Microalgae possess significant advantages in nitrogen and phosphorus removal from nutrient-richwastewater that are highly efficient and independent of the C/N ratio.However,challenges such as low biomass productivity,...Microalgae possess significant advantages in nitrogen and phosphorus removal from nutrient-richwastewater that are highly efficient and independent of the C/N ratio.However,challenges such as low biomass productivity,high variability in nutrient removal under different trophic types,and difficulty in harvesting biomass limits the large-scale application of microalgae wastewater treatment.This study attempted to employmixotrophic microalgae biofilm to address these issues.The biomass production,microalgal activity,and nutrient removal of Chlorella pyrenoidosa biofilms with different trophic types were compared for nutrient-rich wastewater treatment.The results showed that the biomass productivity of the mixotrophic microalgal biofilm(0.215 g/(L·d))was 2.3,8.6,and 6.0 times higher than that of photoautotrophic microalgal biofilm,heterotrophic microalgal biofilm,and photoautotrophic suspended microalga,respectively.Additionally,the dehydrogenase activity(DHA),indicating microalgal activity,of the mixotrophic biofilm was 2.3 and 16.5 times higher than that of photoautotrophic and heterotrophic biofilms,respectively.Meanwhile,the mixotrophic biofilm removed 96.0%of NH_(4)^(+)-N and 99.2%of PO_(4)^(3-)-P,more efficient than that with other types of biofilms and suspended microalgae.In an open-ended air-lift photobioreactor,the mixotrophic microalgal biofilm produced biomass at 0.12 g/(L·d)and removed 90.0%of NH_(4)^(+)-N and 97.6%of PO_(4)^(3-)-P.This study suggests that the mixotrophic microalgal biofilm shows promise in treating nutrient-rich wastewater and producing microalgal biomass for value-added products.展开更多
The 2016–2022 monitoring data from three ecological buoys in the Wenzhou coastal region of Zhejiang Province and the dataset European Centre for Medium-Range Weather Forecasts were examined to clarify the elaborate r...The 2016–2022 monitoring data from three ecological buoys in the Wenzhou coastal region of Zhejiang Province and the dataset European Centre for Medium-Range Weather Forecasts were examined to clarify the elaborate relationship between variations in ecological parameters during spring algal bloom incidents and the associated changes in temperature and wind fields in this study.A long short-term memory recurrent neural network was employed,and a predictive model for spring algal bloom in this region was developed.This model integrated various inputs,including temperature,wind speed,and other pertinent variables,and chlorophyll concentration served as the primary output indicator.The model training used chlorophyll concentration data,which were supplemented by reanalysis and forecast temperature and wind field data.The model demonstrated proficiency in forecasting next-day chlorophyll concentrations and assessing the likelihood of spring algal bloom occurrences using a defined chlorophyll concentration threshold.The historical validation from 2016 to 2019 corroborated the model's accuracy with an 81.71%probability of correct prediction,which was further proven by its precise prediction of two spring algal bloom incidents in late April 2023 and early May 2023.An interpretable machine learning-based model for spring algal bloom prediction,displaying effective forecasting with limited data,was established through the detailed analysis of the spring algal bloom mechanism and the careful selection of input variables.The insights gained from this study offer valuable contributions to the development of early warning systems for spring algal bloom in the Wenzhou coastal area of Zhejiang Province.展开更多
Concrete is subject to the synergistic effects of physical,chemical and biological processes throughout its life cycle.Among them,the corrosion of concrete by physical and chemical effects has been studied in detail.W...Concrete is subject to the synergistic effects of physical,chemical and biological processes throughout its life cycle.Among them,the corrosion of concrete by physical and chemical effects has been studied in detail.With the advance of various basic engineering facilities to the ocean,the deterioration mechanism of concrete caused by Marine fouling organisms remains to be studied.In particular,the corrosion and damage of Marine concrete by algae have rarely been reported by scholars.Therefore,combined with the current research status,we will review the mechanism of algal corrosion,the damage effect of algal adhesion on concrete and its interior,the factors affecting algal adhesion behavior,and the protection technology of algal adhesion.展开更多
