This study proposed the newly-designed Pelagic and demersal trawls for the fishing vessels operating in Cameroonian waters in pelagic and demersal fishing grounds. The engineering performances of both trawls were inve...This study proposed the newly-designed Pelagic and demersal trawls for the fishing vessels operating in Cameroonian waters in pelagic and demersal fishing grounds. The engineering performances of both trawls were investigated using physical modelling method and analytical method based on the predicted equations. In a flume tank, a series of physical model tests based on Tauti’s law were performed to investigate the hydrodynamic and geometrical performances of both trawls and to assess the applicability of the analytical methods based on predicted equations. The results showed that in model scale, the working towing speed and door spread for the pelagic trawl were 3.5 knots and 1.85 m, respectively, and for the bottom trawl net they were 4.0 knots and 1.8 m. At that speed and door spread, the drag force, net opening height, and wing-end spread of the pelagic model trawl were 36.73 N, 0.89 m, and 0.86 m, respectively, and the swept area was 0.76 m<sup>2</sup>. Bottom trawl speed and door spread were 30.43 N, 0.38 m, and 0.45 m, respectively, and the swept area was 0.25 m<sup>2</sup>. The maximum difference between the experimental and analytical results of hydrodynamic performances was less than 56.22% and 41.45%, respectively, for pelagic and bottom trawls, the results of the geometrical performances obtained using predicted equations were close to the experimental results in the flume tank with a maximum relative error less than 12.85%. The newly developed pelagic and bottom trawls had advanced engineering performance for high catch efficiency and selectivity and could be used in commercial fishing operations in Cameroonian waters.展开更多
Ecological adaptation and ecological groups of pelagic ostracods were examined in the East China Sea (23°30′-33°00′N, 118°30′ -128°00′E), in relation to temperature and salinity. The data we...Ecological adaptation and ecological groups of pelagic ostracods were examined in the East China Sea (23°30′-33°00′N, 118°30′ -128°00′E), in relation to temperature and salinity. The data were collected in four surveys conducted from 1997 to 2000. The density, yield density, or negative exponent models were used to determine the optimal temperature and salinity of water for the thriving growth of pelagic ostracods. Thereafter, ecological groups and potential distribution patterns of pelagic ostracods were determined based on the predicted parameters such as optimal temperature and salinity, consulting the geographic distribution. The analytical results indicate that, among the numerical dominant pelagic ostracods in the East China Sea (ECS), Euconchoecia aculeata, E. elongata, E. chierchiae, E. maimai, and Cypridina dentata, etc. are offshore subtropical water species. These species are widely distributed in the area, and they can be brought by the warm current to north offshore during spring and winter. The predicated optimal temperature (OT) and optimal salinity (OS) for Paraconchoecia decipiens, P. echinata, P. spini- fera, P. oblonga, Conchoecia magna and Porroeciaporrecta are all greater than 25℃ and 34 separately. These species are mainly distributed in the waters of the Kuroshio, the Taiwan Warm Current, and the Taiwan Strait, and therefore are designated as ocean- ic tropical water species. On the other hand, Pseudoconchoecia concerttrica is considered as offshore subtropical water species based on its geographical distribution although its OT is 19℃. The other species, though their OSs are approximately 34 and with OTs ranging from 20° to 25℃, are considered as offshore subtropical water species because they were found to be widely distributed from the South China Sea to the East China Sea.展开更多
On the basis of data from four seasonal cruises in the East China Sea (23°30′-33°N, 118°30′-128°E) from 1997 to 2000, horizontal distribution of amphipods, seasonal variations of abundance and ...On the basis of data from four seasonal cruises in the East China Sea (23°30′-33°N, 118°30′-128°E) from 1997 to 2000, horizontal distribution of amphipods, seasonal variations of abundance and their dynamic mechanisms were approached with quantitative and qualitative methods. Results showed that the average value of amphipod abundance in autumn was 115× 10^-2 ind./m^3, the highest in four seasons. The second occurred in summer with a mean value of 44×10^-2 ind./m^3and the lowest occurred in spring with a mean of 10 × 10^-2 ind./m^3. Amphipods were hardly observed in the north nearshore ( 29° 30′- 33° N and 122°30′- 125°E) in winter and spring. In all seasons, except for the north of the sea in autumn and the south in summer, the abundance in the offshore area was higher than that nearshore. The major species influencing the amphipod abundance were Lestrigonus schizogeneios in spring, L. macrophthalmus and L schizogeneios in summer,L bengalensis and Hyperioides sibaginis in autumn and Gammarus sp. in winter. The amphiped abundance showed a prominent linear correlation with the surface water temperature, but no significant correlation with both other water temperatures and salinity in spring. It was found that water temperature and salinity were not significantly correlated with the variation of amphiped abundance in summer, autumn and winter. In addition, the amphiped abundance in all four seasons can be linearly correlated with the bottom water temperature. The highest abundance area was located in the mixture waters near the side of warm water current in summer. Peak of amphiped abundance in autumn, not in summer told a temporal process for amphipeds to develop their populations. The continuance of warm current was beneficial to the development of amphipod abundance from summer to autumn. Amphipeds are kinds of very important diets for fishes in the offshore East China Sea.展开更多
