Abstract:Insulin-like growth factor (IGF) signaling pathway plays an important regulatory role in the development, reproduction and growth of the organism. IGF acid-labile subunit (IGFALS) is an important member of the IGF system. After forming a trimer with IGF and IGFBP, IGFALS can extend the half-life of IGF and thus participate in the regulation of IGF system. In this study, two IGFALS genes were firstly screened and identified from the razor clam Sinonovacula constricta transcriptome, including complete ORF, named IGFALSa and IGFALSb. The length of IGFALSa cDNA sequence is 4 809 bp, encoding 996 amino acids; The length of cDNA sequence of IGFALSb gene is 1 925 bp, encoding 546 amino acids. During the developmental periods, IGFALSa and IGFALSb were only expressed in a small amount in the early developmental stages, and their expression gradually increased with the larval development. In different tissues, IGFALSa was highly expressed, specifically in mantle and gonads. IGFALSb is highly expressed, specifically in siphon. Short-term stimulation to juveniles was performed with different mass concentrations of insulin. When the mass concentration of insulin was 10 mg/L, both IGFALS genes were significantly up-regulated, and the expressions of the downstream genes IRS, PDK1, and MPKP1 were also significantly up-regulated. Further feeding the juvenile with 10 mg/L of insulin for 40 days, the daily growth rates of shell length and shell width were significantly improved.

Abstract:It is of great significance to study the human glycogen storage disease type V (GSDⅤ) caused by PYGM mutation through constructing zebrafish mutants of muscle glycogen phosphorylase gene pygma and pygmb.Two homozygous mutants were successfully obtained using CRISPR/Cas9 genome editing technique. The periodic acid Schiff staining experiment showed that there was obvious glycogen storage in the muscle and heart of pygma^-/- and pygmb^-/- compared with those of wild type (WT).The expression analysis of pygma and pygmb genes in WT at 15 early developmental stages and 12 adult tissues demonstrated that:the expression pattern of pygma and pygmb was similar at early stages, the expression of pygma and pygmb showed an overall upward trend and the increase of pygmb was greater than that of pygma from 24 hpf to 125 hpf.In the 12 tissues tested, pygma and pygmb were expressed only in a few tissues. pygma was mostly expressed in muscle tissue, followed by heart and skin; pygmb was highly expressed in heart, brain and eyes, and also expressed in muscle but at relatively lower level. Zebrafish pygma^-/- and pygmb^-/- mutants have the typical characters of GSDV with glycogen accumulation in muscle. The establishment of the zebrafish disease model provides a basis for further research on the pathogenesis, mechanism and drug screening for treatment of glycogen storage disease.

Abstract:Although morphology has been successfully used to distinguish wild Chinese mitten crabs (Eriocheir sinensis) from the Yangtze River and the Minjiang River, whether morphology could be used to identify the pond-reared offspring of these two wild E. sinensis populations still remains unclear. This study was undertaken to examine the morphological difference of wild E. sinensis (G0) from the Yangtze River (YZ) and Minjiang River (MJ) as well as their pond-reared offspring (G1). The results showed that:G0 populations were clearly divided into two independent groups by the first two principal components in the principal component analysis, but the plots were completely overlapped between two G1 populations; the grid distortion map showed that morphological differences of various populations are mainly manifested in the frontal and lateral spines of carapace; the discriminative accuracies of two G0 populations in the stepwise discriminant analysis both are 100%, but the discriminative accuracies of two G1 populations were 40%-60% with obvious misjudgment risk; cluster analysis showed that two G1 populations were clustered firstly and then were clustered with G0 of YZ population, while G0 of MJ population was formed into another distinct cluster. In summary, morphological differences between two wild E. sinensis populations disappeared after one generation of artificial culture, and morphology thus probably cannot be used to distinguish the pond-reared offspring of wild E. sinensis populations originated from the Yangtze River and Minjiang River.