In this study,sediment organic phosphorus(OP)and organic carbon(OC)in Lake Taihu,China,as well as their relationships,were analyzed during the outbreak and decline of algal blooms(ABs)over a five-month field study.The...In this study,sediment organic phosphorus(OP)and organic carbon(OC)in Lake Taihu,China,as well as their relationships,were analyzed during the outbreak and decline of algal blooms(ABs)over a five-month field study.The results showed synchronous temporal changes in the sediment OP and OC contents with the development of ABs.In addition,there was a significant positive correlation between the sediment OP and OC(p<0.01),suggesting simultaneous deposition and consumption during the ABs outbreak.The sediment OP and OC contents decreased significantly at the early and last stages of the ABs outbreak and increased at the peak of the ABs outbreak and during the ABs decline.These temporal variation patterns suggest that the sediment OC and OP contents did not consistently increase during the ABs outbreak,even though algae are an important source of organic matter in sediments.The depletion or enrichment of OC and OP in sediments may also depend on the scale of the ABs outbreak.The obtained results revealed significant differences in the sediment OC and OP contents between the months(p<0.05).In addition,OP in the sediments was dominated by orthophosphate diester(phospholipids and DNA-P)and orthophosphate monoester during the ABs outbreak and decline,respectively.The active OC contents and proportions in the sediments in the ABs outbreak were significantly lower than those observed in the ABs decline period,demonstrating the significant impacts of the ABs outbreak and decline on the sediment OC and OP in Lake Taihu.展开更多
Algal blooms,the spread of algae on the surface of water bodies,have adverse effects not only on aquatic ecosystems but also on human life.The adverse effects of harmful algal blooms(HABs)necessitate a convenient solu...Algal blooms,the spread of algae on the surface of water bodies,have adverse effects not only on aquatic ecosystems but also on human life.The adverse effects of harmful algal blooms(HABs)necessitate a convenient solution for detection and monitoring.Unmanned aerial vehicles(UAVs)have recently emerged as a tool for algal bloom detection,efficiently providing on-demand images at high spatiotemporal resolutions.This study developed an image processing method for algal bloom area estimation from the aerial images(obtained from the internet)captured using UAVs.As a remote sensing method of HAB detection,analysis,and monitoring,a combination of histogram and texture analyses was used to efficiently estimate the area of HABs.Statistical features like entropy(using the Kullback-Leibler method)were emphasized with the aid of a gray-level co-occurrence matrix.The results showed that the orthogonal images demonstrated fewer errors,and the morphological filter best detected algal blooms in real time,with a precision of 80%.This study provided efficient image processing approaches using on-board UAVs for HAB monitoring.展开更多
As one of the main application directions of quantum technology,underwater quantum communication is of great research significance.In order to study the influence of marine planktonic algal particles on the communicat...As one of the main application directions of quantum technology,underwater quantum communication is of great research significance.In order to study the influence of marine planktonic algal particles on the communication performance of underwater quantum links,based on the extinction characteristics of marine planktonic algal particles,the influence of changes in the chlorophyll concentration and particle number density of planktonic algal particles on the attenuation of underwater links is explored respectively,the influence of marine planktonic algal particles on the fidelity of underwater quantum links,the generation rate of the security key,and the utilization rate of the channel is analyzed,and simulation experiments are carried out.The results show that with the increase in chlorophyll concentration and particle density of aquatic planktonic algal particles,quantum communication channel link attenuation shows a gradually increasing trend.In addition,the security key generation rate,channel fidelity and utilization rate are gradually decreasing.Therefore,the performance of underwater quantum communication channel will be interfered by marine planktonic algal particles,and it is necessary to adjust the relevant parameter values in the quantum communication system according to different marine planktonic algal particle number density and chlorophyll concentration to improve the performance of quantum communication.展开更多
