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.

To better understand the potential of carbon fixation in China Sea, it is necessary to conduct the researches on the mechanism of carbon fixed and stored by benthic seaweeds, the important primary productivities in marine ecosystems. In this paper, some dominant seaweeds from intertidal zones in Dalian were measured on the daily fixed and respired carbon, and daily release of organic carbon. Furthermore, seasonal variation of carbon fixed and stored by intertidal seaweeds from three seaweed beds in Dalian were elucidated, combined with the measurements of the biomass. The results showed that green algae had the strongest capacity in carbon fixation, followed by brown algae and red algae. The carbon fixed and stored, and organic carbon released by intertidal seaweeds in Dalian were higher in December-May, and lower in June-November. The annual total carbon fixed, and organic carbon released by intertidal seaweeds of each seaweed bed were 1.72×10⁵ g/a and 2.1×10⁴ g/a respectively. The amount of monthly fixed carbon was 1.7 times that of stored carbon.

Yellow Sea is a semi-enclosed marginal sea that is significantly impacted by human activities. One of the major characteristics of Yellow Sea is the long-term existence of intensive cold water mass in summer. In order to study the cycling of particulate nitrogen in summer Yellow Sea, we analyzed the organic carbon and nitrogen content and isotope of the suspended particulate matter and of the surface sediments in South Yellow Sea in summer, 2016. We focus on the spatial variances in particulate nitrogen content, isotope character and the controlling factors respectively in coastal waters and cold water masse realm. In the coastal waters, the particulate nitrogen (PN) are comparatively higher and the vertical variances of nitrogen isotope (δ¹⁵N_PN) are small, while total nitrogen content (TN) in coastal sediment are lower and the nitrogen isotope (δ¹⁵N_TN) are mostly negative. In central south Yellow Sea where cold water masses exists, the PN is characterized of low content, significant vertical variances in δ¹⁵N_PN, while TN in sediment are characterized of high content and positive δ¹⁵N_TN. We further run bottom critical shear stress simulation and environmental factors analysis, and found out that the spatial variances of particulate nitrogen content and nitrogen isotopes in the South Yellow Sea was mainly controlled by the vertical mixing in water column, benthic boundary dynamic processes, and partially contributed by re-mineralization and terrestrial PN input.

Based on the concentrations and spatial distributions of heavy metals in 404 surface sediments from the Bohai Sea, we evaluated the marine sediment environmental quality indexes, such as heavy metal potential ecological risk, geoaccumulation index. Moreover, the factors that impact on the concentrations of heavy metals in surface sediments were also analyzed. The results showed that the mean concentrations of all eight heavy metals were highest in the Bohai Bay, and were lowest in the Bohai Strait. The potential ecological risks of Cd and Hg elements were high and moderate-high, respectively. The assessment of total potential ecological risk revealed Bohai Sea belongs to moderate potential ecological risk. Only few stations of Cr and Ni exceed the upper limit of toxic threshold, and the others are less than the lower limit of toxic threshold. This implies the occurrence probability of toxic pollution is low. The concentrations and spatial distributions of heavy metals were mainly dominated by grain size effect of surface sediments from the Bohai Sea. However, Cd element which was rich in the Jinzhou Bay and Fuzhou Bay of Liaodong Bay was mainly contributed by human activities. Hg element, supplied by Yellow River possible impacted by human activities, was rich in the Yellow River Delta and Laizhou Bay.

Measurement of major elements, trace elements and rare earth elements (REY) for sediment Core GC11 collected in the central Indian Ocean Basin were performed. Based on the analysis of interelemental correlation, REY enrichment and post-Archean Australian Shale (PAAS) normalization style, the factors impacting the REY enrichment are discussed. The study suggests that: the total amount of REY varies from 400.64×10⁻⁶ to 742.74×10⁻⁶, with an average of 658.41×10⁻⁶, which is slightly lower than that of Core GC02, however, is equivalent to that of the zeolite-bearing rich deep-sea deposit in the Core DSDP213 . The sediment exhibits distinct negative abnormal δCe and lower (La/Yb)_N为0.42, with obvious positive correlation between REY and P₂O₅. The average value of CaO/P₂O₅ ratio is 2.3, demonstrating that the bio-apatite may be the main host mineral of REY. Although there is positive correlation between REY and Fe and Mn, hydroxyl hydrate of Fe and Mn have low impact to the enrichment of REY for the distinct negative abnormal δCe. The mixture with the terregeneous materials maybe the main cause inducing the differences of REY enrichment degree, δCe and PAAS normalization style.

