calculation results of the two methods. The development trend was to eliminat cages with 40 m circumference year by year and developed large-scale cages, which could not only reduced the number of cage culture, but also reasonably adjusted the density of single cage according to the aquaculture capacity, so as to obtain the maximum economic and environmental benefits.

As necessary support for coastal engineering, non-submerged pile foundation greatly affects the coastal hydrodynamics and ecological environment. Taking Hangzhou bay as an example, we analyzed the influence of non-submerged pile foundation on the tidal dynamics and suspended sediment characteristics using a three-dimensional hydro-sediment numerical model. The results showed that before and after the construction of pile foundation, the distribution of the suspended sediment concentration (SSC) correlated with the currents. Owing to the blocking effect of pile foundations, there was an obvious cylindrical disturbed flow around the piles. The bridge blocked water and formed a low-flow negative pressure zone at the back side, and increased the order of vorticity near the pile foundation; the flow velocity and SSC increased between the pile foundations. The bridge affected the tidal phase and thus the tidal level and tidal asymmetry. The peak and ebb current direction was basically perpendicular to the axis of the bridge. Variations in the near bottom velocity changed the bottom stress, which affected the sediment resuspension and thus changed the SSC. The construction of the bridge accelerated/slowed down the southward sediment flux on the sea/land side. Turbine piles in the open ocean had similar effects with smaller magnitudes.

Based on the simple frame reef, a square diagonal plate separated reef was improved in this paper. In order to study its beach protection effect, the flow blocking effect, flow field effect and local scour condition were analyzed by the combination of physical test and numerical simulation. The experimental results showed that the new reef had different blocking effects under different upstream angles, and the angle arrangement of 0 upstream was obviously better than that of 45. At a distance of the length of reef from the center of the reef, upwelling began to appear. The ratio of maximum rising velocity to incoming velocity hardly changed with the change of incoming velocity. In a certain range, the smaller the opening of the reef, the better the flow blocking effect; the more obvious the internal vortex, the more obvious the water exchange between different layers, and the richer the flow field. The flow and sediment movement around the reef was complex, and the dynamic scouring equilibrium was reached about 2 h when the inflow velocity was controlled at 0.35 m/s. Therefore, when launching this type of reef, the opening size should be reduced as much as possible and the 0°upstream layout should be selected as much as possible, so as to achieve the best effect.

A strain of benthic algae was isolated from the sediment samples collected in Danjiangkou Reservoir using dilution separation and small droplet separation methods. Based on morphological observation and homologous analysis of 18S rDNA, LSU rDNA and rbcL sequences, the strain of diatom SG0529 obtained from Danjiangkou Reservoir was identified as Navicula cryptocephala. Using sodium nitrate, ammonium chloride and urea as nitrogen sources, the change characteristics of the growth and chlorophyll fluorescence parameters (Fv/Fm, α, Ik, ETRmax) of N. cryptocephala under different nitrogen conditions were analyzed. The results showed that the strain of N. cryptocephala grew normally in sodium nitrate, ammonium chloride and urea medium, but the responses to different nitrogen forms were quite different. In sodium nitrate and urea medium, the specific growth rate and the cell density of N. cryptocephala increased with increment of nitrogen concentration. Under ammonium chloride culture condition, the growth rate of N. cryptocephala increased firstly and then reduced as nitrogen concentration increased in culture medium. With the increase of sodium nitrate and urea concentration, the photosynthesis performance of N. cryptocephala increased, and the high concentration of ammonium chloride condition inhibited its photosynthesis reaction, indicating that increasing the concentration of nitrogen within a certain range is beneficial to the growth of N. cryptocephala, improving its photochemical reaction, and high concentration of ammonium nitrogen inhibited its growth and photosynthesis reaction. Compared with ammonia and urea, nitrate was more able to promote the growth of N. cryptocephala. Under the condition of nitro nitrogen culture, the maximum cell density and growth rate of N. cryptocephala are optimal. In addition, N. cryptocephala improved the rate of PSII electron transfer, accelerate the use of light energy, to provide energy for the absorption of nitrate. Moreover, N. cryptocephala improved α value to increase the utilization efficiency of light energy in response to nitrogen deficiency with the consumption of nitrogen for resisting adverse conditions. Our findings provided not only an experimental basis for the molecular identification of N. cryptocephala in fresh water, but also basic data for water quality protection and ecosystem management in Danjiangkou Reservoir.