Economic development around the Daya Bay, China has profoundly affected the marine environment in the bay area in recent years, particularly since the operation of Daya Bay Nuclear Power Station （DNPS） in 1994. This...Economic development around the Daya Bay, China has profoundly affected the marine environment in the bay area in recent years, particularly since the operation of Daya Bay Nuclear Power Station （DNPS） in 1994. This study analyzed the changes of water temperature and harmful algal blooms （HABs） for two periods： 1983-1993 and 1994-2004, using in situ and satellite data. Results showed that yearly mean surface water temperature （SWT） and Chl-a concentration （Chl-a） increased by 1.1 ℃ and 1.9 mg/m^3, respectively, after 1994. The monthly occurrence of HAB was found to have increased also. HABs appeared only in spring and autumn before 1994, but occurred all the year round after 1994. SWT, Chl-a and HABs all increased significantly in May. Those changes were associated with environmental changes in this area, such as thermal discharge from the DNPS and enhancement of eutrophication from human activities around the Daya Bay.展开更多
It was focused on the effect of different sludge concentrations on the performances of an algal-activated sludge symbiotic system in terms of wastewater treatment, algal-activated sludge characteristics and community ...It was focused on the effect of different sludge concentrations on the performances of an algal-activated sludge symbiotic system in terms of wastewater treatment, algal-activated sludge characteristics and community structure. The results showed that the highest nutrient removal efficiencies were obtained in the reactor R^2 with soluble chemical oxygen demand(sC OD), ammonia nitrogen(NH_4^+-N) and phosphate(PO_4^(3-)-P) removal efficiencies of(90.6 ± 2.3)%,(97.69 ± 2.6)% and(83.81 ± 2.3)%, respectively. Further investigation exhibited that sludge concentration has a great effect on the dissolved oxygen(DO) concentration, the pH, the growth of algae and the extracellular polymeric substance(EPS) production, which resulted in influencing the settleability and the performance of symbiotic system. The denaturing gradient gel electrophoresis(DGGE) analysis demonstrated that the sludge concentration had a selective power for particular members of algae. Meantime, the stimulated algal population would selectively excite the members of bacteria benefited for the formation of algal-bacterial consortia.The variation of microbial compositions, which was influenced by the different sludge concentrations, might be ultimately responsible for the different treatment performances.展开更多
Water transfer is becoming a popular method for solving the problems of water quality deterioration and water level drawdown in lakes. However, the principle of choosing water sources for water transfer projects has m...Water transfer is becoming a popular method for solving the problems of water quality deterioration and water level drawdown in lakes. However, the principle of choosing water sources for water transfer projects has mainly been based on the effects on water quality, which neglects the influence in the variation of phytoplankton community and the risk of algal blooms. In this study, algal growth potential(AGP) test was applied to predict changes in the phytoplankton community caused by water transfer projects. The feasibility of proposed water transfer sources(Baqing River and Jinsha River) was assessed through the changes in both water quality and phytoplankton community in Chenghai Lake, Southwest China. The results showed that the concentration of total nitrogen(TN) and total phosphorus(TP) in Chenghai Lake could be decreased to 0.52 mg/L and 0.02 mg/L respectively with the simulated water transfer source of Jinsha River. The algal cell density could be reduced by 60%, and the phytoplankton community would become relatively stable with the Jinsha River water transfer project, and the dominant species of Anabaena cylindrica evolved into Anabaenopsis arnoldii due to the species competition. However, the risk of algal blooms would be increased after the Baqing River water transfer project even with the improved water quality. Algae gained faster proliferation with the same dominant species in water transfer source. Therefore, water transfer projects should be assessed from not only the variation of water quality but also the risk of algal blooms.展开更多
