Although the length of short array multi-channel streamers is limited,the absence of equipment for positioning and depth fixing, e.g., birds, magnetic compass, tail mark, etc., will bring some problems, such as inaccurate seismic geometric definition, to the subsequent procedure of data processing. In addition, different sinking depths without correction of depth fixing at different receiving sections along the short towing cable will destroy the relationship of the theoretical hyperbolic curve between time and distance. As to the short-array multi-channel seismic reflection data, therefore, we utilize the surveying navigation data to calculate the real shot track points, and then the interpolation algorithm weighted with inverse ratio of distance is employed to estimate the trajectory coordinates of the receiving points, which aids in obtaining the authentic geometric parameters of the total array. In order to resolve the distortion of time-distance curve caused by inconsistent depth of receiving cable, we calculate the theoretical reflecting positions of common mid-point (CMP) with hyperbolic curve and gauge the static correction of receiving arrays with different sinking depths. Finally, distortions of the reflection event caused by the non-uniform sinking depths of receiving array are eliminated by the fitting algorithm of static correction. The application of above processing processes to the short-array seismic reflection data collected in the Ross Sea, West Antarctica produces high-resolution stacked seismic reflection profiles, which provides great technical assistance for following work of geological interpretation.

Resuspension and its distribution of sediment depend upon three interacting components namely the characteristics of the mobile sediment, the bed forms and the forcing hydrodynamics. A good understanding of the process of sediment resuspension is important in sediment transport. In this paper, in-situ measurements of wave, current, and suspended sediment concentration profiles in the marine ranching of Xiangyun Bay were carried out. The vertical distribution characteristics of suspended sediment in the bottom boundary layer under the wave-current action were analyzed. The results show that the resuspension of seabed sediments in the study area is controlled by storm-waves. The bottom shear stress under storm wave is 10−15 times of the critical shear stress of sediment, resuspension of sediment lags behind storm-wave for 2−3 hours. The type of vertical distribution of suspended sediment is "I" under small wave load, the vertical distribution of suspended sediment in the bottom boundary layer presents a power exponential function, which is "L" type under storm-wave. Bedforms evolved with wave and current action, and which affected the resuspension process of sediments. ${u_{*w}}{\rm{/}}{u_{*c}} = 1.00$ can be used as a criterion to distinguish the bedfroms under the dominant control of wave or current. The value of ${u_{*w}}{\rm{/}}{u_{*c}}$ under wave load is higher than that under the dominant control of wave, and the cutoff value between them increased with the increase of wave load.

As tidal waves propagate into the estuary, they are featured by significant longitudinal variation in seasonal scale due to the nonlinear interactions between tide and river discharge. In this study, the variations of tide-river dynamics in terms of tidal damping rate, wave celerity and residual water level slope were explored based on long-term time series of tidal water levels from 2002 to 2014 along the tidal reach of the Changjiang River (including the Tianshenggang, Jiangyin, Zhenjiang, Nanjing, Maanshan and Wuhu stations) in together with the monthly averaged river discharge observed at Datong hydrological stations. Subsequently, the underlying controlled factors that influence the tidal wave propagation were discussed. It was shown that the seasonal difference in tide-river dynamics was gradually reduced in the seaward direction. We identified a transitional zone located between the Tianshenggang and Jiangyin stations, where the seasonal differences in tidal range are 0.01 m and −0.04 m, respectively. Generally, upstream from Jiangyin Station the dynamics character was river-dominated, while in the lower reaches it was mainly controlled by the tidal forcing. In addition, we show that there exists a threshold in river discharge in the upper reaches of the tidal reach of the Changjiang River due to the increase of residual water level and hence water depth caused by the residual water level slope. This phenomenon was particularly true in the upstream reach between Maanshan to Wuhu stations, where the threshold of river discharge was approximately 33 000 m³/s. The results obtained from this study can enhance our understanding of tide-river interaction, and will, hopefully, provide guidelines for water resources management in the tidal reach of the Changjiang River.

Sub-bottom profile is based on the acoustic signal (frequency in hundreds to thousands Hz) in the sediment propagation to reflect the sedimentary formation structure. The seabed reflection coefficient is closely related to the sediments physical properties. The Biot-Stoll theoretical model can predict the physical properties of seabed sediments and establish the relationship between acoustic parameters such as reflection coefficient and physical parameters, but the results obtained by using different parameters in different sea areas are different. For this, this article is based on the measured sediments physical parameters in the northern slope of the South China Sea to establish the relationship between the reflection coefficient and the sediments physical parameters based on Biot-Stoll model. The results show that the calculated value of the model is in good agreement with the measured value of the sample, and the equation for the relationship between the bottom reflection coefficient and the porosity, density, mean grain size of sediments at a frequency of 3.5 kHz is established. The equation has a high fitting degree, and the determination coefficient R² is all greater than 0.99. On the basis of calculating the seabed reflection coefficient by the typical Chirp profile data, the porosity, density and mean grain size of the sub-bottom sediments are inversed. The relative errors of the inversion porosity, density, mean grain size and the measured porosity, density, mean grain size are all less than 5%, and the results are basically consistent with the measured values, indicating that the inversion method is feasible in the northern continental slope area of the South China Sea.

