Abstract:Type Ⅱ reovirus of grass carp represents the pandemic strain for grass carp hemorrahagic disease in China. VP56 is the outer most protein on the virion of type Ⅱ reovirus, and is suggested to play a key role during viral entry. To facilitate the study on biological functions of VP56, here, we investigated the prokaryotic and eukaryotic expression of VP56 gene of type Ⅱ reovirus. The VP56 ORF encoded by the S7 genomic fragment was amplified by RT-PCR technology from the cDNA of GCRV-JX02W infected CIK cells, and it was cloned into the pGEX-4T-3 and pFastBacHTA, respectively. After confirmation of the clones by sequencing analysis, the pGEX4T-3-VP56 was transformed into E.coli BL21(DE3) strain to express fusion protein GST-VP56. SDS-PAGE and Western Blot assays indicated that GST-VP56 was successfully expressed in E.coli BL21(DE3) strain with the molecular weight of about 83 ku. The recombinant protein mainly existed in the form of inclusion bodies. Polyclonal antibody was generated by immunization of mices with the purified recombinant VP56 proteins and the specificity of antibodies was determined by Western Blot. pFastBacHTA-VP56 was transformed into E.coli DH10Bac strain to get recombinant bacmid DNA that was analyzed by PCR. Then, the recombinant bacmid DNA was transfected into SF9 cells. Positive SF9 cells transfected with bacmid DNA stopped growth and lysed at 96 h post transfection.Western Blot results showed that the His-tag antibody could be specifically bound to His-VP56 fusion protein with the molecular weight of about 62 ku, which was soluble protein. In this paper, recombinant VP56 proteins were successfully expressed by both prokarotic and eukaryotic expression systems, and polyclonal antiserum against VP56 was generated, which laid a foundation for characterizing the function of VP56 protein during viral infection.

Abstract:There were significant positive correlations between total carotenoids content (TCC) in Hyriopsis cumingii and shell color intensity. A 40-day feeding trial was conducted to evaluate the effect of dietary β-carotene level (5 mg/L, 10 mg/L, 20 mg/L and 40 mg/L) on TCC and shell color in H. cumingii. The results showed that, as the level of dietary β-carotene increased, the TCC in the hepatopancreas and mantle increased accordingly. The total carotenoid content in purple line mussels was significantly higher than that in white line mussels. And the ability of accumulating carotenoids was significantly different between purple line mussels and white line mussels (P<0.05). At the terminal feeding trial, there were no significant differences of color parameters (L^*, a^*, b^*, C^* and ΔE) among the four experimental treatments in purple line mussels (P>0.05), although the color parameters of a^*, b^* and C^* increased with the level of dietary β-carotene increasing. Similarly, in white line mussels there were also no significant differences of color parameters among the four experimental treatments (P>0.05). These results suggest that the ability of accumulating carotenoids in purple line mussels was significantly higher than that in white line mussels.

Abstract:This research was aimed to compare the edible rate and biochemical composition of early-maturing (EM) and late-maturing (LM) Eriocheir sinensis during adult culture stage with the methods of culture experiment,sentisection and biochemical analysis, and individuals without selection were served as the control.The results showed that:(1)No matter for females or males,individuals with similar weight from different groups exhibited no significant difference in gonadosomatic index (GSI), meat yield (MY) and total edible yield (TEY);(2)As for biochemical composition in muscle, hepatopancreas and gonad of females,there were no significant differences in the level of moisture, protein, lipid and ash between different groups though obviously higher level of lipids in the hepatopancreas of EM individuals;(3) As for males, the levels of protein and ash in the gonad of EM individuals were significantly higher than LM individuals and no significant difference existed in other tissues.As a whole, the selective breeding had a little influence on the edible rate yield and biochemical composition of E. sinensis, except for significantly lower HSI, but significantly higher level of protein and ash in the gonad of male EMs compared to LM individuals.

