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Based on multi-channel seismic profiles and MODIS images, the form of internal solitary wave (ISW) packets in Dongsha area of the South China Sea was studied. There are two polar waves: elevation and depression wave, and internal solitary waves can be divided into “bell shape”, “flat shape” and “bowl shape” according to the waveforms. The shape of wave trough is associated with amplitude. Influenced by various factors, the solitions will develop into packets within the propagation process. Two typical wave packets are observed at different locations in Dongsha area: rank-ordered ISW packet and more complex ISW packet, and combined with their locations and propagation, they are considered to be two stages of the propagation process from deep sea to shelf. A rank-ordered wave packet is influenced by submarine topography, Dongsha Reef and wave-wave interaction after Dongsha Island, then turns into a more complex wave packet.

Using in situ hydrographic measurements during June 2015 and satellite altimeter data provided by archiving validation and interpretation of satellite oceanographic data(AVISO), the hydrographical features and circulation with influences of cyclonic-anticyclonic eddy-pair in the northern slope of the South China Sea during June 2015 were studied. The results showed that the low-salinity water in northeast-southwest direction was found in the upper 50 m in the northern slope of the South China Sea during June 2015. The minimum surface salinity values were below 32, which indicated the presence of cross-slope transport in the northern slope of the South China Sea. Due to the existence of cyclonic-anticyclonic eddy-pair in the northern slope of the South China Sea during the observation, the cross-slope currents were found in the upper 100 m,of which the maximum velocity was observed in the intersection of two eddies. In addition, the circulation across the continental slope in the Northern South China Sea derived from the moored current measurements, presented two-layer structure: offshore flow in the upper 100 m and onshore flow beneath 100 m.

The vertical distribution of tidal ellipse parameters (amplitude of the major axis, ellipticity, direction and phase) of the dominant M₂ tidal current in Sanggou Bay are analyzed based on in-situ observed current profile data during kelp-free and kelp-mature periods. The results indicate that the suspended kelp culture has a remarkable effect on vertical structure of tidal current. The parameters of M₂ tidal ellipse vary little in the vertical direction during kelp-free period. In contrast, due to the impact of the suspended kelp, the M₂ tidal ellipse parameters show a significant vertical variation during kelp-mature period. Specifically, moving away from the middle layer towards both surface and bottom boundary layers, the maximum velocity decreases rapidly, the ellipticity increases, the direction of the maximum velocity veers clockwise and the appearing time of maximum velocity becomes earlier. The observed data also indicate that at the middle entrance of Sanggou Bay, the direction of the maximum velocity turns from the north-south direction during the kelp-free period to the northwest-southeast direction during the kelp mature period, which was found to be caused by the relevant change of sea level gradient.

The relationship between the inter-annual variation of hydrological and meteorological factors and the Karenia mikimotoi bloom was analyzed using air temperature, SST(sea surface temperature), wind field and rainfall data from ERA-Interim Dataset, HYCOM+NCODA Global Reanalysis and the stations along Fujian coast in the spring (March to May) of 2005, 2011 and 2012. The results show that decrease of SST in March,increase of SST in May and the higher heating rate may be the main causative factor of Karenia mikimotoi bloom in Fujian coast in 2012. The relatively stronger northerly wind in May formed a stable dynamic environment by gathering the algae onshore, which promoted the Karenia mikimotoi bloom. More rainfall from January to April might provide a well biological and chemical environment for the growth of Karenia mikimotoi by offering a wealth of nutrients and microelements.

The hydrodynamic environment and the salinity field distribution around Liuheng Island are simulated with a 3D current-temperature-salt numerical model and the simulation results are verified with the field data, which shows the computation results are able to reflect the hydrodynamic characteristics and the salty-field objectively. Base on this 3D numerical model, the salinity field distribution after the discharge of the concentrated brine from seawater desalination is calculated and compared with the salinity field distribution before the discharge. The results show that the influence of concentrated brine discharge is mainly centralized at the bottom water layer in a zonation distribution near the outlet around where the salinity is stratified in vertical and the maximum increment of the salinity is about 1.2.

