Blend with the Sea Surface Temperature from Different Satellites and Their Comparison in the Southeast Pacific Ocean

The daily sea surface temperature(SST)data from three kinds of different satellites of GMI,GOES and MODIS were applied to do the blend in the Southeast Pacific Ocean throughout the whole year of 2020.The coverage rates of the SST of the blend result were improved highly and more stable throughout the whole year,compared with the result of the single satellite of GMI,GOES,and MODIS.The yearly average coverage rates of GMI,GOES,MODIS,and blend were 43%,48%,30%,and 76%,and their corresponding yearly average standard deviation(SD)were 4%,6%,7%,and 4%,respectively.All the coverage rates of these three satellites were low from April to September.The valid observation days calculated in the whole year over every grid were used to represent the spatial distribution patterns of the coverage rates.The spatial distribution patterns of coverage rates from GOES and MODIS were similar that their valid observation days were higher in the northwest area and lower in the south area,and those of GMI was contrary to the former two.The ranges of valid observation day was from GOES,GMI,and MODIS were 0-364,6-254,and 9-231 d,respectively.After the blend,all the observation day of every grid in the research region was enhanced(103-366 d).Especially the near shore and south area,and the minimum valid observation day increased largely from the single digits to hundreds digit.

A FISHERIES STUDY ON THE SECTIONAL CIRCULATION IN THE EAST CHINA SEA

Surveys since 1959 showed that the dynamic basis of the East China Sea sectional circulation is the nearshore seawater horizontal divergence caused by wind on the surface compensated by Kuroshio subsurface water convergence caused by meridional current in the lower layer.Fish always tend to migrate along certain routes or stay in certain areas favorable for development of eggs, survival of larvae and living of adults. The movement of water masses supplies a very important driving force for marine animals migrating long distance.The lower part of the sectional circulation formed by the subsurface water of Kuroshio is not suitable for the aggregation offish because of its lack of oxygen, and has therefore a driving influence on demersal fishes.This study of the sectional circulation influence on the distributions of some commercially important species in the East China Sea reveals a close relationship between the circulation and the movement of fish schools.The principal factors influencing zonal

Species composition and diversity of Euphausiacea in the East China Sea

Based on the data of four seasonal oceanographic censuses in the East China Sea （23°30＇-33°00＇N, 118°30＇-128°00＇E） in 1997-2000, the species composition and the diversity of Euphausiacea were discussed as well as their relations with environmental variables. Results showed that there were totally 23 different species of Euphausiacea, in which 16 occurred in spring and autumn respectively; 15 were present in summer and only 10 were observed in winter. According to the calculated alternation fraction （R）, the species composition showed a clear seasonal alternation with the changes of seasons. Moreover, the environmental variables had different impacts on the distribution of Euphausiacea in different seasons. The distribution in summer was not significantly related to water temperature and salinity. However, the surface salinity was a major determinant of the distribution in spring. In autumn, both surface and bottom temperatures were influencing factors. The distribution in winter depended on salinity at the surface and 10 m depth as well as the temperature at 10 m depth. Regarding to the seasonal variation of species composition, the variations in spring, summer and autumn were not so significant as those in winter. Except in summer, the species number changed with synchronous water temperature and salinity, as a result of the presence of warm currents in the East China Sea and the habitability of the dominant species. Since Euphausiacea tend to agglomerate, the distribution of different species was uneven, which was the major reason for the low diversity of Euphausiacea in the East China Sea.

Optimal salinity for dominant copepods in the East China Sea, determined using a yield density model

From 1997 to 2000, four field surveys were conducted in the East China Sea (ECS) (23°30′-33°00′N, 118°30′-128°00′E). A field data yield density model was used to determine the optimal salinities for 19 dominant copepod species to establish the relationship between surface salinities and abundance of those species. In addition, ecological groups of the copepods were classified based on optimal salinity and geographical distribution. The results indicate that the yield density model is suitable for determining the relationship between salinity and abundance. Cosmocalanus darwini, Euchaeta rimana, Pleuromamma gracilis, Rhincalanus cornutus, Scolecithrix danae and Pareucalanus attenuatus were determined as oceanic species, with optimal salinities of >34.0. They were stenohaline and mainly distributed in waters influenced by the Kuroshio or Taiwan warm current. Temora discaudata, T. stylifera and Canthocalanus pauper were nearshore species with optimal salinities of <33.0 and most abundant in coastal waters. The remaining 10 species, including Undinula vulgaris and Subeucalanus subcrassus, were offshore species, with optimal salinity ranging from 33.0-34.0. They were widely distributed in nearshore, offshore and oceanic waters but mainly in the mixed water of the ECS.

