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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. • Introduction of physical, chemical, and biological methods of green tide prevention. • Advantages and disadvantages of each method were evaluated. • Recommendations for further research on Ulva prolifera prevention provided. [ABSTRACT FROM AUTHOR]

Phycoerythrin and phycocyanin were purified from Porphyra yezoensis Ueda with their bioactivity determined in this study. Continuous precipitation with ammonium sulfate at different concentrations (10%, 20%, 40% and 50%) increased the purity (A:A) of phycoerythrin to 1.49, 3.92 fold of the raw extract (0.38) and the purity (A:A) of phycocyanin to 0.70, 3.33 fold of the raw extract (0.21). Two more times of chromatography with hydroxylapatites finally made the purity of phycoerythrin and phycocyanin reach 5.50, 14.47 fold of the raw extract, and 5.10, 24.29 fold of the raw extract, respectviely. The yield of high purity phycoerythrin and phycocyanin were 0.21% and 0.09% of dried P. yezoensis blade, respectively. The photodynamic cytotoxic experiment showed that both phycoerythrin and phycocyanin inhibited the growth of liver tumor cells significantly. It was found that 250 mg L purified phycoerythrin and phycocyanin inhibited the growth of hepatocellular carcinoma cells 24 h after laser-irradiation by 80% and 59%, respectively, and 100 mg L purified phycoerythrin and phycocyanin induced the apoptosis of 31.54% and 32.54% of the cells, respectively, 8 h after photodynamic therapy. Oue findings demonstrated that P. yezoensis can serve as photosensitizer (phycoerythrin and phycocyanin) producer. [ABSTRACT FROM AUTHOR]

As global ecological disasters, green tide outbreaks have been observed in the Southern Yellow Sea (SYS) of China since 2007, resulting in considerable economic losses and environmental damage to the coastal cities of Jiangsu and Shandong Provinces. Therefore, prevention of green tides is crucial. Previous studies have revealed that a relatively small green tide outbreak scale in the SYS was observed in 2018 and 2020, with the green tides covering areas of 193 km2 and 192 km2 and durations of 91 days and 64 days, respectively. Killing green macroalgae attached to cultivation ropes in Neopyropia aquaculture areas, which has been considered a primary source of the blooms, early removal of Neopyropia aquaculture rafts, and green tide prevention in the SYS are the key reasons for the decrease in green tides in 2018 and 2020. Furthermore, to address the challenges associated with the current green tide source prevention measures, we proposed a comprehensive control method that combines ecological farming, early green tide prevention, and resource utilization. Potential secondary pollution caused by the chemicals used to control Ulva prolifera can be minimized. Conversely, Neopyropia yezoensis quality may be enhanced through continuous improvement of its culturing process, which in turn, could reduce the green tide blooming scale. [Display omitted] • Introducing the source prevention measures of green tides in the Southern Yellow Sea • The green tide prevention strategies are effective in 2018 and 2020. • Preliminary analysis of the reasons for the large scale of green tides in 2021 • Providing suggestions for further research on green tide prevention [ABSTRACT FROM AUTHOR]

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−1. Also, the inhibitory effects of dried N. yezoensis toward U. prolifera gametes at 2.4 and 4.8 g DW−1 were >90% at day 21. N. yezoensis culture filtrates and thalli were also used to determine dose-dependent inhibition effects on U. prolifera gamete germination. Both were potent and significantly inhibited germination at 1.75–7 g FW−1; the inhibitory effect 7 g FW−1 was >90% at day 21. As N. yezoensis thalli exhibited high inhibitory effects in laboratory experiments, we also performed field studies. N. yezoensis on ropes displayed high inhibitory effects on Ulva attachment and growth. Thus N. yezoensis powder, culture filtrates, and thalli displayed strong inhibitory effects on U. prolifera gametes, suggesting N. yezoensis attachment to ropes could be used to control green tides at the source. • Neopyropia yezoensis can inhibit the attachment and growth of Ulva zoids. • N. yezoensis thalli can inhibit the rapid growth of Ulva prolifera seedlings. • Cultivation of N. yezoensis on the ropes is a good method to control green tides at the source. [ABSTRACT FROM AUTHOR]

Porphyra yezoensis is one of the most important and widely cultured seaweeds in China. Phycobiliproteins exhibit excellent spectroscopic properties and play versatile roles in the biomedical, food, cosmetics and chemical synthetic dye industries. Here, the purification and crystallization of phycoerythrin and phycocyanin, two phycobiliproteins extracted from P. yezoensis, are described. Using a novel protocol including co-precipitation with ammonium sulfate and hydroxyapatite column chromatography, both phycobiliproteins were produced on a large scale with improved quality and yield compared with those previously reported. Native PAGE analysis indicated that phycoerythrin and phycocyanin exist as (αβ)3 heterohexamers in solution. The crystals of phycoerythrin diffracted to 2.07 Å resolution and belonged to space group R3. The unit-cell parameters referred to hexagonal axes are a = b = 187.7, c = 59.7 Å, with nine (αβ)2 heterotetramers per unit cell. The crystals of phycocyanin diffracted to 2.70 Å resolution in space group P21. Matthews coefficient analysis shows that 10-19 (αβ) heterodimers of phycocyanin in the asymmetric unit would be reasonable. A self-rotation function calculation clarified this ambiguity and indicated that 12 (αβ) heterodimers of phycocyanin are assembled in the asymmetric unit. [ABSTRACT FROM AUTHOR]