Abstract:By analyzing the relationship between gonadal development and sex steroid hormone content during artificial ripening process, the aim of this study is to provide knowledge of artificial induction of maturation in Conger myriaster. A total of 100[body mass:(288.30±62.34) g] wild Japanese conger were collected and divided into four groups:group A (CPE:2 mg/kg), group B (HCG:200 IU/kg), group C (CPE:1 mg/kg and HCG:100 IU/kg) and control group without any hormone injection. The injection was given once a week and lasted for 12 weeks. The results showed that hormones can significantly promote the development of oocytes and induced the development of oocytes to the stage of nuclear transplantation successfully. The gonad of fish from Group C had the best development that about 32% eels' oocytes developed into Ⅳ stage. Moreover, all the fish induced by treatment had developed the oocyte into Ⅲ stage compared to the control group which was still stagnant in the stage Ⅱ. The content of testosterone[(217.00±31.76) ng/g] in the gonads of conger eels from treatment group C was significantly higher than that from the control group[(123.24±21.05) ng/g]. This study revealed that the CPE combined with HCG plays a better role in inducing gonad maturation of Conger myriaster.

Abstract:To investigate the components changing rule in epidermal mucus of discus fish (Symphysodon haraldi) during the breeding period, we measured the contents of cortisol, IgM, total protein, lactic acid and glucose in epidermal mucus. The results showed that the contents of cortisol, IgM, total protein, lactic acid and glucose in the epidermal mucus of S. haraldi were significantly influenced by fish gender, breeding period and there were significant interactions beteween gender and breeding period. In the free-swimming period of larvae, the contents of five components had significant difference between the female and male parent fish. When the discus fish began ‘lactating’, the components of epidermal mucus changed significantly, especially the male fish would secrete more nutrient and immune components for satisfying the needs of larvae.

Abstract:In order to explore the effects of light intensity on the breeding of Litopenaeus vannamei in algal-bacterial biofloc technology system, three different lighting were designed for experiment, including light of 200W (L200), light of 100W (L100) and light of 0W (L0). The light intensity of three groups is (8 422±195) lx,(4 400±204) lx and (3±1) lx. During the experimental period, larvae were cultured for 14 days in a zero-water exchange system. The results showed that the algal-bacterial-based biofloc system can control the water quality well, and increase of the light intensity can effectively reduce the drop of pH and alkalinity. The body length and weight of larvae in L200 were significantly higher than those in other groups (P<0.05). High intensity light improved the survival rate of larvae and reduced the proportion of total Vibrio in water, but there was no significant difference among 3 each groups (P>0.05). Additionally, the moisture content of larvae in L200 was significantly lower than that in other groups (P<0.05). The effect of light intensity on crude protein and crude fat content was not obvious. Significantly, there was no difference in the nutritional composition of BFT in each group (P>0.05). The results demonstrated that the application of a certain amount of light intensity in the algae-bacteria system was beneficial to water quality control and enhancement of shrimp quality.

Abstract:The inner shell color of donor Hyriopsis cumingii, which affects the color of pearls obviously, has become an important trait for genetic improvement of pearl mussels. However, the inner shell color of the mussels is difficult to measure. The measurement difficulties decreased the efficiency of selective breeding. In this study, the 4-8 month-old mussels from purple and white strains were selected for evaluating the correlation between the inner shell color and the outer shell color of mussels. The results are as follows:In purple strain, at 6 months old, the maximum correlation coefficient in a^* between outer shell and inner shell, 0.537, appeared (P<0.01). At 5 months old, the maximum correlation coefficient in b^* between outer shell and inner shell, 0.724, appeared (P<0.01). For a^*, the maximum correlation coefficient between the outer shell of 5-month-old mussels and inner shell of 8-month-old mussels, 0.414, appeared (P<0.01). For b^*, the maximum correlation coefficient between the outer shell of 4-month-old mussels and inner shell of 8-month-old mussels, 0.327, appeared (P<0.01). In white strain, for a^* and b^*, the maximum correlation coefficients between the outer shell of 5-month-old mussels and inner shell of 8-month-old mussels, 0.424 (P<0.01) and 0.326 (P<0.05), appeared. In summary, 5-month-old is the best time to indirectly evaluate the inner shell color by measuring outer shell color in Hyriopsis cumingii. In this study, we revealed that there is correlation between outer shell color and inner shell color in juvenile Hyriopsis cumingii. The result is of great significance to instruct early selection on inner shell color in Hyriopsis cumingii.