The use of agricultural straw for algal bloom control has been studied for more than 30 years.In this article,we have reviewed the promising potentials of using agricultural straw as source of anti-algal agents,includ...The use of agricultural straw for algal bloom control has been studied for more than 30 years.In this article,we have reviewed the promising potentials of using agricultural straw as source of anti-algal agents,including the effectiveness of each major straw type so far used in this regard,and the investigated algal species.Various pre-treatment methods have also been widely reviewed.Significant progress has been made in natural product chemistry and molecular biology with regards to agricultural straw,especially in relation to the extraction of antialgal allelochemicals,degradation processes of agricultural straws and the mechanisms through which these inhibitions occur.The development of biotechnologies using agricultural straw to successfully inhibit growth of bloom forming algae has been generally accepted as environmentally friendly.The current research status and that of the future should include isolation and discovery of antialgal allelochemicals,development of models that would illustrate the sequence of physiologic events that match the species-specific inhibitor phenomenon,and products fit in the field applications.展开更多
Six common algal fatty acids （FAs） with different numbers of double bonds, lipophilic fractions and proteins extracted from the diatom Navicula pelliculosa and algal ceils were chlorinated to evaluate their potentia...Six common algal fatty acids （FAs） with different numbers of double bonds, lipophilic fractions and proteins extracted from the diatom Navicula pelliculosa and algal ceils were chlorinated to evaluate their potential in generating disinfection by-products （DBPs）. The result showed that the more double bonds in the FAs, the higher the amounts of chloroform and dichloroacetic acid （DCAA） produced, but such a pattern was not observed for trichloroacetic acid （TCAA）. Based on the previously reported composition of fatty acids in algal lipids, the DBP generation potentials of algal lipids were calculated. These predicted values were much lower than those measured in the chlorinated algal lipophilic fraction, suggesting unknown lipophilic fraction（s） served as potent DBPs precursors. Another calculation attempted to predict DBP production in algal cells based on algal lipid and protein composition, given quantified measured DBP production per unit algal lipid and proteins. The analysis showed that the observed DBP production was similar to that predicted （〈 35% difference）, suggesting that algal biochemical compositions may serve as a bioindicator for preliminary estimation of chloroform, DCAA and TCAA formation upon chlorinating algae.展开更多
Microalgae cultivation has gained tremendous attention in recent years due to its great potential in green biofuel production and wastewater treatment application. Membrane technology is a great solution in separating...Microalgae cultivation has gained tremendous attention in recent years due to its great potential in green biofuel production and wastewater treatment application. Membrane technology is a great solution in separating the microalgae biomass while producing high quality of permeate for recycling. The main objective of this study was to investigate the filtration performance of Ag/GO-PVDF(silver/graphene oxide-polyvinylidene fluoride) membrane in an algalmembrane photoreactor(A-MPR) by benchmarking with a commercial PVDF(com-PVDF) membrane. In this study, Chlorella vulgaris microalgae was cultivated in synthetic wastewater in an A-MPR for ammoniacal-nitrogen and phosphorus recovery and the wastewater was further filtered using Ag/GO-PVDF and com-PVDF membranes to obtain high quality water. Spectrophotometer was used to analyze the chemical oxidation demand(COD), ammoniacal nitrogen(NH3-N) and phosphate(PO43-). The concentration of proteins and carbohydrates was measured using Bradford method and phenol-sulfuric acid method, respectively. The COD of the synthetic wastewater was reduced from(180.5 ± 5.6) ppm to(82 ± 2.6) ppm due to nutrient uptake by microalgae. Then, the Ag/GO-PVDF membrane was used to further purify the microalgae cultivated wastewater, resulting in a low COD permeate of(31 ± 4.6) ppm. The high removal rate of proteins(100%) and carbohydrates(86.6%) as the major foulant in microalgae filtration, with low membrane fouling propensity of Ag/GO-PVDF membrane is advantageous for the sustainable development of the microalgae production. Hence, the integrated A-MPR system is highly recommended as a promising approach for microalgae cultivation and wastewater polishing treatment.展开更多