Seasonal distribution of Calanus sinicus (Copepoda,Crustacea) in the East China Sea

On the basis of the four-season investigation in 23°30′ ~ 33°N and 118°30′ ~ 128°E of the East China Sea from 1997 to 2000, the seasonal distribution of Calanus sinicus was studied with aggregation intensity, regression contribution and other statistical methods. It was inferred that C. sinicus＇ s predominance presented from winter to summer, especially in spring and summer, because its dominance amounted to 0.62 and 0.29 respectively. The percent of its abundance in copepod abundance was 76.71% in summer, greater than 66.60% in spring, greater than 19.02% in winter, greater than 4.02% in autumn. The occurrence frequency in winter and spring was 83.08% and 93.89% , higher than that in summer and autumn, 76.71% and 73.87%. Compared with other dominant species of copepods, C. sinicus＇ s contribution to the copepod abundance was obviously greater than that of the other species in winter, summer and spring, but smaller in autumn. C. sinicus tended to have an aggregated distribution. The clumping index peaked in summer （50.19） , followed in spring （19.60） , declined in autumn （13.18） and was the lowest in winter （3.04）. The abundance changed in different seasons and areas, relating to temperature but not salinity in spring and autumn, to salinity but not temperature in summer; to neither temperature nor salinity in winter. In spring and summer, its high abundance area was often located in the mixed water mass formed by the Taiwan Warm Current, the Huanghai Sea Cold Water Mass, the coastal water masses and the Changjiang Dilute Water. In spring and autumn, its abundance was affected by the warm current, as well as the runoff from continental rivers affected it in summer. It can be inferred that C. sinicus was adapted to wide salinity and temperature, as a euryhalinous and eurythermous species in the East China Sea.

Study on abundance variation of pteropods in the East China Sea

On the basis of the census in four seasons from 1997 to 2000 in the East China Sea （23°30＇-33°N, 118°0＇-128°E）, the horizontal distribution of pteropods, the seasonal variations of their abundance and dynamic mechanisms of these variations were approached with quantitative and qualitative methods. Results showed that the total abundance of pteropods varied clearly with the seasons in an order of decrease of autumn （108×10-2 ind./m^3）, summer （33×10^-2 ind./m^3）, winter（28×10^-2 ind./m^3） and spring （10×10^-2 ind./m^3）. Pteropods were not observed in the north nearshore of the East China Sea （29°30＇-33°N, 122°30＇-125°E）in winter and spring. In all seasons, the peteropod abundance was higher in the south than that in the north and higher in the offshore than that in the nearshore. The major species influencing the peteropod abundance were Creseis acicula in spring, Creseis virgula in summer, Desmopterus papilio in autumn and Limaeina trochiforrnis in winter. The variation of pteropod abundance showed a prominent linear correlation with the surface water temperature and 10 m water temperature, but no significant correlation with both the bottom water temperature and salinity. In summer, the high-abundance distribution area of pteropods was located in the place where the Taiwan Warm Current branched from the Kuroshio. Inautumn, thedistribution area with anabundance higher than 250×10^-2ind/m^3expanded northward along with the Taiwan Warm Current within the mixing area where the Changjiang freshwater, the Fujian-Zhejiang coastal water and the Huanghai Sea Cold Water met together. Water temperature and warm currents were the most important environmental factors that influenced the changes ofpteropod abundance in the East China Sea.

Current status of small yellow croaker resources in the southern Yellow Sea and the East China Sea

We used data from bottom trawl surveys to study the factors influencing the abundance of small yellow croaker, Larimichthys polyactis, in the southern Yellow Sea (SYS) and the East China Sea (ECS). The resource density index (RDI) was generally higher in summer and autumn than in spring and winter. RDIs were also significantly greater in the SYS than in the ECS in summer and autumn. The bottom water salinity and depth of spatial distribution of small yellow croaker was similar between the two areas in summer, but different in other seasons. Regression analysis suggested that environmental factors such as bottom water temperature, salinity, and depth influenced the RDIs in summer in these areas. Growth condition factor (GCF) in the two areas varied monthly and the croaker in the SYS grew more slowly than those in the ECS. This was likely due to the low bottom temperature of the Yellow Sea Cold Water Mass in summer and autumn or to higher human fishing pressure in the ECS. To ensure sustainable utilization of the croaker stocks in these regions, we recommend reducing the fishing intensity, increasing the cod-end mesh size, and improving the protection of juveniles.

