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Since 2007, the Yellow Sea has undergone a large-scale outbreak of green tide for 15 years. The large biomass of green tide has caused great economic losses to Shandong and Jiangsu Province. The monitoring data in the recent years indicated that the dominant algae in the Southern Yellow Sea (SYS) was a special ecological type of Ulva species (Ulva prolifera). In order to make rational use of green tide algae and avoid the waste of biological resources, the achievements in the research and technical development on the resource utilization of green tide algae were systematically introduced. Moreover, the utilization and development of U. prolifera, such as food, beauty products, feed or feed additives, fertilizer, energy and papermaking engineering, were summarized. In addition, solutions to reduce the losses caused by the outbreak of green tide algae were also proposed.

Invertebrates are considered completely dependent on their innate immunity to defend themselves against pathogens as they lack an adaptive immunity. However, a growing body of evidence has indicated a specific acquired immunity called ‘immune priming’ may exist. The Pacific white shrimp, Penaeus vannamei is one of the most economically important shrimp species in the world. In the previous research, we investigated the hepatopancreas immune response of shrimp immunized with trans -vp28 gene Synechocystis sp. PCC6803 at the protein level. In this study, on the basis of the previous research, the shrimp were then challenged with WSSV, and hepatopancreas analyzed using isobaric tags for relative and absolute quantification (i TRAQ) labeling. In total, 308 differentially expressed proteins (DEPs) were identified including 84 upregulated and 224 downregulated. Upregulated proteins such as calmodulin B and calreticulin, and downregulated proteins such as calnexin, and signaling pathways like Ras, mTOR were differentially expressed in both studies. Data from this study are more significant than previous work and indicate increased sensitivity to WSSV after immunization with trans-vp28 gene Synechocystis sp. PCC6803. In addition, selected DEPs (upregulated: A0A3R7QHH6 and downregulated: A0A3R7PEF6, A0A3R7MGX8, A0A423TPJ4, and A0A3R7QCC2) were randomly analyzed using parallel reaction monitoring (PRM). These data preliminarily confirm immune priming in P. vannamei, and show that the initial stimulation with trans -vp28 gene Synechocystis sp. PCC6803 regulate P. vannamei immune responses and they provide shrimp with enhanced immune protection against secondary stimulation.

White spot syndrome virus (WSSV) has become one of the most widespread causes of mortality in commercial shrimp farming due to its broad host range, rapid spread and high lethality. The tegument protein VP26, which is loosely connected to nucleocapsid and envelope, is one of the major proteins of WSSV and has an important role in the initial stages of viral infection. Recent research has emphasized the vp26 gene, the structure of the VP26 protein, and VP26 binding proteins. Such knowledge is required to develop VP26 immune adjuvant to control WSSV. This paper reviews the related research of VP26 to provide reference for the prevention and treatment of WSSV.

Green tides dominated by Ulva prolifera have be present in the Southern Yellow Sea for 15 consecutive years. They not only damage the marine environment, but also cause economic losses to coastal cities. However, there is still no fully effective approach for preventing green tides. In this article, approaches for the prevention of U. prolifera taken over recent years are reviewed. They can be generally divided into physical, chemical, and biological approaches. Physical approaches have been used to control the overwhelming green macroalgae bloom and inhibit the germination of U. prolifera, including physical salvage approach, refrigeration net technology, improved farming methods and raft technology, and modified clay method. These approaches require significant labor and material resources. Many chemical reagents have been used to eliminate U. prolifera early germination and growth, such as oxidative algaecide, acid treatment, heavy metal compounds, antifouling coating, and alkaloids. Chemical approaches have high efficiency, high economic benefit, and simple operation. Presently, biological control approaches remain in the exploratory stage. The verification of pilot and large-scale experiment results in sea areas is lacking, including the application of large organisms and microorganisms to control U. prolifera, and some of the mechanisms have not been thoroughly studied. This article introduces the three types of approaches, and evaluates the advantages and disadvantages of different methods to facilitate the reduction of the green tide bloom scale in the Southern Yellow Sea.

The growth and nutrient uptake of Gracilaria lemaneiformis under different nutrient conditions, with implications for ecosystem services, were evaluated in the laboratory and in an enclosed mariculture sea area in Yantian Bay at the coast of East China Sea. In laboratory experiments, the specific growth rate (SGR) ranged 1.29%/d–7.99%/d, and nitrogen (N), phosphorus (P), and dissolved inorganic carbon (C) uptake rate was 0.067–1.603 μmol/(g∙h), 0.002–0.069 μmol/(g∙h), and 4.01–31.25 μmol/(g∙h), respectively, under different nutrient conditions. In field experiments, the SGR ranged from 6.30%/d to 13.00%/d, and the average C sequestration rate was 9.25 mg/(g DW·h) and 6.68 mg/(g DW·h) in the G. lemaneiformis cultivation area (region 1) and fish cage area (region 4), respectively. The NH4+-N uptake rate of G. lemaneiformis was the highest in region 1 and region 4 with 56.98 ± 4.81 μg/(g DW·h) and 38.68 ± 7.12 μg/(g DW·h), respectively. The maximum removal efficiency of NH4+-N, NO3−-N, NO2--N, and PO43--P were 45.99–59.79%, 13.10–30.21%, 12.88–14.11%, and 27.07–31.49% in G. lemaneiformis cultivated areas compared with those in fish cage area. The extrapolated results showed that 1192.03 tonnes of C, 128.10 tonnes of N and 15.89 tonnes of P would be simultaneously sequestered from the seawater through G. lemaneiformis cultivation in Yantian Bay. Results indicated that G. lemaneiformis had high growth rates and nutrient removal efficiencies under different nutrient conditions, which made it a good candidate for seaweed/animals integrated multi-trophic aquaculture in nutrient bioextraction and economic diversification.