Abstract:To clarify the effects of different treatments of Chinese horseshoe crab genetic engineering antimicrobial peptide on the survival rate of rainbow trout, in this study, the antimicrobial peptides were applied by soaking and mixed feed in the larvae and adult stages of rainbow trout respectively. In order to verify the effects of different treatments of antimicrobial peptides on immune indexes of rainbow trout, the whole fish tissues of the larvae and the serum and head kidney tissues of the adult fish were collected respectively to detect the levels of the immune-related enzymes of SOD, ALP, CAT, IL-1β, IFN-γ, and TNF-α. The results showed that:soaking 10 times with 84 U/mL antimicrobial peptides of the larvae of rainbow, the immune-related enzyme levels of the experimental group were significantly higher than those in the control group on the 4th day after soaking, such as IL-1β and IFN-γ were extremely significant (P<0.01), while the others were significant (P<0.05); on the 15th day after soaking, the experimental group was still higher than the healthy fish of control group, IL-1β and IFN-γ were extremely significant (P<0.01), while the others were significant (P<0.05). However, the levels of immune-related enzymes in the sick fish of control group were decreased significantly than those of the experimental group. SOD, ALP, IL-1β, IFN-γ were extremely significant (P<0.01), while the others were significant (P<0.05). The survival rate of larvae in the experimental group was up to 95.1%, while the control group was only 29.9%. The adult fish were carried out from two aspects:mixed feed test and soaking test. The results showed that, the optimal dosage of the mixed feed was 50 mg/kg, the optimal concentration of the soaking was 84 U/mL, and the optimal soaking time was 3 min. Compared with the different treatments, it is found that the effects of soaking on the immune index of rainbow trout were most significant at the stage of the larvae. It may be related to the type of antimicrobial peptides, the mode of action and the outbreak characteristics of farmed rainbow trout. The results of this study will provide experimental basis for the application of antimicrobial peptides in rainbow trout culture.

Abstract:To establish a rapid method for the determination of metalaxyl residues in aquatic products, in this paper, the metalaxyl colloidal gold immunochromatographic test strip was based on the immunological method of monoclonal antibody, the colloidal gold labeled metalaxyl, monoclonal antibody was used as gold pad, and metalaxyl-bovine serum albumin conjugate and goat anti-mouse IgG as detection line and quality control line. The results showed that the monoclonal antibody of metalaxyl was IgG1, Kappa type; heavy chain 50 ku, light chain 20 ku, molecular mass about 150 ku; affinity constant was 2.46×10⁹ L/mol; IC₅₀ was 59.57 ng/mL. The test strip can still detect when the mass concentration of metalaxyl is 5 mg/mL, and there was no cross-reactivity with enrofloxacin, sulfamethoxazole, florfenicol, furazolidone, praziquantel, doxycycline, malachite green, methylene blue. The test strips were used to test the aquatic products such as Ctenopharyngodon idellus, Ruditapes philippinarum and Penaeus vannamei. The minimum detection limit for Ctenopharyngodon idellus and Penaeus vannamei samples was 2 mg/kg. The minimum detection limit for Ruditapes philippinarum sample was 1 mg/kg. The test strips were verified by high performance liquid chromatography to detect the residues of metalaxyl, and the results were consistent. Conclusion:The monoclonal antibody-based colloidal gold immunological strip is rapid, sensitive and specific, and is suitable as the primary screening method for the detection of metalaxyl residues in aquatic products.

Abstract:To investigate the effects of germinated broad bean and germinated pea on growth performance and flesh quality of grass carp, Ctenopharyngodon idella, formula diet (Control), germinated broad bean (GBB), and germinated pea (GP) were fed to grass carp with an initial body mass of (1 056.1±30.3) g for 84 days. The results showed that feeding grass carp with GBB or GP significantly reduced mass gain and increased feed conversion ratio (P<0.05). Besides, the flesh of fish fed GBB or GP had lower water loss, higher hardness, chewiness, muscle fiber density and collagen content, and the relative expression of Collagen Ⅰ genes (COL1A1, COL1A2) mRNA in muscle and skin was also up-regulated by dietary GBB or GP (P<0.05), when compared with the formula diet group. Between the two tried groups, the mass gain, muscle hardness, chewiness, muscle fiber density, and collagen content of the GBB group were significantly higher than those of the GP group (P<0.05). In conclusion, feeding grass carp with germinated broad bean or germinated pea improved the flesh quality, but decreased the growth, and feeding germinated broad bean showed better growth and flesh quality than feeding germinated pea.