Species composition,diversity and density of plagic Ostracoda in the East China Sea

On the basis of seasonal investigations at 23°30′ - 33°00′N, 118°30′ - 128°00′E of the East China Sea during 1997 -2000, dynamics on the density and diversity of Ostracoda was discussed. Results showed that totally 26 species were identified. The Ostracoda diversity was opposite to the change of its density in most seasons which reflected an uneven assignment of Ostracoda density among its different species. The Ostracoda density was 0. 70 ind./m^3 in spring, 1.72 ind./m^3 in summer, 2.57 ind./m^3 in autumn and 0. 90 ind./m^3 in winter. Euconchoecia chierchiae in spring and winter, Euconchoecia maimai in summer and Cypridina dentata in autumn were main dominant species in each season. The Ostraeoda density did not show an obvious linear relationship with the hydrologic factors in summer and autumn, but was related to the surface salinity in spring and the surface temperature in winter. Its high density areas mainly distributed in the north offshore in all the seasons while in the south offshore in winter and in spring, and the south nearshore in summer and autumn, implied the zooplankton was a typical warm water animal, whose high density distribution in autumn were located in a similar position to Todarodes pacificus, Navodon Septentrionalis, Scomberjaponicus and other fishes in the sea, so as to be an important indicator for fishing ground. The main species dominating in Ostracoda now are different from the species twenty years ago probably attributes to global warming.

Study on the dominant species of Pteropoda in East China Sea

Based on the data of four seasonal marine surveys in the East China Sea (23°30′–33°N, 118°30′–128°E)during 1997–2000, the author studied the ecological characters of dominant Pteropoda species in the area. Results showed that there were five dominant Pteropoda species, more in summer, less in autumn and even in other seasons. These species, though belonging warm water species, can be categorized into two dif- ferent groups in habitability. The first group was adapted in summer and autumn, including Creseis acicula, Desmopterus papilio and Creseis virgule, while the second group in winter and spring, represented by Limacina trochiformis and Agadina syimpsoni. The first group was more abundant than the second one. Besides, the first group contributed more to the Pteropoda abundance having higher occurrence frequency and aggregation intensity than the second. In horizontal distribution, the first group species reside in near- shore, and they could migrate to shallow place near estuary and aggregated in high density, while the second one was different: lower abundance, less occurred and aggregated because they were halophilic warm water species, and they were usually abundant in offshore area.

Genetic diversity and population structure of Eleutheronema rhadinum in the East and South China Seas revealed in mitochondrial COI sequences

Eleutheronema rhadinum is a potential commercial fisheries species and is subject to intense exploitation in China.Knowledge on the population structure of E.rhadinum in Chinese coastal waters,which is important for sustainable exploitation and proper resource management,is lacking.In the present study,the genetic diversity and population structure of E.rhadinum were evaluated using a 564-base pair fragment of the mitochondrial cytochrome c oxidase subunit I(COI) gene.A total of 76 specimens were collected from three localities around the East(Qidong and Zhoushan) and South China Seas(Zhuhai).Among these individuals,nine polymorphic sites were detected and 11 distinct haplotypes were defined.High levels of haplotype diversity(h=0.759±0.035) and low levels of nucleotide diversity(π=0.001 98±0.003 26) were observed in these populations.Hierarchical analysis of molecular variance(AMOVA) indicated that 96.72% of the genetic variation occurred within the populations,whereas 3.28% occurred among populations.No significant genealogical branches or clusters were recognized on the neighbor-joining tree.Intra-group variation among populations was significant(φst=0.032 85,P<0.01).These results suggest that E.rhadinum populations in the East and South China Seas have developed divergent genetic structures.Tests of neutral evolution and mismatch distribution suggest that E.rhadinum may have experienced a population expansion.The present study provides basic information for the conservation and sustainable exploitation of this species.