The mid-latitude northwest Pacific Ocean is the high incidence area of sea fog, and it is also the way for China to reach the Arctic sea. However, due to the few observations at sea, the understanding of the formation mechanism of sea fog is limited. From September 12 to 14, 2019, the research ship "Xiangyanghong 1" recorded a sea fog event in the Oyashio extension area. In this paper, the formation mechanism of the sea fog was studied mainly by numerical simulation, numerical experiment and observations from scientific research ships. The results showed that: (1) The sea fog occurred in the warm area of the extratropical cyclone, and the warm front of the synoptic scale advanced to the north, forming a large range of front inversion over the cold water of the Oyashio extension providing favorable weather background conditions for the development of the clouds/fog. (2) The atmospheric boundary layer above the cold water side of the ocean front (sea surface temperature front) was a "double inversion" structure. The superposition of subsiding inversions and frontal inversions caused by the subsiding branch of the local low-level secondary circulation forced by ocean front was an important reason for the formation of the "double inversion". The numerical results showed that with the smoothed ocean front, the strength of the sinking branch of the secondary circulation in the boundary layer was weakened, the scope of the "double inversion" structure disappeared, and the scope of the fog area was significantly reduced. (3) Both temperature and humidity in the fog rose, but the actual water vapor pressure rose faster than saturated water vapor pressure, the humidification effect was greater than the warming effect, which was obviously different from the cooling and humidification dominance of sea fog in spring and in summer in the Yellow Sea. This study revealed one of the reasons why sea fog tends to occur on the cold side of the ocean front in the open ocean, which can provide a new theoretical support for sea fog forecast.

The contents of carbon, nitrogen and phosphorus of Saccharina japonica at different growth stages are of great ecological significance to reveal the material circulation and energy flow. Through field investigation and indoor analysis, we measured the contents of C, N, P and the environmental characteristics of aquaculture waters at different growth stages of cultured S. japonica in Xihu harbor. at different growth stages, the content of C in S. japonica ranged from 37.62% to 38.62%, with an average of 37.98 ± 0.38%. With the growth of seaweed, the contents of N and P decreased gradually. N content ranged from 2.33% to 4.25% with an average of 3.33 ± 0.75%. P content varied between 0.15% and 0.30% with an average of 0.20 ± 0.06%. The N / P of seaweed remained stable, with an average of 14.54 ± 1.31. C / N and C / P increased gradually with the growth of S. japonica. The C / N ranged from 9.10 to 16.43 with an average of 12.10 ± 3.00, and C/P ranged from 126.50 to 248.53 with an average of 175.10 ± 51.51. The contents of nitrogen and phosphorus in S. japonica respond significantly to environmental factors and growth characteristics. The main factors are salinity, pH and nutrients. The changes of C / N and C / P reflect that the nutrient utilization efficiency to N and P increases with the rapid growth of S. japonica.

Effects of Cu²⁺ and ocean acidification on the photosynthesis of Phaeodactylum tricornutum have been widely studied, but the studies on their coupling effects are less. The effects of different CO₂ concentration (400 and 1500 μatm CO₂) on the specific growth rate (μ), photosynthetic pigment content and photosynthetic performance of P. tricornutum under different Cu²⁺ concentrations (0.1, 0.25, 0.5 mgL^-1Cu²⁺) were measured. The results showed that the μ, photosynthetic pigment (chlorophyll A and C) content, maximum photochemical quantum yield (Fv/Fm), maximum relative electron transfer rate (rETRmax), energy captured per unit reaction center for electron transfer (ETo/RC) and energy captured per unit reaction center for electron transfer to the PSI electron acceptor side (REo/RC) were inhibited by 0.5 mgL^-1 Cu²⁺ under 400 μatm CO₂ condition, respectively. These parameters were significantly lower than those at 1,500 μatm CO₂ (p<0.05), respectively. Our findings suggested that high concentrations of Cu²⁺ not only restricted the growth of P. trichodensis but also inhibited the activity of photosystem II (PSII) while ocean acidification alleviated the these inhibitions. In the coastal waters where ocean acidification and heavy metal pollution are more serious, ocean acidification could improve the tolerance of P. tricornutum to Cu²⁺ and assist it to survive the complex and changeable environment.