Permian radiolarian biostratigraphy was reexamined in the bedded chert section in Qinzhou area of southeast Guangxi Zhuang Autonomous Region, South China. On the basis of the analyses of characteristic radiolarian com...Permian radiolarian biostratigraphy was reexamined in the bedded chert section in Qinzhou area of southeast Guangxi Zhuang Autonomous Region, South China. On the basis of the analyses of characteristic radiolarian composition, six radiolarian zones are recognized, namely, Pseudoalbaillella longtanensis Zone, Pseudoalbaillella globosa Zone, Follicucullus monacanthus Zone, Follicucullus scholasticus Zone, Follicucullus charveti Zone and Neoalbaillella ornithoformis Zone, in ascending order. Correlation of these radiolarian zones with those in Japan is presented. The Neoalbaillella ornithoformis Zone was firstly discovered in Dachongling Section, which may indicate that pelagic chert of the late Permian existed there, according to the co occurring conodonts.展开更多
To improve fishing gear efficiency, it is important to understand the interactions among sea current, fishing vessel, line hauler, and catches during pelagic longline gear retrieval. In this study, fishing gear config...To improve fishing gear efficiency, it is important to understand the interactions among sea current, fishing vessel, line hauler, and catches during pelagic longline gear retrieval. In this study, fishing gear configuration parameters, operational parameters, and 3 D ocean current data were collected from Indian Ocean. Dynamic models of pelagic longline gear retrieval were built using the lumped mass method and solved using the Euler-Trapezoidal method. From the results, the pulling force of line hauler exerted on the gear was 2800–3600 N. There were no significant differences(P > 0.05) between the time of the hook retrieval measured at sea and that obtained from the simulation. The absolute values of the movement velocity at representative nodes along the X, Y, and Z axes were 0.01–25.5 m s^(-1). These results suggest that the dynamic model of longline fishing gear retrieval can be used to analyze the interactions among sea current, fishing vessel, line hauler, longline gear, and catches, and to acquire the basic data for optimizing the design of the line hauler. Moreover, the model can serve as a reference to study the hydrodynamic performance of other fishing gears during the hauling process.展开更多
Pelagic manganese nodules from the East Pacific Ocean have been studied using polarizing,scanning electron and transmission electron microscopes. It has been revealed that the manganesenodules are composed of cores an...Pelagic manganese nodules from the East Pacific Ocean have been studied using polarizing,scanning electron and transmission electron microscopes. It has been revealed that the manganesenodules are composed of cores and stromatolite coatings. The structures and textures of thesenodules are peculiar to oncolite. Consequently, the pelagic manganese nodules are manganeseoncolites. Based on the stromatolites in the coatings, the manganese oncolites from the East Paci-fic Ocean can be divided into two types. One is smooth on surface and dense inside. Its coatingsare composed mainly of Minima. The other has a knobby surface and is loose internally. Itscoatings consist mainly of Admirabilis. The TEM investigation has also revealed that the con-structors of the manganese oncolites are ultra-microbes. The Minima is constructed byMiniactinomyces chinensis sp. nov. and the Admirabilis is built by Spirisosphaerospora pacifica sp.nov.展开更多
The relationship between the spatiotemporal distribution of three dominant small pelagic fishes,including chub mackerel(Scomber japonicus),horse mackerel(Trachurus trecae)and round sardinella(Sardinella aurita),and th...The relationship between the spatiotemporal distribution of three dominant small pelagic fishes,including chub mackerel(Scomber japonicus),horse mackerel(Trachurus trecae)and round sardinella(Sardinella aurita),and the environmental factors in Mauritanian waters were analyzed by using 4 years of logbook data of commercial purse seine fisheries to improve the efficiency of fishery and management of sustainable exploitation.A Tweedie-generalized additive model(GAM)of 8-day average catches and the monthly geostatistical analysis of daily catches were used in this study to analyze the influence of environmental factors on catch per unit of effort(CPUEs)and to map the spatial distribution of three mixed dominant small pelagic fishes,respectively.A 10'×10' grid was used,and environmental factors were processed from remote sensing,including 8-day average sea surface temperature(SST),the nearest distance between SST fronts and CPUE position(Df),chlorophyll-a(Chl-a)concentration,salinity,and eddy kinetic energy.Results showed that 1)the distribution of three dominant small pelagic fishes might be related to the intensity of upwelling in Mauritanian waters;2)oceanic fronts might play a key role in the ecology of chub mackerel,horse mackerel,and round sardinella;3)Chl-a concentration might be associated with the feeding grounds of chub mackerel;4)the target species distribution appeared sensitive to gradient changes in the amount of salinity;5)three zones(northern,central,and southern)with variable abundances were delineated;and 6)a high concentration of the center of gravity in the central zone might be related to the strong upwelling of nutrient-rich waters.This study can provide new insights to enhance the fishery efficiency and sustainable exploitation management of purse seiners in certain area off Mauritania.展开更多
Chert clast-bearing epi-continental neritic-terrestrial Jurassic and Cretaceous sequences are sporadically distributed in southwestern Japan. Typical and geological entities are the Torinosu Group and Tetori Group. Ra...Chert clast-bearing epi-continental neritic-terrestrial Jurassic and Cretaceous sequences are sporadically distributed in southwestern Japan. Typical and geological entities are the Torinosu Group and Tetori Group. Radiolarian dating of chert clasts enables us to discuss denudation stages of mid Mesozoic accretionary complexes. Chert clast-dominated conglomerate can be used for identifying marine beds within terrestrial sequences.展开更多