Macroalgal blooms have become a serious threat to public health, fisheries, ecosystems, and global economies. Since 2007, in the Yellow Sea, China, Ulva green tides have occurred for 15 consecutive years. However, effective control methods are limited. Ulva prolifera attached to Neopyropia aquaculture rafts are believed to be the main source of blooms, therefore eliminating Ulva from rafts could effectively prevent and control blooms. We investigated this phenomenon and showed that macroalgae germination was significantly inhibited by dried Neopyropia yezoensis at concentrations of 1.2, 2.4, and 4.8 g DW

This study sampled U. prolifera and surface seawater from the same locations where green tide broke out in the southern Yellow Sea, in both the year 2016 and 2017. The revealed nutritive components of U. prolifera samples characterized U. prolifera as a high-protein, high-Fe, high ratio of unsaturated lipid acids and low-fat seaweed food, with an ideal ratio of essential and nonessential amino acids. The concentrations and health risk assessment of major micropollutants (heavy metals, pesticides and polycyclic aromatic hydrocarbon (PAHs)) in U. prolifera were also analyzed, respectively. The results showed that the Target Hazard Quotient values of five heavy metals (

The relationship between Microcystis abundance and environmental variables was studied during a Microcystis bloom in the summer months of 2016 in an artificial lagoon of Hangzhou Bay, China. It was determined that Microcystis abundance increased from 0.16 × 104 cell/L to 5.8 × 107 cell/L within 17 days from 28 July to 14 August, contributing to 96.84–99.56% of the total phytoplankton abundance. Then, Microcystis gradually disappeared 57 days afterwards. The results showed that the growth of Microcystis, including the stage of recovery, outbreak, subsidence and disappearance, was significantly correlated with water temperature, salinity, soluble reactive phosphorus (PO4-P), dissolved inorganic nutrients (DIN), silicate (SiO4-Si), the ratio of DIN/SiO4-Si and zooplankton abundance, and the key environmental triggers which promoted the outbreak of Microcystis were water temperature, PO4-P concentration and zooplankton abundance in this artificial lagoon.

Dense mat formed by duckweeds is a significant threat to fisheries, landscape, ecological environment, and economies around the world. Effective biological management strategies to control duckweeds are quite limited. In the present study, we determined the effect of the extract of Coptis chinensis, a traditional Chinese medicinal herb, on the growth of duckweed (Spirodela polyrhiza). The growth of S. polyrhiza was strongly inhibited by the C. chinensis extract. The number of fronds and fresh weight of the plants were significantly decreased after a 96-h treatment. Furthermore, the chlorophyll (a, b, and a + b) content was remarkably decreased by the C. chinensis extract. The 24-, 48-, 72- and 96-h-IC50 of the C. chinensis extract to S. polyrhiza were 6.56, 1.06, 0.81, and 0.33 g DW eq. extract L−1, respectively. In addition, the C. chinensis extract was found to be safer for the submerged macrophytes (such as Vallisneria natans: 96-h-EC50 was 10.39 g DW eq. extract L−1) and aquatic animals (such as zebrafish: 96-h-LC50 was 20.35 g DW eq. extract L−1). These results showed that the C. chinensis extract was inhibitory to the growth and reproduction of S. polyrhiza. Moreover, the field test results also confirmed that the inhibitory effect of C. chinensis extract on S. polyrhiza. Thus, we recommend the use of the C. chinensis extract as an effective and safe botanical herbicide for duckweed management in water ecosystems.

Species composition and seasonal variations of free-floating Ulva species were investigated in the source area of the world's largest macroalgal blooms during 2009-2015. Based on a combination of a morphological analysis and sequences of nuclear-encoded ITS and 5S rDNA spacer regions, the dominant species in the free-floating Ulva community at the early stage of green tides were Ulva compressa, Ulva flexuosa, and Ulva linza. The first appearance of Ulva prolifera on the sea surface was in mid-May and it dominated the floating Ulva community in June from 2009 to 2011. From 2012-2015, U. prolifera was not only the first species to appear on the sea surface but also the dominant species during the whole early stage of green tides. To explain the successional mechanism, the effects of environmental factors on the growth of four Ulva species were examined in the laboratory under different combinations of light intensity and temperature. It was found that the highest growth rate of U. prolifera was 44.9%/d, which was much higher than the other three Ulva species. The strong tolerance of U. prolifera to extreme conditions also helps it survive and bloom in the Yellow Sea.

Myriophyllum spicatum was cultivated in a low salinity area of Hangzhou Bay (salinity 5.8-6.5), from August to October in 2016, to evaluate the abilities of its nutrient bioextraction and microalgae growth inhibition. During the 72-day cultivation period, M. spicatum had a specific growth rate (SGR) of 6.23%day-1 and increased 20-fold in biomass (wet weight). Tissue C, N and P assimilation quantities of M. spicatum were found to be 3279.39kg, 360.61kg and 26.97kg, respectively. The concentration of NH4-N, NO3-N, NO2-N and PO4-P after M. spicatum cultivation was decreased by 47.92%, 58.28%, 36.40% and 55.57%, respectively. The phytoplankton density was decreased from 1064.60×104cellsL-1 to 12.85×104cellsL-1. These results indicated that cultivation of M. spicatum can help in nutrient bioextraction and microalgae growth inhibition in low salinity marine water bodies.

Massive Ulva blooms became an environmental disaster in the Yellow Sea from 2007 to 2015. In this study, field shipboard observations indicated that Ulva blooms originated in Pyropia aquaculture area, and the morphology of initial floating Ulva seaweed have the structure of rhizoid, which is similar with the attached Ulva on the Pyropia rafts. The spatial distribution of Ulva microscopic propagules in the southern Yellow Sea also supported that the blooms originated in the Pyropia aquaculture area. Besides, numerical model was used in this study, showing the origin of macroalgal blooms was traced to “Sansha” regions which accounted for almost 70% of the total Pyropia aquaculture area. We conclude that the significant biomass (4252 tons) of Ulva species on the Pyropia rafts during the harvesting season in “Sansha” regions played an important role in the early rapid development of blooms in the Yellow Sea.