The samples of Eirene were collected from the Zhanjiang Bay of Guangdong at 21°04′40.52″N 110°30′2.87″E during May, 2010 and May 2016. Two new species of Eirene i.e. E. macrogonia Huang, Sun et Liu , sp. nov. and E. zhanjiangensis Huang, Zhang et Zao sp. nov. are decribed. All type specimens are deposited in College of Ocean and Earth Sciences, Xiamen University. The specific diagnoses of two new species are as follow: Eirene macrogonia Huang, Sun et Liu sp. nov. Unbrella nearly hemispherical; gastric peduncle long, exceeding beyond the velar opening, the base pyramidal shaped; with 4 radial canals and a ring canal; with 4 large sinuous gonads, from near the base of the peduncle to beyond the umbrella margin along the four radial canals with 19−24 marginal tentacles of the same size, its bulbs without excretory papillae, with 5−8 rudumentary bulbs. Eirene zhanjiangensis Huang, Zhang et Zao, sp. nov.Umbrella hemispherical, jelly think; the base of gastric peduncle pyramidal and the end narrow; lenth of manubrium near equal to the one of oral lips; 4 gonads banding shaped, extending from the base of peduncle to near umbrella margin along the 4 radial canals; with 4 radial canals and a ring canal; with 70−125 marginal tentacles of the same size, its bulbs with excretory papillae; the number of statocysts about 1/2 of one of tentacles.

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.

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.

Growth parameters of fish are commonly assumed homogeneous in traditional fish stock assessment. However, increasing studies in recent years have shown that the growth of marine fish is characterized by spatial heterogeneity. To evaluate the spatial heterogeneity of growth traits of the fishes in the Haizhou Bay and its adjacent waters, this study analyzed the spatial distribution of 4 fish species and estimated their von Bertalanffy growth function parameters using otter trawl data collected from 2013 to 2018. We fitted the growth equations for Pholis fangi, Syngnatus acus, Larimichthys polyactis and Thryssa kammalensis using Electronic Length Frequency Analysis method in combination with the Bootstrap and compared the differences in growth parameters between deep- and shallow-water regions. The results show that growth parameters of the fish species exhibit certain levels of spatial heterogeneity, in particular Syngnatus acus and Larimichthys polyactis show substantial spatial heterogeneity. These differences may be attributed to the variations in spatial physical and chemical conditions, community structure and migration of the species.

Emiliania huxleyi, the numerically dominant coccolithophore in the modern oceans and its specific lytic virus EhV exert a critical impact upon the oceanic carbon, sulfur cycle and global climate, thus serving as a key host-pathogen model system. Despite their impact on biogeochemical cycling, the transcriptional dynamics of these important oceanic events is still poorly understood. To understand the host-virus interaction in E. huxleyi-EhV system, the transcriptome of E. huxleyi BOF92 involved in virus infection was investigated by using Illumina HiSeq 2 000 high-throughput sequencing technology. Two cDNA libraries, generated 6 h and 45 h after viral infection (Exp) were compared with two libraries from the corresponding times uninfected cultures (Con). A total of 32 909 unigenes with an average length of 1 153 bp were generated. Totally 2 617 and 5 229 differentially expressed genes (DEGs) associated with viral infection were identified in 6 hpi and 45 hpi, respectively, among which 465 genes were the common DEGs in the two time points. Ten DEGs were random selected for quantitative RT-PCR (qRT-PCR) analysis, and the results confirmed that the transcriptome analysis was reliable. Furthermore, the DEGs were subject to GO and KEGG enrichment analysis. The results showed that most of the DEGs were involved in oxidation-reduction reactions, glutathione metabolism, lipid metabolism, carbohydrate metabolism and signal transduction. Some of the reactive oxygen species (ROS) scavenging genes were screened out, in which 9 genes were up-regulated and 11 genes were down-regulated. These results suggested that ROS signaling molecules might play a central role during host-virus interaction.