Abstract:To investigate the influence of the number of sampling stations on the accuracy of the fishery resource survey along southern Zhejiang offshore,the influence of the number of stations on fish com-munity resources,the absolute dominant species resources and the species detection rate in each season was compared based on bottom trawl survey data in southern Zhejiang offshore in February,May,Au-gust and November,2019,with computer simulation methods,and the optimal number of stations for fishery resource survey in southern Zhejiang offshore was estimated.The results showed that seasonal differences significantly affect the sampling accuracy of fish communities with the same number of sites.The seasonal coefficient of variation(CV)of fish richness sampling ranged from spring to au-tumn and then to winter and summer,and the relative estimation error(REE)and relative bias(RB)varied seasonally,autumn was larger than spring,then winter and finally summer.The species detec-tion rate was also different seasonally,therefore,different numbers of stations were required for the detection rate of a species among different seasons.Changes in studying population influenced the opti-mal number of sites.In spring,the ranges of variation of CV,REE and RB of Trichiurus lepturus were significantly wider than those of Benthosema pterotum,and the optimal number of sites should be ad-justed according to the actual survey needs.Under the premise of choosing REE=10％as the asymp-totic value for determining the optimal number of sampling sites,and by considering the quantified re-sults of community resources,community dominant species resources and species detection rate each season,the optimal number of offshore sites of trawl fishery resources in southern Zhejiang was 27 in spring,24 in summer and autumn and 26 in winter.

Abstract:"Ten-year fishing ban"in Yangtze River Basin is a national strategy.The Ministry of Agri-culture and Rural Affairs has been leading the establishment of an inter-provincial coordination mecha-nism management of Yangtze River Estuary.By setting up the no-catch management area in Yangtze River Estuary,pilot projects for collaborative governance have been implemented,which are running effectively.However,in the process of operation,there are tensions between territorial management based on"boundary demarcation"and cross-domain governance based on"boundary breaking",leading to the dilemma in subject,ownership,process and resource guarantee,either directly or indirectly,in the practice of collaborative governance.Based on the in-depth analysis of organizational structure chan-ges,regional and functional division,inertia of territorial management and departmental management,financial system and management mode,we proposed a reasonable absorption and functional activation of collaborative governance subjects,appropriate design of nested responsibility realization mechanism and law enforcement standards,and"unified"and"divided"law enforcement.The specific paths to-wards breaking the dilemma are proposed,which include the rational absorption and functional activa-tion of collaborative governance subjects,the appropriate design of nested responsibility realization mechanism and law enforcement standards,the adequate coupling of"unified"and"divided"law en-forcement mechanisms,and the diversification of law enforcement resources extraction and deployment.

Abstract:Dosidicus gigas widely distributes in the equatorial,Peruvian and Chilean waters of the east-ern Pacific Ocean,which is a key species in marine ecosystems and an important economic fishing target for Chinese squid-jigging fisheries.Based on the sea surface temperature(SST)and catch data in the range from 20° to 34.5°S and from 88.5° to 71.5°W off Chile from 2011 to 2017 in summer(December-February)and autumn(March-May),we analyzed the temporal and spatial change in the center of gravity of the squid fishery off the coast of Chile each year,and explored the relationship between the change of the gravity center of the squid fishery and the SST in the fishery and its response to abnormal climate events.We found that there are significant seasonal and interannual changes in the center of gravity of squid fishery off the coast of Chile,three clusters in the center of gravity of the fishery in dif-ferent years,and significant seasonal differences in the frequency distribution of fishing effort in sum-mer and autumn in terms of longitude,latitude and SST.Compared to the El Niño year,2015,the SST off Chile was low in 2014.The most suitable temperature of D.gigas shifted southeastward,cor-respondingly,the gravity center of fishing ground of D.gigas moved in southeast direction with a lar-ger suitable habitats.Our findings showed that there are significant seasonal and interannual changes in the spatial and terrestrial distribution of D.gigas fisheries off Chile,which is significantly affected by climate variability.