In this study, we investigated the abundance and distribution of dissolved inorganic phosphorus (DIP) in Meishan bay. We collected water samples from the bay and its sediments (16 stations in the bay and the cecum segment) as well as the input rivers (15 stations in estuaries entering the bay) during the summer of 2019. The dissolved inorganic phosphate was mainly analyzed to reveal the spatial distribution characteristics in the surface water, overlying water, and sediment pore water in Meishan bay and the estuary. Our results showed that the content of dissolved inorganic phosphorus in the estuary and cecum of Meishan bay was generally higher than that in the bay implying riverine transportation as a possibly major external source of phosphorus. Moreover, the P levels in the sediment pore water of the estuary and cecum were overall higher than the overlying water. Our estimation using Fick’s First Law showed that the dissolved inorganic phosphorus would tend to diffuse from the sediment to the overlying water, and the average diffusion flux was on average 0.39 μmol·m^-2·d^-1 (estuary) and 0.98 μmol·m^-2·d^-1 (cecal segment). Therefore, the sediments may be an important source of dissolved inorganic phosphorus in the bottom water. The overall diffusion flux of dissolved inorganic phosphorus in the Meishan bay sediments was smaller than that of other sea areas and estuaries. Thus, our data suggests that the P pollution of the Meishan bay sediment was relatively lighter than its counterparts.

A 42-day experiment was conducted to investigate the effects of red marine yeast Rhodotorula mucilaginosa JM-01 addition in feed on the growth performance, physiological health indices and intestinal bacteria of Penaeus vannamei. In the study, only one control (basic feed without R. mucilaginosa) and one treatment group contained R. mucilaginosa 1×10¹⁰ cfu/kg were set up. The experimental results showed that the survival rate of treatment group and control group were all above 90%, and the difference was not significant (P>0.05). The body weight, specific growth rate, feed efficiency and apparent digestibility of P. vannamei in the treatment group were higher than those in the control group (P<0.05). Compared with the control, the treatment group significantly improved the activities of superoxide dismutase (SOD), alkaline phosphatase (AKP), acid phosphatase (ACP), lysozyme (LSZ) and total nitric oxide synthase (TNOS) (P < 0.05). The 14-day Vibrio parahaemolyticus challenge experiment showed that the mortality rate of the control group (73.06%) was significantly higher than that of the treatment group (40.52%). As compared to the control, the species diversity of intestinal flora increased, the abundance of dominant flora stricture changed, and the flora structure showed an obvious differentiation. In conclusion, R. mucilaginosa JM-01 has a good potential application in the culture of P. vannamei.

To enrich the basic data of the toxic effects of marine environmental hormones on benthic animals, the acute toxicity of decabromodiphenyl ether (BDE-209) with different mass concentrations to and its effect on the digestive enzyme activities of Urechis unicinctus were analyzed in this study. The experimental results showed that LC₅₀ of BDE-209 for U. unicinctus at 48 h, 72 h, and 96 h was 153.170 mg/L, 96.791 mg/L, and 60.042 mg/L, respectively, while BDE-209 was safe at the concentration of 6.004 mg/L. BDE-209 at the concentration of 60 μg/L or less can induce alkaline protease, acid protease, cellulase and lipase significantly, and the maximum induction degree was found at 0.6 μg/L. After 3 days of exposure, there was a positive correlation between alkaline protease activity and dose concentration in the treatment group with stress concentration of 0.6 μg/L and below (P<0.01). Amylase activity was inhibited in all treatments, and a significant negative correlation was observed between amylase activity and concentration after 1 day of exposure (P<0.05). The activities of digestive enzymes decreased under the long-time stress of BDE-209. After exposure for 15 d, the activities of digestive enzymes in all treatments were significantly lower than those in control group except alkaline protease in 60 μg/L or less treatments. Although 6,000 μg/L of BDE-209 was slightly lower than the safe concentration (6.004 mg/L), it showed an inhibited effect on the digestive enzyme activities. BDE-209 was low-moderate toxic to U. unicinctus, and a certain concentration of BDE-209 can induce digestive enzymes except amylase, but long-term stress at low concentration or at near-safe concentration can inhibit digestive enzyme activities.