Abstract:In order to explore the effects of vitamin D₃ content in the feed on growth performance, calcium and phosphorus metabolism, liver antioxidant capacity, serum biochemical indexes and anti-infection ability of largemouth bass, Micropterus salmoides, 0 IU/kg, 15 IU/kg, 30 IU/kg, 45 IU/kg and 60 IU/kg vitamin D₃ were added to the basic feed respectively. Five kinds of isonitrogenous and isoenergetic experimental diets feeds with vitamin D₃ contents of 1 370 IU/kg, 1 385 IU/kg, 1 400 IU/kg, 1 415 IU/kg and 1 430 IU/kg were set up. The largemouth bass with an initial body mass of (14.19±0.05)g was reared for nine weeks. The results showed that different levels of vitamin D₃ in the feed significantly affected the mass gain rate, specific growth rate and feed conversion rate of largemouth bass, but had no significant effect on survival rate, condition factor and viscera ratio. The addition of vitamin D₃ significantly reduced the liver to body ratio of largemouth bass. With the increase of vitamin D₃ content in the feed, the contents of crude ash, calcium and phosphorus and serum calcium ions in the spine of largemouth bass increased. However, there was no significant effect on the content of crude protein, crude fat, crude ash and moisture in the muscle. The total superoxide dismutase activity, catalase activity and total antioxidant activity in the liver of largemouth bass were significantly increased by the addition of vitamin D₃ in the feed, and the activity of transaminase in the serum was significantly decreased. The anti-infection ability of the body to Aeromonas hydrophila was also enhanced with the increase of vitamin D₃ content in the feed. All the results indicated that dietary vitamin D₃ between 1 370 IU/kg and 1 430 IU/kg could improve growth and health of largemouth bass.

Abstract:Suzhou is one of the central cities in the Yangtze River Delta, which has recently been facing increasingly serious eutrophication-related problems in the river courses in its urban area. To investigate the structural composition, annual succession and responses to environmental factors of phytoplankton functional groups in the river courses in the urban area of Suzhou, a bimonthly survey and its analysis were conducted in 2018. A total of 209 phytoplankton species were identified from 85 genera and 7 phyla throughout the year, 29 phytoplankton functional groups were markerd out, among which 19 (B, C, D, G, H1, J, Lo, M, MP, P, S1, S2, T, TC, W1, X1, X2, Y and Z) were the dominant functional groups in this area. The annual succession of phytoplankton functional groups was characterized as follows:B+C+D+H1→W1+H1→P+G+H1→M+S1+H1. H1 was found to be dominant throughout the year. The RDA analysis showed that water temperature (WT), total nitrogen content (TN), total phosphorus content (TP) and electrical conductivity (Ec) were identified as the main factors affecting the changes in phytoplankton functional groups in the urban river courses of Suzhou City.

Abstract:Life activities such as bioturbation and excretion of benthos affect nutrient content and migration at the sediment-water interface. The effects of Sinonovacula constricta bioturbation and its ammonia excretion on nitrogen nutrients in overlying water were studied based on a laboratory experiment in this study. Three treatment groups and a control group were set up according to different biological densities (63.66 ind/m²、127.32 ind/m²,190.99 ind/m²), and a 25-day laboratory experiment was carried out in the conditions of water temperature 23℃, salinity 22, and pH 8. The overlying water was collected every 5 days for analyzing the nitrogen nutrients and flux. The results show that the bioturbation of S. constricta. promoted the content of NH₄⁺ and NO₃^-+NO₂^- in the overlying water. With the increase of the density, the NH₄⁺ content increased obviously, while the content of NO₃^-+ NO₂^- increased first and then decreased. The NH₄⁺ flux is -0.195-0.273 mmol/(m²·d), that is, the ammonia nitrogen in the sediment is released into the overlying water. And the NO₃^-+NO₂^- flux is from -0.554 to 0.038 mmol/(m²·d), indicating that the sediment absorbed nitrate nitrogen from the overlying water. Considering the effect of ammonia metabolism of S. constricta. the ammonia nitrogen content was checked by ammonia data. Although the NH₄⁺ content decreased slightly, but the trend with time did not change. In addition, the NH₄⁺ flux changed greatly in the initial stage of the experiment, and it changed from sediment to overlying water release to migrate from the overlying water to the sediment, and then stabilized without obvious changes. Therefore, the bioturbation of S. constricta promoted the exchange of nitrogen nutrients between the sediment and the overlying water. The ammonia metabolism has a great influence on the flux in the early stage of the experiment, and the effect of ammonia metabolism gradually decreases over time.