Harmful algal blooms(HABs)in the Southern Yellow Sea(SYS)have shown a trend of increasing diversity and detrimental ef fects.While the Bohai Sea,East China Sea,and South China Sea have experienced a high incidence of ...Harmful algal blooms(HABs)in the Southern Yellow Sea(SYS)have shown a trend of increasing diversity and detrimental ef fects.While the Bohai Sea,East China Sea,and South China Sea have experienced a high incidence of HABs since the 1980s,the Yellow Sea provides a relatively healthy ecological environment in which fewer HABs have been documented before the 21s t century.Yet largescale blooms of the green macroalga Ulva prolifera(so-called“green tides”)have occurred annually since 2007 in the Yellow Sea.Six people were poisoned and one person died in Lianyungang in 2008 due to ingestion of algal toxins.Moreover,the Yellow Sea experienced co-occurrence of harmful red tides,green tides,and golden tides in 2017.This combination of events,rare worldwide,indicates the potential for further deterioration of the marine environment in the Yellow Sea,which may be related to climate change,aquaculture,and other human activities.Using the SYS as an example,we collected data of the frequency and scale of HABs over the years,as well as that of marine algal toxins,and analyzed the trend in the diversity of HABs in the SYS,to explore the causes and impacts of HABs,as well as the interrelationships among dif ferent types of HABs,including harmful red tides,green tides,and golden tides.We also attempted to improve our understanding of HAB evolution under the influence of global climate change and intensified human activities.展开更多
To understand the potential impact of the Three Gorges Reservoir on the aquatic ecosystem after the damming of the Yangtze River,we studied the community composition and temporal abundance distribution of algae in two...To understand the potential impact of the Three Gorges Reservoir on the aquatic ecosystem after the damming of the Yangtze River,we studied the community composition and temporal abundance distribution of algae in two types of water bodies:a segment of the Jialing River near its confluence with the Yangtze River as an example of the river-lake type,and Shuanglong Lake in Chongqing as an example of the lake type.In total,107 species belonging to 58 genera of 7 phyla were identified in the study area of the Jialing River,dominated by three groups with 49.5% diatoms,29.0% chlorophytes,and 11.4% cyanobacteria in the community composition.There were 122 species belonging to 66 genera of 8 phyla in Shuanglong Lake,dominated by the same three groups with 19.7% diatoms,48.4% chlorophytes,and 22.2% cyanobacteria.The densities of total algae and individual dominant groups were all much higher in the lake.More species of diatoms were found in the river-lake segment;whereas more chlorophyte species and cyanobacteriaum species were in the lake.There were 17 dominant species including 8 diatoms,4 chlorophytes,3 cyanobacteria and 2 cryptophytes in the river-lake segment,and 21 species in the lake,including 2 diatoms,9 chlorophytes,6 cyanobacteria,3 cryptophytes and a dinoflagellate.In eutrophic conditions,chlorophytes and cyanobacteria may proliferate in a lake-type area and diatoms may cause algal bloom in a relatively faster-flow lake-river type area.展开更多
^ 15N isotope tracer techniques and ecological modeling were adopted to investigate the fractionation of nitrogen, its uptake and transformation in algae and snail （Bellamya aeruginosa Reeve）. Different algal specie...^ 15N isotope tracer techniques and ecological modeling were adopted to investigate the fractionation of nitrogen, its uptake and transformation in algae and snail （Bellamya aeruginosa Reeve）. Different algal species were found to differ in their uptake of nitrogen isotopes. Microcystis aeruginisa Ktitz. demonstrated the greatest ^15N accumulation capacity, with the natural variation in isotopic ratio （δ^15N） and the isotope fractionation factor （ε,‰） being the highest among the species investigated. The transformation and utilization of ^15N by snails differed depending on the specific algae consumed （highest for Chlorella pyrenoidosa Chick., lowest for M. aeruginisa）. When snails was seeded in the experimental pond, the algae population structure changed significantly, and total algal biomass as well as the concentration of all nitrogen species decreased, causing an increase in water transparency. A model, incorporating several chemical and biological parameters, was developed to predict algal biomass in an aquatic system when snails was present. The data collected during this investigation indicated that the gastropods such as snails could significantly impact biological community and water quality of small water bodies, suggesting a role for biological control of noxious algal blooms associated with eutrophication.展开更多