Using a large-scale enclosed sea area in northern Hangzhou Bay as a case study, the trophic interactions, energy flows, and ecosystem properties of a coastal artificial ecosystem were analyzed by ecotrophic modeling using Ecopath with Ecosim software (EwE, 5.1 version). The model consists of 13 functional groups: piscivorous fish, benthic-feeding fish, zooplanktivorous fish, herbivorous fish, crabs, shrimp, mollusca, infauna, carnivorous zooplankton, herbivorous zooplankton, macrophytes, phytoplankton, and detritus. Input information for the model was gathered from published and unpublished reports and from our own estimates during the period 2006-2007. Results show that the food web in the enclosed sea area was dominated by a detritus pathway. The trophic levels of the groups varied from 1.00 for primary producers and detritus to 3.90 for piscivorous fish in the coastal artificial system. Using network analysis, the system network was mapped into a linear food chain, and five discrete trophic levels were found with a mean transfer efficiency of 9.8% from detritus and 9.4% from primary producer within the ecosystem. The geometric mean of the trophic transfer efficiencies was 9.6%. Detritus contributed 57% of the total energy flux, and the other 43% came from primary producers. The ecosystem maturity indices-total primary production/total respiration, Finn's cycling index, and ascendancy-were 2.56, 25.0%, and 31.0%, respectively, showing that the coastal artificial system is at developmental stage according to Odum's theory of ecosystem development. Generally, this is the first trophic model of a large-scale artificial sea enclosure in China and provides some useful insights into the structure and functioning of the system. [ABSTRACT FROM AUTHOR]

Green macroalgal blooms caused by Ulva species have influenced the Shandong Province for 15 consecutive years since 2007, leading to serious damage to the marine environment. Great biomasses of attached Ulva prolifera on Neopyropia aquaculture rafts in the Yellow Sea were considered as sources of blooms. However, it is still unclear whether U. prolifera could survive and settle in the Qingdao coastal environment, Shandong, thus leading to local Ulva blooms in the future. In this research, sampling of Ulva macroalgae in seven Portunus trituberculatus aquaculture ponds along the coast of Qingdao was conducted on August 21, 2019. In total, 24 samples collected from the ponds were analyzed through methods of molecular biological identification (ITS, 5S, and rps2- trn L sequences) and genetic analysis. All the aquaculture ponds contained large amounts of floating Ulva macroalgae, which consisted of three species: U. prolifera , Ulva meridionalis , and Ulva pertusa. Among these species, U. meridionalis , which is usually found in southern Japan, also causes the green tide. In addition, all Ulva macroalgae floated on the surfaces of aquaculture ponds, and were discarded into the local coastal area by aquaculturist. This research raised our awareness of the importance of controlling the spread of the green tide related macroalgae. • Ulva macroalgae within Portunus trituberculatus aquaculture ponds in Qingdao were studied. • Sequences called ITS, 5S and rps2- trn L were amplified by DNA barcoding. • All ponds contained large amount of free-floating macroalgae called Ulva prolifera , Ulva meridionalis , and Ulva pertusa. • U. meridionalis was usually found in southern Japan, it has now appeared within ponds in Qingdao, China. [ABSTRACT FROM AUTHOR]

Simple Summary: The environment within which human beings exist is progressively becoming more complex. A multitude of external factors prompt the body to produce excessive amounts of reactive oxygen species (ROS), thereby leading to heightened levels of oxidative stress, which is detrimental to health. In recent years, researchers have discerned the potential of secondary metabolites derived from brown algae in combating diseases. Additionally, Sargassum horneri has witnessed a large-scale outbreak in China, exerting a severe negative influence on the local ecology and economic development. We extracted polysaccharides (SHPs) from S. horneri and discovered that SHPs possess outstanding antioxidant properties and can be utilized as a natural antioxidant. Our work can alleviate the environmental stress caused by algae and achieve the utilization of algae resources, which hold considerable social value and significance. The extensive outbreak of Sargassum horneri in China has not merely imposed a severe threat to the ecological environment and human life in coastal waters but also impeded the development of waterway transportation and the local economy. Consequently, we isolated polysaccharides from S. horneri, designated as SHP, and evaluated the antioxidant activity of SHP both in vitro and in vivo by investigating the effect of SHP on H2O2-induced African green monkey kidney cells (Vero cells) and zebrafish. The results demonstrated that SHP can enhance the activities of superoxide dismutase, catalase, and glutathione peroxidase in zebrafish. It also effectively inhibits micro malondialdehyde and ROS levels in Vero cells and zebrafish to mitigate the oxidative damage caused by H2O2, thereby achieving the protective effect of SHP on Vero cells and zebrafish. In conclusion, SHP holds the potential as a natural antioxidant. SHP can be contemplated for utilization as a natural antioxidant in the biomedical, cosmetic, and food industries, thereby alleviating the environmental stress caused by S. horneri and achieving resource utilization. [ABSTRACT FROM AUTHOR]

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. • Golden tides in the Yellow and East China Sea were all identified as S. horneri. • S. horneri showed slight different morphological characters from different habitats. • The attached S. horneri from East China Sea were the main source of golden tides. [ABSTRACT FROM AUTHOR]

Aims: Greenhouses are widely used in agriculture systems to shield crops from unfavourable weather to achieve a year‐round food supply. In recent years, aquaculture ponds have been placed in greenhouses in many regions. The impacts of the greenhouses on planktonic bacterial communities should be uncovered. Methods and Results: In this study, two polyolefin film greenhouses accommodating aquaculture ponds were established and planktonic bacterial communities were compared from samples taken in aquaculture ponds inside and outside the greenhouses, using Illumina 16S rRNA sequencing. Conclusions: The results showed there were significant variations in bacterial community structure between indoor and outdoor samples. Obvious differences were also found between two greenhouses, whereas the differences in indoor samples were weaker than outdoor samples. Significantly higher temperature (in summer), pH and permanganate index were found in the outdoor pond samples. Results of redundancy analysis showed that Proteobacteria and Bacteroidota were positively related to the dissolved oxygen, total nitrogen and total phosphorus, and Actinobacteriota were positively related to pH, temperature and permanganate index, whereas Cyanobacteria were positively related to the salinity, conductivity, total dissolved solids and ammonia nitrogen. Significance and Impact of the Study: The results of this study revealed that greenhouses significantly influenced planktonic bacterial communities in aquaculture ponds. This study is expected to provide a scientific basis for aquaculture in greenhouses. [ABSTRACT FROM AUTHOR]