A fuzzy mathematical method is used to discriminate the similarities of pelagic fishes land- ed in the 9180 hauls by 10 light-seine information vessels in the southern Fujian waters from 1989 to 1998. The results indi...A fuzzy mathematical method is used to discriminate the similarities of pelagic fishes land- ed in the 9180 hauls by 10 light-seine information vessels in the southern Fujian waters from 1989 to 1998. The results indicate that the dominant species of the communities had an obvious alternation and the fuzzy adjacency of annual species composition varied between 0. 659 and 0. 923 with an average value of 0. 791. The fuzzy clustering analysis indicates that the annual fuzzy adjacency in general remains good although the species composition of the pelagic fishes has changed to a certain degree since 1992. This paper concludes that the community structure of pelagic fishes in the southern Taiwan Strait remains rel- atively stable and the state of fish stocks shows a good potentiality for a larger utilization.展开更多
The seasonal occurrence of Acartia pacifica ( Copepoda: Calanoida) and their resting eggs in the sediment of Xiamen Bay were documented between October 2002 and September 2003. The numher of viable eggs in the sedi...The seasonal occurrence of Acartia pacifica ( Copepoda: Calanoida) and their resting eggs in the sediment of Xiamen Bay were documented between October 2002 and September 2003. The numher of viable eggs in the sediment increased from January to May with the increase in the numher of planktonic females. When the population ofA. pacifica disappeared from the water cohinm, the number of eggs in the sediment began to decrease and reached a low value due to lack of input. The peak of nauplii abundance occurred when the hatching potential of eggs from the sediment was high under the natural environment from February to June. The hatching of resting eggs of A. pacifica was essentially temperature-dependent after suspension, while photoperied regimes had no significant effect on the hatching. The mean density of subitaneeus eggs was 1. 122 0 g/cm^3 with a standard deviation (SD) of 0. 000 2 g/cm^3. The mean density of diapause eggs was 1. 151 2 g/cm^3 with a SD of 0.000 1 g/cm^3. The sinking rates of subitaneons eggs ranged from 19.55 to 26.17 m/d, while those of diapause eggs ranged from 30.29 to 31.28 m/d. The comparison of the egg deposition time and egg hatching time suggested that in most cases virtually all subitaneous eggs of A. pacifica would settle to the bottom before their hatching even though the eggs have high potential to hatch. The evidence was provided that the seasonal dynamics of A. pacifica is accompanied by benthic-pelagic coupling.展开更多
Collected in September-October 2016 in the 48th cruise of SRS “Academician Oparin” the plankton samples with the assistance of Norpac net with the cell of 150 μm in the horizon 15-0 m have shown the plenty of pelag...Collected in September-October 2016 in the 48th cruise of SRS “Academician Oparin” the plankton samples with the assistance of Norpac net with the cell of 150 μm in the horizon 15-0 m have shown the plenty of pelagic larvae of bivalve mollusk in Chukchi Sea. Its biggest quantity was found in the period from the 22nd of September until the 1st of October. The most yield area was situated on the opposite side of the Bering Strait and the second maximum of larvae quantity was found on the Herald’s bank. Most valuable factors influencing the territorial allocation of the researched larvae are the water surface temperature and the water depth.展开更多
This report provides a result obtained by the First Chinese Antarctic and Southern Ocean Expedition. Specimens were collected by investigators of the Second Institute of Oceanography, SOA, with plankton nets in Februa...This report provides a result obtained by the First Chinese Antarctic and Southern Ocean Expedition. Specimens were collected by investigators of the Second Institute of Oceanography, SOA, with plankton nets in February and March of 1985 from the South Shetland Islands, the Biscoe Islands and their vicinities, between 61°15'20S-65°30'16S, 56°18'72W-67°59'45W. Eight species belonging to 5 genera in 4 families have been identified, of which 4 species, namely Maupasia coeca Viguier, Rhyn-chonerella petersii (Langerhans), Rhynchonerella bongraini (Gravier), and Tomopteris planktonis Aps-tein are recorded for the first time from the South Shetland Islands and 2 species, namely Rhynchonerella bongraini (Gravier), and Tomopteris carpenteri Quatrefages are endemic species of Antarctica.展开更多
Small coastal pelagic fish are one of the fish families most affected by sea fishing. This man-made phenomenon leads to an imbalance in the marine and coastal ecosystem and is one of the main causes of migration north...Small coastal pelagic fish are one of the fish families most affected by sea fishing. This man-made phenomenon leads to an imbalance in the marine and coastal ecosystem and is one of the main causes of migration north and offshore of the ranges. We used the ordinary differential equations to model the interactions existing between small pelagic resources and fishermen. Modelling follows the same of the Lotka-Volterra equations with a difference in the number of variables. This study confirmed the instability of the marine ecosystem. The objective is first of all to model a system of three interacting individuals composed of two distinct types of predators and two types of prey, and then optimise this interaction with the aim of conserving biodiversity in the ecosystem under study. Determining the Jacobian matrix made it possible to calculate the reproduction rate basic (<em>R</em><sub>0</sub>). The study of the strong connectedness has made it possible to reduce the number of variables without losing the objective of the study. A computer program implemented on the language computer python facilitated the visualisation of the results.展开更多
