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Due to the lack of geological and geophysical data of the Diaoyudao Uplift, the previous studies on this area are unsystematic, so there are many controversies about its tectonic evolution. Based on gravity, magnetic, and multichannel seismic data, the tectonic and sedimentary characteristics of the middle Diaoyudao Uplift were analyzed, which located to the east of the Xihu Depression, East China Sea Basin. The evolution model of the middle Diaoyudao Uplift was further refined. More residual sags are found in the north than in the south of the middle Diaoyudao Uplift. Accordingly, the middle Diaoyudao Uplift can be divided into the north and south segments. The boundary of the two segments is on the extended trace of the Zhoushan-Guotou Fault. In addition, magmatic intrusions are confined below the T20 unconformity in the west, whereas a basement pinnacle caused by magmatic activity exists in the east. It is found that the gradient zone of gravity anomaly corresponds exactly to the western edge of the basement pinnacle. Taking the west edge of the basement pinnacle as the boundary, the middle Diaoyudao Uplift can be divided into two parts from west to east. And the western zone can be further divided into two subzones, including part Ⅰ with magnetic rocks and part Ⅱ with residual sags. The western part of the middle Diaoyudao Uplift is from the strong tectonic and magmatic deformation of the eastern Xihu Depression, whereas the east part retained the original Diaoyudao Uplift. The comprehensive analysis of above features showed that the present-day middle Diaoyudao Uplift was formed by many episodes of tectonic events and magmatic activities around an ancient uplift.

The Andaman Sea is highly valued because of its large number of internal solitary waves. Most of its research is based on remote sensing but lacks field observation. A mooring system located in the central Andaman Sea from 2016 to 2017 to investigate internal solitary waves, and the body forcing theory, as well as three internal solitary wave theories: shallow water Kortweg-de Vries (KdV), deep water and finite-depth theory have been used to explore the sources of the internal solitary waves. The result shows that the internal solitary waves in the study area mainly propagate to the northeast, and the maximum amplitude of them is above 100 m. the sources calculated by body forcing theory are consistent with the previous remote sensing results, however, it could provide a ability estimation of different sources to excite internal solitary waves. The phase velocity of internal solitary waves shows that the central Andaman Sea may have a Lee waves generation mechanism, and the finite-depth theory is proved to correspond to the observation result in the Andaman Sea.

The climatology distribution of isopycnal layer in the Indian Ocean were analyzed based on the WOA18 (World Ocean Atlas 2018) dataset firstly. And then three time periods were defined as 1985-1994, 1995-2004 and 2005-2017 to research the decadal variation. The results show the climatology distributions of 11 isopycnal layers. As far as σ₀=26.00kg/m³ (reference pressure as 0 dbar) isopycnal layer was concerned, the layer was outcropping at roughly 40°S. As the potential density increased, the outcrop area of the isopycnal layer gradually moved southward until it disappeared. When the potential density was greater than σ₀=26.95 kg/m³ and less than or equal to σ₂=37.00kg/m³, the deepest part of the isopycnal layers were located in southern Madagascar, and the depth of the North Indian Ocean was almost the same. Furthermore, present study investigates the decadal variances of depth and salinity of isopycnal layers, where the three layers include σ₀=26.00 kg/m³, σ₁=31.87 kg/m³ (reference pressure as 1 000 dbar) and σ₂=36.805kg/m³ (reference pressure as 2 000 dbar). Studies show that the depth and salinity of the isopycnal layer had significant decadal changes in the three periods from 1985 to 2017. For the isopycnal layer of σ₀=26.00kg/m³, the depth decreased first and then increased during the three periods. And the decadal variation of the isopycnal depth was mainly located in 30°S-40°S(the rapid change area of the isopycnal depth). The difference of salinity between 1995-2004 and 1985-1994 was basically opposite to the difference between 2005-2017 and 1995-2004 when the isopycnal layer was σ₀=26.00kg/m³. For the isopycnal layer of σ₁=31.87kg/m³ and σ₂=36.805kg/m³, the decadal variations of the depth were concentrated on 40°S-50°S. Overall, the salinity of σ₁=31.87kg/m³ show a decreasing trend but σ₂=36.805kg/m³ show an increase trend.

The annual greatest tidal bore in the Qiantang River almost occurs during typhoons. Based on the measured tidal data and combined with the harmonic analysis of astronomical tides, the influence of typhoon on tide downstream of the tidal bore formation section in the Qiantang River Estuary was studied, and then the tidal bore changes indirectly caused by tidal changes was discussed. The results show that typhoons cause the changes in low tide level, tidal range, tidal bore arrival time and duration of flood tide, and indirectly affect tidal bore through typhoons, resulting in the changes in tidal bore height, steepness, propagation speed, arrival time and flow velocity. In general, during a typhoon, the tidal bore height at Yanguan increases by 0.18 m on average, and the time of tidal bore arrives 37 min earlier on average, the propagation speed of tidal bore from Ganpu to Yanguan increases by 8.9% on average, the steepness of tidal bore increases, and the velocity of tidal bore increases or decreases, but the unit width flow rate increases.