Background: Ecological restoration of coastal wetlands has become particularly urgent worldwide as wetland areas have declined dramatically over the past two decades. Aims: To understand the nitrogen allocation strategy of Scirpus mariqueter (S. mariqueter) and provide theory support for future wetland management and restoration. Methods: The study investigated the response mechanism of S. mariqueter to altitude spatial changes in Nanhui Dongtan from 2017 to 2019 using remote sensing imagery and field surveys. The ecological adaptability of S. mariqueter at different elevations (denoted as A, B, and C for elevations 2.40, 3.15, and 3.49 m, respectively) was analyzed through 15N stable isotope tracing technology. In July and September 2020, 15N‐enriched urea solution was uniformly sprayed onto the leaf surfaces of S. mariqueter at different sites. Plant samples were collected at the end of July and September, and the aboveground, belowground, seed, and rhizome biomass were measured, followed by 15N isotope tests. Results: (1) From 2017 to 2019, the biomass of S. mariqueter significantly increased in the elevation change of 0.44–0.48 m, with the maximum aboveground biomass increase of 488.70 g dm−2. The density also increased significantly in the elevation change of 0.13–0.43 m, peaking at 674.02 plants m−2; (2) during the growing period, the biomass of A, B, and C increased. The aboveground portion of the 15N allocation rate accounted for 74%–84%. The belowground portion of the 15N allocation rate positively correlated with elevation; (3) during the reproductive period, elevation positively correlated with the 15N distribution rate of seeds and corms, as well as the biomass allocation rate of seeds and aboveground portions. The 15N allocation rate of the corms was higher than that of seeds. Additionally, elevation exhibited a negative correlation with belowground biomass allocation rate. (4) Point A has the highest difference of above and belowground biomass proportion, and 15N isotope allocation. Area of point A is the critical area affecting vegetation expansion and should be paid more attention in the future work of coastal management and restoration. Conclusion: There is an adaption strategy of S. mariqueter that affects the plant‐soil interaction and the biogeomorphological development process along the elevation gradient. [ABSTRACT FROM AUTHOR]

Simple Summary: The spread of large green algae in oceans causes green tides, particularly in the South Yellow Sea of China, where Ulva prolifera has led to the world's largest green tide events. This review looks at how allelopathy, a process where plants release chemicals to affect the growth and development of other plants, influences green tide dynamics. We focus on four main types of these allelochemicals—fatty acids, aldehydes, phenols, and terpenes—explaining how they influence the algae's growth and behavior. We also discuss new methods for quickly detecting these allelochemicals and how these methods can help monitor green tides. By combining allelochemical detection with advanced technologies like satellite observations and environmental DNA analysis, we can better understand and manage green tides. The proliferation of large green macroalgae in marine environments has led to the occurrence of green tides, particularly in the South Yellow Sea region of China, where Ulva prolifera has been identified as the primary species responsible for the world's largest green tide events. Allelopathy among plants is a critical factor influencing the dynamics of green tides. This review synthesizes previous research on allelopathic interactions within green tides, categorizing four extensively studied allelochemicals: fatty acids, aldehydes, phenols, and terpenes. The mechanisms by which these compounds regulate the physiological processes of green tide algae are examined in depth. Additionally, recent advancements in the rapid detection of allelochemicals are summarized, and their potential applications in monitoring green tide events are discussed. The integration of advanced monitoring technologies, such as satellite observation and environmental DNA (eDNA) analysis, with allelopathic substance detection is also explored. This combined approach addresses gaps in understanding the dynamic processes of green tide formation and provides a more comprehensive insight into the mechanisms driving these phenomena. The findings and new perspectives presented in this review aim to offer valuable insights and inspiration for researchers and policymakers. [ABSTRACT FROM AUTHOR]

Different populations of the same species may have different physiological responses to environmental factors due to the adaptation to their environment. We tested interactive effects of temperatures (10,15, 20, 25, and 30 ℃) and nutrients (low nutrients: 5 μM NO3− and 0.5 μM PO4− (LN); medium nutrients: 50 μM NO3− and 5 μM PO4− (MN); high nutrients: 500 μM NO3− and 50 μM PO4− (HN)) in three different Ulva prolifera strains (one Chinese and two Korean strains). The results showed that all three strains of Ulva survived within the temperature range of 10 to 30 ℃. The photosynthetic rates of all strains increased with increasing temperature from 10 to 30 ℃ under MN. However, at the higher temperature (30 ℃) there was a significant reduction in the photosynthetic rate under HN in all three strains. A positive relationships between tissue nitrogen (N) and chlorophyll or soluble protein were observed in all three strains. The Chinese strain showed the lowest C:N ratio but the highest photosynthetic rate and tissue N contents. Our results show that the bloom forming Chinese strain may have higher nutrient uptake and assimilation ability, leading to higher photosynthetic activity. The Ulva strains may have lower tolerance to higher temperature at high nutrients conditions. These results suggest that the physiological responses of U. prolifera to different temperature and nutrients conditions can be population-specific. [ABSTRACT FROM AUTHOR]