Abstract:The high-resolution COSMO model in climate mode(CCLM)was used to simulate the 3-hour wave characteristics in the Bohai Sea,the Yellow Sea and the East China Sea.The simulation results for the base period(from 1979 to 2005)were compared with the wave characteristics changes from 2021 to 2050 under the RCP2.6 scenario.The results showed that the average annual wave height increased from the northwest Bohai Sea to the middle and east Yellow Sea.The average annual wave height in-creased the most in the middle and east Yellow Sea,and decreased in the east China Sea.In terms of the average annual cycle,most of the sea areas in the East China Sea were in a decreasing trend,and the decrease in the central and eastern parts could reach more than 0.02 s,while most of the Bohai Sea and Yellow Sea were in an increasing trend.The results could provide better climate change prediction data for the east China seas,and provided scientific basis for assessing the impact of future climate change and putting forward adaptive measures.

Abstract:Spartina alterniflora,introduced to China for coastal protection early,exhibits wave attenu-ation,sediment accretion,and carbon sequestration functions.However,its widespread invasion sig-nificantly impacts the ecological environment of coastal estuaries and intertidal zones in China.In this paper,we reviewed the research findings in the dispersal mechanisms,spatial distribution characteris-tics,influencing factors,ecological impacts on intertidal environments,carbon sink characteristics,and management measures of S.alterniflora communities.We explored the interactions between S.al-terniflora communities and intertidal habitats,proposed ecological management measures,and provid-ed a theoretical support for assessing the ecological impacts of the invasive plants in coastal intertidal zones and formulating ecological restoration measures.

Abstract:With the increase of people's demand for aquatic products,some problems have gradually e-merged,which include unclear information about the origin,confusing the real with the false,shoddy among others.Stable isotopes contain abundant environmental information of origin,and they have a great application prospect in origin traceability.To protect abalone products with geographical indica-tions and trace the origin of abalones,in this study,abalone samples were collected from Lianjiang,Changdao,Rongcheng and Dalian.The stable isotope ratios of carbon and nitrogen in gastropod mus-cle,muscle edge,digestive glands and gonads and mantle of abalones were analyzed on a stable isotope mass spectrometer.Origin traceability model was established through Fisher discriminant analysis,and verified with leave-one-out method.It was pointed out that the fingerprint characteristics of overall sta-ble isotope ratios of abalones from different regions,and the recognition ability of stable carbon and ni-trogen isotopes in different tissues to the origin traceability were evaluated.The results showed that the overall original correct discrimination rate of abalone of origin traceability is 90.5％,the correct dis-crimination rate of cross validation is 89.0％,and Fujian and Rongcheng regions have the best effect on abalone traceability.The correct rate of individual identification each tissue was below 80％,less than the correct rate of identification for all tissues.It was suggested that all organizations should be combined to trace the origin to improve the accuracy of origin traceability.In addition,distinguishing Lianjiang abalones from those of Rongcheng can be achieved using the traceability index of mantle alone.Our findings provided a scientific basis for establishing a new traceability system of aquatic products origin in China.

Abstract:In order to realize all-day and all-weather wave observation at low cost,this paper proposes a design scheme of a gravitational wave gauge based on MEMS attitude sensor.The wave gauge collects original signal through attitude sensors including a three-axis accelerometer,a three-axis gyroscope,and a three-axis geomagnetometer,and converts the coordinate system through the quaternion method to obtain the vertical acceleration signal,and uses the Fourier transform to convert the time-domain ac-celeration signal into a frequency-domain signal for quadratic integration to obtain the wave height data,and completes the analysis of the wave eigenvalues by the upper-span zero point method.A wave simu-lation device was used to conduct a simulated wave measurement experiment,and compare the full wave height data measured by the self-developed wave gauge with the standard sine function,and to an-alyze the indication error of the wave eigenvalues.The results showed that the indication error met the first-level accuracy.Finally,a comparison experiment of marine wave measurement was carried out with the SBY1-1 wave gauge in the offshore area of Rongcheng city,and the wave measurement results were strongly correlated.Experiments showed that the wave gauge could stably and accurately com-plete the task of ocean wave measurement.

