The recognition of ocean red tide with hyper-spectral-image based on EMD

A new technique is introduced in this paper regarding red tide recognition with remotely sensed hyper-spectral images based on empirical mode decomposition （EMD）, from an artificial red tide experiment in the East China Sea in 2002. A set of characteristic parameters that describe absorbing crest and reflecting crest of the red tide and its recognition methods are put forward based on general pictre data, with which the spectral information of certain non-dominant alga species of a red tide occurrence is analyzed for establishing the foundation to estimate the species. Comparative experiments have proved that the method is effective. Meanwhile, the transitional area between red-tide zone and non-red-tide zone can be detected with the information of thickness of algae influence, with which a red tide can be forecast.     

Spherical pattern of tide-isostasy model and its application

1Sphericalpatternoftide-isostasymodelThe criterion of strong tide is simultaneous occur-rence of lunar perigean, solar the and lunar tide. If two of them concur simultaneously, it belongs to stronger tide. If three of them(or the former two)simultaneous-l…     

The Monitoring of Red Tides Based on Modular Neural Networks Using Airborne Hyperspectral Remote Sensing

This paper proposes a red tide monitoring method based on clustering and modular neural networks. To obtain the features of red tide from a mass of aerial remote sensing hyperspectral data, first the Log Residual Correction （LRC） is used to normalize the data, and then clustering analysis is adopted to select and form the training samples for the neural networks. For rapid monitoring, the discriminator is composed of modular neural networks, whose structure and learning parameters are determined by an Adaptive Genetic Algorithm （AGA）. The experiments showed that this method can monitor red tide rapidly and effectively.     

Impact of seasonal tide variation on saltwater intrusion in the Changjiang River estuary

An improved 3-D ECOM-si model was used to study the impact of seasonal tide variation on saltwater intrusion into the Changjiang River estuary, especially at the bifurcation of the North Branch (NB) and the South Branch (SB). The study assumes that the river discharge and wind are constant. The model successfully reproduced the saltwater intrusion. During spring tide, there is water and salt spillover (WSO and SSO) from the NB into the SB, and tidally averaged (net) water and salt fluxes are 985 m3/s and 24.8 ton/s, respectively. During neap tide, the WSO disappears and its net water flux is 122 m3/s. Meanwhile, the SSO continues, with net salt flux of 1.01 ton/s, much smaller than during spring tide. Because the tidal range during spring tide is smaller in June than in March, overall saltwater intrusion is weaker in June than in March during that tidal period. However, the WSO and SSO still exist in June. Net water and salt fluxes in that month are 622 m3/s and 15.35 ton/s, respectively, decreasing by 363 m3/s and 9.45 ton/s over those in March. Because tidal range during neap tide is greater in June than in March, saltwater intrusion in June is stronger than in March during that tidal period. The WSO and SSO appear in June, with net water and salt fluxes of 280 m3/s and 8.55 ton/s, respectively, increasing by 402 m3/s and 7.54 ton/s over those in March. Saltwater intrusion in the estuary is controlled by the river discharge, semi-diurnal flood-ebb tide, semi-monthly spring or neap tide, and seasonal tide variation.     

The Impact of Large-Scale Reclamation on Hydro-Dynamic Environment——A Case Study of Xinghua Bay

A hydro-dynamic model is established on basis of MIKE21 FM to simulate the hydro-dynamic characteristics of Xinghua Bay and investigate the influence of reclamation project on the tidal elevation and tidal currents. Tidal elevation data was obtained at the six tide gauge stations around the Xinghua Bay, and another six current stations were established to observe the tidal current velocity and direction. Validation shows that the model-simulated tidal elevation and tidal currents agree well with observations made at different stations. Predictions are made according to the reclamation project proposed in the regional marine planning of Hanjiang Industrial Park around the port in Putian City. The variations of hydro-dynamic factors, such as tide, current velocity and direction and tidal influx are obtained, and the adverse effect of reclamation on marine environment is discussed. It is shown that the tidal level inside the Xinghua Bay during high tide decreases after the reclamation project is completed. The tidal currents during flooding tide generally decrease in the southeast of the reclamation region, with the maximum decreasing amplitude reaching 0.44 m s^-1. On the other hand, the tidal currents during flooding tide increase around the southeast and southwest corners of the reclamation region. The tidal currents during ebb tide increase around the southeast and southwest corners of the reclamation region, with the maximum increasing amplitude attaining 0.18 m s^-1. The results in this paper can give some guidance for the marine environment management and the effective utilization of land in Putian.     