In order to promote the management and protection of urban water bodies, a survey of large benthic invertebrate communities was carried out on 23 river sections in Suzhou. On this basis, the core indicators suitable for urban water ecological health assessment were selected by analyzing the distribution range, discrimination ability and correlation of the candidate indicators. The ratio method was used to calculate the core index values, and the macrobenthic invertebrate biological integrity index value (Benthic Macroinvertebrate Index of Biotic Integrity, BIBI value) were obtained by accumulating and summing. The results show that 22 species of macrobenthic invertebrates were found in the Suzhou urban water and reference points, belonging to 3 phyla, 6 classes, 9 orders and 14 families. After screening, the BIBI that was suitable for evaluation of Suzhou was composed of the following 6 indicators: the total number of taxons, the number of arthropod taxa, the Shannon-Wiener diversity index, the percentage of widespread species, the percentage of individuals in the class of insects, and the percentage of individuals in pollution-tolerant groups. The optimal expected value of the calculated BIBI value is 4.01, even the BIBI value ≥ 4.01 is healthy, 3.01-4.01 is good, 2.01-3.01 is fair, 1.01-2.01 is poor, and <1.01 is extremely poor(the interval range is left closed and right open, and BIBI value ≥ 0). According to the results of BIBI, the ecological health of the water in Suzhou was uneven. There were more fair and good sites than healthy ; the health status of each point in different seasons is different. The correlation analysis between BIBI and various water quality factors proves that BIBI can be used to evaluate the ecological health of urban water and has scientific guiding significance for the evaluation of urban water ecological health. [ABSTRACT FROM AUTHOR]

The red macroalga Pyropia/ Porphyra is one of the most important marine crops in the world; Pyropia cultivation is severely affected by the green macroalga Ulva spp., a fouling organism. In this study, growth competition and acquisition of dissolved inorganic carbon (Ci) by Ulva prolifera and Pyropia yezoensis were investigated to understand the physiological characteristics of the two species. Competition experimental results showed that the relative growth rate of U. prolifera was not affected, whereas the growth rate of P. yezoensis was significantly inhibited. U. prolifera exhibited a competitive advantage when these two species were cultured together. The two algal species displayed high pH compensation points, suggesting that U. prolifera and P. yezoensis can photosynthesize by using HCO; the utilization ability of U. prolifera is stronger than that of P. yezoensis. The net photosynthetic rates of P. yezoensis and U. prolifera were significantly inhibited by the carbonic anhydrase (CA) inhibitors acetazolamide and 6-ethoxyzolamide indicating that CA is implicated in carbon-concentrating mechanisms (CCM). 4,4′-diisothiocyano-stilbene-2,2′-disulfonate (DIDS), another inhibitor that prevents direct HCO uptake, did not significantly affect U. prolifera. Conversely, DIDS can sharply decrease the photosynthetic rate of P. yezoensis, particularly at high pH. U. prolifera and P. yezoensis also showed CO-limited photosynthesis by which the half-saturating concentration of Ci exceeds that of seawater. U. prolifera did not show active HCO uptake; instead, U. prolifera used HCO via extracellular CA for photosynthetic carbon fixation. U. prolifera also utilizes extracellular CA-mediated HCO absorption to a higher extent than P. yezoensis. By contrast, P. yezoensis shows active HCO uptake and extracellular CCMs for photosynthetic carbon fixation. Therefore, these two algal species can survive in changing environments with high pH and low Ci concentration because of the action of CCMs. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

• The regulation was most active within 24 h of carbon restriction. • There are characteristics of both biophysical and biochemical CO 2 concentrating mechanisms in U. prolifera. • After inorganic carbon restriction for 24 h, the biophysical CO 2 concentration mechanism is more effective. Ulva prolifera is a dominant species in green tides and has been affecting marine ecosystem for many years. Due to the low availability of CO 2 in the environment, U. prolifera utilizes the CO 2 concentrating mechanisms (CCMs) to increase intracellular inorganic carbon concentration. However, the transcriptional response mechanism and temporal changes of U. prolifera CCMs based on transcriptomics have not been thoroughly described. Therefore, we induced U. prolifera CCMs in a low CO 2 environment to explore the dynamic regulation of CCMs expression under inadequate inorganic carbon supply. The results showed that inorganic carbon limitation increased the inorganic carbon affinity of U. prolifera , upregulating CCMs. The first 24 h of inorganic carbon environmental changes were the most active period for U. prolifera 's expression regulation. U. prolifera gradually achieved a new steady state by regulating metabolic processes such as nucleic acids, energy, and ethylene-activated signaling pathways. In the carbon fixation system of U. prolifera , there are characteristics of both biophysical and biochemical CCMs. After 24 h of inorganic carbon limitation, the biophysical CCMs becomes more effective under conditions of inorganic carbon depletion. This study aids in exploring the CCMs of U. prolifera and their evolution in response to environmental changes. [Display omitted] [ABSTRACT FROM AUTHOR]

Over the past 18 years, green tides have persistently occurred in the Yellow Sea. Micropropagules of these algae are key to bloom formation, yet their species composition and succession during dissipation remain underexplored. During the dissipation process of accumulated green tide algae, a large number of micropropagules are released. This study monitored the dissipation of green tide algae at a coastal site, tracking micropropagules in water and sediment using an internal transcribed spacer (ITS) and 5S rDNA primers. Results showed that the dissipation lasted about one month, with significant micropropagule release. Initially, micropropagules matched 5S-II Ulva prolifera , but later species like Ulva torta , Ulva simplex , Ulva flexuosa , and Ulva meridionalis emerged. Ulva meridionalis dominated sediment in July and August, while U. torta was prevalent in water, and U. flexuosa was dominant in other months. Accumulated U. prolifera in the intertidal zone may not contribute to the seeding of the next year's bloom. This study sheds light on the dissipation process and succession patterns of micropropagules in coastal environments. [Display omitted] • Green macroalgae naturally dissipate in intertidal zones in about a month. • During green tide dissipation, many Ulva micropropagules are released. • Micropropule species in water and sediment differ slightly. • Accumulated Ulva prolifera in the intertidal zone may not seed the next year's bloom. [ABSTRACT FROM AUTHOR]