Abstract:Scomber japonicus is one of the main target species of fishery in northwest Pacific.Its re-source recruitment often fluctuates significantly due to the impact of climate change and other factors.To study the impact of climate change on the change of S.japonicus resource northwest Pacific,and analyze the general change rules of transportation distribution and resource recruitment under abnormal climate conditions,the individual based early ecological dynamics model of S.japonicus in northwest Pacific was used to simulate the distribution and recruitment of S.japonicus resource in northwest Pa-cific from 1997 to 2010.The differences of transport and distribution paths and changes of recruitment amount of larvae fish under different climatic conditions in El Niño year(2002),normal climate year(2006)and La Niña year(2010)were compared.The simulation results showed that the resource dis-tribution and recruitment of S.japonicus in northwest Pacific have fluctuated significantly in the simu-lated 14 years,and the resource distribution and recruitment of S.japonicus resource are different un-der different climatic conditions.our findings indicated that the changes of marine environments inclu-ding temperature,ocean current among others caused by climate change impact the resource of S.ja-ponicus.

Abstract:The mid-latitude northwest Pacific Ocean is the high incidence area of sea fog,and it is also the way for China to reach the Arctic sea.However,due to the few observations at sea,the under-standing of the formation mechanism of sea fog is limited.From September 12 to 14,2019,the re-search ship"Xiangyanghong 1"recorded a sea fog event in the Oyashio extension area.In this paper,the formation mechanism of the sea fog was studied mainly by numerical simulation,numerical experi-ment and observations from scientific research ships.The results showed that:(1)The sea fog oc-curred in the warm area of the extratropical cyclone,and the warm front of the synoptic scale advanced to the north,forming a large range of front inversion over the cold water of the Oyashio extension pro-viding favorable weather background conditions for the development of the clouds/fog.(2)The atmos-pheric boundary layer above the cold water side of the ocean front(sea surface temperature front)was a"double inversion"structure.The superposition of subsiding inversions and frontal inversions caused by the subsiding branch of the local low-level secondary circulation forced by ocean front was an impor-tant reason for the formation of the"double inversion".The numerical results showed that with the smoothed ocean front,the strength of the sinking branch of the secondary circulation in the boundary layer was weakened,the scope of the"double inversion"structure disappeared,and the scope of the fog area was significantly reduced.(3)Both temperature and humidity in the fog rose,but the actual water vapor pressure rose faster than saturated water vapor pressure,the humidification effect was greater than the warming effect,which was obviously different from the cooling and humidification dominance of sea fog in spring and in summer in the Yellow Sea.This study revealed one of the reasons why sea fog tends to occur on the cold side of the ocean front in the open ocean,which can provide a new theo-retical support for sea fog forecast.

Abstract:Promoting the transformation of fishermen's livelihood based on the non-agricultural employ-ment of rural labor is the top priority of governmental decision-making departments and research com-munity.Based on the three-dimensional framework of buffering-self-organizing-learning constructed based on the theory of"livelihood resilience"and combined with two methods of necessary condition a-nalysis(NCA)and fuzzy set qualitative comparative analysis(fs/QCA),the key driving conditions,ac-tion paths and differences among Jiangsu Provincial sample locations of non-agricultural employment choices of fishermen were analyzed from a perspective of configuration.(1)A single condition cannot constitute a necessary condition to explain fishermen's non-agricultural employment choices;however,earning ability,especially skill training,plays an important role in non-agricultural employment of fish-ermen.(2)Buffering,self-organization and learning ability are coordinated and concurrent.We ex-plored and proposed three adaptation paths towards promoting non-agricultural employment of fisher-men,namely,the adaptation mode explained by independent learning ability,the joint explanation by learning and self-organization ability.The adaptation model explained by buffering and self-organization ability drives the choice of fishermen's livelihood strategies in the same way.(3)In further comparison between sample districts and counties of Jiangsu Province,it was found that the difference in factor en-dowments makes the development paths of fishermen's non-agricultural employment very different.Based on the advantages of local resources and the characteristics of the fishermen,the government should comprehensively consider the combination of multiple conditions under the overall perspective,and form a diversified realization path for fishermen to shift to employment.

Abstract:In this study,we described the status of the basic fishery research using bibliometrics and competitiveness index.We found that the breadth and depth of fishery research have been broadening and deepening,and the quality of literatures has also been increasing.So far,a large number of fishery research institutes are running,and the literatures published by American federal research institutes and Japanese public research institutes exhibited a high quality.The influence of their literatures stayed also ahead of other countries.In addition,the publications of China and the citations of these publica-tions in fishery are constantly increasing,and have transcended four benchmarking countries,the Unit-ed States,Japan,Australia and Canada,for a time.Besides,there is still a gap in the efficiency index of scientific research resources between China and these benchmarking countries.Our findings should aid to deepen our understanding of the competition situation in basic fishery research among various countries,and provide some theoretical and practical implications for the formulation of relevant fishery science and technology policies.