Benthic macrofauna are considered to have important effects on the microbial-driven cycling of nutrients in sediments. The response of the microbial community to bioturbation by macrofauna is not fully understood. This study investigated variations in the microbial communities and nutrient profiles after bioturbation by the clam Meretrix meretrix and polychaete Perinereis aibuhitensis . The total nitrogen, total phosphorus, total organic carbon and dissolved inorganic nitrogen contents of sediments decreased dramatically in the presence of Meretrix meretrix and Perinereis aibuhitensis . In total, 64 bacterial phyla and three archaeal phyla were identified, where Proteobacteria were dominant and they accounted for > 30% in all reads with a stable percentage among all samples. Eleven bacterial phyla, i.e. unclassified, AC1, Acidobacteria, Actinobacteria, Cyanobacteria, Gemmatimonadetes, KSB3, Lentisphaerae, Nitrospirae, Spirochaetes, Verrucomicrobia and WS3, were influenced significantly by bioturbation using Meretrix meretrix or Perinereis aibuhitensis . Analysis of similarities and non-metric multidimensional scaling analysis demonstrated that the bacterial communities did not differ significantly in the control and macrofauna-inhabited sediments. The number of bacterial amoA copies increased significantly in the presence of macrofauna, but not the number of archaeal amoA copies. The results of this study demonstrate that bioturbation by Meretrix meretrix or Perinereis aibuhitensis can cause structural and compositional changes in sediment microbial communities by increasing the abundance of nitrogen-cycling bacteria and decreasing the nutrient levels in sediments.

A new Bis-sesquiterpene, Nanji A ( 1 ), has been isolated together with 7 known compounds, debromolaurinterol ( 2 ), laurinterol ( 3 ), laurinterol acetate ( 4 ), isolaurinterol ( 5 ), 3α-hydroperoxy-3-epiaplysin ( 6 ), 3β-hydroperoxyaplysin ( 7) , Laurokomurenene A ( 8 ), from the Nanji red alga Laurencia okamurai . The structure of 1 was elucidated on the basis of extensive spectroscopic analysis of its EIMS, 1D and 2D NMR data. Furthermore, the chemotaxonomic significance of these compounds was also summarized.

Ulva usually attached to aquaculture rafts, rocks, and floating objects. Previous studies have shown that the world's largest green tides in the Yellow Sea originated from the attached Ulva on rafts. However, a large biomass of Ulva thalli has recently been found attached to Littorina sp. (periwinkles) in the Subei intertidal zone, but it is rarely observed on Bullacta exarata, Portunus sp., and other intertidal benthic animals. The population density of Littorina sp. on the Zhugen sand ridge is approximately 39.2 specimens/m2. A maximum of seven Ulva macroalgae were attached to one periwinkle, and an average of 1.24 Ulva macroalgae were attached to each periwinkle. To determine the contribution of epizoic Ulva on Littorina sp. to floating green tides, these macroalgae were identified with a molecular biology method using internal transcribed spacer (ITS) sequences. Results showed the Ulva attached to Littorina sp. comprised just one species, Ulva flexuosa. Epizoic Ulva attached to intertidal benthic animals in the Zhugen sand ridge does not appear to be the main source of the green tide (the only dominant species is Ulva prolifera) outbreaks in the Southern Yellow Sea.

To develop a more comprehensive understanding of the efficacy of trans-vp28 gene Synechocystis sp. PCC6803 and its effect on white spot syndrome virus (WSSV), this study investigated the activities of several immune-related enzymes including acid phosphatase (ACP), alkaline phosphatase (AKP) and peroxidase (POD) in muscle and hepatopancreas of Penaeus vannamei, and conducted a more intuitive analysis from the perspective of histopathology. P. vannamei were orally fed trans-vp28 gene Synechocystis sp. PCC6803 for 10 days and then challenged with WSSV. The cumulative survival rate, activities of enzymes and the histopathology were determined. The results show that on the 7th day after challenge, the survival rate of the experimental group (i.e., challenged and fed mutant Synechocystis sp. cells) and the wild type group (i.e., challenged and fed wild type Synechocystis sp. cells) were 80.2% and 26.4%, respectively, while all shrimp in the positive control group (i.e., challenged, but no vaccination) died. There was no death in the negative control group (i.e., no vaccination or challenge). After immunization, the activities of ACP, AKP and POD in both tissues were the highest in the experimental group. After challenge, the final enzyme activities of the three enzymes in the experimental group were higher than those in the positive control group and the wild type group. The results of histopathology showed that muscle fibers in the negative control group were neatly arranged with numerous and evenly distributed nuclei, while muscle fibers in the positive control group and the wild type group were wavy. The nuclei of muscle fibers in the positive control group were also swollen and unevenly distributed. The nuclei of the muscle fibers in the experimental group were slightly clustered, and the muscle fibers were arranged neatly. In hepatopancreas samples, narrow cell gaps and regular nuclei were observed in the negative control group. The connective tissue and cell walls were severely damaged and the cells were degraded in the positive control group. However, although the connective tissue of the experimental group was slightly loose, the cells were orderly and the nuclei were arranged neatly. These results indicated that trans-vp28 gene Synechocystis sp. PCC6803 could improve the immunity of shrimp.

In January 2020, golden seaweed tides accumulated in the world's largest Pyropia aquaculture areas in the Yellow Sea of China again, resulting in great economic loss to local seaweed farmers. A large number (~40,000 km2) of Sargassum thalli floated around Pyropia aquaculture areas until May 2020, drifting northeastward and becoming an ecological threat to the coastal areas of Jiangsu and Shandong provinces. In response, the local government is developing an emergency plan to prevent future golden tides, and this process requires an understanding of the mechanisms by which form the Sargassum blooms. As the global climate continues to change and the increase in human activities, sea surface temperatures rise, nutrient emissions and other factors that affect Sargassum blooms may lead to gradually enlarged ecological crises in the Pacific Northwest unless mitigation protocols are developed.