In order to improve the utilization rate of shrimp meal feed, in this study, we attempted to screen an acid-producing protease strain L-22 from the shrimp meal hydrolysate in combination with modern fermentation technology. Physiological, biochemical, and 16S rDNA identification of the strain was carried out. The sequences were compared with BLAST and use to construct a phylogenetic tree. The nucleic acid sequence was deposited into GenBank with an accession number through Bankit. The conditions that affected the fermentation of the strain were explored under liquid fermentation conditions. The results showed that the bacterium was a safe strain that can tolerate high temperature and high salt environments, and hydrolyze gelatin, starch, tyrosine among others. It was determined to be Bacillus subtilis. The molecular weight of its proteins as were shown in SDS-PAGE electrophoresis varied between 29.0 KDa and 44.3 KDa. Under liquid fermentation conditions, the free amino acid content and enzyme activity were used as indicators. The amino acid content in the fermentation broth changed from initial 4.29±0.259 mg/mL to 6.65±0.20 mg/mL, and the enzyme activity increased from 25.17±0.840 U/mL to 39.90±0.95 U/mL after a partial optimization of the conditions. The strain obtained has a good effect on improving the utilization rate of shrimp meal.

Salinity is an important water environmental factor, which has influence on heavy metals accumulation. However, there is few study on how the effect of salinity on the bioaccumulation of hexavalent chromium (Cr(VI)). In this study, the semi-static method was used to exposure juvenile coral trout (Plectropomus leopardus) with acute aqueous phase Cr(VI) concentration (5, 20, 50 mg/L; 4, 8, 12, 24 h) experiments for different salinity (16; 32). Cr content was calculated with atomic absorption spectrophotometry (AAS-Y193S) method, and the bioaccumulation factors and carcinogenic risks were assessed. The results showed that Cr content at 16 salinity was high than that at 32 salinity within 24 h in each tissues significantly (P < 0.05). The highest value was 82.15 mg/kg which appeared in liver. Tissues can be ordering as liver > intestine > heart > muscle in the content. The BAF value at 16 salinity was mostly higher than that at 32 salinity, and the highest value was 3.62 which appeared in intestine, 5 mg/L at 24 h. Carcinogenic risk exceeded the acceptable range under 12 and 24 h treatment. The highest value of CR was 1.189×10^-3 at 16 salinity, 50 mg/L at 24 h. In this study, we found that 16 salinity not only effectively increased the Cr accumulation in juvenile coral trout but also increased the BAF and CR. Our findings improved our understanding of the relationship between the Cr bioaccumulation and salinity, and provided the basic data for studying the relationship between Cr bioaccumulation and salinity in marine fish.

Scomber japonicus is one of the main economic fish species in the Northwest Pacific, and plays an important role in the marine fishery of China. Based on the full understanding of the early life history of S. japonicus in the northwest Pacific, in this study, we used lagrange particle method to couple FVCOM physical model and individual-based-model, and constructed an individual-based ecological dynamic model of S. japonicus in the northwest Pacific to predict its transportation distribution and resource recruitment in the early life stage. The recruitment of S. japonicus and the transport of eggs and larvae from ground to the nursery were simulated under normal climate conditions from mid-March to the end of July. The results showed that the model could well simulate the early growth, resource recruitment and transportation trend of S. japonicus in the northwest Pacific. The number of S. japonicus recruitment continued to decrease from March to July, and decreased almost linearly from March to April. The mortality rate reached its peak from the end of March to the end of April. From May, the mortality gradually decreased. From June to July, the mortality of larval fish decreased due to biological and environmental factors. Regarding the transport and distribution of S. japonicus, from the beginning of the simulation to the end, the transport of fish eggs and larvae are obviously controlled by the Kuroshio, and they have been passively transported along the direction of the mainstream axis of the Kuroshio.

Phthalate esters (PAEs) are of widespread concern due to their high toxicity and wide distribution. Solid phase extraction and gas chromatography were used to analyse the levels of four common phthalate esters, DMP, DEP, DBP and DEHP, in water and organisms from Qingdao's nearshore waters, and to assess the ecological risk of PAEs in water to biota such as algae, fish and crustaceans, as well as the health risk to adults and children due to the consumption of marine organisms. The results showed that the total PAEs concentrations in seawater ranged from 3.31-16.2 μg/L and the total PAEs concentrations in marine organisms ranged from 125.3-865.4 μg/kg. The ecological risk of DMP and DEP in seawater was low and largely negligible, but DBP and DEHP posed a moderate to high risk to algae, crustaceans and fish, especially DEHP for algae and crustaceans with mean risk entropy values of 29.80 and 3.55 respectively. In particular, the carcinogenic risk levels caused by the consumption of shrimp nuns and pike crabs exceeded the risk thresholds. Therefore, the ecological and health risks of PAEs in Qingdao's nearshore waters need further attention.