Coastline is important natural resource,the change of coastline may affect the ecological balance and people's life. the remote sensing images of the Xiushan Island of Zhejiang Province in 1970,1980,2003,2008 and 2014 were taken as data resource,while the remote sensing and GIS technology,especially DSAS shoreline analysis method were used to reveal the temporal and spatial variation of shoreline of Xiushan Island over the past 50 years. The results show that a large-scale shoreline change of natural coastline and artificial coastline have taken place in Xiushan Island under the double factors of natural and artificial influence. In general, the coastlines have been reduced, and the overall reduced value is 4 226 m, and 2.491 km² new land area has been created. The artificial coastline has been reduced 4 046 m, the seawall area has been created 1.971 km². Characterized by massive advance to the sea,spatial and temporal changes are significant. The natural coastline has been reduced 214 m,mainly because of the change of sandy coast and muddy coast. In general, the natural coastline appears a small-scale retreat,but in some places, the coastline appears advancing to the sea.

The ecological distribution of ichthyoplankton around Oujiang estuary was surveyed via horizontal trawl in spring and autumn in 2015. 16 species were identified in the two seasons, belonging to 15 genera of 14 families in 8 orders, with most species in Perciformes. 42 individual fish eggs and 295 individual fish larvae and juveniles were collected in the two seasons totally. The species number and abundance of fish eggs, larvae and juveniles in spring were both higher than those in autumn. The dominant species of fish eggs was Konosirus punctatus in spring and Cynoglossus sp. in autumn, and the dominant species of fish larvae and juveniles were Liza haematocheila, Lateolabrax japonicus and Chaeturichthys stigmatias in spring and Stolephorus sp. in autumn. The high abundance value areas of fish eggs, larvae and juveniles were both located around Damen Island in spring, while were scattered to the outer area relatively in autumn, thus the area around Damen Island should be considered in delimiting the Red-line of ecology. A significant correlation between fish larvae and juveniles and salinity and nutrient was detected in spring. Compared to the data in the early 1990s, species composition and abundance of ichthyoplankton in the study area both have been changing. The abundance of ichthyoplankton around Oujiang estuary was lower than that in other inshore areas along Zhejiang Province.

In order to know whether there are impacts of the digestive system during over-wintering stage in Larimichthys crocea, some anatomical, histological, microscopic and submicroscopic technologies were used to study the changes of morphological structure of digestive tract and liver for the cultured large yellow croaker in Xiangshan Bay. The results show that liver weight is significantly decreased (P<0.05) and liver index (HSI) is also extremely decreased (P<0.01) after over-wintering. By microscopic observation, the thickness of wall becomes higher (P<0.05) and submucosa becomes thinner extremely (P<0.01) in esophagus after over-wintering. The thickness of submucosa of stomach is increased extremely (P<0.01) and muscle is reduced significantly (P<0.05) after over-wintering. Furthermore, gastric gland cells is shrinked and the cells' gaps become bigger after over-wintering. Before over-wintering, the gaps of villus in foregut are short, but it become larger after over-wintering. The height of epithelial cell of foregut is reduced extremely (P<0.01) and the long diameters of goblet become smaller extremely (P<0.01) after over-wintering. The height of wall and the diameters of lumen in the midgut are reduced significantly (P<0.05) after over-wintering. The width of wall in the midgut is reduced extremely (P<0.01) but the thickness of serous is increased significantly (P<0.01) after over-wintering. The long and short diameters of goblet cells in the hindgut become extremely smaller (P<0.01). While the thickness of serous in the hindgut is increased significantly (P<0.05). Before over-wintering, the gaps of the liver lobule boundary are not obvious and there are lots of fat droplets in the liver cells. However, after over-wintering, the liver lobule boundary becomes obvious and the fat droplets are decreased. Transmission electron microscope show that the fat droplets are small but abundant in the liver cells and the rough endoplasmic reticulum are developed around the nuclear before over-wintering. While after over-wintering, the fat droplets become bigger and the number of droplets are reduced in the liver cells. Moreover, the rough endoplasmic reticulum is reduced too. This research shows that histological structures of digestive tract and liver of large yellow croaker juveniles have been changed after over-wintering. The lipid of liver has been consumed and the synthesis of protein of liver cells has been weakened. It is proposed that the staff should strengthen the management of feeding lager yellow croaker for restoring the structure and functions of digestive tract and liver.