Responses of the germination and growth of Ulva prolifera parthenogametes to gradients of temperature and light were evaluated. Results showed that U. prolifera parthenogametes could not germinate at 5 °C and 35 °C, and at all temperatures combined with dark conditions, but had high germination rates at the temperature of 15–25 °C and photosynthetically active radiation (PAR) of 80–160 μmol m–2 s–1. There was a significant interaction between temperature and PAR on the growth rate of U. prolifera germlings germinated from parthenogametes (P

Green macroalgal blooms have occurred in the Yellow Sea for 13 consecutive years since 2007. However, effective control methods have not yet been successfully developed. Ulva prolifera attached on Pyropia aquaculture rafts was identified as the main source of the blooms, thus, eliminating the attached Ulva from the rafts should be the most efficient method to prevent and control these blooms. In this study, we designed a new molecular marker (rps2-trnL) to identify U. prolifera collected from the aquaculture site. Samples identified as U. prolifera were cultured, and different concentrations of sodium hypochlorite (NaClO) solution (0.2, 0.4, 0.6, 0.8, and 1.0%) were used to kill the alga. The measured chlorophyll content, light quantum yield, and photosynthetic oxygen release rate data from the laboratory experiment suggested that the appropriate concentration of NaClO solution should be 0.6–1.0%. To carry out a small-scale field trial, we developed a device that can spray NaClO on Ulva blades and recycle the residual liquid. Results showed that only the 1.0% NaClO solution could quickly kill the Ulva in outdoor experiments. During the treatment, very little NaClO dripped on the tidal flat, which indicated that the recycling device avoided a potential negative impact of residual solution on the marine ecosystem. By the beginning of November 2019, the Pyropia aquaculture area treated by NaClO was about 13,000 ha, covering about one-third of the total area at the coast of Jiangsu Province. Monitoring by an unmanned aerial vehicle showed that very little attached Ulva was present on the ropes after NaClO treatment, which indicated that it was an effective method to control the green tide. Also, the range of residual active chlorine within seawater during the treatment was only from 0.003 to 0.012 mg/L, which complied with Chinese national standards. However, further monitoring of the formation process of green tides should be conducted in future years to evaluate the effect of NaClO treatment.

Nutrient removal ability of seaweeds on Pyropia yezoensis aquaculture rafts was studied during the P. yezoensis aquaculture season of 2012–2013 at the offshore farm along the radial sandbanks of Jiangsu Province, China. During the P. yezoensis cultivation season, three Ulva species, including Ulva prolifera , Ulva linza , and Ulva flexuosa , were present on the cultivation rafts. These Ulva spp. were then removed from the rafts or floated away when rafts were recycled in April 2013. The quantities of nitrogen and phosphorus removed by the harvest of P. yezoensis were 3688 and 106 tons, respectively. The nitrogen and phosphorus removal of Ulva were 77 and 3 tons, respectively. These results indicate that P. yezoensis can efficiently remove excess nutrients from coastal waters. The Ulva if harvested can also be utilized as an additional nutrient management tool in eutrophic waters. In addition, introduction of high-temperature adapted seaweeds would be a useful way to continue algal bioremediation during the off season of P. yezoensis aquaculture.

In recent years, green tides caused by water eutrophication, has brought serious environmental problems. Enteromorpha prolifera (E. prolifera), an opportunistic macroalgae, is one of the main source contributing to the formation of green tides. It has been estimated that the excessive growth of E. prolifera is closely related to various reproductive ways of germ cells which are at the micrometer scale. Here we report a microfluidic device named Germ Cell Capture Chip (GCChip) to investigate the E. prolifera reproductive mechanism. GCChip integrates the functions of algal growing, and the release, capture and selective culture of germ cells. Automatic separation and capture of germ cells on the chip allows to study germ cells’ response to different stimuli. The novel device greatly facilitates long-term live-cell imaging at cellular resolution and implements the rapid and accurate exchange of growth medium without manual intervention. Results showed that the starting time of germ cell releases were earlier on the chip than that of traditional experiments with more concentrated breakout. Moreover, GCChip can be widely applied on the study of other algae. The study of algae growth process, including the elongation of somatic cell, the generation, and the release of reproductive cells, can all be improved by using this microfluidic platform.

From 2008 to 2016, massive floating green macroalgal blooms occurred annually during the summer months in the Yellow Sea. The original source of these blooms was traced based on the spatio-temporal distribution and species composition of Ulva microscopic propagules and settled Ulva vegetative thalli monthly from December 2012 to May 2013 in the Yellow Sea. High quantities of Ulva microscopic propagules in both the water column and sediments were found in the Pyropia aquaculture area along the Jiangsu coast before a green macroalgal bloom appeared in the Yellow Sea. The abundance of Ulva microscopic propagules was significantly lower in outer areas compared to in Pyropia aquaculture areas. A molecular phylogenetic analysis suggested that Ulva prolifera microscopic propagules were the dominant microscopic propagules present during the study period. The extremely low biomass of settled Ulva vegetative thalli along the coast indicated that somatic cells of settled Ulva vegetative thalli did not provide a propagule bank for the green macroalgal blooms in the Yellow Sea. The results of this study provide further supporting evidence that the floating green macroalgal blooms originate from green macroalgae attached to Pyropia aquaculture rafts along the Jiangsu coastline of the southern Yellow Sea.

Marine organisms are known to play important roles in transforming nutrients in sediments, however, guidelines to optimize sediment restoration are not available. We conducted a laboratory mesocosm experiment to investigate the role of hard clams, polychaetes, the degree of physical disturbance and denitrifying bacterial concentrations in removing total nitrogen (TN), total phosphorus (TP), and total organic carbon (TOC) in marine sediments. Response surface methodology was employed to analyze the results of initial experiments and in a subsequent experiment identified optimal combinations of parameters. Balancing the TN, TP, TOC removal efficiency, our model predicted 39% TN removal, 33% TP removal, and 42% TOC removal for a 14-day laboratory bioremediation trial using hard clams biomass of 1.2kgm(-2), physical disturbance depth of 16.4cm, bacterial density of 0.18Lm(-2), and polychaetes biomass of 0.16kgm(-2), respectively. These results emphasize the value of combining different species in field-based bioremediation.