As a new type of coastal ecological protection measure, ecological buffer zone formed by woody plants in coastal areas has attracted more and more attention in coastal engineering projects. It is an urgent problem to be solved that how to carry out the research on the protection effect of woody plants. The numerical simulation method is used in this paper. Firstly, a theoretical model of surface wave attenuation for wave climbing along a slope under the protection of woody vegetation is proposed by including the drag forces of branches and trunks in the N-S equation. Next, the MAC method is used to track the trajectories of water particles on the free surface. Then, taking the wave climbing along a slope of 1/30 as an example, the wave propagation process along an inclined beach with or without vegetation is discussed. The validity of the numerical model is verified by comparing the numerical result and those of the previous experiments. Finally, influences of the vegetation characteristics, such as height, density and tilt angle of plant branches and those of wave factors on wave dissipation are discussed and analyzed, respectively. Additionally, the rules of wave dissipation are summarized. The calculation results of this model can also be applicable to the design of revetment structures and ecological landscape.

Using the ECMWF ORAS4 reconstruction data, the different response characteristics of the South China Sea Sea Level Anomaly (SLA) to the Eastern Pacific (EP) El Niño and the Central Pacific (CP) El Niño were analyzed. The South China Sea SLA showed different spatial and temporal evolution during the two types of El Niño. For the EP El Niño, the average SLA in the South China Sea decreased significantly in the autumn and winter of the developing year, with a minimum of −2 cm, and began to rise in the following year, up to 2 cm in the following winter. In terms of spatial distribution, in the autumn and winter of developing year, except for the existence of a positive anomaly to the southeast of Vietnam, in most of the South China Sea, SLAs are characterized by significant negative anomalies; from the spring of the following year, SLA negatively weakens, while the southeastern part of Vietnam was beginning to develop abnormally until the majority of the South China Sea is dominated by positive anomalies. For the CP El Niño, the South China Sea SLA showed significant negative anomalies throughout the El Niño development and decline, the outliers were always maintained at around −2 cm, and spatially represented as a consistent negative anomaly of the whole basin. Compared with the traditional empirical orthogonal decomposition (EOF), the seasonal EOF (S-EOF) can better characterize the temporal and spatial evolution of the South China Sea SLA during the two types of El Niño. The first mode of the S-EOF is CP El Niño mode, while the second mode is more characterized by the evolution of the South China Sea SLA during the EP El Niño. The different variations of the South China Sea SLA during the two types of El Niño are mainly due to the thermal specific volume effect caused by the thermal advection transport anomaly at the channel, but the contribution of the thermosteric sea level is mainly concentrated in the interior South China Sea. While in the coastal regions, such as the western South China Sea, the mechanism of sea level change needs further study.

In April, July, October 2012, and January, April 2013, marine nematode dominant genera and feeding types were sampled for diversity analysis from five mangrove wetlands（Zhangjiang Estuary in Yunxiao Country, Jiulongjiang Estuary in Longhai City, Fenglin in Xiamen City, Luoyangjiang Estuary in Quanzhou City, Wanwu in Ningde City）in Fujian Province. It was found that the nematode dominant genera with dominance of percentages≥5% were Sabatieria, Ptycholaimellus, Parasphaerolaimus, Terschellingia, Daptonema, Viscosia and Dichromadora, which had dominance by 19.82%, 7.88%, 7.45%, 7.26%, 6.79 %, 6.00%, 5.25%, respectively. Sabatieria was the most predominant genus in the mangroves wetlands of Zhangjiang Estuary, Jiulongjiang Estuary and Luoyangjiang Estuary, with dominances are 27.87%, 28.37%, and 23.40%, respectively. Terschellingia was the most dominant genus in Fenglin mangrove wetlands, with a dominance of 18.10%. Daptonema was the most dominant genus in Wanwu mangrove wetlands, and dominance was 22.86%. The seasonal variations in abundance of their feeding types were as follows, in Zhangjiang Estuary wetlands, 1B>2A>2B>1A. In Jiulongjiang Estuary wetlands, 1B>2B>2A>1A. In Fenglin wetlands, 1B>2A>2B>1A. In Luoyangjiang Estuary wetlands, 2B>1B>2A>1A. In Wanwu wetlands, 2A>1B>2B>1A. Therefore, type 1B marine nematode showed to be the dominant in Zhangjiang Estuary, Jiulongjiang Estuary and Fenglin, type 2A was dominant in Wanwu wetlands, type 2B was dominant in Luoyangjiang Estuary wetlands, type 1A are the lowest in five regions.