Based on the survey data of Tianjin coastal waters in Bohai Bay from 2009 to 2018, the interannual variation trend and spatial distribution characteristics of petroleum in surface seawater were systematically analyzed, the pollution status was evaluated, and the correlation between petroleum and other environmental factors was discussed. The results showed that the content of petroleum in the surface seawater of Tianjin coastal area in summer from 2009 to 2018 ranged from 0.024 9 to 0.056 0 mg/L, with an average of 0.037 9 mg/L, showing a downward trend with time. The spatial distribution characteristics were higher in the near shore and lower in the far shore, and showed a decreasing trend from north to south. From 2009 to 2018, the proportion of relative clean and above (grade 1-3) water quality stations has been increasing, reaching 95% in 2018. There was a significant positive correlation between petroleum and active phosphate and inorganic nitrogen (p<0.01), and the correlation coefficients were 0.191 and 0.398, respectively. There was a significant negative correlation between petroleum and salinity (p<0.01), and the correlation coefficient was -0.306. There was a significant positive correlation between the petroleum and COD (p<0.05), the correlation coefficient was 0. 168. Compared with other sea areas in China. The concentration of petroleum in surface seawater in summer was at a medium level, and the petroleum pollution was relatively light.

Snow cover regulates the water cycle and energy exchange in most parts of the Northern Hemisphere (NH). It is important to study the temporal and spatial dynamic snow cover frequency (SCF), snow cover area (SCA) and snow cover phenology (SCP) in the NH. Based on Google Earth engine cloud platform and MODIS satellite data, this study analyzed the temporal and spatial variation characteristics of SCF and SCA in the NH from 2000 to 2019, as well as the large-scale variation and contribution of SCP. The results showed that there were obvious interannual and regional differences in the variation trend of SCA in the NH. The SCF decreased at the rate of 0.4~0.6 (d/a) near Eurasia (55 °~65 ° N, 30 °~120 ° E), Mongolia Plateau, Stanov Plateau and Greenland. The SCA in spring and winter in the NH decreased significantly, and the average annual downward trend in winter reached 1.9×10⁵ km². The number of snow cover duration days increased significantly in areas near Kazakhstan and the Central Plains of North America, with an average annual increase of 1.1d. The change of SCP was mainly due to the change of snow cover end date, and the correlation between them was 0.89. The analysis of regional contribution to the change of SCP in the NH showed that the change of SCP in the NH was mainly dominated by the change of SCP in Eurasia, and the contribution rate was about 60%.

To explore the effects of climate change on the abundance and suitable habitat of Dosidicus gigas off Chile, a combination of fishery data (2011-2017) of D. gigas and environmental data (sea surface height above geoid anomaly, sea surface salinity, and water temperature at 400 m) from CMIP6 under the climate scenarios of SSP126, SSP370 and SSP585 were used to predict the spatiotemporal variations in the habitat and resource abundance from 2015 to 2100. The results showed that SSHAGA and SSS declined under ssp370 and ssp585 scenarios while remaining were relatively stable under ssp126 scenario. In contrast, Temp_400 m showed a consistent increase across all scenarios. The environmental factors also displayed significant spatial differences across different climate periods. From 2015 to 2100, the habitat suitability index (HSI), percentage of suitable habitat area and resource abundance of D. gigas showed an increasing trend under SSP370 and SSP585 with a decline in percentage of unsuitable habitat area while changes were more stable under SSP126. In different periods of climate change, relatively higher resource abundance and suitable habitat were mainly distributed in the central and northern Chile during the three periods under SSP370 and SSP585 scenarios and in the south of 42°S under SSP126 scenarios. Compared with the short-term climate change, the suitable habitat and resource abundance of D. gigas within exclusive economic zone off Chile increased more than those in the high seas, and decreased less than those in the high seas in medium and long term. In addition, the center of gravity of suitable habitat for D. gigas tended to move northeastward with SSHAGA identified as the relatively key environmental factor influencing the spatial distribution.

According to the measured wave data from September 2018 to August 2019 in the sea area of western Guangdong, this paper mainly studied the characteristics of wave variation, and the joint distribution of wave height and period and wave type distribution characteristics month by month. The differences in the wave spectrum for different typhoon waves were explored. The results showed that the maximum wave height was 14.7 m, which caused by typhoon “Mangkut”, and the maximum monthly average significant wave height was 1.6 m in December. There were more wind waves in winter,and the swells accounted only 38%. While in other seasons, swells accounted for more than 60%. There were obvious differences in wave spectrum type, peak frequency and frequency range during the transit of typhoon “Mangkut” and “Baijat”. The wave type was mixed wave, in which the swell and wind wave predominated respectively. The research results could provide references for marine disaster prevention and reduction, ocean environmental assessment and ocean engineering design.