Since 2007, Ulva macroalgal blooms have occurred along the coastal areas of the Yellow Sea, China. These blooms are dominated by fragments of Ulva prolifera in the early stages of development. The objectives of this study were to identify the primary mode of asexual reproduction for U. prolifera and to evaluate the contribution of these thalli fragments to the formation of blooms. Four different growth and reproductive strategies of U. prolifera segments were found including: 1) tubular diameter becoming larger; 2) formation of new branches; 3) release of zoids; and 4) polarized growth. This is the first report showing the development of numerous blade-lets from a single segment, which is remarkably different from previous studies on other Ulva species. The results in the present study provide critical information to understand how this species is able to support its explosive growth during a bloom.

Large-scale Sargassum blooms, known as golden tides, have been occurring along the coast of the Yellow Sea in recent years, resulting in an enormous loss of Pyropia yezoensis production. To locate the source of the blooms, we performed large-scale spatio-temporal sampling in the South Yellow Sea, East China Sea, and Jeju Island, South Korea. Based on morphology and molecular traits, the attached and floating Sargassum samples collected from the three regions were all identified as Sargassum horneri, although slight differences were observed in morphology among samples. Genetic distance and automatic barcode gap discovery analysis revealed very low genetic diversity among the three regions. The 33 samples from 12 sites were divided into six haplotypes, and the samples from the ECS shared more haplotypes than samples from other two regions. Our results suggested that S. horneri in the ECS was responsible for the formation of blooms in the Yellow Sea.

A graphene-cobalt microsphere (CoMS) hybrid paste electrode was developed for the determination of carbohydrates in honey and milk in combination with capillary electrophoresis (CE). The performance of the electrodes was demonstrated by detecting mannitol, sucrose, lactose, glucose, and fructose after CE separation. The five analytes were well separated within 9 min in a 40 cm long capillary at a separation voltage of 12 kV. The electrodes exhibited pronounced electrocatalytic activity, lower detection potentials, enhanced signal-to-noise characteristics, and higher reproducibility. The relation between peak current and analyte concentration was linear over about three orders of magnitude. The proposed method had been employed to determine lactose in bovine milk and glucose and fructose in honey with satisfactory results. Because only electroactive substances in the samples could be detected on the paste electrode, the electropherograms of both food samples were simplified to some extent.

To evaluate spatial distribution pattern of intertidal macrofauna, quantitative investigation was performed in January to February, 2013 around Fildes Peninsula, King George Island, South Shetland Islands. A total of 34 species were identified, which were dominated by Mollusca, Annelida and Arthropoda. CLUSTER analysis showed that macrofaunal assemblages at sand-bottom sites belonged to one group, which was dominated by Lumbricillus sp. and Kidderia subquadrata. Macrofaunal assemblages at gravel-bottom sites were divided into three groups while Nacella concinna was the dominant species at most sites. The highest values of biomass and Shannon-Wiener diversity index were found in gravel sediment and the highest value of abundance was in sand sediment of eastern coast. In terms of functional group, detritivorous and planktophagous groups had the highest values of abundance and biomass, respectively. Correlation analysis showed that macrofaunal abundance and biomass had significant positive correlations with contents of sediment chlorophyll a, phaeophorbide and organic matter.

The Ulva blooms have been observed at the coast of Gouqi Island, East China Sea recently, which was never reported before 2011. This study was designed to identify the species composition, phylogenetic correlation and geographical exchange of the two free-floating Ulva populations in the Yellow Sea and East China Sea. The results showed that the two populations were all consisted of Ulva prolifera (type 5S-A) and U. prolifera (type 5S-B) using ITS and 5S rDNA spacer region sequences. Based on the further sequence analysis, the samples in the East China Sea were genetically same with the green tide samples in the Yellow Sea, revealing that the two populations originated from one source. Besides, a numerical circulation modeling experiment confirmed that the Ulva blooms in the East China Sea had drifted from the Southern Yellow Sea. This study increases our understanding of the importance of controlling the spread of Ulva macroalgae blooms and their impacts.

Compositions, changes and biomass of attached Ulva species on Porphyra rafts along the radial sandbank in the Yellow Sea were investigated, and potential contributions to green tides was analyzed. Ulva prolifera, Ulva flexuosa and Ulva linza were all appeared throughout the investigated period. U. prolifera and U. flexuosa dominated attached Ulva population on Porphyra rafts. Attached Ulva species biomass showed obviously spatial and temporal variations. Temperature, Ulva microscopic propagules and human activities were main factors to influence attached Ulva species biomass. The total attached Ulva species biomass was more than 20,000 fresh weight tons in April, and the green tide causative species U. prolifera accounted 51.03% in April 2013 before green tides occurred. The high biomass of attached Ulva species would contribute most to green tides in the Yellow Sea. But how attached Ulva species on Porphyra rafts contributing to green tides in the Yellow Sea should be further studied.

Massive green algae blooms became an environmental disaster in the Yellow Sea from 2008 to 2013. Recent studies suggested that recurrences of early aggregates of macroalgae were found over the Subei Bank, a unique shallow radial sand ridge system off the Jiangsu coast, China. Yearly field surveys have been carried out over this bank during the past five years (2009-2013), with an aim at identifying and qualifying the physical-biological mechanism for the early aggregation of algae. Data synthesis showed that early aggregation of macroalgae usually occurred from April-May as small-scale patches either over the intertidal mudflat of the Subei Bank or along local isobaths in the northern coastal area north of the bank. Both hydrographic and current measurements were performed by tracking a narrow patchy area of floating macroalgae (nearly 4 km in length and 5-10 m in width) on April 26, 2013, and the results showed that the algae aggregation was mainly caused by tide-induced convergence. This convergence was produced by the local geometrically controlled interaction of tidal currents with mudflats, which is believed to be a key physical mechanism for the early development of algal blooms in addition to marine ecosystem responses and human aquaculture activities.