Abstract:Continuous degradation of coastal seagrass bed in Hainan Island needs to be solved urgently.We used the iron frame fixation method with a constant distance to transplant Thalassia hemprichii and Enhalus acoroides in Xincun Port,Hainan.The repair scale was 100 transplantation units(40 T.hemprichii and 60 E.acoroides)within an area of about 1500 m2.The survival rate decreased signifi-cantly after 8 months to the the lowest in 14 months(51.25％)but increased after 16 months,reaching 67.81％after 24 months.The growth of E.acoroides was stable,and the overall trend fluctuated slightly.The average survival rate and coverage of E.acoroides were higher than those of T.hemp-richii,but the average germination rate of E.acoroides was significantly lower than that of T.hemp-richii.The repair effect of seagrass transplantation in Xincun Port was mainly affected by weak water exchange and macroalgal outbreaks.To ensure the restoration effect,long-term monitoring of seagrass growth should be carried out,warning signs should be set up,local fishermen should be hired to take care of the transplanted seagrass,and fence protection should be carried out.Our findings can provide basic data and theory for future seagrass restoration in other lagoon areas.

Abstract:In the development of marine resources,the effects of internal solitary waves and ocean cur-rents on the structural foundation of the constructed offshore platform cannot be ignored,and the load characteristics of the structural foundation under the combined action of the two are particularly com-plex.In this paper,the fluid simulation program FLOW-3D based on the finite difference method and the source term method were used to generate waves and boundary conditions to generate flow.The hy-drodynamic load on the cylinder under the action of the steady flow direction and the characteristics of the surrounding flow field under the action of the internal solitary wave were studied.The results showed that:(1)By comparing the theoretical solution of the internal solitary wave with the numerical solution of the steady flow at different velocities,it is found that the steady flow directly affected the waveform of the internal solitary wave;(2)The flow velocity of the steady flow would cause the propa-gation of the internal solitary wave;(3)The increase of the amplitude of the inner solitary wave or the increase of the steady flow velocity would lead to the increase of the resultant force on the cylinder,and the force of the wave in the same direction was greater than that in the opposite direction of the wave.

Abstract:According to the measured wave data from September 2018 to August 2019 in the sea area of western Guangdong,this paper mainly studied the characteristics of wave variation,and the joint dis-tribution of wave height and period and wave type distribution characteristics month by month.The differences in the wave spectrum for different typhoon waves were explored.The results showed that the maximum wave height was 14.7 m,which caused by typhoon"Mangkut",and the maximum monthly average significant wave height was 1.6 m in December.There were more wind waves in win-ter,and the swells accounted only 38％.While in other seasons,swells accounted for more than 60％.There were obvious differences in wave spectrum type,peak frequency and frequency range during the transit of typhoon"Mangkut"and"Baijat".The wave type was mixed wave,in which the swell and wind wave predominated respectively.The research results could provide references for marine disaster prevention and reduction,ocean environmental assessment and ocean engineering design.

Abstract:It is important to understand the near-shore hydrodynamic processes under the influence of super typhoons to guide the construction of coastal engineering,coastal disaster prevention and mitiga-tion.In this paper,a numerical model based on the FVCOM-SWAVE was established in the China Seas to simulate the offshore hydrodynamic processes under the influence of three super typhoons.The dis-tribution characteristics of marine elements under the influence of super typhoons were analyzed,and the influence of wave-current interaction on the simulation of hydrodynamic processes was investigated.The results showed that:the location of the maximum significant wave height was related to the tracks of the typhoons,and the maximum significant wave height was generally located in the right of the ty-phoon centre;the distribution of typhoon waves on both sides of the typhoon path was related to the landing sites of typhoons;the coupled model could better consider the impact of wind and air pressure;the wind speed and direction were the main factors which affected the distribution of nearshore surge,and the storm surges and wave heights were significantly correlated under the effects of super ty-phoons.

