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.

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.

The technical bottlenecks of threshold determination and key parameter calibration in carrying capacity of resources and environment urgently need to be broken through, and then establish a standardized quantitative evaluation method. In the present study, several key parameters such as primary productivity, phytoplankton organic carbon content and trophic level were obtained through investigation and experimental analysis. The nutrition dynamic model and the Tait coastal energy flow model were used to estimate the total quantities of marine biological resources. Then, the threshold of carrying capacity of marine biological resources was calculated based on the “resource-consumption” model. For example, according to the survey results in 2016, the annual average primary productivity of sea area under Rizhao jurisdiction was 428.22 mg/(m²·d) and the annual production of phytoplankton was 9.19×10⁶ t. Meanwhile, the average trophic levels of fishes, shrimps and crabs, and cephalopods were 3.85, 3.92 and 3.90, respectively. The annual production of fishery resources (fish, shrimp and crab, and cephalopod) in the sea area was 38.9 thousand tons calculated by the “nutritional dynamic model”. In addition, the shellfish resources in shallow sea within 10 m depth contour was 55 thousand tons calculated by the Tait coastal energy flow model. Thus, according to the annual per capita intake of aquatic products of 21 kg, the total carrying capacity of marine biological resources in Rizhao coastal waters was 1.928 6×10⁶ people. Meanwhile, according to the annual per capita protein intake of 30 kg, the total carrying capacity of marine biological resources in Rizhao area was calculated to be 1.687×10⁵ people. Taken together, this paper describes a quantitative assessment technique with wide applicability for carrying capacity of marine biological resources. This will contribute to substantial utilization of the marine biological resources and establishment of the monitoring and early warning of resources and environment carrying capacity in a way of overall planning of land and sea.

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 seven comprehensive surveys in the coastal area of Rushan Bay in summer of 2009 and 2014, the distribution of nitrogen and phosphorus nutrients and nutrient structure were analyzed, and the budgets of dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) were estimated based on the water balance calculated by Princeton Ocean Model (POM). The results show that the high concentrations of DIN and DIP in adjacent area of Rushan Bay in summer appears in the mouth area of Rushan Bay. Their concentrations and distributions are influenced by the terrestrial inputs, tides and currents significantly. The DIN and DIP effluxes from the sediment to the overlying water at the sediment-water interface result in the higher concentrations of DIN and DIP in the bottom water than those in the surface water. The budget of DIN shows that internal cycling is the dominant source of DIN for the primary production, accounting for 86% of uptake by primary production, followed by water exchange (11%), and benthic efflux (3%); the removal of DIN in the water column is dominant by sedimentation (80%), export to the offshore (16%), and denitrification (4%). The DIP budget shows that internal cycling in the water column is the dominant source of DIP for the primary production, accounting for 91% of uptake by primary production, followed by water exchange (9%), and benthic efflux (lower than 1%); the removal of DIP in the water column is also dominant by sedimentation (67%) and export to the off shore by water exchange (33%). Based on the budgets of DIN and DIP, internal recycling is the dominant source for both of DIN and DIP supplies in the coastal water column, and the burial efficiency of P is higher than N into the sediment in the area off Rushan Bay. However, the different nutrient structure between external and internal sources of the study area would result in a long-term effect on the nutrient balance and primary production due to the differential budget of DIN and DIP.

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.

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.

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.

Transient electromagnetic method (TEM) is an effective method for deep-sea polymetallic sulfide exploration. High-grade metal components in seafloor polymetallic sulfides cause extremely strong induced polarization effects and have a significant impact on transient electromagnetic response. In this paper, the inductive effects of deep-sea polymetallic sulfides were analyzed through laboratory measurement and numerical simulation. First, systematic electrical tests were carried out on rock ore samples from the hydrothermal vent fields on the southwest Indian Ocean Ridge. The complex resistivity of typical sulfides has a phase shift of up to 160 mrad in the frequency domain. The time domain and frequency domain measurements show that the polarizability parameter is a good indicator to distinguish sulfide minerals and surrounding rocks. Using the Cole-Cole model to interpret the complex resistivity to obtain the characteristic parameters of complex resistivity, the relationship between parameters and the composition and structure of the massive sulfide was analyzed, and the typical sulfides were classified based on the polarizability parameter. The induced polarization parameters of the typical sulfides were used to calculate the transient electromagnetic response of the layered medium, which show that the influence of induced polarization effect can be observed simultaneously in the best observation window of the TEM response of the deep-sea polymetallic sulfide deposit. Although the transient response is distorted in the late stage of the acquisition window, in the early stage of signal reception, the induced polarization effect effectively enhances the detection capability of the TEM for deep-sea polymetallic sulfides, which provides an explanation basis for the transient electromagnetic measurement data.

Based on the investigation of dissolved organic matter (DOM) in the Yellow Sea from August to September 2017, the spatial distributions of dissolved organic carbon (DOC) and chromophoric dissolved organic matter (CDOM) were studied in the Yellow Sea. In surface seawater, CDOM was higher in the nearshore water, which might be caused by the relatively significant influence by the river input, while colorless DOC concentration in the north Yellow Sea Cold Water (YSCW) area was enhanced by aquaculture. The DOC concentration decreased along depth in the water column, but an inverse trend for CDOM, especially in the YSCW area. Terrestrial DOC input and primary production were mainly responsible for the surface DOC enhancement, while photobleaching induced the decrease of CDOM. Additionally, photobleaching also decreased the molecular weight and aromaticity of CDOM in surface water. In the YSCW, O₂ was slightly unsaturated, with the saturation degree of 80%–93%. In this area, strong stratification prevented the vertical diffusion of O₂ to bottom water. Additionally, stratification could also restrain the vertical mixing of DOC and CDOM, which was mainly responsible for the large difference of DOC and CDOM between surface and bottom waters.