Maldane sarsi Malmgren, 1865 is affiliated to Maldanidae Malmgren, 1867. It is a common polychaetous species in the benthic ecological research and widely distributed in the world ocean. Specimens of M. sarsi deposited in the Marine Biological Museum of the Chinese Academy of Sciences in the Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China (MBM, IOCAS) were examined. Important taxonomic features were analyzed based on the specimens and literatures. Maldane sarsi Malmgren, 1865 was redescribed based on the specimens collected from Chinese coastal and Chukchi sea areas. It can be identified through the following characteristics: head plate and anal plate present; cephalic keel high; cephalic rim laterally notched, posterior part of the rim extends anteriorly to form a pocket structure; pigments on the anterior body present or not; rim of anal plate laterally notched, dorsal rim smooth, ventral rim smooth or crenulated.

Rhodococcus sp. EPR-134, Rhodococcus sp. EPR-147, Rhodococcus sp. EPR-157 and Rhodococcus sp. EPR-279 were isolated from water samples of East Pacific Ocean, extraction of pigment and pigment full wavelength scan were carried out in this study. Based on the whole genome sequencing, the related genes in carotenoid metabolic pathways were analyzed. Pigment full wavelength scan results show that strain EPR-134 does not have a kind of caroteniod production ability, while other 3 strains of Rhodococcus can produce carotenoids, and the carotenoid composition was different. Genome analysis show that there are more complete gene clusters in the 4 bacterial genomes. crt E gene、crt B gene and crt I gene are very important in the metabolic pathway of caroteniod producing, and by analyzing amino acid sequence homology of these genes in different strains, it is find that amino acid sequences of these genes in the strain EPR-134 share the lowest sequence homology compared with other 3 strains. This may be the key reason why strain EPR-134 can't produce carotenoid. The results of this study may lay a preliminary foundation for genetic modification of the carotenoid producing Rhodococcus and construction of carotenoids producing engineering bacteria.

In order to study the extent of eutrophication in Shenzhen Bay, spatial and temporal distributions of bacterioplankton biomass were seasonally investigated at three sampling stations in Shenzhen Bay in May, June, September, October and December in 2015 and March in 2016. The seasonal bacterioplankton biomass ranged from 4.90×10^-2 μg·mL^-1to 86.90×10^-2 μg·mL^-1, with an annual average of 3.14×10^-1 μg·mL^-1. The bacterioplankton biomass was the greatest in winter (5.98×10^-1 μg·mL^-1), followed by autumn (3.02×10^-1 μg·mL^-1), summer (2.79×10^-1 μg·mL^-1), and spring (7.52×10^-2 μg·mL^-1) in turn, revealing different seasonal patterns in this bay. The bacterioplankton biomass decreased horizontally from the center of the bay to the mouth of the bay and the top of the bay, with a higher biomass at station near the area for cultivation. The bacterioplankton biomass was significantly po sitively relatived to NO^-₂-N and NH⁺₄-N in Shenzhen Bay. The seasonal abundance of bacterioplankton ranged from 2.45×10⁶ ind·mL^-1 to 43.50×10⁶ ind·mL^-1, with an annual average of 1.57×10⁷ ind·mL^-1, implying serious eutrophication in this bay and revealing a decreasing pattern from the center to the mouth and the top of the bay.