The pelagic manganese nodules from the East Pacific Ocean have been studied using polarizing and electron microscope since 1994. Based on the surface morphology and the type of stromatolites in the coatings, these man...The pelagic manganese nodules from the East Pacific Ocean have been studied using polarizing and electron microscope since 1994. Based on the surface morphology and the type of stromatolites in the coatings, these manganese nodules can be divided into smooth and knobbly ones. The coatings of smooth nodules are composed of Minima. The coatings of knobbly ones consist of Admirabilis. The authors have reported the first discovery of the beaded ultra-microfossils in the manganese nodules, but did not classify展开更多
Lake Caohai has experienced extensive Microcystis blooms in recent years,and to improve its water quality,the local government carried out a series of water control measures.To better understand the dynamics of both p...Lake Caohai has experienced extensive Microcystis blooms in recent years,and to improve its water quality,the local government carried out a series of water control measures.To better understand the dynamics of both pelagic and benthic Microcystis and their characteristics in Lake Caohai,we conducted a 1-year investigation from December 2015to December 2016 to gain a seasonal outlook on the distribution and dynamics of cell abundance,colony size and intracellular microcystins(MCs)of Microcystis.The results indicated that the Microcystis bloom occupied primarily the northeastern region and then moved gradually from lakeshore to lake center.The perennial southwesterly winds and the water inflow from northeast to southwest in Lake Caohai determined the spatiotemporal distribution of pelagic Microcystis.Benthic Microcystis was mainly distributed in the northeastern region in summer,occupied the lake center in autumn and then occupied the southeastern region in winter,determined by the sedimentation of pelagic Microcystis and the death of benthic Microcystis.Small colonies(20-60μm)overwintered more easily in both water column and sediment.The concentrations of intracellular toxin of benthic Microcystis were observed to be significantly higher than those of pelagic Microcystis.This might be because Microcystis synthesized large amount of MCs to acclimate to an unfavorable benthic environment.This knowledge on the dynamics of Microcystis expands our understanding of mechanisms underpinning the formation of Microcystis blooms.展开更多
“The 21st century is the century of the ocean.”In recent years,China has paid more and more attention to the promotion and development of the marine industry,especially the ocean fishery has brought immeasurab...“The 21st century is the century of the ocean.”In recent years,China has paid more and more attention to the promotion and development of the marine industry,especially the ocean fishery has brought immeasurable economic benefits to China.The development of the marine field is becoming more and more important in the national political,economic and cultural development.All coastal countries have included marine development in their national development strategies and continuously improved their marine legislation under the provisions of the United Nations Convention on the law of the sea.China’s pelagic fishing began in 1985,but because China’s pelagic fishing started too late,after the entry into force of the United Nations Convention on the law of the sea at the end of 1994,nearly 36%of the richest high seas on earth became the exclusive economic zone of coastal countries,and the development space of China’s pelagic fishing has become very limited.After just more than 30 years of development,***.However,before that,China’s pelagic fishing was still subject to the dual norms of international conventions and domestic laws,and China had not yet formulated a special law on pelagic fishing,and there were still many deficiencies in the legal system norms of pelagic fishing.Therefore,the biggest problem facing China’s pelagic fishery is how to better develop the marine industry under the system of laws and regulations,drive the coordinated economic development,provide legal guidance and help for pelagic fishermen,and provide solid technical support for building a marine power with Chinese characteristics.展开更多
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 aggregati...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.展开更多
Cretaceous oceanic red beds (CORBs) represented by red shales and marls, were deposited during the Cretaceous and early Paleocene, predominantly in the Tethyan realm, in lower slope and abyssal basin environments. D...Cretaceous oceanic red beds (CORBs) represented by red shales and marls, were deposited during the Cretaceous and early Paleocene, predominantly in the Tethyan realm, in lower slope and abyssal basin environments. Detailed studies of CORBs are rare; therefore, we compiled CORBs data from deep sea ocean drilling cores and outcrops of Cretaceous rocks subaerially exposed in southern Europe, northwestern Germany, Asia and New Zealand. In the Tethyan realm, CORBs mainly consist of reddish or pink shales, limestones and marlstones. By contrast, marlstones and chalks are rare in deep-ocean drilling cores. Upper Cretaceous marine sediments in cores from the Atlantic Ocean are predominantly various shades of brown, reddish brown, yellowish brown and pale brown in color. A few red, pink, yellow and orange Cretaceous sediments are also present. The commonest age of CORBs is early Campanian to Maastrichtian, with the onset mostly of oxic deposition often after Oceanic Anoxic Events (OAEs), during the early Aptian, late Albian-early Turonian and Campanian. This suggests an indicated and previously not recognized relationship between OAEs, black shales deposition and CORBs. CORBs even though globally distributed, are most common in the North Atlantic and Tethyan realms, in low to mid latitudes of the northern hemisphere; in the South Atlantic and Indian Ocean in the mid to high latitudes of the southern hemisphere; and are less frequent in the central Pacific Ocean. Their widespread occurrence during the late Cretaceous might have been the result of establishing a connection for deep oceanic current circulation between the Pacific and the evolving connection between South and North Atlantic and changes in oceanic basins ventilation.展开更多