Abstract:To study the effect of processing fish droppings in two different ways on biofloc components, two kinds of methods were used to treat the waste of eel, and then we made these wastes cultured boil-floc.The results showed that the concentration of ammonia nitrogen in the two groups decreased during the culture. The average concentration of ammonia nitrogen in the freeze-dried group was (0.86±0.22) mg/L, and the fresh group was (0.83±0.42) mg/L. After the sixth day, the concentration of nitrite nitrogen in both groups was below 0.03 mg/L. On the seventeenth day, the concentration of nitrate nitrogen in both groups was reduced to below 0.04 mg/L.The contents of crude ash in the two groups were decreased in the later stage of culture, the contents were the freeze-dried group 6.80%±0.00% and the fresh group 5.97%±0.01% respectively. The crude protein content of the freeze-dried group was 33.44%±7.80%, fresh group 33.65%±3.17%, the difference was not significant; the free amino acid type had 16 kinds in freeze-dried group, and 23 kinds in fresh group. In the fatty acids, DHA was (0.15±0.10) mg/g in the fresh group and (0.07±0.13) mg/g in the freeze-dried group.The difference was significant (P<0.05). The results show that both two treatments are suitable to cultivate floc, the freeze-dried group was good for fatty acids, and the fresh group was good for essential amino acids.

Abstract:Taking the crucian carp as the research object, the tolerance to different depressurization rates under high water pressure conditions is explored by experimental investigation with the variable-controlling method and the statistical analysis method. The effects of water pressure changes on crucian carps and the pressure tolerance difference of individuals of various sizes are analyzed. The results show that two closely related factors, initial pressure and the depressurization rate, both have obvious effects on the health of crucian carp. Generally speaking, the crucian carps stay uninjured under the pressure within 3 MPa; when the pressure comes within the range of 4-10 MPa, the greater the pressure and the depressurization rate are, the more likely the carp gets injured; the crucian carp will die under the pressure exceeding 10 MPa, and the greater pressure results in the decline of the death depressurization rate threshold. In addition, it is found that the crucian carp tolerance to the pressure change does not seem to have any significant relationship with their individual size. The research is expected to provide some theoretical basis and guidance significance for deepwater aquaculture and deepwater fishing technology in the future high-tech oceanic fishery.

Abstract:Chinese sea perch (Lateolabrax maculatus) is an important farmed species in the coastal area of China. In order to promote the sustainable development of its production sector, this study evaluated the economic efficiency of the sea perch farms located in Zhuhai and Fuding city. The research result revealed that the total unit cost of pond aquaculture farms is the lowest, which is 15.69 yuan/kg. As for the cage farms, the cost range is 31.48 yuan/kg-36.62 yuan/kg. And the cost structure of the above modes had one similarity:the proportion of the variable cost is higher than that of the fixed cost. Because feed cost is the most expensive expenditure for sea perch farming industry. What's more, the break-even and sensitivity analysis stated that the economic performance of the traditional cage farms is the best. Combined with the actual situation, the recommendations are as follows:The value chain of the fish in Zhuhai should be extended; The fish farmers who practiced in cages should adopt advanced technologies to increase the economic efficiency and reduce the pollution;Related departments should inspect the quality of the aquatic fingering industry and the pollution of the production.

Abstract:The technique of combining two or more kinds of organisms to treat eutrophic water in ecological restoration has drawn much attention. In this paper, Daphnia magna and Vallisneria natans were used as the representatives of the zooplankton and submerged macrophytes to establish the combined system of daphnia-grass, the treatment of Vallisneria natans was used as the control group, and the eutrophic water as the blank group. Then we researched the process of water quality indicators, sediment indicators and aquatic biomass changes.The results showed that the quality indexes of water and sediment in the system were superior to that of the bitter Vallisneria natans group. The final removal rates of total nitrogen, total phosphorus and ammonia nitrogen were 87%, 88% and 96%, and the maximum removal rates were 70%,70% and 86%respectively. The removal rate of total nitrogen in sediment was 39% and the removal rate of total phosphorus was 38%. After 27 days of water clearing, the growth rate of Vallisneria natans reached 740%. In the control group, the final removal rates of total nitrogen, total phosphorus and ammonia nitrogen were 35%, 33% and 57%, and the maximum removal rates were 35%, 30% and 57% respectively, and the removal rate of the total nitrogen and total phosphorus was 40% and 32%, respectively. The water was not clear enough to see the bottom after 48 days, and the growth rate of Vallisneria natans was 470%.Therefore, Daphnia magna promoted the settlement of suspended solids, which is conducive to the growth of Vallisneria natans and the stability of the system. The ability of daphnia-grass system to deal with eutrophic water is greater than single aquatic systems, and it can speed up the transparency of water, achieve a higher growth rate of Vallisneria natans and is easier to maintain the stability. All in all, the experimental results provide reference for guiding the ecological restoration engineering practice.