To explore eutrophication and algal bloom mechanisms in channel type reservoirs, a novel enclosure experiment was conducted by changing light intensity （LI） in the Daning River of the Three Gorges Reservoir （TGR）....To explore eutrophication and algal bloom mechanisms in channel type reservoirs, a novel enclosure experiment was conducted by changing light intensity （LI） in the Daning River of the Three Gorges Reservoir （TGR）. Square enclosures （side 5.0 m） were covered on the surface with shading materials of different thickness, and with their bases open to the river. Changes and characteristics of the main eutrophication factors under the same water quality and hydrodynamic conditions but different LI were evaluated. All experimental water samples were neutral and alkalescent, with high nitrogen and phosphate concentrations, low potassium permanganate index, stable water quality, and different LI. At the same water depth, LI decreased with increasing shade material, while dissolved oxygen and water temperature were both stable. The growth peak of phytoplankton was with light of 345-4390 lux underwater or 558-7450 lux above the water surface, and water temperature of 25.6--26.5℃. Algae were observed in all water samples, accounting for 6 phylum and 57 species, with algal density changing frequently. The results showed that significantly strong or weak light was unfavorable for phytoplankton growth and the function together with suitable temperature and LI and ample sunshine encouraged algal blooms under the same water quality and hydrodynamic conditions. Correlation analysis indicated that algae reduced gradually lengthwise along water depth in the same enclosure while pH became high. The power exponent relationship between chlorophyll a （Chl-a） and LI was found by curve fitting, that is Chl-a = K（LI）n.展开更多
To study how global warming and eutrophication affect water ecosystems, a multiplicative growth Monod model, modified by incorporating the Arrhenius equation, was applied to Lake Taihu to quantitatively study the rela...To study how global warming and eutrophication affect water ecosystems, a multiplicative growth Monod model, modified by incorporating the Arrhenius equation, was applied to Lake Taihu to quantitatively study the relationships between algal biomass and both nutrients and temperature using long-term data. To qualitatively assess which factor was a limitation of the improved model, temperature variables were calculated using annual mean air temperature （AT）, water temperature （WT）, and their average temperature （ST）, while substrate variables were calculated using annual mean total nitrogen （TN）, total phosphorus （TP）, and their weighted aggregate （R）, respectively. The nine fitted curves showed that TN and AT were two important factors influencing algal growth; AT limited growth as algal photosynthesis is mainly carried out near the water surface; N leakage of phytoplankton and internal phosphorus load from sediment explains why TN was the best predictor of peak biomass using the Monod model. The fitted results suggest that annual mean algal biomass increased by 0.145 times when annual mean AT increased by 1.0℃. Results also showed that the more eutrophic the lake, the greater the effect AT had on algal growth. Subsequently, the long-term joint effect of annual temperature increase and eutrophication to water ecosystems can be quantitatively assessed and predicted.展开更多
It is important to assess the effect on zooplankton when perform the environmental protection or restoration technology, especially removing algal blooms, because algae were the major primary producer in algal lakes. ...It is important to assess the effect on zooplankton when perform the environmental protection or restoration technology, especially removing algal blooms, because algae were the major primary producer in algal lakes. The influence on zooplankton community after half a year of algal blooms removed by chitosan-modified soils in Taihu Lake was assessed and the rationality of carrying out the process semiannually was evaluated in the present study. Morphological composition and genetic diversity of zooplankton community were investigated by microscope checkup and polymerase chain reaction-denatured gradient gel electrophoresis （PCR-DGGE）. A total of 44 zooplankton taxa （23 protozoa, 17 rotifers, 3 copepoda and 1 cladocera） were detected by microscope checkup, and a total of 91 bands （28 bands amplified by primers