The breeding of Sargassum vachellianum on artificial reefs was firstly performed in the Gouqi Island coast, Zhejiang Province, China. A new algal reef with pedestal and breeding boards was designed and produced for breeding S. vachellianum . The adult male and female plants with receptacles were collected and cultured in a breeding room for 7 days for eggs releasing out of conceptacles and for fertilizing. Approximately 3.41 million fertilized eggs were collected, and then sprayed evenly onto 105 breeding boards in 3 tanks for breeding. Fertilized eggs then sank and were attached on the bottom breeding boards for germination. After 35 days of culture, the seedlings' average length reached approximately 5 mm. And then, one hundred and five breeding boards with seedlings were transported to the Houtou coast of Gouqi Island by boats, and 21 artificial algal reefs (five breeding boards to one pedestal) were installed underwater at both Site A (slow current) and Site B (rush current). After being cultivated for 45 days in the open sea, the average length and density of seedlings on artificial reefs at Site A and Site B were 31.85 ± 0.62 and 41.31 ± 1.39 mm, 4.70 ± 1.40 and 5.19 ± 2.65 seedlings dm − 2 , respectively. One year later, the length of the plants on artificial algal reefs in the Gouqi Island coast reached up to 15.51 ± 3.42 cm. All the results indicated that large scale artificial breeding of S. vachellianum with artificial algal reefs was feasible.

In this study, the land use/cover vector data for 1960, 1980, 1990, 2000, 2010, and 2015 were used to calculate and characterize the landscape metrics and dynamics of the Yangtze Estuary. The hypsometric 6 m curve was first delineated and considered in the research of the Yangtze Estuary wetlands landscape patterns. The associated landscape-changing driving forces were then analyzed through correlation analyses using socioeconomic variables. Three main conclusions were obtained from the results. First, from 1960, the total area of coastal wetlands consistently increased while the trend of landscape patterns became more complicated. According to the associated economic development policy during the studied period, the year 2000 was found to be a boundary after which the landscape metrics differed from prior years. Second, the hypsometric 6 m curve can provide indispensable information for characterizing wetland patterns. Even though the patterns are similar when the hypsometric 6 m curve is not considered, the change range of the landscape metrics differs, and the extent and intensity of the metrics are higher than when the hypsometric 6 m curve is not considered. Third, agriculture and urban development are recognized as the major factors driving landscape evolution. This study emphasizes the importance of integrating land and sea when crafting wetlands conservation policies on coasts around the world.

This study was aimed to assess the effect of oral administration of trans-vp28 gene Synechocystis sp. PCC6803 against white spot syndrome virus (WSSV) on the juveniles of Litopenaeus vannamei. Shrimp were immunized with trans-vp28 gene Synechocystis sp. PCC6803 for 10 days, followed by challenge with WSSV. The survival rate of each group of L. vannamei was then determined. We also detected the activities of phenoloxidase (PO), superoxide dismutase (SOD), catalase (CAT) and lysozyme (LYZ) in muscle and hepatopancreas at different time after immunization and after viral challenge. On the 7th day after challenge, the relative survival rate (RPS) of the experimental group (challenge, feeding mutant of Synechocystis sp. cells) was 88.42%, which was 3.47 times higher than that of the wild type group (challenge, feeding wild type of Synechocystis sp. cells), while all of the positive control group (challenge and no vaccination) died. Ten days after infection, the survival rate of experimental group was still as high as 62.5%, but the survival rate of wild type group was only 4.83%. There was no death in negative control group (neither vaccination nor challenge). The results showed that oral administration of trans-vp28 gene Synechocystis sp. PCC6803 could significantly enhance the ability of shrimp to resist WSSV. The analysis of immunological parameters after immunization showed that the activities of PO, SOD, CAT and LYZ in muscle and hepatopancreas in the experimental group were the highest, followed by the wild type group, control groups (positive and negative control group). The analysis of immunological parameters post challenge showed that the activities of the four enzymes in both tissues in the experimental group were higher than those in the wild type group and the positive control group, but the final enzyme activities of these three groups were lower than the negative control group. These results indicated that oral administration of trans-vp28 gene Synechocystis sp. PCC6803 could increase the activity of immune enzymes and enhance the defense ability of juvenile shrimp against WSSV infection.

Nutrient bioextraction using Gracilaria lemaneiformis co-cultured with Crassostrea gigas in a eutrophic, intensive mariculture area was evaluated over 49 days in Yantian Bay, which is an enclosed bay within Sansha Bay, China. The amount of nitrogen removed by G. lemaneiformis was 4.07 ± 0.25 kg and 4.49 ± 0.57 kg per ton (FW) at depths of 0.4–0.8 m and 1.0–1.2 m, respectively. The ranges of ammonium-nitrogen (NH4-N), nitrite-nitrogen (NO2-N), nitrate-nitrogen (NO3-N), and inorganic phosphate (PO4-P) reduction efficiencies in the co-cultured area were 39.22–80.34%, 4.70–26.14%, 13.42–48.84%, and 25.33–41.36%, respectively. The total wet weight of harvested G. lemaneiformis was 5.44 and 3.92 times greater than the initial mass (500 g FW/m), with highest specific growth rates (SGR) of 4.67 ± 0.21%/d and 3.44 ± 0.18%/d at 0.4–0.8 m and 1.0–1.2 m, respectively. A total of 3.11 kg of nitrogen could be removed from the co-cultured area per ton of C. gigas harvested with a total length (TL) of 80 ± 12 mm. Based on the nitrogen balance in this co-cultured system, the largest proportion of nitrogen removal from the co-cultured system was the harvest production of G. lemaneiformis (25.44%), followed by C. gigas (8.27%). The quantity of nitrogen excreted and metabolized by C. gigas was 33.40 kg, which could be entirely assimilated by the G. lemaneiformis during the experimental period. Based on these results, at least 6.76 tons of G. lemaneiformis should be co-cultured per ton of C. gigas (77–80 mm TL) to remove the nitrogen produced by C. gigas in this mariculture area. The results of this study indicate that the co-culture G. lemaneiformis with C. gigas is an environmentally-friendly mariculture method which could effectively remove surplus nutrients and reduce the environmental impact of mariculture areas.