A two-year(2020–2021)observation of marine phycotoxins in phytoplankton in typical mariculture areas of East China Sea

To learn the marine phycotoxins(MPTs)contamination status in mariculture areas in the East China Sea(ECS),from May 2020 to October 2021,80 net-concentrated phytoplankton samples were collected from 12 stations in three typical areas with high incidence of red tides,namely,Gouqi Island,Sandu’ao-Lianjiang,and Zhangzhou-Dongshan Island in ECS,and MPTs of the samples were detected.Six types of toxins were detected in 24 samples from 9 stations.Lipophilic marine toxins(LMTs)were more common and diverse in these areas.Pectenotoxin 2(PTX2)was the main lipophilic marine toxin(LMT)in the concentrated phytoplankton samples and the occurrence showed seasonal differences from north to south.According to the potential risks of pectenotoxin(PTXs)to seafood safety,it is suggested to execute regular monitoring on PTXs in ECS and a mandatory standard should be formulated based on the comprehensive analysis of in-situ monitoring and lab research.Meanwhile,contamination risks of cyclic imine toxins in the north and domoic acid(DA)in the south of ECS should also be paid with attention to.Only 2 paralytic shellfish toxins(PSTs),N-sulfocarbamoyl toxin C2(C2),and decarbamoyl gonyatoxin 3(dcGTX3),were found from spring samples in the north of ECS.As the biggest mussel culture county of China,Gouqi Island showed higher toxin diversity and the toxin detection rate was higher than the other two areas.In Gouqi Island area,PSTs were a serious potential threat in spring,and LMTs instead of PSTs became the main risk in summer-autumn seasons.To ensure the safety of seafood and marine environmental health,it is recommended to conduct long-term targeted tracking and monitoring of MPTs in this and similar mariculture areas.

Overview of China's Antarctic research progress 1984–2016

It is more than 30 years since the first Chinese National Antarctic Research Expedition(CHINARE) landed in Antarctica in 1984, representing China’s initiation in polar research. This review briefly summarizes the Chinese Antarctic scientific research and output accomplished over the past 30 years. The developments and progress in Antarctic research and the enhancement of international scientific cooperation achieved through the implementation of the CHINARE program have been remarkable. Since the 1980 s, four permanent Chinese Antarctic research stations have been established successively and 33 CHINAREs have been completed. The research results have been derived from a series of spatiotemporal observations in association with various projects and multidisciplinary studies in the fields of oceanography, glaciology, geology, geophysics, geochemistry, atmospheric science, upper atmospheric physics, Antarctic astronomy, biology and ecology, human medicine, polar environment observation, and polar engineering.

Evaluation and fusion of SST data from MTSAT and TMI in East China Sea, Yellow Sea and Bohai Sea in 2008

Two typical satellite sea surface temperature (SST) datasets, from the Multi-functional Transport Satellite (MTSAT) and Tropical Rainfall Measuring Mission Microwave Imager (TMI), were evaluated for the East China Sea, Yellow Sea, and Bohai Sea throughout 2008. Most monthly-mean availabilities of MTSAT are higher than those of TMI, whereas the seasonal variation of the latter is less than that of the former. The analysis on the one-year data shows that the annual mean availability of MTSAT (61%) is greater than that of TMI (56%). This is mainly because MTSAT is a geostationary satellite, which achieves longer observation than the sun-synchronous TMI. The daily availability of TMI (28%-75%) is more constant than that of MTSAT (9%-93%). The signal of infrared sensors on MTSAT is easily disturbed on cloudy days. In contrast, the TMI microwave sensor can obtain information through clouds. Based on in-situ SSTs, the SST accuracy of TMI is superior to that of MTSAT. In 2008, the root mean square (RMS) error of TMI and MTSAT were 0.77 K and 0.84 K, respectively. The annual mean biases were 0.14 K (TMI) and -0.31 K (MTSAT). To attain a high availability of SSTs, we propose a fusion method to merge both SSTs. The annual mean availability of fusion SSTs increases 17% compared to MTSAT. In addition, the availabilities of the fusion SSTs become more constant. The annual mean RMS and bias of fusion SSTs (0.78 K and -0.06 K, respectively) are better than those of MTSAT (0.84 K and -0.31 K).

The Research Progress of Endogenous Formaldehyde in Aquatic Products

Endogenous formaldehyde in aquatic products is a hot research topic, as it is an urgent problem to be solved. This paper summarized the advance in background concentration, generation mechanism and detection methods of endogenous formaldehyde in aquatic products, and the work in the future was prospected.