With the increase of high-intensity human activities in the coast of northern Jiangsu, a large amount of nitrogen and phosphorus pollutants discharged into the coastal area, which caused the deterioration of water quality. Especially in the radial sand ridges area, the ecosystem health continued to decline, associated with the aggravated water eutrophication. Aimed to the eutrophication problem of the radial sand ridges area in northern Jiangsu, the environmental carrying capacity of nitrogen and phosphorus pollutants on the town-jurisdiction scale in Dongtai and Dafeng counties were calculated. Based on the three-dimensional hydrodynamic water quality model, a water quality-based simulation optimization method was established, with the development of the sea-basin-jurisdiction division. The results showed that the environmental carrying capacity of DIN was 2 366 t/a under the national sea water quality criteria in Dongtai and Dafeng counties, with the top proportion in Xinfeng town, and the bottom proportion in Huangshagang town. The environmental carrying capacity of PO₄-P was 202 t/a, with the top proportion in Dafeng port economic development zone management committee, and the bottom proportion in Dazhong town. The research results can provide a quantitative basis for the differential total pollution discharge control on the town-jurisdiction scale in Dongtai and Dafeng countries.

As a key area of land-sea interaction, flow and sediment play an important role in material transport in the estuary. Based on the multi-time-space measured hydrology and suspended sediment data of the Oujiang estuary, the characteristics of tidal current and suspended sediment were analyzed, and the harmonic analysis method was used to the quantitative separation of suspended sediment concentration (SSC). The results showed that the SSC was mainly controlled by the resuspension effect during the observation period, and the residual flow and suspended sediment flux were seaward transport. The temporal and spatial variation of bed shear stress was one of the main dynamic mechanisms of the ‘lag effect' of suspended sediment, which showed that the phase of suspended sediment lagged behind the phase of flow velocity for about 2 h, resulting in the peak values of SSC at the slack times.

In the perspective of the “profound change unseen in a century”, frequent and cutting-edge issues in ocean governance, serious ideological divisions and challenges to governance regulations have been emerging. Global ocean governance is facing numerous contradictions including the mismatch between the supply and demand of public goods, the ideological conflict between neoliberal institutionalism and populism and the misalignment of the rights, responsibilities and capabilities of governance actors. As a specific form of global ocean governance, the South China Sea (SCS) governance is facing severe challenges including legal and institutional deficiencies and geopolitical issues. The COVID-19 pandemic, populism threatening to cooperative governance and intensification of geopolitical competition hindering governance development have put additional pressures on the human-ocean relationship, further exacerbating the contradictions in SCS governance. In the new era, China should fully leverage the enhanced discourse power brought about by the peaceful rise of China, improve the efficiency of governance product provision through the advancement of island and reef functional construction, deepen the construction of governance regulatory systems to safeguard maritime order, and cooperate with ASEAN to develop the blue economy, so that a community of ASC can share the future of the South China Sea, and jointly address the coming challenges.

The data of cross-calibrated multi-platform (CCMP) (1991—2020) wind field were used as the background wind field to reconstruct the wind field in the Yellow Sea and Bohai Sea for 30 years. By comparison, the observed wind field and the reconstructed wind field were in good agreement. Using the reconstructed wind field data to drive the SWAN model, the calculated significant wave height and the measured data at the Caofeidian station were in good agreement. Based on the calculation results of SWAN, the wave elements of the 10-year return period were calculated to provide input boundary conditions for MIKE21 SW model. By calculating the wave fields near the fishing ports, the hidden dangers of marine disasters in ten fishing ports in Tangshan were analyzed. The results showed that there were no hidden dangers of marine disasters in the ten fishing ports in Tangshan, but there were potential marine disaster risks in Xindaihe fishing port.