X591 200401540 挪威和巴伦支海深海食物网中137Cs的生物积累=BioaccumulatiON of137 Cs in pelagic food webs in the Norwegian and Barents Seas[刊,英]/Hilde Elise Heldal…//J.Environ.Radioactivity.-2003.65(2).- 177-185
文摘This study proposed the newly-designed Pelagic and demersal trawls for the fishing vessels operating in Cameroonian waters in pelagic and demersal fishing grounds. The engineering performances of both trawls were investigated using physical modelling method and analytical method based on the predicted equations. In a flume tank, a series of physical model tests based on Tauti’s law were performed to investigate the hydrodynamic and geometrical performances of both trawls and to assess the applicability of the analytical methods based on predicted equations. The results showed that in model scale, the working towing speed and door spread for the pelagic trawl were 3.5 knots and 1.85 m, respectively, and for the bottom trawl net they were 4.0 knots and 1.8 m. At that speed and door spread, the drag force, net opening height, and wing-end spread of the pelagic model trawl were 36.73 N, 0.89 m, and 0.86 m, respectively, and the swept area was 0.76 m<sup>2</sup>. Bottom trawl speed and door spread were 30.43 N, 0.38 m, and 0.45 m, respectively, and the swept area was 0.25 m<sup>2</sup>. The maximum difference between the experimental and analytical results of hydrodynamic performances was less than 56.22% and 41.45%, respectively, for pelagic and bottom trawls, the results of the geometrical performances obtained using predicted equations were close to the experimental results in the flume tank with a maximum relative error less than 12.85%. The newly developed pelagic and bottom trawls had advanced engineering performance for high catch efficiency and selectivity and could be used in commercial fishing operations in Cameroonian waters.
基金The Major Research Plan of the National Natural Science Foundation of China under contract No.90511005"908" Project of China un-der contract No.908 -02-01-03
文摘Ecological adaptation and ecological groups of pelagic ostracods were examined in the East China Sea (23°30′-33°00′N, 118°30′ -128°00′E), in relation to temperature and salinity. The data were collected in four surveys conducted from 1997 to 2000. The density, yield density, or negative exponent models were used to determine the optimal temperature and salinity of water for the thriving growth of pelagic ostracods. Thereafter, ecological groups and potential distribution patterns of pelagic ostracods were determined based on the predicted parameters such as optimal temperature and salinity, consulting the geographic distribution. The analytical results indicate that, among the numerical dominant pelagic ostracods in the East China Sea (ECS), Euconchoecia aculeata, E. elongata, E. chierchiae, E. maimai, and Cypridina dentata, etc. are offshore subtropical water species. These species are widely distributed in the area, and they can be brought by the warm current to north offshore during spring and winter. The predicated optimal temperature (OT) and optimal salinity (OS) for Paraconchoecia decipiens, P. echinata, P. spini- fera, P. oblonga, Conchoecia magna and Porroeciaporrecta are all greater than 25℃ and 34 separately. These species are mainly distributed in the waters of the Kuroshio, the Taiwan Warm Current, and the Taiwan Strait, and therefore are designated as ocean- ic tropical water species. On the other hand, Pseudoconchoecia concerttrica is considered as offshore subtropical water species based on its geographical distribution although its OT is 19℃. The other species, though their OSs are approximately 34 and with OTs ranging from 20° to 25℃, are considered as offshore subtropical water species because they were found to be widely distributed from the South China Sea to the East China Sea.
基金the Major Research Plan of the National Natural Science Founda-tion of China under contract No. 90511005 the National Key Science Foundation Research “973” Project of the Ministry of Science and Technology of China under contract No. 2001CB409707.
文摘On the basis of data from four seasonal cruises in the East China Sea (23°30′-33°N, 118°30′-128°E) from 1997 to 2000, horizontal distribution of amphipods, seasonal variations of abundance and their dynamic mechanisms were approached with quantitative and qualitative methods. Results showed that the average value of amphipod abundance in autumn was 115× 10^-2 ind./m^3, the highest in four seasons. The second occurred in summer with a mean value of 44×10^-2 ind./m^3and the lowest occurred in spring with a mean of 10 × 10^-2 ind./m^3. Amphipods were hardly observed in the north nearshore ( 29° 30′- 33° N and 122°30′- 125°E) in winter and spring. In all seasons, except for the north of the sea in autumn and the south in summer, the abundance in the offshore area was higher than that nearshore. The major species influencing the amphipod abundance were Lestrigonus schizogeneios in spring, L. macrophthalmus and L schizogeneios in summer,L bengalensis and Hyperioides sibaginis in autumn and Gammarus sp. in winter. The amphiped abundance showed a prominent linear correlation with the surface water temperature, but no significant correlation with both other water temperatures and salinity in spring. It was found that water temperature and salinity were not significantly correlated with the variation of amphiped abundance in summer, autumn and winter. In addition, the amphiped abundance in all four seasons can be linearly correlated with the bottom water temperature. The highest abundance area was located in the mixture waters near the side of warm water current in summer. Peak of amphiped abundance in autumn, not in summer told a temporal process for amphipeds to develop their populations. The continuance of warm current was beneficial to the development of amphipod abundance from summer to autumn. Amphipeds are kinds of very important diets for fishes in the offshore East China Sea.