Abstract:Based on the unstructured triangular irregular grid finite volume three-dimensional offshore ocean model(FVCOM),a large-scale three-dimensional hydrodynamic numerical model was construc-ted with mountains as the center radiating outward,including the Yangtze River Estuary,Hangzhou Bay and nearby waters.The accuracy of the model was verified by measured tidal level and tidal current data.The results showed that the numerical simulation results were in good agreement with the meas-ured data,and the model results were meaningful.In addition,on the basis of verifying the reliability of the model,the hydrodynamic numerical simulation was carried out in the Dayangshan sea water area,and the complex flow regime and flow energy distribution of the waterway in the sea area were ana-lyzed.The results can be used for further research on the influence of hydrodynamic forces on sediment movement,and have certain scientific significance for preventing ships from running aground in the waterway.

Abstract:Focusing on the disasters of storm surge,wave disaster and sea ice disaster during 1949-2015 which affected North China Sea(government jurisdiction areas to the north of Xiuzhen river estu-ary located on borderline between Shandong and Jiangsu province),the loss index system of historical marine disaster and the index system of nature variations were constructed on the basis of collection and integration of historical marine disaster literature,observed data during the disaster process and the im-age data.Using Oracle database platform,historical marine disaster database was built up.The marine disaster data management platform of North China Sea which synthesizes the spatial query,graphical statistics and digital data management was established using ArcGIS platform.The platform can pro-vide critical technical supports for marine disaster prevention&mitigation and relevant technical refer-ences on risk area cataloging,risk assessment,disaster forecasting and disaster losses post-assessment,and can also be an important reference to standardize the construction of marine disaster database do-mestically.

Abstract:Extreme wave height is an important environmental condition in offshore and ocean engineer-ing design,and the study of the design values of wave height is of great significance.Based on the tra-ditional compound extreme value distribution,this paper classified the maximum wave height data of the wave disaster process according to their source,and selected the optimal extreme value distribution by fitting various wave height sequences respectively.Finally,the design value of wave height was cal-culated jointly and compared with the design value of Poisson compound extreme value distribution model and annual extreme value model.The results showed that the Pearson type 3 distribution had the best fitting effect on the wave height in the Beihai area.Compared with the traditional model,the de-sign wave height of the multi-source compound extreme distribution model was more conservative.The multi-source compound extreme distribution model proposed in this paper can provide some reference for the design of offshore and ocean engineering.

Abstract:At present,80％of marine pollution is caused by land-based pollution,and the discharge of pollutants into the sea is the main body of land-based pollution.An appropriate market trading mecha-nism for the emission rights of pollutants into the sea can effectively reduce pollutant discharge and co-ordinate economic development.Based on the necessity and feasibility of establishing a market trading mechanism for the emission rights of pollutants into the sea,this paper used hierarchical analysis and game analysis to build the three-level market trading mechanism for the emission rights of pollutants into the sea according to the different trading subjects and leading mechanisms.In addition,sugges-tions were put forward to promote the effective operation of the market trading mechanism for emission rights of pollutants into the sea in terms of trading rule design,supervision mechanism,reward and punishment mechanism.It is expected to provide reference for the formation of a virtuous circle of trading market of marine pollutant emission rights in China.

Abstract:Shark conservation and management are important components of global fishery resource gov-ernance.Since the 1990s,the five tuna regional fisheries management organizations of the world have issued many legal documents and introduced various measures to vigorously support shark conservation and management.While improving the protection level of the global shark resources,such trial also faces a series of problems like decision-making difficulties,non-existent management system and limit-ed ability of developing contracting parties to implement the contract.In this regard,it is suggested that these organizations should develop a strong decision-making mechanism,strengthen the binding force and implementation of the system,and support the capacity-building of developing state parties to break through the developmental bottleneck and further deepen the shark conservation and management process.At present,these organizations are constantly improving and updating shark conservation and management measures.As a member of the four regional fisheries management organizations,the or-ganization of China should attach importance to and regulate shark fishery data statistics,establish the shark fishery scientific committee system,improve the compliance ability of fishery practitioners,and strengthen research and participation in the organization,so as to enhance the international status of China in deep-sea fisheries and establish the image of a responsible fishery power.