Temporal and spatial distributions of dominant shrimp stocks and their relationship with the hydrological environment in the East China Sea

To provide a scientific and technological base for fishery administration, holding a moratorium on fishing, and combating habitat degradation, a shrimp stock survey was carried out in May, August, and November 1998 and in February 1999. The study was conducted in the area between 26o00′ N and 33o00′ N and to the west of 127o00′ E in the East China Sea using a multi-sac trawl-net, with 115 stations being sampled. Up to 2001, we had found 121 species, which belong to 63 genera under 22 families, and 41 species are of high economic value and in great abundance. Nine shrimp species were of great economic importance, whose stock accounted for 76.8% of the demersal total. They were Parapenaeus fissuroides, Metapenaeopsis philippi, Palaemon gravieri, Metapenaeopsis barbata, Solenocera koelbeli, Solenocera crassicornis, Trachypenaeus curvirostris, Solenocera melantho and Parapenaeopsis hardwickii (listed in stock order). The nine species belong to the eurythermal and eurysaline community and high thermal and high saline community, had different migration patterns and stocks, and their distribution patterns could be generally classified into three types:(1) dominating in the north or the south;(2) dominating to the north of and in the coast to the south of 30o00′ N;and (3) dominating to the east of 60 m isobath, which were related to six water masses in the ECS near two lines, i.e., the 60 m isobath and 30o00′N latitudinal lines. Densely habited shrimps were found in all four seasons due to temperature and salinity frontiers and upwelling. The general stock density index was relatively higher in spring, summer, and autumn, when it surpassed 10 kg/h, while in winter, it was only 6.8 kg/h which might be caused by overfishing. According to the spawning areas of the nine species and their distribution patterns, to attain sustainable development of the shrimp fishery in the ECS, it is imperative to protect fishing areas and to hold a moratorium on catching to the west of 60 m isobath from April through October, and between 60 m and 100 m isobaths and to the south of 30oN from June through August and to limit fishing in winter.

Isolation via enrichment and characterization of ten polymorphic microsatellite loci in the cuttlefish, Sepiella maindroni de Rochebruns

Ten novel polymorphic microsatellite loci were developed using an enrichment and colony hybridization protocol and characterized for the cuttlefish,Sepiella maindroni.Polymorphism was explored by using 30 individuals from the coastal waters of Zhanjiang,Guangdong province,China,in December 2007.The number of alleles ranged from 5 to 13.The ranges of observed and expected heterozygosity were from 0.578 9 to 1.000 0 and 0.682 8 to 0.925 7,respectively,and the average polymorphic information content （P IC） was 0.778 5.These microsatellite loci will certainly facilitate the detection of the genetic variation and population structure of S.maindroni.

Tidal analysis in the venturi-shaped area between Zhenhai and Shenjiamen in the East China Sea

In order to better understand the general tidal features in the venturi-shaped area between Zhenhai and Shenjiamen in the northern coastal region of Zhejiang Province in the East China Sea, the tidal data were obtained from both the three permanent tide stations of Zhenhai, Dinghai and Shenjiamen, and four temporary tide stations of Mamu, Chuanshan, Guoju and Liuheng, along with the current speed being observed at Luotou Waterway. Results from harmonic analysis show that: (1) The area was dominated by shallow water tides with irregular semi-diurnal features, and the smallest tidal range occurred in the area near a crossing line between Zhenhai and Dinghai stations, indicating that a tidal node existed in the southern Hangzhou Bay; (2) Formulae, HS2/HM2 >0.4 and gM2-(gK1+gO1)=270° (where H and g are harmonic constants), could be used as judging criteria for high and low tidal level diurnal inequalities; (3) The duration difference between ebb and flood tides could be roughly assessed by the ratio of HM4 vs. HM2; and the larger the ratio is, the bigger the duration difference is. At the same time, the duration period could be assessed by 2gM2-gM4, the epoch difference between M2 and M4 tidal constituents. If 2gM2-gM4 <180°, then the ebb duration is longer than the flood duration; if 180°< 2gM2-gM4 <360°, the result is reversed; (4) Taking Dinghai station as a center point, the highest tidal levels and the average high tidal levels, as well as the average tidal ranges at all stations became higher and larger both southeastwards and northwestwards, while the lowest tidal levels and the average low tidal levels appeared to be lower both southeastwards and northwestwards; and (5) The tidal patterns were not all in line with the tidal current patterns. As a conclusion, the smallest tidal range occurred in the narrow part of the venturi-shaped area. Along the both sides of the area, the highest tidal level and tidal range became higher and larger, while the lowest tidal level became lower with the increase of the distance from the narrow throat area. This is somehow different from the theory that the tidal level increases gradually when it moves towards the top narrow area of a V-shaped bay or estuary.