The application of drones and VR (virtual reality) technology in the teaching is a trend. The landform of rocky coast in the Shilaoren area in Qingdao, China, was taken as a case in this paper, to create the VR spherical panorama of the bedrock coastal landform with a UAV and field work. Firstly, the types, features and evolution of bedrock coastal landform in the Shilaoren area were generalized. Secondly, the production steps and key technology of the VR spherical panorama of bedrock coastal landform were presented. Finally, a VR spherical panorama of bedrock coastal landform with functions of non-contact, immersion, and remote interactive operation, was created. In addition, the influence of tide and wave on panorama making and its solution were discussed. Through online and offline teaching practices, the VR spherical panorama of bedrock coastal landform had proven to be a beneficial tool for class teaching, arousing great interests and getting high recognition. Besides online teaching, this VR spherical panorama could also be applied to ocean science popularization and ocean tourism.

The conservation and management of shark resources is an important part of global fishery resources governance. With the continuous decline of shark resources in the world, the Indian Ocean Tuna Commission, as one of the five major tuna regional fisheries management organizations in the world, has also paid increasing attention to the conservation and management of shark resources. From 2005 to 2022, the Indian Ocean Tuna Commission adopted a total of 17 resolutions on the conservation and management of shark resources, and the fishery management systems formulated, which include mandatory data statistics requirements, fishing vessel position regulation among others, and greatly ensured the effective implementation of the resolutions. Based on the analysis of the current situation of the conservation and management of shark resources, in this paper, we pointed out the future development trend of shark resources, which includes strengthening the statistics of shark data, stricter conservation and management measures, increasingly strengthening fishery management cooperation, and assuming greater responsibility of flag states. These developments are of great significances to form a shark resources conservation and management system with the guiding concept of promoting the balance between the scientific and rational development and utilization of shark resources and the healthy and sustainable development.

In order to realize all-day and all-weather wave observation at low cost, this paper proposes a design scheme of a gravitational wave gauge based on MEMS attitude sensor. The wave gauge collects original signal through attitude sensors including a three-axis accelerometer, a three-axis gyroscope, and a three-axis geomagnetometer, and converts the coordinate system through the quaternion method to obtain the vertical acceleration signal, and uses the Fourier transform to convert the time-domain acceleration signal into a frequency-domain signal for quadratic integration to obtain the wave height data, and completes the analysis of the wave eigenvalues by the upper-span zero point method. A wave simulation device was used to conduct a simulated wave measurement experiment, and compare the full wave height data measured by the self-developed wave gauge with the standard sine function, and to analyze the indication error of the wave eigenvalues. The results showed that the indication error met the first-level accuracy. Finally, a comparison experiment of marine wave measurement was carried out with the SBY1-1 wave gauge in the offshore area of Rongcheng city, and the wave measurement results were strongly correlated. Experiments showed that the wave gauge could stably and accurately complete the task of ocean wave measurement.

Xiong'an new area is a millennium plan and it is a great national event. The lake Baiyangdian, located in the central-south part of Xiong'an new area, plays a regulating role in the weather, climate, and water resources in both the local and the North China region due to its lake effects. This study analyzed the multi-scale variations in the land-lake breeze characteristics in different areas of the lake Baiyangdian using observations of 13 stations in the lake and its surroundings. The meteorological and statistical methods were applied. The results showed that the land-lake breeze phenomenon existed in all areas, with alternating wind directions between day and night in 2023. On average, the mean wind speeds at the stations near the lake in both the v-direction (north-south) and the u-direction (east-west) exhibited an obvious out-of-phase feature. The maximum lake breeze reached 0.5 m/s and typically occurred in the afternoon (13:00-16:00), while the maximum land breeze was 0.4 m/s and appears in the morning (6:00-09:00). In general, the lake breeze was stronger than the land breeze, with the lake breezes in the northern and eastern parts of the lake Baiyangdian being stronger and lasting longer than those in the southern, western, and central regions. Within the lake, the v-direction lake breeze formed one hour later than in the u-direction, and the northern area's lake breeze was the strongest, reaching 0.5 m/s. In the Xiong'an north urban area, which was farther from the lake, a distinct land-lake breeze pattern was observed in the v-direction, whereas it was less pronounced in the u-direction. Anxin experiences the earliest land-lake breeze, and Rongcheng the latest, with the maximum lake breezes ranging from 0.6 to 0.7 m/s, which were stronger than those in both the lake interior and the areas near the lake. Significant monthly and seasonal variations also existed in the land-lake breeze, which was the strongest from January to June, followed by October to December, and weakest from July to September. Spring was the strongest, followed by winter, and relatively weak in summer and autumn. A specific land-lake breeze case from April 18 to 19, 2023, along with Xiong'an Ruisi real-time field data, showed consistent results with the general characteristics of land-lake breeze, highlighting the alternating wind directions between day and night and the increase in wind speed across different areas of the lake Baiyangdian.