文摘Permian radiolarian biostratigraphy was reexamined in the bedded chert section in Qinzhou area of southeast Guangxi Zhuang Autonomous Region, South China. On the basis of the analyses of characteristic radiolarian composition, six radiolarian zones are recognized, namely, Pseudoalbaillella longtanensis Zone, Pseudoalbaillella globosa Zone, Follicucullus monacanthus Zone, Follicucullus scholasticus Zone, Follicucullus charveti Zone and Neoalbaillella ornithoformis Zone, in ascending order. Correlation of these radiolarian zones with those in Japan is presented. The Neoalbaillella ornithoformis Zone was firstly discovered in Dachongling Section, which may indicate that pelagic chert of the late Permian existed there, according to the co occurring conodonts.
基金funded by the National High Technology Research and Development Program of China (No. 2012 AA092302)the Specialized Research Fund for the Doctoral Program of Higher Education (No. 20113104110004)Shanghai Municipal Education Commission Innovation Project (No. 12ZZ168)
文摘To improve fishing gear efficiency, it is important to understand the interactions among sea current, fishing vessel, line hauler, and catches during pelagic longline gear retrieval. In this study, fishing gear configuration parameters, operational parameters, and 3 D ocean current data were collected from Indian Ocean. Dynamic models of pelagic longline gear retrieval were built using the lumped mass method and solved using the Euler-Trapezoidal method. From the results, the pulling force of line hauler exerted on the gear was 2800–3600 N. There were no significant differences(P > 0.05) between the time of the hook retrieval measured at sea and that obtained from the simulation. The absolute values of the movement velocity at representative nodes along the X, Y, and Z axes were 0.01–25.5 m s^(-1). These results suggest that the dynamic model of longline fishing gear retrieval can be used to analyze the interactions among sea current, fishing vessel, line hauler, longline gear, and catches, and to acquire the basic data for optimizing the design of the line hauler. Moreover, the model can serve as a reference to study the hydrodynamic performance of other fishing gears during the hauling process.
基金This Research was supported by the foundations from the National Committee of Education,the Cenire for Materials Analysis and the Laboratory of Mineral Deposits,Nanjing University.
文摘Pelagic manganese nodules from the East Pacific Ocean have been studied using polarizing,scanning electron and transmission electron microscopes. It has been revealed that the manganesenodules are composed of cores and stromatolite coatings. The structures and textures of thesenodules are peculiar to oncolite. Consequently, the pelagic manganese nodules are manganeseoncolites. Based on the stromatolites in the coatings, the manganese oncolites from the East Paci-fic Ocean can be divided into two types. One is smooth on surface and dense inside. Its coatingsare composed mainly of Minima. The other has a knobby surface and is loose internally. Itscoatings consist mainly of Admirabilis. The TEM investigation has also revealed that the con-structors of the manganese oncolites are ultra-microbes. The Minima is constructed byMiniactinomyces chinensis sp. nov. and the Admirabilis is built by Spirisosphaerospora pacifica sp.nov.
基金funded by the Ministry of Agriculture and Rural Affairs of the P.R.China under Project of Fishery Exploration in 2017(No.D-8006-17-0138)
文摘The relationship between the spatiotemporal distribution of three dominant small pelagic fishes,including chub mackerel(Scomber japonicus),horse mackerel(Trachurus trecae)and round sardinella(Sardinella aurita),and the environmental factors in Mauritanian waters were analyzed by using 4 years of logbook data of commercial purse seine fisheries to improve the efficiency of fishery and management of sustainable exploitation.A Tweedie-generalized additive model(GAM)of 8-day average catches and the monthly geostatistical analysis of daily catches were used in this study to analyze the influence of environmental factors on catch per unit of effort(CPUEs)and to map the spatial distribution of three mixed dominant small pelagic fishes,respectively.A 10'×10' grid was used,and environmental factors were processed from remote sensing,including 8-day average sea surface temperature(SST),the nearest distance between SST fronts and CPUE position(Df),chlorophyll-a(Chl-a)concentration,salinity,and eddy kinetic energy.Results showed that 1)the distribution of three dominant small pelagic fishes might be related to the intensity of upwelling in Mauritanian waters;2)oceanic fronts might play a key role in the ecology of chub mackerel,horse mackerel,and round sardinella;3)Chl-a concentration might be associated with the feeding grounds of chub mackerel;4)the target species distribution appeared sensitive to gradient changes in the amount of salinity;5)three zones(northern,central,and southern)with variable abundances were delineated;and 6)a high concentration of the center of gravity in the central zone might be related to the strong upwelling of nutrient-rich waters.This study can provide new insights to enhance the fishery efficiency and sustainable exploitation management of purse seiners in certain area off Mauritania.