Hydrodynamic coefficients of a simplified floating system of gravity cage in waves

Numerical simulation and experimental tests were carried out to examine the hydrodynamic behaviors of a double-column floating system of gravity cage under wave conditions. A floating system of gravity cage can be treated as a small-sized floating structure when compared with the wavelengths. The main problem in calculating the wave loads on the small-sized floating structure is to obtain the reasonable force coefficients, which may differ from a submerged structure. In this paper, the floating system of gravity cage is simplified to a 2D problem, where the floating system is set symmetrically under wave conditions. The motion equations were deduced under wave conditions and a specific method was proposed to resolve the problem of wave forces acting on a small-sized floating system of gravity cage at water surface. Results of the numerical method were compared with those from model tests and the hydrodynamic coefficients Cn and Cτ were studied. It is found that Cn ranges from 0.6 to 1.0 while Cτ is between 0.4 and 0.6 in this study. The results are useful for research on the hydrodynamic behavior of the deep-water gravity sea cages.

Sea State Primitive Object Creation from SAR Data

Wide swath Synthetic Aperture Radar (SAR) images acquired over sea areas contain a variety of information regarding small scale and mesoscale phenomena in the ocean and marine boundary layer e.g. spills, slicks, surface or internal waves, eddies, oceanic fronts. One of most challenging processing step is to create image objects describing these phenomena on SAR images. The most significant problem in the wide swath images is the backscattering trend at the range direction, which results a progressive brightness reduction over images from near to far range. This reduction affects the detection and classification of sea surface features on wide swath SAR images and a normalization step is needed in a certain incidence angle for compensating the brightness reduction. The aim of the present paper is to investigate the result of image normalization to a set of Wide Swath Mode SAR images. Dark areas were initially detected in SAR images using thresholds, adapted or not. Afterwards, SAR images were normalized and a global threshold was calculated for each image. Images were segmented and objects were created for each dark area. The results were compared to a reference dataset created from theoretical modeled values and extracted in a GIS environment. Results clearly indicate that overall accuracy of the detected dark areas has been increased after normalization. On the contrary, local thresholds were insufficient in producing acceptable results. The proposed normalization can be used as a pre-processing step in image classification.

Exploring the Big Data Using a Rigorous and Quantitative Causality Analysis

Causal analysis is a powerful tool to unravel the data complexity and hence provide clues to achieving, say, better platform design, efficient interoperability and service management, etc. Data science will surely benefit from the advancement in this field. Here we introduce into this community a recent finding in physics on causality and the subsequent rigorous and quantitative causality analysis. The resulting formula is concise in form, involving only the common statistics namely sample covariance. A corollary is that causation implies correlation, but not vice versa, resolving the long-standing philosophical debate over correlation versus causation. The applicability to big data analysis is validated with time series purportedly generated with hidden processes. As a demonstration, a preliminary application to the gross domestic product (GDP) data of United States, China, and Japan reveals some subtle USA-China-Japan relations in certain periods.