Numerical study on effect of tidal phase on storm surge in the South Yellow Sea

Because of the special topography and large tidal range in the South Yellow Sea, the dynamic process of tide and storm surge is very complicated. The shallow water circulation model Advanced Circulation(ADCIRC) was used to simulate the storm surge process during typhoon Winnie, Prapiroon, and Damrey, which represents three types of tracks attacking the South Yellow Sea, which are, moving northward after landing, no landing but active in offshore areas, and landing straightly to the coastline. Numerical experiments were carried out to investigate the effects of tidal phase on the tide-surge interaction as well as storm surge. The results show that the peak surge caused by Winnie and Prapiroon occurs 2–6 h before the high tide and its occurring time relative to high tide has little change with tidal phase variations. On the contrary, under the action of Damrey, the occurring time of the peak surge relative to high tide varies with tidal phase. The variation of tide-surge interaction is about 0.06–0.37 m, and the amplitude variations of interaction are smooth when tidal phase changes for Typhoon Winnie and Prapiroon. While the interaction is about 0.07–0.69 m, and great differences exists among the stations for Typhoon Damrey. It can be concluded that the tide-surge interaction of the former is dominated by the tidal phase modulation, and the time of surge peak is insensitive to the tidal phase variation. While the interaction of the latter is dominated by storm surge modulation due to the water depth varying with tide, the time of surge peak is significantly affected by tidal phase. Therefore, influence of tidal phase on storm surge is related to typhoon tracks which may provide very useful information at the design stage of coastal protection systems.     

Tidal effects on diel variations of picoplankton and viruses in the Changjiang estuary

Spatial distributions and seasonal variations of picoplankton (i.e. Synechococcus spp., Prochlorococcus spp., picoeukaryotes and heterotrophic bacteria) and viruses in the Changjiang estuary have been reported in the past. However, short-term variations (e.g. at a tidal timescale) of these organisms and their regulating factors remain unclear. We determined the time-series of fluctuations of picoplankton and viruses with tide simultaneously in flow cytometry in the Changjiang estuary during a cruise in June 2006, in which a tidal model based rectangle equation was applied. The results indicate that high cell abundances of picoplankton and viruses occurred during flood tide and low cell abundances during ebb tide. The period of the surface cell abundance variations was about 13 h, suggesting the surface cell abundances in the Changjiang estuary were largely regulated by tide. However, cell abundances in middle and bottom waters varied in different periods due to influences of tidal induced physical forces such as resuspension and stratification. Therefore, tidal action is an important factor for the diel variations of picoplankton and viruses in the Changjiang estuary.     

APPLICATION OF CLAYS TO REMOVAL OF RED TIDE ORGANISMS Ⅲ.THE COAGULATION OF KAOLIN ON RED TIDE ORGANISMS

This article reports studies on the coagulation of kaolin(from Wuxian,Jiangsu,China)on various red tide organisms,and the observation for the first time that the coagulation of kaolin is much greaterthan that of montmorillonite so that kaolin is a more effective clay for removing red tide organisms.The authors’theoretical explanation and analysis by a mathematical-physical model prove that comparedto montmorillonite,kaolin has greater attraction for organism cells and therefore greater coagulation capabil-ity.This project’s studies on the effects of pH and acid-treatment show that the acid-treatment does not have much influence on the kaolin system;whereas the effect of pH on the kaolin system is the same asthat on the montmonrillonite system.     

Bacterial diversity in surface water of the Yellow Sea during and after a green alga tide in 2008

From May to August 2008, a large "green tide", consisting of the alga Ulva (Enteromorpha) prolifera, occurred in the Yellow Sea, China, affecting the local marine ecosystem and human activities. We investigated the influence of the green tide on the microbial community in the surface seawater, at four sites from July to August 2008, using bacterial 16S rRNA gene clone libraries. We sequenced 228 clones of unique patterns identified by restriction fragment length polymorphism (RFLP) techniques. The results show that 228 sequenced clones fell into six bacterial phyla:Proteobacteria, Bacteroidetes, Cyanobacteria, Verrucomicrobia, Actinobacteria, and Planctomycetes. Alphaproteobacteria (33%), Gammaproteobacteria (25%), Bacteroidetes (23%) and Cyanobacteria (9%) dominated the assemblage. Comparison between samples collected in July (during the tide) and those collected in August (after the tide) showed that, in the microbial community, diversities of Alphaproteobacteria and Cyanobacteria increased after the tide, while those of Gammaproteobacteria and Bacteroidetes decreased. These results indicate that the green tide influenced the growth of some bacteria, and provide information for further studies on the interactions and relationships between U. prolifera and the bacterial community. This study suggests that microbial community analysis is a good approach to monitoring green tides.     