Based on the SRTM15_Plus depth data, the submarine canyons in the Asian Continental Margin were identified by using the method of combining topographic surface flow analysis with contour geometry analysis. And the morphology, distribution characteristics and evolution process of the canyons in the study area were analyzed. A total of 531 submarine canyons are identified and divided into linear, meandering and dendritic according to the plane shape. The numbers of each type of canyon are 239, 75 and 217 respectively. Linear canyons are mainly distributed in the Bering Sea Basin, the Kuril Basin and the South China Sea. Meandering canyons are mainly distributed in the subduction zone east of the Bay of Bengal. Dendritic canyons are mainly distributed in the junction of the Japan Trench, the Izu Bonin Trench and the Nankai Trough, the South China Sea and the Sumatra subduction zone. According to the distribution of the canyons and the tectonic background in the study area, the morphological evolution process of “Linear-Meandering” was discussed. According to the morphological information of the main valley of dendritic canyons, it is inferred that there are “Linear-Dendritic” and “Meandering-Dendritic” morphological evolution processes.

Pyropia haitanensis is one of the most important economic seaweeds for mariculture in China. In order to investigate genetic diversity of P. haitanensis, we collected 125 individuals from 11 populations along the southeast coast of China. We amplified 408 bp length of COX gene fragments and 488 bp length of rbcL gene fragments. The concatenated COX and rbcL gene fragments had a length of 896 bp, and the ratios of T, C, A, G were 34.9%, 14.6%, 34.2% and 16.3%, respectively. We detected 128 mutation sites, including 19 single-base mutation and 109 simple information sites. The mean nucleotide and haplotype diversity of 11 populations were 0.035 9±0.028 4 and 0.817 0±0.024 0, respectively. The concatenated COX and rbcL gene fragments defined 31 haplotypes from 125 individuals, and Hap1,Hap10 and Hap16 were the core haplotypes, accounting for 32.8%, 12.8% and 24.8% of all individuals, respectively. The result of distance analysis showed a linear correlation between population-pairwise genetic distances and geographic distances (R²=0.002 2, p=0.735 4). Genetic distance increased with the increased geographic distance, but geographic isolation had not yet been formed. The ML tree constructed from haplotypes showed no obvious geographical lineage structure in P. haitanensis, indicating potential gene exchange among populations.

In order to study the occurrence and distribution of organotin compounds(OTs) in marine shellfishes from coastal areas of Zhejiang, six OTs including butyltin and phenyltin species were determined in shellfishes which were collected from seven sampling sites of Zhejiang by GC-FPD after sample treatment with pentylized derivatization, and then the health risk assessment was studied. The results showed that phenyltin species were the main contaminants in shellfishes, while the concentration ranges of phenyltin compounds were from nd to 203.6 ng·g^-1(dw). The concentrations in shellfishes varied from nd to 8.2 ng·g^-1(dw) for butyltin compounds. DPT and TBT were high levels in phenyltin compounds and butyltin compounds, respectively. Concentrations of OTs in mussels (Mytilus edulis) were obviously higher than those in other species, indicating that they had stronger abilities of enrichment for OTs. The distributions of OTs concentrations in different sampling sites showed that both butyltin and phenyltin compounds mainly came from antifouling paints for ships. The results of human health risk assessment showed that food exposure of OTs posed no health risks for consumers living the coastal areas.

Based on 2007-2018 Landsat series of multi-source remote sensing satellite data, the spatial-temporal characteristics and affecting analysis were carried. The radiative transfer equation algorithm and split-window algorithm were used to retrieve sea surface temperature. After verifying the algorithm through Landsat-MODIS comparison, it shows that the inversed results have a significant linear correlation with the MODIS SST products. Based on the temperature retrieve results of the study area, the characteristics of the seasonal, annual and tidal variation were analyzed. In the aspect of seasonal distribution, the range of spring thermal discharge which is the largest in four seasons is 7 times of autumn one. In the aspect of interannual distribution, with the expansion of installed capacity, the range of thermal discharge continues to expand, reaching to the peak in 2018. In terms of the influence of tides on thermal discharge, the thermal discharge at the moment of high water slack is larger than that of the low water slack. West wind is beneficial to the diffusion of thermal discharge, but its impact on thermal discharge is limited.

With the increasing saturation of coastal nuclear power plant sites, it is a new idea to select islands as nuclear power plant sites. In view of the problem that the island sites are vulnerable to typhoon disasters, the design basis flood level of the sites is determined by studying astronomical high tide, sea level rise, possible maximum storm surge and maximum typhoon wave. The results show that the astronomical high tide level of 10% superfrequency in this region is 3.14 m and the predicted sea level rise in the next 80 years will be 0.31 m. Based on MIKE21 model, a variety of hypothetical typhoon paths were constructed using tropical cyclone parameters. The northwest moving path of typhoon with 0.5R (R is the maximum wind speed radius of typhoon) to the left of the site produces the possible maximum storm surge, with the maximum water level of 2.99 m. When the typhoon moves in the direction of west, with R to left of the site, the maximum H_1/100 wave height reaches 8.02 m, especially on the east side of the island, which suffers from severe typhoon wave threats. Considering the superposition of various basis flood factors, the design basis flood level of the island nuclear power plant site reaches 11.25 m. Because the proposed site is located on an island and surrounded by sea waters, compared with other coastal sites, the storm surge level is relatively small, but the impact of waves is more significant.