Abstract:Based on the analysis of water samples collected at Sansha Bay during March 30 to April 3, 2016, totally 38 species belonging to 3 phyla and 22 genera were identified, including 34 diatom species belonging to 19 genera, accounting for 89.47% of the total species and it is the main group in the investigated sea area. 3 dinoflagellate species belonging to 2 genera, and 1 chrysophyta species belonging to 1 genus. In spring, the average abundance of phytoplankton was 1.63×10⁵ cells/L. The high value area appears in northwest to Shasha Bay, the Jiaoxi river, Baima port and the waters near the Lumen port. The dominant specie was the Skeletonema costatum, the frequency of occurrence was 100%,but it was mainly distributed in the estuary. The relationship between phytoplankton and environmental factors was studied by Redundancy Analysis(RDA).The results of Redundancy Analysis(RDA) indicated that Dissolved Oxygen (DO),Salinity (SAL), Temperature (T), and Soluble Reactive Phosphorus (SRP),were the most important environmental factors influencing phytoplankton of Sansha Bay in spring.

Abstract:In order to study the effect of composite vertical subsurface flow constructed wetlands on the removal of heavy metals in pond aquaculture water, the correlation between different plant roots and their substrates near roots on heavy metal enrichment effect, different environmental factors and heavy metal enrichment rate were analyzed by measuring water quality index and heavy metal. The results showed that the removal efficiencies of Pb and Cu in constructed wetlands were 77.20% and 41.70%, respectively. Compared with other types of wetlands, the composite vertical subsurface flow constructed wetlands had some advantages for the removal of Pb and Cu; the As was released in wetland with an average release rate of 8.40%. The roots of Polygonum hydropiper and Thalia dealbata Fraser have enrichment effect on Cr, As, Pb and Cu, and the roots of Pontederia cordata L. have only enrichment of Cr and As. The substrates near the roots of Polygonum hydropiper, Pontederia cordata L., and Thalia dealbata Fraser have a good enrichment effect on chromium, and among them, the maximum rate of the concentration of Pontederia cordata L. to chromium is 0.987mg/(kg·d). The enrichment rate of Pb and Cu in Polygonum hydropiper root was negatively correlated with temperature and the enrichment rate of Cr and Cu was negatively correlated with pH; the enrichment rate of Cr and As in Pontederia cordata L. root was negatively correlated with temperature; the enrichment rate of Pb in Thalia dealbata Fraser root was negatively correlated with temperature and pH, the enrichment rate of Cu was negatively correlated with temperature. The results of this study provide a theoretical basis and reference for the application of composite vertical subsurface flow constructed wetlands and the selection of wetland plants from the perspective of heavy metal removal.

Abstract:Based on FVCOM numerical model and with the support of relevant measurement materials at Ningbo-Zhoushan waters, the Epoxy Chloropropane has been selected as typical dissolved hazardous chemical substance to simulate the diffusion after the emergent leakage of hazardous chemical substance in the waters. According to different grades of the accidents, as is indicated by the simulation result, the concentration of epoxy chloropropane will be diffused to below safe concentration (0.02 mg/L) after 24 hours of leakage for ordinary and relatively big accidents. As to major accidents, however, there are still large areas of waters (30~190 km²) which have been polluted with concentration exceeding the safe limit after 24 hours of leakage. From the aspect of different tides time at diffusion, the diffusion is faster at ebb tide than at flood tide, and the diffusion process to below safe concentration at ebb tide is 2 to 6 hours faster than at flood tide. From the aspect of different regions of leakage, the diffusion at Cezi channel is faster than at Zhenhai port. The pollutants are basically diffused along the water channels when the leakage occurs at Cezi channel, and they will be detained along the bank of Beilun district and at Beilun and Daxie Island when the leakage occurs at Zhenahi port.