Phytochemical profiling and biological activity of Plectranthus amboinicus(Lour.) mediated by various solvent extracts against Aedes aegypti larvae and toxicity evaluation

Objective:To analyze the phytochemical compounds and to investigate the bio-toxic efficacy of various solvent extracts of Plectranthus amboinicus against mosquito larvae activity and lethality on non-targeting organisms.Methods:The methanol,ethyl acetate,hexane,and aqueous extracts of Plectranthus amboinicus were subjected to analyze the mosquitocidal activity against the dengue vector,Aedes aegypti and toxicity assays on zebra fish and brine shrimp.Three replications were performed,and negative control was also maintained.Amongst,ethyl acetate extract of Plectranthus amboinicus was chosen for the determination of bio-active compounds.Results:The mosquitocidal assays of methanol and ethyl acetate extracts of Plectranthus amboinicus showed the maximal activity with minimal concentration against the 4 th instar mosquito-larvae of Aedes aegypti through the following lethal concentration(LC50 and LC90)values:53.36&92.51μg/m L and 13.64&86.09μg/mL,respectively.In addition,the plant extracts showed no toxicity on zebra fish embryo and brine shrimp assays.The gas-chromatography analysis of the ethyl acetate extract of Plectranthus amboinicus revealed the presence of seven different compounds.Among them,PAEA-fraction 60 contained a major active bioactive compound,hexadecanoic acid,methyl ester(270.0).Conclusions:Plectranthus amboinicus possesses mosquitocidal properties and could be used as a potential alternative source for preparing the mosquitocidal agents.

The complete mitochondrial genome of the grey bamboo shark (Chiloscyllium griseum) (Orectolobiformes: Hemiscylliidae): genomic characterization and phylogenetic application

The complete mitochondrial genome of the grey bamboo shark, Chiloscyllium griseum （Orectolobiformes： HemiscyUiidae） was obtained, with a total of 16 755 base pairs （bp）. The mitogenome encoded 13 protein- coding genes, two ribosomal RNAs, 22 transfer RNAs and a noncoding control region, a gene arrangement identical to the most common type found in vertebrates. All tRNA sequences were folded into typical clover- leaf secondary structure with the exception of tRNA-Ser2, in which the DHU arm stem was replaced with 12 unpaired nucleotides and formed a simple loop. In the control region, the putative termination-associated sequences （TAS） with hairpin-loop structure and the conserved sequence blocks （CSB） I-III were identified and considered to be associated with the replication and transcription of mtDNA. No repeat motifs were found in the mitogenome of C. griseum. On the basis of the mitogenomic data available in the Class Chon- drichthyes from both Genbank and this study, and the phylogenetic analyses using maximum likelihood （ML） and Bayesian inference （BI） methods, the results strongly support the basal division between batoids and sharks and the monophyly of the Superorder Galeomorphii, and confirm the phylogenetic position of C. griseum in the Subclass Elasmobranchii. This study suggests that the mitogenomic data are more robust for reconstructing phylogenetic relationships than individual genes in the Elasmobranchii.

Fluid-driven Hydrovolcanic Activity along Fracture Zones and near Seamounts:Evidence from Deep-sea Fe-rich Spherules,Central Indian Ocean Basin

An insight on occurrence of Fe-rich spherules from the Central Indian Ocean Basin(CIOB)provides an understanding of their distribution at a water depth of>5,000 m.In the present study,Fe-rich spherules are identified to occur in two different sediment types(i.e.,siliceous and pelagic)and tectonic settings(i.e.near seamounts and fracture zones).These are single spheres or aggregates,of different sizes(63 to 390μm)and show textural variability(smooth/quenched,brickwork,corkscrew,interlocking and dendritic).A comparative study based on physical morphology and chemical composition suggests a common mechanism of formation.The association of spherules with fracture zones(FZ)and seamounts signifies that morpho-tectonic features play an important role in fluid-driven hydrovolcanism.Based on the evidence and geologic conditions existing in the basin,we conclude that molten fuel-coolant interaction(MFCI)coupled with submarine hydrothermal exhalations could be an ideal mechanism for the formation of spherules and Fe-particles.The accretion of the spherules on the surface sediments could be a result of recent volcanic phenomena,while those occurring at different depths(280-355,and 460-475 cm-bsf)within the sediment core indicate two different episodes.The study provides a global implication in understanding fluid-driven magmatism in a deep-sea intraplate environment.

