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Denmark Strait Ocean Front(DSOF) has higher value in oceanographic research, such as provides a reference to the research on local climate change, fish distribution and the mesoscale eddy around the Denmark Strait. In addition, the research of the DSOF also has a higher application value in the military field. However, there has been lack of systematic research domestically and internationally for the DSOF. In this study, using WOA13 data, the location, spatial intensity distribution and the corresponding seasonal variations of the DOSF were analyzed. The results indicate that: the front axis at the west of 34°W is relatively stable above 150 m, whereas it varies with depths as well as seasons at the east of 34°W. The front intensity distribution is not uniform vertically and horizontally, and in general, the difference between maximum and minimum values are as higher as 3 times in the horizontal direction. The vertical salinity front mainly concentrates above 100 meters, and its intensity is decreasing with depth. The maximum value of temperature front intensity locates below the surface, and when the water depth is below 300 meters, it gradually decreases with the increase of water depth, but in some areas, such as at 27°W and 28°W, the front intensity increases quickly because of the affection of the bottom topography.

An astronomical tide and tsunami coupled numerical model of East China Sea was established by adding tidal boundary conditions into COMCOT tsunami model. Two different tsunami waves, positive leading wave and negative leading wave, were designed according to the dislocation direction of earthquake plates during an undersea earthquake with magnitude of 7.6, which occurred in Ryukyu Trench. The tsunami wave crest and astronomic high tide level occurred at the same time through the modification the phase of tsunami wave. Comparison about the summation of astronomic tide level and tsunami wave level was made between the result of coupling model and linear sum. It demonstrates that in both cases mentioned above, the tsunami wave is in advance no matter for the positive leading wave or negative leading wave. And it's higher for the result of linear sum with respect to tsunami wave height.

Harmful algal blooms(HAB) is one of the most serious marine disasters, which not only reduces fishery production, deteriorates the marine environment, affects coastal tourist industry, but also causes human poison. The satellite remote sensing technology has the characteristics of large-scale, low cost, synchronized and rapid monitoring, therefore it becomes an important method for HAB observation. In this paper, a HAB remote sensing monitoring system is developed based on C++ language. The system can achieve the whole procedure automatically from the satellite remote data acquirement and satellite image process, products generation, and it can automatically identify the HAB region using the spectral reflectance and inherent optical properties derived from remote sensing data. Currently, the national monitoring department has adopted this system for the operational monitoring of HABs in the East China Sea. From April to September 2013,the system had produced 55 red tide remote sensing monitoring products, and had a good application effect. The system was used to extract the location and area of 27 large red tide events which occurred in the East China Sea in recent years. Compared with the results of the field observation, it has a good effect on the recognition of most red tide range, and the discriminating accuracy of red tide is about 80%.

Sediment samples were collected from two sites in the artificial channel salt marsh of the Duliujian River, through continuous sampling along the side wall of artificial dig pits. The chronology was developed using ²¹⁰Pb and ¹³⁷Cs dating methods, and grain size, foraminifera and hydrologic data were used to study the deposition of modern flooding events. The results show that ²¹⁰Pb_exc activities are obviously lower in 3~6 cm and 10~14 cm layers, corresponding to the main peak and minor peak of ¹³⁷Cs. In addition, comparing with the adjacent layers, these two layers show coarse-grained, poorly sorted, low foraminiferal abundance and high foraminiferal brokenness percentage. The results of ²¹⁰Pb dating show that the main peaks of ¹³⁷Cs was 1963, corresponding to the global ¹³⁷Cs fallout well; however, the minor peaks was not 1986, so it was not caused by the accident of the Chernobyl Reactor. The hydrological data show that there were two flood events in 1963 and 1996 in this area. Therefore, it can be concluded that these two special layers of S4 and S5 sites were caused by the flood events. It is indicated that multi indexes can help to reconstruct flood deposition, which also can help to find disasters and climate events in geological periods, and to provide scientific data for disaster prevention and future plan.