Abstract:Due to the improper use, antibiotic residues became one of the highly persistent pollutants and have damaged the water ecosystem. In this paper, the growth characteristics, physiological condition and photosynthesis related genes of Microcystis aeruginosa were tested at five different mass concentrations of florfenicol. The results showed that in lower mass concentrations group (lower than 0.1 mg/L), the contents of chlorophyll a significantly increased, while no obvious effect on the phycobiliprotein content and the secretion of polysaccharide. In higher mass concentration group (higher than 1.0 mg/L), the synthesis of cyanobacteria chlorophyll a was inhibited, but the contents of phycobiliprotein and polysaccharides secreted increased. The photosynthesis related genes rbcL, psaB and psbD1 of Microcystis aeruginosa were changed with florfenicol treatment groups. The expression levels of rbcL and psaB genes were down-regulated in first three days, and up-regulated after 5th and 7th day exposure. The expression level of the psbD1 gene in the 0.1 mg/L group was not significantly different with the control group at 3-5 days after treatment, while the 1.0 mg/L group was significantly up-regulated than that of other groups. The results showed that 1.0 mg/L florfenicol in the water had a good impact on growth of Microcystis aeruginosa.

Abstract:In order to solve the problem that it is difficult to separate graphene oxide (GO) from aqueous solution after adsorption of pollutants, PEI-GO composite was prepared by modifying GO with PEI, and the structure and morphology of the composite was characterized by FT-IR, Raman, SEM and EDS. The effects of different adsorption time and adsorbent dosage on the adsorption performance of MB were analyzed, and the kinetic and temperature line models were used to fit them. The separation time of MB adsorbed by GO and PEI-GO was recorded respectively. The results show that PEI-GO composite still has a good two-dimensional nanostructure and the O=C-NH covalent bond which is formed by the reaction of the oxygen-containing functional group in the nano film and the amino group in PEI. The composite PEI-GO has good adsorption property for MB. When the initial concentration of MB is 25mg/L and the input amount of PEI-GO is 30 mg, the adsorption capacity of PEI-GO can reach 204.87mg/g. The adsorption behavior conformed to quasi second-order kinetic model and Freundlich isothermal model. After adsorption, compared with GO adsorption, the separation rate is 4-5 times faster.

Abstract:This study is conducted based on the bottom trawl surveys in the Wenzhou-Taizhou area, off the waters of the southern Zhejiang. Survey data were collected from 2016-2018 in all four seasons:Early March(winter), May (spring), August (summer), and November (autumn). The generalized linear model (GLM) and 9 linear mixed-effect models (LMEM) were used to analyze the fork length-mass relationship (W=aL^b) and its heterogeneity for Pampus echinogaster.The results showed that the fork length of Pampus echinogaster in this region was from 53.00 mm to 238.00 mm, with an average fork length of 128.54 mm. The dominant fork length group was from 110.00 mm to 160.00 mm. The mass range was from 3.80 g to 420.50 g, with an average mass of 63.61 g. The dominant body mass group was from 60.00 g to 180.00 g. According to the Akaike Information Criterion (AIC), the best fitting model was the model with a combination of both seasonal and yearly random effects on the growth parameters a and b of Pampus echinogaster. The root-mean-square error results also showed that this model had the best effect. In the optimal model, the fixed value of parameter a was 1.75×10^-5, and the fixed value of parameter b was 3.083, which indicates that Pampus echinogaster follows a positive allometric growth and presents better condition. The results of the optimal linear mixed model showed that the largest value of a was recorded in autumn, followed by summer and winter, and the smallest in spring; opposite trend was obtained for parameter b. From different years, the value of a was the largest in 2016, followed by 2018 and 2017; the value of b was the largest in 2017, followed by 2018 and 2016. The annual and seasonal impact on the fork length-mass relationship of Pampus echinogaster is analyzed through the mixed effect model.It shows that the year and the season have significant effects on the fork length-mass relationship of Pampus echinogaster, and that the model has important reference value in the study of the heterogeneity for the fork length-mass relationship of Pampuse chinogaster, and provides a scientific basis for the rational development and management of its resources.