The research progress on food organism culture and technology utilization in crab seed production in ponds in China

Eriocheirsinensis, Portunus trituberculatus and Scylla paramamosain are important commercial culture crab species in China. Traditional factory breeding of crabs depends on Artemia nauplius. The rising price of Artemia cysts has led to the decline of the economic benefit of the crab breeding factory. Factory crab breeding has been gradually replaced by pond breeding in recent years. E. sinensis and P. trituberculatus have been bred mainly in ponds. Meanwhile, S. paramamosain is still mainly bred in factories because of the crudeness of pond breeding. The research progress on food organism utilization in the three species of commercially bred crabs was reviewed in this paper. In the workshop seeds production, rotifer and Artemia nauplii were necessary in the early stages from zoea I to zoea II in the three crab species. Adult artemia, minced fish and shellfish were fed to the larvae in the later zoea stages from zoea III to Megalopa.?The rising of the price of artemia eggs made people find other feed organism to replace artemia. Copepods have been used in crab seeds production in pond from zoea III stage to replace artemia in recent years, which has reduced the cost of seeds production.

Spatial-Temporal Change of Phytoplankton Biomass in the East China Sea with MODIS Data

A ten-year chlorophyll-a concentration dataset from Moderate Resolution Imaging Spectro-radiometer(MODIS) were used to analyze the variation of phytoplankton biomass and its potential relation with climate in the East China Sea. The result indicated that the phytoplankton biomass generally had a regular pattern every year, and phytoplankton bloom mainly occurred between May and July. The highest phytoplankton biomass appeared near the Yangtze River Estuary. The lowest phytoplankton biomass located near the Taiwan Strait. In general, the starting bloom time was earlier in the south than in the north, and the span time of the former was also longer. During the recent ten years, the phytoplankton biomass around the Yangtze River Estuary decreased obviously. The change of phytoplankton biomass was found to be related with the Ni?o3.4 Index. The correlation between the intensity of phytoplankton bloom with the number and square of red tide were 0.63 and 0.74, respectively.

ON THE DEEP SEA DEMERSAL FISH COMMUNITIES OF THE EAST CHINA SEA

Cluster analysis of data on the species similarity index offish samples taken at various sampling stations of different depths by the R /V " Dongfang " of the East China Sea Fisheries Research Institute, Chinese Academy of Fisheries Science, during the deep sea demersal fish resources survey in May - November, 1981, showed deep sea demersal fish fauna of the western part of the East China Sea can be grouped into the following communities :1)The outer continental shelf community ,2)The continental slope community, and3)The western Okinawa Trough community .The authors found that not only the species diversity index, but also the species similarity index are important criteria to reflect the structure of biotic community.

Statistical analysis on ecological adaptation of pelagic Amphipoda in the East China Sea

This article studied the diversity of Amphipoda＇s environmental adaptation using statistic method- ology based on the seasonal investigation data obtained from the East China Sea waters （23°30′- 33°N, 118°30′128°E） from 1997 to 2000. Fifty-four Amphipoda species were identified： among which eight species could stand a temperature difference over 10 ℃ and eight species could tolerate the temperature gap ranged from 5 to 10 ℃; while only six species could stand the salinity fluctuation more than 5. Based on above facts as well as calculated optimal temperature and salinity we divided all Amphipoda species into four groups： （1） eurythermic and euryhalinous species including Lestrigonus schizogeneios, L. macrophthalmus, Tetrathyrus forcipatus, L. bengalensis and Hyperi- oides sibaginis; （2） temperate-warm species containing Hyperoche medusarum, Parathemisto gau- dichaudi, Themisto japonica and Hyperia galba; （3） oceanic tropical species consisted of Oxycephalus clausi~ Lyeaea pulex, Eupronoe minuta, Simorhychotus antennarius, O. poreelus, Platyscelus ovoides and Rhabdosoma ahitei; （4） subtropical species involving one nearshore subtropical water species （Corophium uenoi） and 37 offshore subtropical ones. Compared with other zooplankton such as Eu- phausia and Chaetognatha, Amphipoda was characterized by low dominance but wide distribution in the East China Sea, and this could be ascribed to its high adaptation diversity.

DELINEATION OF DIFFERENT PHYTOPLANKTON COMMUNITIES IN THE EAST CHINA SEA MACKEREL AND CARANGOID FISHING GROUND

Delineation of phytoplankton communities in this study was based on : 1 ) cluster analysis by Preston’s Equation (1962) and 2) analysis of the number of individuals . Results obtained by these two methods were very similar to that obtained in a previous study (Fig . 1 , Gu and Guo , 1982) based on analysis of the number of planktonic species of different ecological nature . Among these three methods , that based on cluster analysis (by which some subcommunities could be recognized ) proved to be the best.