The sediment transport patterns were revealed in the Qiongdongnan Basin on the Northern Slope of South China Sea since Late Miocene by the research of the sediment filling patterns since the period of post-rift accelerated subsidence. On the basis of the previous analysis on the potential provenance, combined with the summary and induction of the exploration achievement in the research area, the types of the deep-water sedimentation were identified and the combinations of the deep-water depositional packages which have genetic relationship or the same source were built. In addition, the sediment transport patterns were classified tentatively. The results show that since Late Miocene, there are 4 potential sedimentary sources in the Qiongdongnan Basin: they are Hainan Island' sources, West Yinggehai' sources, Southern uplift' sources and Shenhu uplift' sources, respectively. The sedimentary transport patterns can be divided into three types: they are vertical direction, axial direction and turning direction sedimentary transportation.

Underwater archeology is a new research field in China. In China's coastal waters, there exist a large number of sunken ships along the ancient “Maritime Silk Road”. Recently, underwater archeology has become an active research for the coastal provinces. As such, it is necessary to establish an appropriate survey procedure, using high precision marine geophysical prospecting equipments, e.g., the multibeam sounding system, shallow seismic profiler, side scan sonar, magnetometer, and even ROV systems. In the present contribution, we report the basic procedures adopted for underwater archeological survey over the Chuan Island sea area, Guangdong Province, together with a preliminary description of some new archeological findings. Chuan Island is an important mooring place associated with the ancient “Maritime Silk Road”. Using the multibeam bathymetry system and the side scan sonar, some relict pieces of ancient porcelain in Qing Dynasty, as well as some iron cannons, have been found in the coastal waters of Mud Bay, Datie Bay and Wuzhuzhou Island. The discovery of underwater cultural relic in Chuan Island can promote the activity on the cultural relic investigation along the ancient “Maritime Silk Road”, and the underwater archeology can also gained more attention.

The variation regularity of submarine pipeline's status in Hangzhou Bay was analyzed based on inspecting data over years. The variational reasons of pipeline's exposed and buried status were explored based on the hydrodynamic numerical model and the integrated factors such as the self-burying design of Spoiler, the flow characteristics and the seabed evolution, the human activities in Hangzhou Bay and so on. The results show that above 80% of the pipelines are buried under seabed,while some parts of pipeline are chronically unburied, and the unburied pipelines are mainly located in the deep groove of north shore and the frontier of Andong Beach. The pipeline's scouring is close related to the seabed variational characteristics, the angle between the flow and pipeline, and the self-burying design of Spoiler. In addition, the reclamation project in the south beach of Hangzhou Bay may play an important rule for the pipeline's exposed and buried status.

Based on the Instrument Control Toolbox in Matlab, DGPS signal data can be received via the serial port, so this technique can be used for real-time visualization in ship-mounted ACDP survey. The method was tested at Zhoushan sea area for 28-hour continuous ship-mounted ADCP observation. During the test, the real-time visualization system worked fine, tracks of DGPS, the speed of the vessel, and the direction of the vessel renewed automatically every second, which was satiable the requirement of real-time visualization. The only thing we need to do before the survey is to prepare one background map, the system is stable and is easy to use, and the most important, the system workes stably during the 28-hour observation.

The uncertainties and randomness are the most general issues existing in the risk assessment of heavy metals in sediments, the Monte Carlo technique was introduced for simulating the Hakanson potential ecological risk index, in order to make the risk assessment more scientific and rational. Potential ecological risk assessment modified with the Monte Carlo technique was used to analyze the ecological risk of heavy metals (Cu、Pb、Zn、Cr、Cd、Hg、As) in surface sediments from adjacent waters of Dushan Port. The results show that the pollution degrees of Cu, Pb and Zn are medium contaminated, while others belongs to slight contaminated. The results also illuminate that the probabilities for slight degree and medium degree pollution levels of C_d (the comprehensive pollution index) are 38.32% and 61.68% respectively.As for the ecological risk, all of 7 heavy metals and RI(the potential ecological risk index) are at a slight risk 1evel. The sensitive analyses indicate that Cu、Zn and Cr play leading roles in C_d and RI.