Abstract:This study took four coastal counties in Ningde as examples to carry out risk assessment of harmful algal blooms (HABs) disaster. The index systems of risk assessment of HABs disaster were established based on leading, measurable and available principles. The weights of evaluation indexes were determined by entropy method. In addition, hazard assessment model, vulnerability assessment of hazard-bearing body model and risk assessment model were set up, respectively. Finally, this study utilized GIS platform to realize visualization of the assessment results. The research revealed that the HABs with the medium risk were detected along Fuding coast and Xiapu coast. Along Jiaocheng coast and Fuan coast, HABs caused low risk. The evaluation results are consistent with the historical data, actual situation and related literature of HABs in the east coast of Fujian. This paper provides technical support for HABs monitoring, disaster prevention and mitigation and aquaculture.

Abstract:In order to understand the bird diversity of different habitats and the impacts of human disturbance in the Northern Experimental Area of Yancheng Nature Reserve, Jiangsu, seasonal bird surveys were carried out with the methods of line transects during the period from October 2015 to July 2016. The habitats of study area were classified according to 3S technology, and the characteristics and variation of bird diversity in different habitats were analyzed. 67 bird species from 12 orders, 27 families were recorded in this region. The major floristic composition and residence type were palaearctic species and migratory birds. The index of bird diversity in different habitats was the highest in artificial wetlands and the lowest in human activity areas. There was a significant negative correlation between uniformity index and human disturbance index (y=1.883x+1.738, R²=0.903, P<0.05), which leads to the highest value in shallow sea waters and the lowest in human activity areas. Also, the highest values of bird diversity among different habitats occurred between salt marshes and artificial wetlands. In different habitats and different seasons, bird diversity in artificial wetlands and salt marshes was generally higher than that in other habitats, and the highest and lowest values appeared in autumn and summer, respectively.

Abstract:Ommastrephes bartramii is a commercially important cephalopod in the northwest Pacific Ocean, and as ecological opportunist, the spatial distribution of its stock is determined by marine environment. Using the relationship between the spatio-temporal variation of the migratory path and the oceanic environment to predict the spatial distribution of the squid resources is the research emphasis of fishery resources. It has great significance to practical production. According to the fishing production data from Chinese fishing fleet, combined with sea surface temperature (SST), sea surface salinity (SSS), chlorophyll-a concentration (chl-a) and Trans-Niño index (TNI) in the northwest Pacific Ocean during August to November in 2004 to 2015, We used hierarchical cluster analysis and neural network to analyze the relationship between the spatio-temporal variation of the migratory path and the oceanic environment to predict the change of the migratory path of the squid under the influence of the oceanic environment.The results showed that the proportion of production of the migratory gravity of the squid is significantly negatively correlated with the dispersion degree in October and November. There is a significant positive correlation between the change of the migratory gravity in the latitude and the TNI, which does not appear in the longitude.The model of predicting the spatio-temporal variation of the migratory path of the squid was established by using the neural network combined with sea surface temperature, salinity and chlorophyll concentration. The results of forecasting showed that during August to November, the migration gravity of squid shows the change trend of south-north-south in the latitude, and the change trend of west-east-west in the longitude.In August and September, the estimated proportion of production of the migratory gravity area was 64% and 68% respectively. In October and November, the prediction accuracy rate has obviously improved, and the estimated proportion of production of the migratory gravity area was 83% and 89% respectively.