文摘Chert clast-bearing epi-continental neritic-terrestrial Jurassic and Cretaceous sequences are sporadically distributed in southwestern Japan. Typical and geological entities are the Torinosu Group and Tetori Group. Radiolarian dating of chert clasts enables us to discuss denudation stages of mid Mesozoic accretionary complexes. Chert clast-dominated conglomerate can be used for identifying marine beds within terrestrial sequences.
基金This project is funded by the Fujian Department of Fisheries (Min Shui Ke 1998-08).
文摘A fuzzy mathematical method is used to discriminate the similarities of pelagic fishes land- ed in the 9180 hauls by 10 light-seine information vessels in the southern Fujian waters from 1989 to 1998. The results indicate that the dominant species of the communities had an obvious alternation and the fuzzy adjacency of annual species composition varied between 0. 659 and 0. 923 with an average value of 0. 791. The fuzzy clustering analysis indicates that the annual fuzzy adjacency in general remains good although the species composition of the pelagic fishes has changed to a certain degree since 1992. This paper concludes that the community structure of pelagic fishes in the southern Taiwan Strait remains rel- atively stable and the state of fish stocks shows a good potentiality for a larger utilization.
基金We appreciate the support from the National Natural Science Foundation of China under contract Nos 40506002 and 40076034the State 0ceanic Administration Foundation for Young Scientists of China under contract No.2006119the Polar Research Institute of China Innovation Foundation of Polar Science for Young Scientists of China under contract No.JDQ200502.
文摘The seasonal occurrence of Acartia pacifica ( Copepoda: Calanoida) and their resting eggs in the sediment of Xiamen Bay were documented between October 2002 and September 2003. The numher of viable eggs in the sediment increased from January to May with the increase in the numher of planktonic females. When the population ofA. pacifica disappeared from the water cohinm, the number of eggs in the sediment began to decrease and reached a low value due to lack of input. The peak of nauplii abundance occurred when the hatching potential of eggs from the sediment was high under the natural environment from February to June. The hatching of resting eggs of A. pacifica was essentially temperature-dependent after suspension, while photoperied regimes had no significant effect on the hatching. The mean density of subitaneeus eggs was 1. 122 0 g/cm^3 with a standard deviation (SD) of 0. 000 2 g/cm^3. The mean density of diapause eggs was 1. 151 2 g/cm^3 with a SD of 0.000 1 g/cm^3. The sinking rates of subitaneons eggs ranged from 19.55 to 26.17 m/d, while those of diapause eggs ranged from 30.29 to 31.28 m/d. The comparison of the egg deposition time and egg hatching time suggested that in most cases virtually all subitaneous eggs of A. pacifica would settle to the bottom before their hatching even though the eggs have high potential to hatch. The evidence was provided that the seasonal dynamics of A. pacifica is accompanied by benthic-pelagic coupling.
文摘Collected in September-October 2016 in the 48th cruise of SRS “Academician Oparin” the plankton samples with the assistance of Norpac net with the cell of 150 μm in the horizon 15-0 m have shown the plenty of pelagic larvae of bivalve mollusk in Chukchi Sea. Its biggest quantity was found in the period from the 22nd of September until the 1st of October. The most yield area was situated on the opposite side of the Bering Strait and the second maximum of larvae quantity was found on the Herald’s bank. Most valuable factors influencing the territorial allocation of the researched larvae are the water surface temperature and the water depth.
文摘This report provides a result obtained by the First Chinese Antarctic and Southern Ocean Expedition. Specimens were collected by investigators of the Second Institute of Oceanography, SOA, with plankton nets in February and March of 1985 from the South Shetland Islands, the Biscoe Islands and their vicinities, between 61°15'20S-65°30'16S, 56°18'72W-67°59'45W. Eight species belonging to 5 genera in 4 families have been identified, of which 4 species, namely Maupasia coeca Viguier, Rhyn-chonerella petersii (Langerhans), Rhynchonerella bongraini (Gravier), and Tomopteris planktonis Aps-tein are recorded for the first time from the South Shetland Islands and 2 species, namely Rhynchonerella bongraini (Gravier), and Tomopteris carpenteri Quatrefages are endemic species of Antarctica.
文摘Small coastal pelagic fish are one of the fish families most affected by sea fishing. This man-made phenomenon leads to an imbalance in the marine and coastal ecosystem and is one of the main causes of migration north and offshore of the ranges. We used the ordinary differential equations to model the interactions existing between small pelagic resources and fishermen. Modelling follows the same of the Lotka-Volterra equations with a difference in the number of variables. This study confirmed the instability of the marine ecosystem. The objective is first of all to model a system of three interacting individuals composed of two distinct types of predators and two types of prey, and then optimise this interaction with the aim of conserving biodiversity in the ecosystem under study. Determining the Jacobian matrix made it possible to calculate the reproduction rate basic (<em>R</em><sub>0</sub>). The study of the strong connectedness has made it possible to reduce the number of variables without losing the objective of the study. A computer program implemented on the language computer python facilitated the visualisation of the results.
基金Project supported by Foundation of the National Committee of Education, Foundation of the Center for Materials AnalysisFoundation of the Laboratory of Mineral Deposits, Nanjing University.