In recent years, the rapid development of the large-scale aquaculture industry has generated substantial economic benefits, positioning it as one of the fastest-growing sectors in global agricultural production. However, improper management practices in aquaculture, including overfeeding, improper feed selection, antibiotic misuse, high stocking densities, inappropriate choice of aquaculture species, and improper discharge of aquaculture wastewater, have resulted in significant watershed pollution in agriculture and the wastage of valuable resources. To address these challenges, extensive research and application of wastewater treatment technologies have been conducted in large-scale aquaculture in China. This review provides an overview of current cases and applications of wastewater treatment in large-scale aquaculture in China, focusing on four common intensive wastewater treatment methods: constructed wetland treatment model, ecological ditch treatment model, Integrated Multi-trophic Aquaculture model, and recirculating aquaculture model. The constructed wetlands utilize plants and microorganisms to purify both organic and inorganic pollutants in water, while ecological ditches employ engineering measures such as sedimentation ponds, interception ditches, and aeration devices to achieve wastewater treatment. Additionally, other aquaculture models are highlighted, such as Integrated Multitrophic Aquaculture (IMTA), which emphasizes synergistic interactions between aquaculture species and the recycling of nutrients, and the Recirculating Aquaculture Systems (RAS), which utilize water circulation and treatment equipment for wastewater treatment. The consequences and benefits of these systems in pollution reduction are described. These treatment technologies have made significant progress, offering theoretical guidance for environmentally friendly aquaculture production and the maintenance of ecological stability in aquaculture water bodies. Each wastewater treatment model has a different function, target, and methodology. Finally, this paper proposes directions and recommendations for future pollution management in large-scale aquaculture in China, including strengthening technological research and development, the combined application of multiple treatment models, promoting industry collaboration, and achieving resource sharing. These efforts will contribute to further promoting the sustainable development of China's aquaculture industry and provide valuable experiences and references for other countries and regions. • CWs and ecological ditch use plants and microorganisms to purify wastewater. • IMTA maximizes species interactions for efficient nutrient cycling. • RAS uses equipment to remove pollutants from aquaculture water for recirculation. • Utilizing multiple purification modes can enhance wastewater treatment efficiency. [ABSTRACT FROM AUTHOR]

Simple Summary: High light stress is one of the main factors affecting the normal growth of Ulva prolifera. The response mechanism of U. prolifera to 12 h of high light stress was explored by the multi-omics method. We found that short-term high light could inhibit the assimilation process of U. prolifera, destroy the cellular structure, and inhibit respiration. Moreover, it was raised by the genes associated with photosynthetic pigment synthesis, optical system I, and electronic transport, and may be able to make up the ATP defects by circulating electronic transport. At the same time, it reduced NADPH production by attenuating photosystem II synthesis. The carbon fixed approach was also transformed from the C3 pathway to the C4 pathway. Revealing the response mechanism of U. prolifera to high light can provide a more theoretical basis for studying the outbreak of green tide of U. prolifera in the Yellow Sea. The main algal species of Ulva prolifera green tide in the coastal areas of China are four species, but after reaching the coast of Qingdao, U. prolifera becomes the dominant species, where the light intensity is one of the most important influencing factors. In order to explore the effects of short-term high light stress on the internal molecular level of cells and its coping mechanism, the transcriptome, proteome, metabolome, and lipid data of U. prolifera were collected. The algae were cultivated in high light environment conditions (400 μmol·m−2·s−1) for 12 h and measured, and the data with greater relative difference (p < 0.05) were selected, then analyzed with the KEGG pathway. The results showed that the high light stress inhibited the assimilation of U. prolifera, destroyed the cell structure, and arrested its growth and development. Cells entered the emergency defense state, the TCA cycle was weakened, and the energy consumption processes such as DNA activation, RNA transcription, protein synthesis and degradation, and lipid alienation were inhibited. A gradual increase in the proportion of the C4 pathway was recorded. This study showed that U. prolifera can reduce the reactive oxygen species produced by high light stress, inhibit respiration, and reduce the generation of NADPH. At the same time, the C3 pathway began to change to the C4 pathway which consumed more energy. Moreover, this research provides the basis for the study of algae coping with high light stress. [ABSTRACT FROM AUTHOR]

Litopenaeus vannamei is the most important shrimp species throughout the world. However, diseases are increasing with the development of the industry, so enhancing the immunity of shrimp is of great significance. In this study, 1800 shrimp were divided into two groups randomly: the control group (N, feed with brine shrimp flake) and the experimental group (M, feed with mutant of Synechocystis sp. cells) (300 shrimp/group/replication) and each trial was conducted in triplicates. After immunization, sixty shrimp (with three replicates of twenty) were collected at 0 h in group N and 24, 72, and 144 h in group M, respectively, and the hepatopancreas were isolated for transcriptomic and metabolomic analysis. Transcriptome data revealed that compared with group N, genes related to antimicrobial peptides, cytoskeleton remodeling, detoxification, apoptosis, blood coagulation, immune defense, and antioxidant systems were differentially expressed in group M. In addition, combined transcriptomic and metabolomic analysis revealed that some immune-related differential genes or differential metabolites were consistently expressed in both omics. All the above results indicated that trans- vp28 gene Synechocystis sp. PCC6803 could improve the immunity of L. vannamei. This is the first report of the integration of dynamic transcriptomics combined with metabolomics to study the effect of trans- vp28 gene Synechocystis sp. PCC6803 in the hepatopancreas of L. vannamei and provided important information about the defense and immune mechanisms used by invertebrates against pathogens. • It's the first study of the integration of transcriptomics combined with metabolomics in shrimp immunized by Synechocystis sp.. • The immune-related DEGs were up-regulated in transcriptomics. • Some immune-related differential genes or differential metabolites were consistently expressed across transcriptomics and metabolomics. • Several immune-related signaling pathways were consistently enriched in transcriptomics and metabolomics. [ABSTRACT FROM AUTHOR]