Marketing Program Implementation of Greek Fisheries Firms

This study analyses the marketing program implementation in Greek fisheries firms.In this perspective,quantitative research with personal interviews to fisheries firms’executives is elaborated.Data were analyzed elaborating cluster and discriminant analysis.Findings reveal that there are two distinct groups of Greek fisheries firms regarding their decisions about the components of marketing mix.The results demonstrate that there are differences among the two groups mainly in terms of price and distribution policies.Particularly,62.6% of sample firms seem to dispose a differential marketing mix,while 37.4% of sample firms seem to dispose a non-differential marketing mix.Notably,both clusters are not aware of quality and sustainability assurance certifications regarding seafood products.From this perspective,there is a potential for a better organized marketing program implementation aiming to respond efficiently in modern market needs.

Characteristics of Algal Succession Following Rock Scraping at Imwon Area in the East Coast of Korea

This study was conducted to clarify the characteristics of algal succession following rock scraping using hoe or high-pressure water sprayer in the period from June 2010 to April 2011. We divided the research area off the eastern coast of Korean near Imwon into 3 categories depending upon the severity of the barren ground, i.e., the urchin barren-affected, urchin barren-ongoing and urchin barren-free areas. In April 2011, in the urchin barren-affected area with 25 seaweed species, the cover percentage and importance value(IV) of crustose coralline algae were higher than those of other species. In the urchin barren-ongoing area with 33 seaweed species, crustose coralline algae(mean IV = 62%) as well as Sargassum sp.(mean IV = 28%), and Gelidium amansii(mean IV = 19%) were observed following rock scraping. In the urchin barren-free area where seaweed communities were relatively abundant with 42 species, a variety of algal species including G. amansii(mean IV = 32%) underwent algal succession. Overall, it was observed that, as an aspect of algal succession, the weaker the barren ground severity was, the more frequent and diverse the seaweeds were, and the more complex the succession pattern was in the study. As an aspect of recovering algal community, rock scraping using hoe was shown to be superior to the method using high-pressure water spraying. Therefore, we conclude that rock scraping using hoe is a very effective strategy for recovering the algal community in urchin barren-ongoing area.

Assessment of carbon sink potential and methane reduction scenarios of marine macroalgae(Gracilaria)cultivation

Marine macroalgae cultivation is an important part of the effort to address climate change through carbon sinks.Gracilaria,especially Gracilaria lemaneiformis and Gracilaria lichenoides are the major macroalgae cultivated in China.This study proposes a method to assess the net carbon sink of marine macroalgae(Gracilaria)cultivation.First,the net carbon sink of Gracilaria cultivation in China is calculated based on the yield of annual cultivated Gracilaria recorded in China Fishery Statistical Yearbook from 2011 to 2020.Next,we predict the net carbon sink trend of Gracilaria cultivation from 2021 to 2030 using the autoregressive integrated moving average model(ARIMA).Finally,the potential carbon sink increase and methane reduction related to Gracilaria cultivation in China is explored through a scenario analysis.We find that the net carbon sink of Gracilaria cultivation in China was about 32.1-92.4 kilotons per year from 2011 to 2020,and shows a great annual growth trend.Moreover,the predicted net carbon sink of Gracilaria cultivation would increase to 77.8-191.4 kilotons per year from 2021 to2030,thereby could contribute considerably in the achievement of China's carbon peak goal.Under a scenario of producing ruminant green feed with additional Gracilaria cultivation,each ton of macroalgae is predicted to reduce carbon emission(i.e.,methane)by 0.33-0.68 tons.Thus,marine macroalgae cultivation might form a synergistic chain of"carbon sink increase-water purification-economy-methane reduction".This study proposes a synergistic new model that operates through marine macroalgae cultivation,economic aquaculture,and green feed production.

Enhanced calcification ameliorates the negative effects of UV radiation on photosynthesis in the calcifying phytoplankter Emiliania huxleyi

The calcifying phytoplankton species,coccolithophores,have their calcified coccoliths around the cells,however,their physio-logical roles are still unknown.Here,we hypothesized that the coccoliths may play a certain role in reducing solar UV radiation(UVR,280-400 nm) and protect the cells from being harmed.Cells of Emiliania huxleyi with different thicknesses of the cocco-liths were obtained by culturing them at different levels of dissolved inorganic carbon and their photophysiological responses to UVR were investigated.Although increased dissolved inorganic carbon decreased the specific growth rate,the increased coccolith thickness significantly ameliorated the photoinhibition of PSII photochemical efficiency caused by UVR.Increase by 91%in the coccolith thickness led to 35%increase of the PSII yield and 22%decrease of the photoinhibition of the effective quantum yield(ΦPSII) by UVR.The coccolith cover reduced more UVA(320-400 nm) than UVB(280-315 nm) ,leading to less inhibition per energy at the UV-A band.