The movement of bed-load discharge near the shore of Shijiu harbour

Shijiu Harbour is to be constructed at southern Shandong as an important shipping center with a docking capacity of 100 thousand tonnages of a single vessel.Tides and tidal currents were frequently observed at three different layers from December 1979 to April 1980. Bed-load discharge was sampled and calculated for different weather conditions. Some of the results are as follows:1. The amount of bed-load discharge is 0.1359 g/cm2/day during the spring tide, 0.09 g/cm2/day during the neap tide, 0.488 g/cm2/day during storm weather, which is four times as high as that during average tides.2. The maximum amount of the sediments that settle to the waterway is less than 46.7768 g/cm2 per year, therefore the waterway will not be blocked by the transported sand and clay even after a storm weather.     

Early development of grateloupia turuturu (Halymeniaceae, Rhodophyta)

Grateloupia turuturu is a commercial red alga with potential value in nutraceuticals and pharmaceuticals. To supplement information on its life history and verify whether carpospores can be used for seedling culture, early development of G. turuturu was investigated under culture conditions (27°C, 10-13 mol/(m2.s) in irradiance, photoperiod 10:14 h L:D). Three physiological stages were recognized by continuous microscopic observation: division stage, discoid crust stage, and juvenile seedling stage. At the beginning of the division stage, the carpospores developed germ tubes into which the carpospore protoplasm was evacuated, and then the carpospore protoplasm in the germ tubes began to divide continuously until discoid crusts formed. Finally, upright thalli appeared on the discoid crusts and developed into juvenile seedlings. It took about 60 days for carpospores to develop into juvenile seedlings. The growth parameters, including germination rate for carpospores and discoid crust diameter, were recorded. These results contribute more information on the life cycle, and at the same time are of great significance in the scaling-up of artificial seedling cultures of G. turuturu.     

Effects of temperature and irradiance on early development of Chondrus ocellatus Holm (Gigartinaceae, Rhodophyta)

Chondrus is a type of commercially produced red seaweed that widely used for food and carrageen extraction. Although the natural life history of the alga had been well understood, the factors influencing development of the tetraspore and carpospore remain poorly understood. In the perspective of seedling resources, the regulation of early development is crucial for the seedling nursing; therefore, it is necessary to understand the physiological influences during its early development. In this study, we studied the effects of temperature and irradiance on the early development of Chondrus ocellatus Holm under laboratory conditions. The released tetraspores and carpospores were cultivated at different temperatures (10–28°C) and irradiances (10, 60 μmol photons m⁻²s⁻¹) with a photoperiod of 12L:12D. The results indicate that both tetraspores and carpospores are tolerant to temperatures of 10–25°C, and have the highest relative growth rate at 20°C. Irradiance variances influenced the growth of the discoid crusts, and the influence was more significant with increasing temperature; 60 μmol photons m⁻²s⁻¹ was more suitable than 10 μmol photons m⁻²s⁻¹. The optimum temperature and irradiance for the development of seedlings was 20°C and 60 μmol photons m⁻²s⁻¹, respectively.     

Formation and early development of tetraspores of Polysiphonia urceolata （Rhodomelaceae, Rhodophyta）

Polysiphonia urceolata is one type of potential commercial red seaweeds used for breeding and cultivation, because of its significant biochemical and biomedical application. However, the information of breeding and seedling incubation for cultivation is limited, especially the early development. In this study, tetrasporohyte and gametophyte of P. urceolata were taken as the study materials in Huiquan Bay, Qingdao, China. The cleaned and sterilized tetrasporophytes and gametophytes were pre-cultured in sterilized seawater, then nurtured at 18°C, 25 μmol photons m⁻² s⁻¹ in 12:12 h (light:dark) photoperiod. Continuous observation under microscope showed that the early development consists of bipolar division stage and seedling stage. In the division stage, tetraspores germinate into bipolar sporelings that further differentiate into a colorless rhizoidal portion and a lightly pigmented upright shoot. The lightly pigmented rhizoidal cell develops to a rhizoid and the larger pigmented cell transforms to an erect axis. In the seedling stage, several quasi-protuberances appear on the erect axis and form juvenile seedlings. The results demonstrate the culture of P. urceolata from tetraspores under laboratory conditions. Supported by National Key Technology Support Program, Development Program of China (No.2006AA09Z21), National Natural Science Foundation of China (No. 40618001 and N_CUHK438/06) and Shandong Agricultural Seed Stock Breeding Project     