In order to study the impact of coastal pollution in Bohai Bay on the microecology of sea areas with different distances from the shore, the bacterioplankton community compositions (BCCs) in surface seawater samples from 6 stations with different offshore distances along the coastal region of Bohai Bay were analyzed through high throughput sequencing technology, and the main factors affecting the variation of BCCs were explored by combining environmental and spatial factors in this region. The results showed that there was gradient change of environmental factor in the studied region, such as the contents of nitrogen nutrients were higher in the nearshore station than those in the offshore station. Although there was no significant difference tested for the alpha diversity among different sites, the diversity indexes were still relatively higher in the nearshore stations. The bacterioplankton community compositions were significantly varied with the change of offshore distances. Members of Gammaproteobacteria and Bacteroidetes were mainly enriched in nearshore stations which were closely related with the contents of nitrogen nutrients, members of Cyanobacteria were mainly enriched in offshore stations, which were closely related to ammonia nitrogen, transparency and conductivity. The variance partitioning analysis showed that PCNM variables purely contributed most (38.1%) to the variation of community structure, indicating that there may be environmental variables with spatial structure within the research scope that had not yet been measured may affect the spatial distribution of the bacterioplankton community. Meanwhile, the results of functional prediction indicated that the eutrophication, hydrocarbon pollution and other environmental conditions in the nearshore station may contribute to the change of BCCs. This study explored the variation of offshore-distance-varied BCC in the coastal region of Bohai Bay from environmental and spatial impact, which may provide reference for the study and protection of marine environment in Bohai Bay.

Kinetic dissolution and the reactive continuum model were combined to characterize the reactivity of iron (Fe) and phosphorus (P) in surface sediments of the Changjiang (Yangtze) River Estuary and the adjacent East China Sea. Two kinetic parameters, i.e., theoretical amounts (m ₀) and apparent rate constant (k) of reactive Fe, were extracted by fitting kinetic dissolution data to the reactive continuum model. Results showed that Fe(Ⅱ) phases occurred in all surface sediments studies, which could be ascribed to rapid reduction of highly reactive organic-bound Fe(Ⅲ) flocculated/precipitated to the sediments. It is inferred that Fe(Ⅱ) occurs mainly as FeCO₃ in both the Changjiang (Yangtze )River Estuarine sediments and the adjacent East China Sea sediments. The m ₀ and k values of Fe(Ⅱ) were controlled mainly by total organic carbon (TOC) contents and clay fractions. Simultaneous release of Fe(Ⅱ) and associated P (mainly exchangeable P and authigenic P) resulted in similar pattern of dissolution kinetics. Relative to P adsorbed on surfaces of Fe(Ⅱ) solid phases, coprecipitated P with Fe(Ⅱ) phases has higher m ₀ but lower k. In fine-grained sediments with high TOC contents, Fe(Ⅲ) oxides have lower m ₀ values but higher k in comparison with those in coarse-grained sediments with lower TOC contents, which is caused by different processes of Fe redox cycling. Overall, the dissolution reactivity of P associated with Fe(Ⅲ) phases is largely controlled by the reductive reactivity of Fe(Ⅲ) phases. Our kinetic characterization indicates that flocculation/precipitation has caused reactive Fe enrichment in the estuarine sediments, occurring mainly in a narrow zone of low salinity, but the enrichment could not be revealed by conventional Fe speciation.

Water temperature is one of the important factors affecting the growth, reproduction and supplement of the winter fishes of Todarodes in the Pacific. According to the fishery data of the Pacific winter Todarodes from 2004 to 2015 and its habitat environment data, including the January spawning ground (28°–35°N, 125°–130°E) and the September feeding ground (31°–38°N, 128°–132°E) sea surface temperature (SST), a surplus production model based on SST factor was established to analyze the effect of SST on the resources of the winter migrating fish population of the North Pacific Todarodes. By verifying the indicators of the model of the surplus production model, this study find that the model has higher prediction accuracy. The results show that the resources and catches of the winter fishes of Todarodes pacificus are mainly affected by the SST of the feeding ground, but the spawning ground SST has no significant effect on its catch in the current year. Therefore, it is recommended to strengthen the research on whether the SST factor of the spawning ground may affect the catch and resources of the next year, and the fishery management department should also determine its maximum sustainable yield according to the state of the marine environment every year, and the management plan should be adjusted in real time.