Lattice Boltzmann simulations of oscillating-grid turbulence

The lattice Boltzmann method is used to simulate the oscillating-grid turbulence directly with the aim to reproduce the experimental results obtained in laboratory. The numerical results compare relatively well with the experimental data through dete- rmining the spatial variation of the turbulence characteristics at a distance from the grid. it is shown that the turbulence produced is homogenous quasi-isotropic in case of the negligible mean flow and the absence of secondary circulations near the grid. The direct numerical simulation of the oscillating-grid turbulence based on the lattice Boltzmann method is validated and serves as the founda- tion for the direct simulation of particle-turbulence interactions.

Home range establishment and utilization by reintroduced lions(Panthera leo)in a small South African wildlife reserve

Understanding of animal spatial behavior is essential for informed management decisions.In southern Africa,reintroduction of lions(Panthera leo)to small reserves(<1000 km2)has increased since the early 2000s,however studies on their ranging behavior in these enclosed systems remain lacking.We applied Time Local Convex Hull(T-LoCoH)methods to study the home range establishment and utilization of 11 lions reintroduced to Dinokeng Game Reserve,South Africa,during 2011 through 2014.Lions established home ranges close to their release sites and during the following 3 years their home range sizes continued to increase,but in each individual case the size remained smaller than half of the reserve area(<70 km2).Space use strategies differed between the core and the entire home range,with higher frequency of visits found in core areas.Exceptionally high rates(>60 separate visits)around the largest dam and along rivers suggest the importance of water and its surrounding vegetation in the lions’space utilization pattern.The home range size did not differ with season or sex of the individuals,whereas shifts in locations of home ranges revealed differences in the response of the 2 sexes to territorial conflicts and management interventions.Our study shows a dynamic home range utilization pattern and highlights the importance of both fine-scale space use patterns(frequency and duration of visits)and broadscale home range changes in understanding the ranging behavior of reintroduced animals.

Gulf of Mannar Island coral reef associated gastropods assemblages:Distribution and diversity pattern

Objective:To study the spatial and temporal variations of the distribution and diversity pattern of coral reef associated gastropods assemblages in Gulf of Mannar Island and to clarify the relationship between gastropods and surrounding coral reef ecosystem.Methods:Gastropods were collected from three islands-Hare(Picnic spot),Vaan(Church Island)and Koswari(Karsuvar Island).The samples were taxonomically identified according to external structure of typical shells and classified according to their feeding habits.Statistical tool Primer(Ver.6.1.11)was employed to find the species diversity,richness and evenness.Results:A total of forty species of gastropods from 19 families were identified.The gastropods population density varied differently at stations,479 species from Vaan islands,390 species from Koswari islands and 254 species from Hare island were recorded.The gastropods species diversity,richness and evenness indices also varied differently at stations.The highest species diversity indice was recorded at Vaan Island(2.968),while both the highest richness and evenness indices were recorded at Hare Island with 0.937 and 0.942 respectively.Conclusions:The results of present study provides useful informtation for biodiversity conservation as well as the management of coral reef habitat in India.

Light Scattering by Pure Water and Seawater: Recent Development

Light scattering by pure water and seawater is a fundamental optical property that plays a critical role in ocean optics and ocean color studies.We briefly review the theory of molecular scattering in liquid and electrolyte solutions and focus on the recent developments in modeling the effect of pressure,extending to extreme environments,and evaluating the effect of salinity on the depolarization ratio.We demonstrate how the modeling of seawater scattering can be applied to better understand spectral absorption and attenuation of pure water and seawater.We recommend future efforts should be directed at measuring the polarized components of scattering by pure water over a greater range of wavelengths,temperature,salinity,and pressure to constrain and validate the model and to improve our knowledge of the water’s depolarization ratio.