In this paper, the breakup, reflection and polarity transformation of internal waves propagating over the seabed were simulated in the flume, based on the topography of the South China Sea. Both qualitative and quantitative analyses of the evolution of the internal waves along the bottom topography were conducted by application of the dyeing technique and high-speed image recording system. It was found that the energy dissipation of internal waves was related to the ridge heights and the distance between the two submarine ridges. The amplitudes (a) of the internal waves decreased after two ridges, but grew larger when propagating up the slope prior to polarity transformation. The waveforms observed in the experiments matched well with the KdV theory predictions for small wave amplitude cases. For an internal wave of medium size of amplitude, the experimental results were in between the KdV and mKdV theory predictions. For large wave amplitude cases (a/H>0.09), the results were more consistent with the mKdV theory.

The submerged breakwater is mainly used for coastal protection due to its function of eliminating waves, so that the beach from the submerged embankment to the shoreline is subject to less wave impact. The traditional submerged breakwater is mainly composed of trapezoidal or vertical wall sections. The movement of the wave particles hits the embankment which breaks the waves. However, it faces the problem of erosion and damage due to the strong action of the water in front of the embankment on the foundation and the embankment. If the cross section of the submerged breakwater is designed as a concave curved surface, the water quality points of the waves will come along the curved surface of the breakwater to impact the upper water body to achieve the function of wave attenuation, and at the same time, the impact on the foundation and the breakwater will be reduced, so that the cross section size of the submerged breakwater will be reduced and the safety will be ensured. In order to explore the wave dissipation performance of the concave curved submerged embankment and the rectangular vertical submerged embankment under different wave heights and water depths, an indoor model test was carried out in a wave tank. The results showed that: the shape of the headwind surface had a significant influence on the wave elimination effect of the submerged embankment. The influence of wave height and water depth factors was smaller than that of rectangular vertical embankment.

Under the background of the goal of "emission peak and carbon neutrality" and power shortage, new energy is a significant problem for China's sustained development. As an inevitable choice, nuclear power plants (NPPs) have ushered in a period of rapid development. However, the operation of NPPs requires large amounts of water resources as cooling water and produces continuous thermal pollution, impingement and entrainment effect simultaneously, which may produce significant impacts on the receiving water body. Therefore, it is extremely necessary to understand the negative effects of the NPPs construction on aquatic ecosystem. Previous studies proved that the water intake and drainage of circulating cooling water affected the ecological environment balance of the adjacent sea area, emerged some ecological problems such as ecological disasters, and caused the evolution of the regional ecological environment. It is not easy to describe the long-term ecological impacts of the construction and operation period of the NPPs on the coastal areas. Specifically, this review comprehensively elaborated on how circulating cooling water and thermal discharge affects the marine ecological environment, aiming to provide substantial scientific support for the ecological and safe use of coastal nuclear power, long-term reliable utilization of nuclear power, and the monitoring and protection of the marine ecological environment in China.

The species composition, dominant species, abundance, biomass, biodiversity and community structure of polychaetes were analyzed based on the data collected from Yellow Sea in spring (April and May) of 2014. A total of 110 polychaete species in 67 genera, 37 families, were collected. The mean abundance and mean biomass of polychaetes were 1362 inds./m² and 6.92 g/m², respectively, in spring. The Shannon-Wiener diversity index (H') was 3.94. The dominant species were Mediomastus californiensis, Ampharete acutifrons, Sternaspis scutate, Terebellides stromii and Sigambra bassi in the surveyed area. It was shown that the abundance of polychaetes was higher in the western part than in the central and eastern parts. The distribution of polychaetes mainly was affected by sediment type and water depth.

The storm surge flooding numerical model was based on the ADCIRC model. The computation of submergence on the typhoon and extratropical storm surge was proceed. Combing the results from the computation and the astronomical tides, the hazard distribution can be defined. The vulnerability analysis was determined by the land use types. With the hazard distribution and the vulnerability, the risk assessment and zoning of storm surge disaster were carried out. It was shown that the influence from the typhoon storm surges was greater than the extratropical storm surges. And the area of risk under the influence 955 hPa typhoon storm surge was 646.67 square kilometers that was the biggest. The seven littoral towns were all in the risk area. The results were meaning for raising the emergency response & recover capability.