Since 2007, the world's largest macroalgal blooms have occurred along the coastal area of the Yellow Sea for 6 consecutive years. In 2012, shipboard surveying and satellite remote sensing were used to monitor the whole blooming process. The blooms originated in Rudong sea area of the South Yellow Sea where bloom patches were of dark green and filamentous thalli were the dominant morphology. The scale of the blooms reached its peak size in Rizhao sea area of the North Yellow Sea, and decreased promptly and became insignificant in Qingdao coast where the blooms turned yellow, mostly with air sac blades. Meanwhile, vegetative cells of the green tide algae changed into cytocysts gradually from which germ cells were released as the blooms drifted northward. Additionally, chlorophyll contents and fluorescence activity of free-floating thalli in the North Yellow Sea were both significantly lower than that in the South Yellow Sea. Those studies presented here contributed to increasing our understanding about how the green tide declined gradually in the North Yellow Sea.

The world's largest trans-regional macroalgal blooms during 2008-2012 occurred in the Yellow Sea, China. This review addresses the causes, development and future challenges in this unique case. Satellite imagery and field observations showed that the macroalgal blooms in the Yellow Sea originated from the coast of Jiangsu province and that favorable geographic and oceanographic conditions brought the green macroalgae from the coast offshore. Optimal temperature, light, nutrients and wind contributed to the formation and transport of the massive bloom north into the Yellow Sea and its deposition onshore along the coast of Shandong province. Morphological and genetic evidence demonstrated that the species involved was Ulva prolifera, a fouling green commonly found growing on structures provided by facilities of Porphyra aquaculture. Large scale Porphyra aquaculture (covering >20,000 ha) along the Jiangsu coast thus hypothetically provided a nursery bed for the original biomass of U. prolifera. Porphyra growers remove U. prolifera from the mariculture rafts, and the cleaning releases about 5000 wet weight tonnes of green algae into the water column along the coast of Jiangsu province; the biomass then is dispersed by hydrographic forcing, and takes advantage of rather high nutrient supply and suitable temperatures to grow to impressive levels. Certain biological traits of U. prolifera -efficient photosynthesis, rapid growth rates, high capacity for nutrient uptake, and diverse reproductive systems- allowed growth of the original 5000 tonnes of U. prolifera biomass into more than one million tonnes of biomass in just two months. The proliferation of U. prolifera in the Yellow Sea resulted from a complex contingency of circumstances, including human activity (eutrophication by release of nutrients from wastewater, agriculture, and aquaculture), natural geographic and hydrodynamic conditions (current, wind) and the key organism's biological attributes. Better understanding of the complex biological-chemical-physical interactions in coastal ecosystems and the development of an effective integrated coastal zone management with consideration of scientific, social and political implications are critical to solving the conflicts between human activity and nature. (c) 2013 Elsevier Ltd. All rights reserved.

In this paper, species compositions and seasonal variations of attached Ulva species on Porphyra aquaculture rafts and free floating Ulva species at Rudong coastal area, Jiangsu Province of China were investigated during 2010–2011. Based on the sequences analysis of nuclear-encoded ITS (including 5.8S rDNA regions) and 5S rDNA spacer regions, dominant species of both attached and free-floating Ulva samples were identified as Ulva compressa, Ulva linza, Ulva prolifera and Ulva flexuosa. Phylogenetic tree based on sequences of ITS and 5S rDNA spacer regions for attached and free-floating Ulva species was constructed, respectively. Species compositions of the Ulva population attached on aquaculture rafts varied with seasons, and U. prolifera was only found on aquaculture rafts in March 2011 during the 2010–2011 Porphyra yezoensis cultivation season, which had the same sequences of ITS and 5S rDNA spacer regions as that of the dominant species bloomed in the Yellow Sea of China in 2008. Dominant species of the free-floating Ulva population at the early stage of the green tide were U. compressa, U. flexuosa, and U. linza. Free-floating U. prolifera appeared in the middle of May, 2011. ITS sequence similarity rates of U. compressa and U. flexuosa between the attached and free-floating species were 100%. And ITS and 5S rDNA spacer sequences of the attached and the free-floating U. prolifera population also showed no differences. Further study showed that there were two types of free-floating U. prolifera population (Type 5S-A and Type 5S-B) based on 5S rDNA spacer sequences. The present study would provide some useful information for clarifying the outbreak mechanism of green tides occurred in the Yellow Sea, China.

The red algae, Gracilaria verrucosa , was co-cultivated with the fish Pseudosciaena crocea in an integrated multi-trophic aquaculture (IMTA) system for nearly two months in summer at coastal waters of Xiangshan harbor in the East China Sea. The nutrient reduction efficiency of ammonium and phosphorus was determined. Prior to the G. verrucosa co-cultured, the eutrophication index ( E ) values of cage areas ranged from 4.2 to 32.0, indicating serious eutrophication conditions, and the high ratio of N/P and relative high P concentration indicated a nitrogen surplus. During the co-culture period, G. verrucosa showed efficiently at removing inorganic nitrogen (IN) and inorganic phosphate (IP), and maintained a more stable dissolved oxygen (DO) and chlorophyll a (Chl a ) level in the IMTA system. The maximum reduction efficiency of PO 4 –P, NO 2 –N, NH 4 –N and NO 3 –N was 58%, 48%, 61% and 47%, respectively. Based on the DIN balance in the IMTA system, the optimal co-cultivation proportion of P. crocea to G. verrucosa in this area was 1 cage, 144.95 m 2 or 1 kg, 7.27 kg, respectively. Results of the present study indicated that environmental advantage could be achieved by integrating the red alga G. verrucosa co-cultured with fish at the open coastal waters in the East China Sea.