Formation and early development of tetraspores of Polysiphonia urceolata (Rhodomelaceae, Rhodophyta)

Polysiphonia urceolata is one type of potential commercial red seaweeds used for breeding and cultivation, because of its significant biochemical and biomedical application. However, the information of breeding and seedling incubation for cultivation is limited, especially the early development. In this study, tetrasporohyte and gametophyte of P. urceolata were taken as the study materials in Huiquan Bay, Qingdao, China. The cleaned and sterilized tetrasporophytes and gametophytes were pre-cultured in sterilized seawater, then nurtured at 18℃, 25 μmol photons m-2 s-1 in 12:12 h (light:dark) photoperiod. Continuous observation under microscope showed that the early development consists of bipolar division stage and seedling stage. In the division stage, tetraspores germinate into bipolar sporelings that further differentiate into a colorless rhizoidal portion and a lightly pigmented upright shoot. The lightly pigmented rhizoidal cell develops to a rhizoid and the larger pigmented cell transforms to an erect axis. In the seedling stage, several quasi-protuberances appear on the erect axis and form juvenile seedlings. The results demonstrate the culture of P. urceolata from tetraspores under laboratory conditions.     

A new “tetrasporangial” species ofLiagora (Rhodophyta. Nemaliales) from Hawai’i

A new species ofLiagora, L. perennis sp. nov. from Hawai’i, is described. Unlike species of this genus in China, it is carpotetrasporangial, and at the place of expected carposporangia bears cruciately divided tetrasporangia, a detail which differentiates it from the usual species ofLiagora without tetraspores that have been reported in China. Notes are provided on otherLiagora species that have an impact on the taxonomy of species found in China. Dedicated to the memory of Zhang Junfu(C. F. Chang) whose studies on marine algae I respect highly, and whose good-humored friendship I treasure.     

Estimating areal carbon fixation of intertidal macroalgal community based on composition dynamics and laboratory measurements

The community dynamics and potential carbon ?xation of intertidal macroalgae were investigated monthly from April 2014 to April 2015 in the northwest coast of Yellow Sea. Seasonal variations in biomass and carbon ?xation were presented and showed close relationship with community structure.The carbon ?xation rate ranged from 0.48±0.13 mg C/(g FW ·d) to 4.35±0.12 mg C/(g FW ·d). Sargassum thunbergii, Chondrus ocellatus and Ulva intestinalis were three most in?uential species which contributed27%, 21.9% and 18.5% variation of carbon ?xation rate, respectively. Standing carbon stocks ranged from7.52 g C/m~2 to 41.31 g C/m~2, and estimated carbon stocks varied from 11.77 g C/m 2 to 96.49 g C/m~2. The larger dif ference between estimated and standing carbon stocks implied that more ?xed carbon was exported from the community in summer and autumn than in winter. This study suggested that intertidal macroalgal community could provide a potential function in carbon ?xation of coastal ecosystem.     

Ultrastructural observations on sporogenesis ofMyxobolus Kwangsiensis Hsieh,Gong & Xiao from the kidney of daceLabeo rohita

The early stages and capsulogenetic stages of sporogenesis ofMyxobolus kwangsiensis were studied in detail by electron microscopy.M. kwangsiensis is an intracellular myxosporean infecting the epithelial cells of kidney tubules of young daceLabeo rohita. TheM. kwangsiensis sporogensis presents the typical features of myxosporea. The initial stages are multinucleate primary cells, with one primary cell typically enclosing one secondary cell. The secondary cells are formed directly by cytokinesis inside the primary cells. The primary cell participates in the formation of the secondary cell nucleus. The nuclear division of primary cell is asynchronous by amitosis. The parasitic organisms may degenerate inside the epithelial cells at any stage. The modes of sporoblast formation, the typical features of myxosporea and the cause of its degradation are discussed. This research was supported by the NSFC. (No. 39070675)     