Watershed and catchment area-based water quality management are important methods for comprehensive management of rivers and lakes. The impacts of land use/land cover (LULC) on river water quality vary with spatial scales, such as watersheds, catchments, and riparian zones. Achieving an effective spatial scale relationship between LULC and water quality, determining priority management areas, and reaching sustainable development of large estuarine deltas remain problematic. In this study, buffering analysis on the water quality data of the Yangtze River Estuary from 2009 to 2018 was conducted based on LULC, and the priority management areas of the basin were identified. Also, we infer that future river restoration or management efforts should focus on priority management area construction of a 1500 m riparian zone and a 150 km reach zone. Conclusively, establishing a priority management area within the effective buffer zone is key to watershed water quality management. [ABSTRACT FROM AUTHOR]

Green tide is a harmful algal bloom formed by the accumulation and floating of large amounts of green algae that have been present continuously in the southern Yellow Sea for 17 years, causing serious damage to the economy and ecological environment of coastal cities. Control measures effectively reduced the scale of the green tide outbreak in 2022, which was the smallest in history since 2008. This review provides a comprehensive overview of the development process, prevention and control measures, and future recommendations related to the Yellow Sea green tide in 2022. The 2022 green tide drifted in a south to north direction, reaching the maximum coverage area of 135 km2 on June 25 and the maximum distribution area of 18,002 km2 on July 1. Various tools were used to monitor the event; the combination of extensive front-end salvage and source control was applied for the first time. In the future, eradicating the green tide requires addressing seawater eutrophication. The amalgamation of source control, along with front-end salvage, should be considered as an emergency measure rather than a comprehensive solution. This review aims to serve as a valuable reference for the future management of green tide in the Yellow Sea and other regions. [Display omitted] • The maximum coverage area of green tide in the southern Yellow Sea in 2022 was 135 km2. • Various tools were used to monitor the green tide in the southern Yellow Sea. • The combination of front-end salvage and source control was applied for the first time. [ABSTRACT FROM AUTHOR]

The Neopyropia aquaculture area located in Subei Shoal has garnered considerable attention due to the green tide in the Yellow Sea. Acid treatment is widely used in Neopyropia culture, both in the seedling and mature stages. In light of this, we propose the implementation of acid treatment technology in the Neopyropia aquaculture area within Subei Shoal, with the primary aim of mitigating the proliferation of green macroalgae on the rafts. This, in turn, is anticipated to elevate the yield and overall quality of Neopyropia. In this paper, we provide a comprehensive overview of the application of acid treatment technology in Neopyropia aquaculture, elucidating the key acid solutions used and the underlying mechanisms governing acid treatment. Furthermore, we delve into early prevention strategies for countering the green tide within the Neopyropia aquaculture region of northern Jiangsu Province, ultimately striving to augment the quality of Neopyropia cultivation and propose effective measures for curtailing the scale of green tide. [Display omitted] • Introducing the acid treatment in the Neopyropia aquaculture. • Introducing the damage mechanism of acid solution to green macroalgae. • Providing suggestions for further research on green tide prevention. • Acid treatment will not have harmful effects on marine environment. [ABSTRACT FROM AUTHOR]

We conducted continuous monitoring at 13 stations along the Jiangsu coast to study the spatiotemporal distribution, population succession of micropropagules of green algae, and their impact on the outbreak of Southern Yellow Sea green tide. The study discovered that: 1) Green algae micropropagules had obvious temporal and spatial distribution and population changes along the Jiangsu coast. The monthly average abundance of micropropagules of green algae at station BH1, which was the high-value area, was 1230 inds/L. Station XS2 had the second-highest value area. Green algae micropropagules had an average monthly abundance of 836 inds/L. Between stations XS2 and BH1, the amount of green algae micropropagules steadily declined in comparison to other stations. The abundance was greatest from spring to early summer, and Ulva prolifera micropropagules predominated; 2) Compared with salinity, temperature had a more obvious effect on the micropropagules of green algae along the Jiangsu coast; 3) Green algae micropropagules on the Jiangsu coast could be a potential additional source on the outbreak of Southern Yellow Sea green tide. More data are needed to corroborate this conclusion. For the purpose of preventing and managing green tide, it is crucial to investigate the Southern Yellow Sea's potential supplementary source. This study analyzes the spatiotemporal distribution and population changes of green algae micropropagules along the Jiangsu coast, as well as their impact on green tide outbreaks, providing scientific data support for the prevention and control of green tides in the Southern Yellow Sea. • Analysis of spatial and temporal distribution and population composition of green algae micropropagules along the coast of Jiangsu. • The temperature has an important effect on the distribution of micropropagules of green algae along the Jiangsu coast. • Green algae micropropagules along the Jiangsu coast have little impact on the green tide in the Southern Yellow Sea. [ABSTRACT FROM AUTHOR]

Abstract: 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. [Copyright &y& Elsevier]