Abstract:The net position, net body status and overall status of trawl are important indices to evaluate the trawling performance during trawling operation. The trawl operation status of an Antarctic krill trawl is expressed by the depth difference between the different parts of the trawl (headline, section 3-4 net body connection, upper midpoint of the cod-end mouth). In order to determine the trawling status of midwater trawl,the effects of fishing operations, marine environment and catch on the status of trawling operations were investigated in this study. The results showed that:The depth difference between the headline and the section 3-4 net body connection range from -0.20 to 8.02 m, and the depth difference between the headline and the upper midpoint of the cod-end mouth ranged from 6.49 to 30.16 m; Warp length, towing speed, wind speed and water velocity at 150 m depth had significant effects on the depth of the headline (P<0.05); The headline depth was positively correlated with the warp length and water velocity at 150 m depth, there was a negative correlation between the headline depth and towing speed, and the headline depth decreased first and then increased with the increase of wind speed; Towing speed, water velocity at 200 m depth and wave height had significant effects on the depth difference between the headline and the section 3-4 net body connection(P<0.05), The depth difference between the headline and the section 3-4 net body connection increased first and then decreased with the towing speed and water velocity at 200 m, When the towing speed was 2.6 kn and the water velocity at 200 m was 0.3 kn, the depth difference between the headline and the section 3-4 net body connection was the largest, and the depth difference was the smallest when the wave height was 2 m; The catch was positively correlated with the depth difference between the headline and upper midpoint of the cod-end mouth; Warp length was the most important factor affecting the status of trawling operations, followed by towing speed, wind speed, wave height, and water flow velocity.

Abstract:The morphological characteristics of sagittal otoliths of 135 individuals of Carangidae (Decapterus macrosoma, D. tabl, D. kurroides, Trachurus japonicus, Alectis ciliaris, Caranx equula, Selar crumenophthalmus) collected from the Dongsha Islands in the South China Sea were studied in this paper. The entire morphology of sagittal otolith of 7 species of Carangidae was long oval, quadrilateral and semicircular curved hooked. There were knobs around the otolith with the development of rostrum and sulcus. The sulcus extends from the excisural notch of the anterior part of otolith to the posterior part of otolith. The results show that the morphological characteristics of otoliths of 7 species of Carangidae were obviously different among species. The systematic classification and retrieval table established by otolith morphology and the application of cluster analysis were effective in identifying otolith morphology. This study will provide some reference for the stock identification and systematic classification of Carangidae.

Abstract:In the design and production of the bionic squid, the combination of the wrist contraction fin flapping and jet propulsion enables the squid to swim in a variety of motions. In order to study the flapping propulsion mechanism of squid fin, the computational fluid dynamics (CFD) method was adopted to conduct numerical modeling of the biological squid in equal proportion, and to calculate and analyze the hydrodynamic characteristics of squid fin at different flapping angles. On this basis, the effects of different parameters on the propulsion performance of squid fin flapping were analyzed and discussed by changing the parameters of fin proportion and fin shape. The results show that:during the flapping process of the squid fin, there appeared obvious vortex zone and pressure difference on the upper and lower surfaces of the fin. Under the action of the pressure difference, the squid completed the heave movement and horizontal movement; when the proportion of fin in the squid body exceeded 0.3, the heave force and horizontal propulsion force both showed an obvious upward trend with the increase of the proportion of fin, while the change of resistance tends to be stable, therefore, a proper increase in the proportion of fin in the squid body can obtain a higher flapping propulsion efficiency; The transverse lozenge fin had higher propulsion efficiency and lower swimming resistance, which is an ideal choice for the design of the bionic squid. The results could provide a theoretical reference and calculation method for the design and manufacture of bionic robotic squid.