In the summer of 2008, free-floating green algae bloomed in the Yellow Sea. Samples were collected in a wide area (119 degrees 32'-122 degrees 00'E, 32 degrees 25'-36 degrees 49'N). We calculated the sequence divergences of nuclear ITS, chloroplast rbcL, and psbA data of free-floating samples collected from the Yellow Sea and Ulvaceae from Europe and Japan. In the ITS sequence, 19 out of the 21 Yellow Sea samples of 2008 were identical to those of a sample taken at Qingdao in 2007. A low divergence (0.2%) was found in remaining two samples. Similar evidence was shown by pairwise distances of rbcL and psbA gene sequence data, implying the uniformity of the Yellow Sea blooms in 2007 and 2008. The ITS sequence of the Yellow Sea samples differed 8.1-10.8% from free-floating Enteromorpha or Ulva reported worldwide. ITS-based molecular phylogenetic results and rbcL sequence data grouped the free-floating alga in the Yellow Sea into one clade with Enteromorpha procera, Enteromorpha linza and Enteromorpha prolifera. Furthermore, both morphological characteristics and ribotype network of the ITS sequences imply that the blooming algae in 2007 and 2008 were E. prolifera. The haplotypes of the Yellow Sea free-floating E. prolifera are closely related to those from the Japanese coast but less to European and American algae. (C) 2010 Elsevier B.V. All rights reserved.

The bioremediation capability and efficiency of large-scale Porphyra cultivation in the removal of inorganic nitrogen and phosphorus from open sea area were studied. The study took place in 2002-2004, in a 300 ha nori farm along the Lusi coast, Qidong County, Jiangsu Province, China, where the valuable rhodophyte seaweed Porphyra yezoensis has been extensively cultivated. Nutrient concentrations were significantly reduced by the seaweed cultivation. During the non-cultivation period of P. yezoensis, the concentrations of NH4-N, NO2-N, NO3-N and PO4-P were 43-61, 1-3, 33-44 and 1-3 micromol L(-1), respectively. Within the Porphyra cultivation area, the average nutrient concentrations during the Porphyra cultivation season were 20.5, 1.1, 27.9 and 0.96 micromol L(-1) for NH4-N, NO2-N, NO3-N and PO4-P, respectively, significantly lower than in the non-cultivation season (p0.05). Compared with the control area, Porphyra farming resulted in the reduction of NH4-N, NO2-N, NO3-N and PO4-P by 50-94%, 42-91%, 21-38% and 42-67%, respectively. Nitrogen and phosphorus contents in dry Porphyra thalli harvested from the Lusi coast averaged 6.3% and 1.0%, respectively. There were significant monthly variations in tissue nitrogen content (p0.05) but not in tissue phosphorus content (p0.05). The highest tissue nitrogen content, 7.65% in dry wt, was found in December and the lowest value, 4.85%, in dry wt, in April. The annual biomass production of P. yezoensis was about 800 kg dry wt ha(-1) at the Lusi Coast in 2003-2004. An average of 14708.5 kg of tissue nitrogen and 2373.5 kg of tissue phosphorus in P. yezoensis biomass were harvested annually from 300 ha of cultivation from Lusi coastal water. These results indicated that Porphyra efficiently removed excess nutrient from nearshore eutrophic coastal areas. Therefore, large-scale cultivation of P. yezoensis could alleviate eutrophication in coastal waters economically.

To study the protective effect and possible mechanism of Porphyra yezoensis polysaccharide (PYP) in hepatotoxicity mice, acute liver injury was successfully induced by injecting 0.2% carbon tetrachloride (CCl(4)) intraperitoneally. Levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum and liver homogenate, content of malondialdehyde (MDA), activities of total superoxide dismutase (T-SOD) in liver were measured by biochemical methods. Liver index was calculated and pathological changes of the liver tissue were observed microscopically. PYP was found to significantly decrease the activities of ALT and AST (P

The developmental regulation of mass cultures of “free-living” conchocelis (suspension cultures) of Porphyra leucosticta from Groton, CT (USA) has been studied in laboratory culture. The conchocelis filaments were vegetatively propagated and maintained in 15 l volumes at 15 °C, 40 μmol m− 2 s− 1 and 16 L:8 D. Conchosporangia formation was induced after four weeks by increasing the temperature up to 20 °C, maintaining a photon fluence rate of 40 μmol m− 2 s− 1 and decreasing the photoperiod to 8 L:16 D. Conchosporangial filaments were vegetatively propagated and maintained at these conditions for up to 24 weeks. Suspension cultures of conchosporangial filaments were induced to form and release conchospores (after 6–10 days) by decreasing the temperature to 15 °C, increasing the photon fluence rate to 60–100 μmol m− 2 s− 1 and lengthening the photoperiod to 12 L:12 D. Conchosporangial formation was found at all photoperiods, however, the ratio of conchosporangia to vegetative conchocelis increased as the photoperiod decreased. With higher photon fluence levels, conchospore release time was decreased, whereas at a temperature of 25 °C spore germination decreased. At their peak release, the quantity of conchospores increased from 7.14 to 18.3 million per gram of conchosporangia with a decrease in conchosporangia density from 1.582 to 1.125 mg ml− 1, respectively. On the average, one gram (dw) of free conchosporangia could release about 20 million conchospores at the peak period. These released conchospores were able to attach, germinate and develop into juvenile blades on the synthetic twine (3–5 mm in diameter) of standard nori nets (1.5 × 18 m). A total of 16 standard nets and eight small nets (2.0 × 2.5 m) were seeded by fixing the culture nets over a rotary wheel in a 2.5 × 2.5 × 0.5 m− 3 tank containing the mature conchospore inoculum from the free-living conchosporangia cultures. Four seeded standard nori nets were transferred to the sea for nursery culture in Long Island Sound (USA). Conchosporeling densities from 255 to 325 conchosporelings cm− 1 were produced. After 43 days of nursery culture, the blades grew to 1.49 ± 0.14 cm in length. Our results indicate that the use of “free-living” conchocelis suspension cultures may be an effective alternative technology in the commercial production of the Porphyra.