Ulva spp. have outstanding survivability in copper-rich environments, but research into the interactions between these algae and copper is required. This study combined transcriptomics, proteomics, and metabolomics to investigate the expression of various metabolites in Ulva prolifera after exposure to 10 mg L−1 of copper sulfate for 12 h. The results showed that copper stress in U. prolifera mainly manifested as a reduction in transcription and translation, which was related to gene expression, protein activity, and metabolite content in cell division and energy metabolism. However, the resistance, signal transduction, and metabolism of U. prolifera were enhanced to respond actively to acute copper stress in many aspects. These findings demonstrate the impact of 12 h of 10 mg L−1 copper sulfate exposure on U. prolifera. [ABSTRACT FROM AUTHOR]

• Microcystis significantly impacts survival and reproduction in Moina mongolica. • 572 DEGs were detected in M. mongolica exposed to Microcystis aeruginosa. • The change of metabolism are the major molecular events triggered by microcystis. • The findings greatly advances cyanobacterial bloom ecotoxicology research. To investigate the detrimental impacts of cyanobacterial bloom, specifically Microcystis aeruginosa , on brackish water ecosystems, the study used Moina mongolica , a cladoceran species, as the test organism. In a chronic toxicology experiment, the survival and reproductive rates of M. mongolica were assessed under M. aeruginosa stress. It was observed that the survival rate of M. mongolica fed with M. aeruginosa significantly decreased with time and their reproduction rate dropped to zero, while the control group remained maintained stable and normal reproduction. To further explore the underlying molecular mechanisms of the effects of M. aeruginosa on M. mongolica , we conducted a transcriptomic analysis on newly hatched M. mongolica cultured under different food conditions for 24 h. The results revealed significant expression differences in 572 genes, with 233 genes significantly up-regulated and 339 genes significantly down-regulated. Functional analysis of these differentially expressed genes identified six categories of physiological functional changes, including nutrition and metabolism, oxidative phosphorylation, neuroimmunology, cuticle and molting, reproduction, and programmed cell death. Based on these findings, we outlined the basic mechanisms of microcystin toxicity. The discovery provides critical insights into the mechanisms of Microcystis toxicity on organisms and explores the response mechanisms of cladocerans under the stress of Microcystis. [Display omitted] [ABSTRACT FROM AUTHOR]

The ecological fabric of coastal zones is intricately linked to the vitality of seagrass meadows, with Zostera caespitosa serving as a foundational species. Integral to biodiversity conservation and the carbon cycle, these ecosystems are facing unprecedented thermal stress due to global warming. Our research delves into the temperature-dependent physiological responses of Z. caespitosa , focusing on growth rates, photosynthetic activity, and nutrient uptake dynamics across varying thermal regimes. We pinpoint an optimal temperature window of 10–20 °C for these critical physiological processes. These findings not only chart a course for the protective measures of seagrass beds but also furnish pivotal data for predictive models assessing the resilience of these ecosystems under climatic fluctuations. The insights gained offer a strategic advantage for the restoration and stewardship of seagrass habitats, informing climate change mitigation strategies, biodiversity preservation, and the sustained provision of ecosystem services along coastal frontiers. This research, by bridging gaps in our ecological understanding, underscores the imperative of nuanced ecosystem management in an era of changing global temperatures. • Critical temperatures impacting Z. caespitosa's photosynthetic physiology and nutrient absorption kinetics are pinpointed. • An optimal temperature range of 10-20 °C was identified for Z. caespitosa 's critical physiological processes. • Elevated temperatures between 25-35 °C led to the degradation or death of Z. caespitosa. • A low temperature range utilized found in this study contributes to extending the survival of Z. caespitosa. • These findings fill a research gap by emphasizing Z. caespitosa's sensitivity to temperature changes. [ABSTRACT FROM AUTHOR]

Due to the rising atmospheric p CO 2 , the greenhouse effect in the natural environment has intensified, leading to ocean acidification and frequently extreme temperature events. Limited research has been conducted on the effects of near-shore temperature fluctuations and ocean acidification on macroalgae. In this study, Neopyropia yezoensis (Bangiales, Rhodophyta) was cultured under two CO 2 concentrations (LC: 400 μatm and HC: 1000 μatm) and three temperature conditions (10 ℃, 14 ℃, and fluctuation: increased from 10 ℃ to 14 ℃ and then decreased back to 10 ℃ with a fluctuation of 1 ℃ per day). The growth, chlorophyll fluorescence, photosynthetic pigments, and soluble carbohydrate of N. yezoensis were measured. The results showed that the relative growth rate, rETR max , contents of chlorophyll a , phycoerythrin, and carotenoid in the thalli increased at 14 ℃ and thermal fluctuation, while the content of soluble carbohydrate were inhibited. Moreover, the effect of p CO 2 on growth was significant only under temperature fluctuation. Even when the temperature dropped to 10 ℃, the physiological responses of N. yezoensis were still promoted by the thermal fluctuation condition. These findings indicate that the yield and quality of N. yezoensis could potentially improve in the future warming scenarios, and changes observed in N. yezoensis could serve as an early indicator for global climate change. • The growth and pigment contents of Neopyropia. yezoensis improved by the increase of temperature and CO 2. • When the temperature dropped, the growth and pigment of thalli were still promoted by the short-term thermal fluctuations. • Thermal fluctuations and CO 2 enrichment synergistically accelerate biomass yield of N. yezoensis under the greenhouse effect. [ABSTRACT FROM AUTHOR]