Abstract:Coilia nasus is an important migration type species in the Yangtze River, and has now become a national key protection resource. In order to investigate the temporal-spatial distribution of Coilia nasus in the Yangtze River estuary, according to the survey data of the fishery resources investigation in Shanghai Yangtze estuarine nature during year 2012-2014, we analyzed the relationship between relative abundance index (RAI) and water depth, water temperature and salinity in the Yangtze River estuary, meanwhile established habitat Suitability Index (HSI) model. The results show that the RAI of spring and winter was higher, and was mainly distributed near southern branch of the Yangtze estuary. The population of Coilia nasus habitat in the pelagic area where water depth below 10 m, salinity range of 0-1.0. There is a gentle change between Tem and Suitability Index (SI) in spring, and the maximum value of SI in summer and autumn appeared at 22.5℃ and 28.5℃ respectively, in winter the population had concentrated distribution with the temperature about 15℃.Regression analysis shows that using the geometric mean method can reflect the temporal-spatial distribution in the Yangtze River estuary better. We analyzed that the influence of different seasons and different environmental factors on the distribution of Coilia nasus,based on HSI model we discussed the temporal-spatial distribution of Coilia nasus,also evaluated the selection of HSI model.Aimed at providing some references for protecting Coilia nasus population and then rehabilitating the Yangtze estuary ecosystem.

Abstract:Based on 50 samples of Sepia pharaonic and 100 samples of Sepia kobiensis collected in the East China Sea in 2015, the paper studied the species identification between Sepia pharaonic and Sepia kobiensis by principal component analysis and stepwise discriminate analysis. Results showed that there were highly significant differences in the 12 morphological parameters of beak between two species except LHL/ML. There were not significant differences between male and female in both species. The total successful discrimination rate for Sepia pharaonic and Sepia kobiensis by stepwise discriminate analysis was 94.8%. The total successful discrimination rate for Sepia pharaonic and Sepia kobiensis based on the result of principal component analysis was 83.6%. The total successful discrimination rate for male Sepia pharaonic and male Sepia kobiensis was 93.8%. The total successful discrimination rate for female Sepia pharaonic and female Sepia kobiensis attained 96.6%.

Abstract:In this study, 11 normal characters and 16 frame traits had been measured in 89 Pseudorasbora parva among different geographical populations (Zhenyuan, Mojiang and Jiangcheng) from Lixianjiang, Red River drainage. These data were analyzed by three different methods, the principal component analysis (PCA), the discriminant analysis and the coefficient of difference analysis to compare the morphological differences among the three geographical populations of P. parva. The results showed that Zhenyuan population was independent from the other populations. In PCA analysis, the contribution rates of PC1, PC2 and PC3 were 55.094%, 8.397%, and 6.988% respectively, and cumulatively to 70.469%. Furthermore, largely independent samples in Zhenyuan were separated in the scatter plot results by the PC1 and PC2. Also in the discriminant analysis, the discriminant rate based on 7 characters variable (P<0.01) reached 100% in Zhenyuan populations, while 96.7% both in Mojiang and Jiangcheng populations. Then, the same 7 traits with body length ratio were used for coefficient of difference analysis, and it was found that both with 3 characters with the more difference coefficient than 1.28 between Jiangcheng and Zhenyuan, Mojiang and Zhenyuan populations. It is speculated that there are morphological variations in Zhenyuan P. parva. Except the real source of the P. parva, environmental factors, genetic factors may also play a significant role in morphological variation. Therefore, it is necessary to study it by means of molecular biology in future.

Abstract:EU Marine Strategy Framework Directive (hereinafter as ‘the Directive’) adopted ecosystem-based management with aims to attaining a good environmental status, which could shed light on the development of marine ecological civilization in China. This paper analyzed the components of the Directive and its indicators, and highlighted the similarities and differences between the Directive and China's marine ecological civilization. Recommendations were made at the end that China's marine ecological civilization, in the light of the practice of the Directive, particularly its coordination mechanism, should integrate all its relating components into a coherent and interrelated system, and improve the participation of the public as well.