Abstract:Illegal, unreported and unregulated (IUU) fishing has become a major problem in global ocean governance. In recent years, the European Union and the United States have adopted various measures in combating IUU fishing and developed relatively systematic and rigorous regulatory frameworks. This study compares the arrangements of the EU and the US from three dimensions (management system, legal framework and international participation), exploring their efforts in defining IUU fishing behaviors, selecting fisheries management modes, establishing responsible departments, introducing relevant laws and regulations, implementing regulatory measures, providing financial services, and promoting international cooperation. Certain suggestions for China have been put forward:Remain cautious of the unilateral actions from the EU and the US under the pretext of strictly cracking down on IUU fishing in order to uphold China's international rights and interests; add special provisions about IUU fishing in relevant laws and regulations; strengthen law enforcement cooperation; fulfill due responsibilities and obligations, severely punish "Three No" fishing vessels and the distant water fishing vessels participating in IUU activities; enhance fishermen's capacity building and provide legal and ethical training, striving to become a globally-recognized responsible fisheries power.

Abstract:Fishing effort is one of the important parameters in the field of fishery resource management and assessment. Traditional fishing effort calculation methods cannot satisfy the needs of real-time, large-scale and rapid statistics. This study takes the stow net vessels operating offshore in China as the research object, and adopts the BP (Back Propagation) neural network model. Through the state judgment of the latitude and longitude coordinates, speed, heading and other information of the five consecutive voyages acquired by the Beidou Fishing Vessel Monitoring System in 2016 and 2017 of Zhangwangchuan 155, the net position coordinates of each voyage operation were obtained. By screening the position and time of the fishing net through the threshold and calculating the fishing time, the fishing effort can be calculated by the fishing net opening area multiplied the fishing time. Combined with the judgment results of BP neural network and threshold analysis, the accuracy of obtaining the network position data is 82%. The cumulative fishing time of the four voyages was 3 562.62 h, and the accumulated fishing effort was 712 524 (m²·h). The state judgment, net position identification, extraction of release time, and calculation method of fishing effort designed by this paper may provide new research ideas for the analysis of the net operation and the quantification of its fishing intensity.

Abstract:In order to meet the needs of consumers who can taste fresh fish which are from different places, keep-alive transportation of fish is particularly important. Anesthesia keep-alive transportation plays an important role in reducing transport injury and improving transport survival rate This article summarizes the application of four common fishery anesthetics in fish anesthesia keep-alive transportation, discusses the main factors affecting the survival rate of anesthesia keep-alive transportation, the effects of anesthetics on fish physiology and biochemistry, and the detection technology of anesthetic residues and summarizes the current problems and development prospects of anesthesia keep-alive transportation. At present, researches on anesthetics for fisheries are mainly focused on the anesthetic effects for different aquatic products and the effects on fish physiology and biochemistry, and there are few studies on the effects of fish flavor. New types of fishing anesthetics and rapid detection technology for anesthetic residues will be the focus of future research.

Abstract:Foodborne diseases of aquatic products are one of the major public health and safety problems. It is very important to control the growth of pathogenic bacteria. The abuse of antibiotics leads to drug resistance of pathogens, so it is necessary to find another safe and effective method to replace antibiotics to inhibit pathogens in aquatic products. Bacteriophages have attracted much attention because of their ability to cleave pathogens and are considered to be the most promising biological bacteriostatic agent to replace antibiotics. Based on the introduction of the definition and mechanism of bacteriophage, the research progress of bacteriophage on Vibrio parahaemolyticus, Salmonella, Vibrio alginolyticus and Vibrio cholera was reviewed. The main problems and solutions in the application of bacteriophage were put forward and its future development prospect was also prospected so as to provide the theoretical reference for the research and application of bacteriophage in aquatic products.