Ulva linza is one of the species that causes green tides in the Yellow Sea, China. Due to the difficulties in chromosomal preparation, the large numbers of chromosomes, and their relatively small sizes, there have been no reported studies on Ulva macroalgae chromosomes. The karyotypes and chromosomes in U. linza were observed after a series of treatments. The chromosomes were pretreated with 0.1% colchicine for 12 h and then mixed with enzymes. The samples were dropped from 30 cm height onto glass slides, which spread out the surface coat. These pretreatments were the optimal chromosomes preparation treatments. The prepared chromosomes were stained with 4′,6-diamidino-2-phenylindole (DAPI), which is a fluorescent probe sensitive and specific to DNA. The chromosome number in the haploid male and female gametophytes was n=9, and was 2n=18 in the diploid sporophytes. The female gametophyte chromosomes were between 0.804 and 2.292 um in size, the male gametophyte chromosomes were between 0.917 and 2.916 µm, and the sporophyte chromosomes were between 0.912 and 2.167 µm. The relative sizes of the chromosomes were used to analyze the karyotypes of the female and male gametophyte chromosomes. The results provide a solid foundation for the basic technique that can be used to localize molecular markers of Ulva chromosomes. [ABSTRACT FROM AUTHOR]

Large-scale green tide disasters have been occurring for more than 10 years in China, with serious ecological consequences. However, limited research has focused on epiphytes that feed on macroalgae. In this study, amphipods were found living on the surface of Ulva lactuca, a green-tide-forming alga, around Gouqi Island, China. Through morphological and molecular methods, the amphipods were identified as Ampithoe lacertosa Bate, 1858, which has not previously been recorded in China. Sequence information about cytochrome c oxidase subunit I (mitochondrial COI) gene from China was compared to sequences reported from 5 coastal countries around the Pacific region. Network diagrams, phylogenetic trees and other methods of analysis revealed evidence of genetically distinct subspecies in the northeastern and northwestern Pacific. We believe that research on herbivorous amphipods will provide preventative strategies and control measures against green tide algae. International cooperation among Asian and North American biologists within the Pacific region will lead to a better understanding of the family Ampithoidae in the future. [ABSTRACT FROM AUTHOR]

Green tides have long occurred in the Yellow Sea for 17 years, with 5S-II Ulva prolifera being the dominant species. Previous studies indicate the Neopyropia aquaculture area in Jiangsu to be the main source of green tides in the Southern Yellow Sea. Little is known regarding the occurrence of this species in coastal dykes in Jiangsu Province. We investigated the species composition, diversity, and biomass of green macroalgae in these dykes during 2022 using internal transcribed spacers and 5S rDNA and identified U. prolifera , Ulva linza , Blidingia spp., Ulva meridionalis , Ulva torta , Ulva flexuosa , Ulva compressa , Ulva aragoensis , Ulva australis , and Ulva simplex. Ulva prolifera occurred in every month of the survey. Species diversity was highest in October, and the Ulva spp. biomass was highest in February. Attached 5S-II U. prolifera occurred in the coastal dykes in February, April, and June 2022. Dyke characteristicsand elevations may affect the biomass and species of Ulva spp. observed. Green tide blooms in the Yellow Sea have enabled 5S-II U. prolifera to colonize the Jiangsu coast dykes. • Ulva prolifera, a dominant sp. in green tides, was found in Jiangsu coastal dykes. • Attached and floating 5S-II U. prolifera bear close affinities. • Different dyke types may affect the Ulva spp. species present. • Ten species of green macroalgae were found in Jiangsu coastal dykes. [ABSTRACT FROM AUTHOR]

Green tide with the main dominant species is Ulva prolifera O.F. Müller have been reported in the Southern Yellow Sea since 2007. This study investigated differences in the morphology, growth, chlorophyll fluorescence parameters, and chloroplast pigment content of different day-aged U. prolifera gametophytes. Gametes had two flagella and exhibited positive phototaxis. On the 7th day of culture, young gametophytes began to branch out. Changes in the length and width of the main branches, and the length of the first-level branches showed "S"-shaped growth within 0–30 days, while the fresh weight of single algae exhibited "J"-shaped growth. The average fresh and dry weight of U. prolifera was 12.32 and 1.38 g per thallus, respectively, when cultured from one gamete to 30 days. The average number of first-level branches of 10-day-aged thalli was 119 per blade, and the maximum branching level was one. The average number of first-level branches of 30-day-aged thalli was 243 per thallus, and the maximum branching level was five. Except for the NPQ and I K values of 0 d thalli compared with 10 d thalli, the I K value of 0 d compared with 20 d, the NPQ , ETR max and I K value of 10 d compared with 20 d, and the Alpha value of 10 d compared with 30 d, the Fv / Fm , Y II , NPQ , ETR max , I K and Alpha values of the other 0 d, 10 d, 20 d and 30 d thalli showed significant or extremely significant differences. There was no significant difference in the Chl b / Car value between 0 d and 10 d, the Chl b value between 10 d and 20 d, the Chla / Car value between 10 d and 30 d, and the Car value between 20 d and 30 d was significantly different. The Chl a , Chl b , Car , Chl a / Chl b , Chl a / Car and Chl b / Car values of the other 0 d, 10 d, 20 d and 30 d were highly significantly different. These results not only verify that U. prolifera gametophytes can directly develop into new thalli by parthenogenesis, but also reveal the morphological and physiological characteristics of different day-aged gametophytes. In addition to presenting the typical morphology of different-day-aged gametophytes, this study also reports significant differences in growth, chlorophyll fluorescence parameters, and chloroplast pigment contents among them. This revealed the physiological mechanism of varying growth rates of different day-aged U. prolifera. These findings provide essential reference information for green tide prevention and outbreak mechanism research. • The typical morphology of Ulva prolifera gametophytes at different day-ages was reported. • The change of fresh weight showed a "J"-shape growth curve. • Growth, chlorophyll fluorescence, and pigment content significantly varied with day-age. • Average U. prolifera wet and dry weight at 30 days was 12.32 and 1.38 g/plant, respectively. • This is the first report of "day-age" in the U. prolifera. [ABSTRACT FROM AUTHOR]