Embryology of Maldives clownfish, Amphiprion nigripes (Amphiprioninae)

This study investigated the embryonic development of Maldives clownfish Amphiprion nigripes under natural conditions (28 - 30℃) at a lagoon of Agatti Island, Lakshadweep, India. The newly deposited fish egg was capsule-shaped and orange-red, with a (0.73 ± 0.04) mm3 yolk containing 5 - 10 fat globules. The embryonic development of fertilized eggs was divided into 26 stages and the time elapsing for each stage was recorded. Results showed that the cleavage was rapid, with the first division observed 1 h 20 min after fertilization. Blastulation occurred 4 h later, followed by gastrulation 12 h after fertilization, with a yolk volume of (0.61 ± 0.06) mm3. The organogenesis process started 22 h after fertilization when the blastopores closed and notochord formation began. The embryonic stage was recorded 24 h later, with the appearance of forebrain, midbrain, hindbrain, melanophores on yolk-sac and 22 somites, and a decreased yolk volume of (0.54 ± 0.08) mm3. Other organs developed well 31 h after fertilization, whereas the heart started beating and blood circulation began 78 h later. Red pigmentation (erytrophores) appeared 96 h after fertilization, with a small yolk volume of (0.22 ± 0.02) mm3. Mouth developed well and eyes were noticeable 120 h later, with head, pectoral fin and tail frequently moving 144 h after fertilization. The embryo reached the pre-hatching stage 168 h later and started to hatch after 170 - 180 h incubation. This study first detailed the embryonic development and yolk absorption of A. nigripes under natural conditions.     

Early development of Costaria costata (C. Agardh) Saunders and cultivation trials

Costaria costata (C. Agardh) Saunders is one of common kelps distributed in many coastal areas worldwide; however, in China, no reports have been made on cultivation of the genus. To investigate potential cultivation of the species in the northern part of China, trials on isolation and preservation of the gametophytes were conducted using C. costata from Korea; growth and development of the gametophytes were observed. We showed that at 10±1°C, 60 μmol m⁻²s⁻¹ and 12:12 h (L:D), freshly released zoospores settled down within 1 hour, and then developed into the primary cell during the following 2 days. After a vegetative growth phase lasting 6–8 days, female gametophytes became 3–4 times larger in diameter than that of the primary cell, but still remained at a unicellular stage, while male gametophytes divided into 4–10 cells with only a slight change in size. Fertilization occurred within 10 days after the zoospores were released from the sporangia, and the apical and basal tissues of the juvenile sporophyte divided and differentiated into the blade and stipe. Temperature and irradiance influenced gametophytic vegetative growth and developmental patterns. Generally, low irradiance (15 μmol m⁻²s⁻¹ and 30 μmol m⁻²s⁻¹) was unfavorable to the induction of fertility, but it enhanced female gametophyte division. The optimal conditions for vegetative growth were 15°C and 30 μmol m⁻²s⁻¹. After transplantation of the juvenile seedlings and after eight months cultivation, the harvested mature blade reached 194 cm in length and 32.7 cm in width. Our study proves that it is feasible to implement propagation and large scale cultivation of C. costata in northern China.     

Variations of ion-transport enzyme activities during early development of the shrimps <Emphasis Type="Italic">Fenneropenaeus chinensis</Emphasis> and <Emphasis Type="Italic">Marsupenaeus japonicus</Emphasis>

The ion-transport enzyme activities were studied in the nauplii 1–2, zoea 1–3, mysis 1–3, and postlarva 1–7 of the shrimps Marsupenaeus japonicus and Fenneropenaeus chinensis. The results showed that total ATPase, Na⁺-K⁺-ATPase, and V-ATPase (V-type H⁺-ATPase) activities increased during the early development for both the species, from zero in nauplii to stable levels after zoea stage. The enzyme activities of the latter species were significantly higher than those of the former species after zoea stage (F>F _0.05). The contributions of Na⁺-K⁺-ATPase, V-ATPase and HCO₃ ⁻-ATPase to the total ATPase activity of the two species varied in different developmental stages and accounted for 40%–70%, 22%–46% and 2%–13% in M. japonicus from zoea to postlarva stage, whilst the shares of them were 42%–69%, 28%–44% and 2.5%–22%, respectively in F.chinensis. These findings suggest the possible culture of the two species with varying water quality, especially the salinity and pH.