Abstract:Acidic electrolyzed water is a new type of non thermal processing technology, which was widely used in preserving the quality of aquatic products. In order to investigate the possible preservation mechanism, this study starts from the microbial control perspective, focuses on the inhibitory effect of acidic electrolyzed water towards total number of bacteria and spoilage bacteria in shrimp, then analyzes the correlation between them and shrimp meat quality. Results showed that AEW not only has a high capability to reduce the number of total bacteria and specific spoilage bacteria (Pseudomonas and Shewanella spp, P<0.05), but also sustained suppressing the growth of total bacteria and specific spoilage bacteria in the subsequent 4℃ cold storage. In addition, AEW had an obvious capability in limiting the changes of pH, total volatile basic nitrogen (TVB-N) and color changes in shrimp. Correlation analysis showed that microbial indexes and quality indexes of shrimps during storage has a good consistency. Acidic electrolyzed water can preserve the quality of shrimp by inhibiting the growth of total bacteria and specific spoilage organisms. In conclusion, this paper provided theoretical basis for further exploring the mechanism of AEW on improving the quality and safety of food.

Abstract:Using the selective medium with carboxymethyl cellulose (CMC) as the sole carbon source, through direct screening and screening after enrichment, separation, purification as the preliminary screening methods, and the transparent circle method and shake flask fermentation as the second screening methods, two strains of cellulase-producing microorganisms with higher cellulase activity, MA35 and MC, were screened out from intestines of Megalobrama amblycephala and Ctenopharyngodon idellus. 16S rDNA/ITS molecular identification and morphological observation showed that:MA35 from Megalobrama amblycephala belonged to Aspergillus niveus, MA1 from Megalobrama amblycephala and CI10 from Ctenopharyngodon idellus were actually identical bacteria, MC, belonged to Aeromonas veronii. Fermentation trend studies indicated that MA35 had a higher extracellular and intracellular cellulase activity compared to MC. This study not only screened out cellulase-producing strains from the intestines of Ctenopharyngodon idellus, but also isolated a new cellulase-producing strain from Chinese unique aquatic organism Megalobrama amblycephala, providing a scientific research basis for the rational aquaculture of herbivorous fish and the dietary ratio of fish feed.

Abstract:Shoreline is described as an intersection of coastal land and water surface indicating water edge movements as the tides rise and fall. Remote sensing technology can provide a wide range dynamicmonitoring of the shoreline. However, traditional hard classification methods are mainly used to extract coastal waterline at the pixel level, and achieve the low accuracy. Whereas sub-pixel coastal waterline extraction is an attractive and challenging task due to the complex features in the coastal region. Therefore, an improved sub-pixel coastal waterline extraction method (ISPCW) is presented to achieve the higher accuracy of coastal waterline extraction. Firstly, a Water-Vegetation-Impervious-Soil (W-V-I-S) model is presented to detect W-V-I-S mixed pixels and determine endmember spectrum in the coastal region. Secondly, the linear spectral mixture unmixing technique based on Fully Constrained Least Squares (FCLS) is applied to the W-V-I-S mixed pixels for water abundance estimation; and finally, spatial attraction model is used to extract coastal waterline. In the experiment performed on EO-1 Hyperion data of Shanghai study area, Multiple Endmember Spectral Mixture Analysis (MESMA), Mixture Tuned Matched Filtering (MTMF), Sequential Maximum Angle Convex Cone (SMACC), and Constrained Energy Minimization (CEM), and classical Normalized Difference Water Index (NDWI) methods are chosen for the coastal waterline extraction comparison. The results indicate that the proposed ISPCW method achieved the best accuracy of 0.38 pixels in the experiment, and the accuracy of ISPCW method improved by 22.4%,33.3%,42.4%, 43.2%, and 51.3%compared with MESMA, MTMF, SMACC, CEM, and NDWI methods, respectively. Therefore, from these results, the ISPCW method exhibits better performance for coastal waterline extraction than the traditional pixel level method and sub-pixel level method, and can be effectively applied to coastal waterline extraction in the coastal region.