文摘The pelagic manganese nodules from the East Pacific Ocean have been studied using polarizing and electron microscope since 1994. Based on the surface morphology and the type of stromatolites in the coatings, these manganese nodules can be divided into smooth and knobbly ones. The coatings of smooth nodules are composed of Minima. The coatings of knobbly ones consist of Admirabilis. The authors have reported the first discovery of the beaded ultra-microfossils in the manganese nodules, but did not classify
基金supported by the National Natural Science Foundation of China (Nos. 31670465, 31800390 and 31460130)the Joint NSFC-ISF Research Program+1 种基金jointly funded by the National Natural Science Foundation of Chinathe Israel Science Foundation (No, 41561144008)
文摘Lake Caohai has experienced extensive Microcystis blooms in recent years,and to improve its water quality,the local government carried out a series of water control measures.To better understand the dynamics of both pelagic and benthic Microcystis and their characteristics in Lake Caohai,we conducted a 1-year investigation from December 2015to December 2016 to gain a seasonal outlook on the distribution and dynamics of cell abundance,colony size and intracellular microcystins(MCs)of Microcystis.The results indicated that the Microcystis bloom occupied primarily the northeastern region and then moved gradually from lakeshore to lake center.The perennial southwesterly winds and the water inflow from northeast to southwest in Lake Caohai determined the spatiotemporal distribution of pelagic Microcystis.Benthic Microcystis was mainly distributed in the northeastern region in summer,occupied the lake center in autumn and then occupied the southeastern region in winter,determined by the sedimentation of pelagic Microcystis and the death of benthic Microcystis.Small colonies(20-60μm)overwintered more easily in both water column and sediment.The concentrations of intracellular toxin of benthic Microcystis were observed to be significantly higher than those of pelagic Microcystis.This might be because Microcystis synthesized large amount of MCs to acclimate to an unfavorable benthic environment.This knowledge on the dynamics of Microcystis expands our understanding of mechanisms underpinning the formation of Microcystis blooms.
文摘“The 21st century is the century of the ocean.”In recent years,China has paid more and more attention to the promotion and development of the marine industry,especially the ocean fishery has brought immeasurable economic benefits to China.The development of the marine field is becoming more and more important in the national political,economic and cultural development.All coastal countries have included marine development in their national development strategies and continuously improved their marine legislation under the provisions of the United Nations Convention on the law of the sea.China’s pelagic fishing began in 1985,but because China’s pelagic fishing started too late,after the entry into force of the United Nations Convention on the law of the sea at the end of 1994,nearly 36%of the richest high seas on earth became the exclusive economic zone of coastal countries,and the development space of China’s pelagic fishing has become very limited.After just more than 30 years of development,***.However,before that,China’s pelagic fishing was still subject to the dual norms of international conventions and domestic laws,and China had not yet formulated a special law on pelagic fishing,and there were still many deficiencies in the legal system norms of pelagic fishing.Therefore,the biggest problem facing China’s pelagic fishery is how to better develop the marine industry under the system of laws and regulations,drive the coordinated economic development,provide legal guidance and help for pelagic fishermen,and provide solid technical support for building a marine power with Chinese characteristics.
基金This study was funded by the Major Research Plan of the National Natural Science Foundation of China under contract No.90511005the National Key Science Foundation Research"973"Project of the Ministry of Science and Technology of China under contract No.2001CB409700-07.
文摘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.
基金part of the research programs supported by the specialty Program of the National Basic Research Program of China(Grant No.2006CB701402)the National Science Foundation of China(Grant No.40332020).
文摘Cretaceous oceanic red beds (CORBs) represented by red shales and marls, were deposited during the Cretaceous and early Paleocene, predominantly in the Tethyan realm, in lower slope and abyssal basin environments. Detailed studies of CORBs are rare; therefore, we compiled CORBs data from deep sea ocean drilling cores and outcrops of Cretaceous rocks subaerially exposed in southern Europe, northwestern Germany, Asia and New Zealand. In the Tethyan realm, CORBs mainly consist of reddish or pink shales, limestones and marlstones. By contrast, marlstones and chalks are rare in deep-ocean drilling cores. Upper Cretaceous marine sediments in cores from the Atlantic Ocean are predominantly various shades of brown, reddish brown, yellowish brown and pale brown in color. A few red, pink, yellow and orange Cretaceous sediments are also present. The commonest age of CORBs is early Campanian to Maastrichtian, with the onset mostly of oxic deposition often after Oceanic Anoxic Events (OAEs), during the early Aptian, late Albian-early Turonian and Campanian. This suggests an indicated and previously not recognized relationship between OAEs, black shales deposition and CORBs. CORBs even though globally distributed, are most common in the North Atlantic and Tethyan realms, in low to mid latitudes of the northern hemisphere; in the South Atlantic and Indian Ocean in the mid to high latitudes of the southern hemisphere; and are less frequent in the central Pacific Ocean. Their widespread occurrence during the late Cretaceous might have been the result of establishing a connection for deep oceanic current circulation between the Pacific and the evolving connection between South and North Atlantic and changes in oceanic basins ventilation.
文摘X591 200401540 挪威和巴伦支海深海食物网中137Cs的生物积累=BioaccumulatiON of137 Cs in pelagic food webs in the Norwegian and Barents Seas[刊,英]/Hilde Elise Heldal…//J.Environ.Radioactivity.-2003.65(2).- 177-185