Base on the investigation of Dongshan Bay in May (spring) and August (summer) 2011, the horizontal distribution and its influencing mechanism of dissolved heavy metals (Cu, Pb, Zn, Cd and Cr_(T)) in seawater were analyzed. The results indicated that: (1) The distribution of the heavy metals tended to be a peak source in the southwest sea areas and gradually decreased from west to east, whereas the trend of seasonal variation showed that the heavy metal contents in summer were higher than those in spring except Zn. (2) Since 1980s, changing trend of Cu, Pb and Cd contamination basically showed inverse “U” pattern conforming to environmental Kuznets curves while the content of Zn in seawater increased year after year. (3) The correlations between the dissolved heave metals were analyzed using the mathematic statistic method. It showed that except Cr_(T), among the rest 4 heavy metals, each two had a significant positive correlation in spring, while in summer, only Cu-Cd and Cd-Cr_(T) had a positive correlation. (4) Temperature, salinity, pH, COD, DO, nutrient and the biological effects were the main affecting factors for the variation of dissolved heavy metal contents in seawater.

Based on the macrozoobenthos and environmental materials from 35 stations in Dongtou Islands and adjacent sea area investigated in April 2015, the characteristics of macrozoobenthic community structure and its relationship with environmental factors were analyzed. Results show that a total of 122 species are identified, including 57 species of Polytraeta, 34 species of Crustacea, 19 species of Mollusca, 5 species of Echinodermata and 7 others species. The number of species is about 1~22 at each station, with lower values of species number concentrated in Oujiang River Estuary. The average biomass of macrozoobenthos is 3.35 g/m², and the average inhabited density is 321 ind/m². Polytraeta has an advantage on the species compositions, while Mollusca has the more advantages on the biomass and abundance. The average of Shannon-Wiener index(H′) is 1.29, the average of Margalef's species richness index (d) is 2.45, and the average of Pielou's evenness index (J′) of species is 0.66. By species similarity cluster analysis and multidimensional scaling ordination analysis, three communities of macrozoobenthos can be divided in Dongtou Islands and adjacent sea area, those are: Heteromastus filiforms-Yoldia similis-Raphidopus ciliatus-Sternaspis scutata (Community Ⅰ), Yoldia similis-Heteromastus filiforms-Aglaophamus dibranchis-Sternaspis scutata (Community Ⅱ), and others (Community Ⅲ ). Canonical correspondence analysis show that the sea water temperature, water salinity, activated phosphate, activated silicate, dissolved inorganic nitrogen, chemical oxygen demand and the total organic carbon in surface sediment are the main environmental factors affecting the macrozoobenthic community. The ABC curves indicate that the macrozoobenthic communities in Dongtou Islands and adjacent sea area have suffered contamination or have disturbed to a certain degree. Compared with historical data, the average biomass and abundance of macrozoobenthos have not obviously changed. The dominant organism of the species compositions are Polytraeta and Crustacea, instead of Polytraeta and Mollusca, and the number of Turritella bacillum in the area has obviously declined.

Green Turtles(Cheloniamydas)were cultured at the water temperature 15, 20, 25 and 30 ℃ for 90 days to study the effects of different water temperature on 17 blood biochemical parameters. Results showed total cholesterol (CHOL) and triglyceride (TG) of cardiac function increased first and then decreased with the increase of water temperature and reached the maximum at 25 ℃, with the values of 3.83±0.30 mmol/L and 0.60±0.08 mmol/L respectively. High density lipoprotein (UHDL) tended to decrease first and then increase. The concentration of creatine kinase decreased with the water temperature increased. Of the liver function, albumin (ALB) and total protein (TP) increased first and then decreased with the temperature rise and reached the maximum at 25 ℃ with the values of 6.47±0.66 g/L and 36.33±1.96 g/L. Other index such as A/G, lactate dehydrogenase (LDH), alkaline phosphatase (ALP), aspertate aminotransferase (AST), alanine aminotransferase (ALT) and total bilirubin (TBIL) showed no significant changes while the water temperature raised (P>0.05). For the index of renal function, the concentration of blood uric (URIC) and creatinine (CREA) decreased while the water temperature increased and the concentration of urea nitrogen (BUN) had no significant change (P>0.05). Integrating the effect rule of water temperature on the plasma biochemistry, green turtles cultured at the water temperature 25 ℃ had a low storage material consumption.