F1427-GC and R1616, 63 bands amplified by primers Fung-GC and NS1） were detected by PCR-DGGE. The results of cluster analysis or detrended correspondence analysis indicated that there was no considerable difference in morphological composition of zooplankton and DGGE profiles between experimental and control sites, and DGGE profiles could represent the biologic diversity. The study showed that zooplankton community could recover original condition after half year of algal blooms removed by chitosan-modified soils and it was acceptable to apply this process semiannually. In addition, the results revealed that PCR-DCJGE could be applied to investigate the impacts of the environmental protection or restoration engineering on zooplankton community diversity.展开更多
Blooms of Phaeocystis globosa have been frequently reported in Chinese coastal waters, causing serious damage to marine ecosystems. To better understand the ecological characteristics of P. globosa in Chinese coastal ...Blooms of Phaeocystis globosa have been frequently reported in Chinese coastal waters, causing serious damage to marine ecosystems. To better understand the ecological characteristics of P. globosa in Chinese coastal waters that facilitate its rapid expansion, the effects of temperature, salinity and irradiance on the growth of P. globosa from the South China Sea were examined in the laboratory. The saturating irradiance for the growth ofP. globosa （Is） was 60 μmol/（m^2·s）, which was lower than those of other harmful algal species （70-114μmol/（m^2·s））. A moderate growth rate of 0.22/d was observed at 2 μmol/（m^2·s） （the minimum irradiance in the experiment）, and photo-inhibition did not occur at 230 μmol/（m^2·s） （the maximum irradiance in the experiment）. Exposed to 42 different combinations of temperatures （10- 31 ℃） and salinities （10-40） under saturating irradiance, P. globosa exhibited its maximum specific growth rate of 0.80/d at the combinations of 24℃ and 35, and 27℃ and 40. The optimum growth rates （〉0.80/d） were observed at temperatures ranging from 24 to 27℃ and salinities from 35 to 40. While P. globosa was able to grow well at temperatures from 20℃ to 31℃ and salinities from 20 to 40, it could not grow at temperatures lower than 15℃ or salinities lower than 15. Factorial analysis revealed that temperature and salinity has similar influences on the growth of this species. This strain ofP. globosa not only prefers higher temperatures and higher salinity, but also possesses a flexible nutrient competing strategy, adapted to lower irradiance. Therefore, the P. globosa population from South China Sea should belong to a new ecotype. There is also a potentially high risk of blooms developing in this area throughout the year.展开更多
Urban lake ecosystems are significant for social development,but currently we know little about the geographical distribution of algal community in urban lakes at a large-scale.In this study,we investigated the algal ...Urban lake ecosystems are significant for social development,but currently we know little about the geographical distribution of algal community in urban lakes at a large-scale.In this study,we investigated the algal community structure in different areas of urban lakes in China and evaluated the influence of water quality parameters and geographical location on the algal community.The results showed that obvious differences in water quality and algal communities were observed among urban lakes in different geographical areas.Chlorophyta was the dominant phylum,followed by cyanobacteria in all areas.The network analysis indicated that algal community composition in urban lakes of the western and southern area showed more variations than the eastern and northern areas,respectively.Redundancy analysis and structural equation model revealed that nutrients and p H were dominant environmental factors that affected the algal community,and they showed higher influence than that of iron,manganese and COD Mn concentration.Importantly,algal community and density exhibited longitude and latitude relationship.In general,these results provided an ecological insight into large-scale geographical distributions of algal community in urban lakes,thereby having potential applications for management of the lakes.展开更多
基金supported by the Natural Science Foundation of Guangdong Province(No.2020A1515011113)the Applied Basic Research Project of Guangzhou(No.202002030455)Zhongshan Science and Technology Plan Project(No.2020AG021).
文摘Microalgae possess significant advantages in nitrogen and phosphorus removal from nutrient-richwastewater that are highly efficient and independent of the C/N ratio.However,challenges such as low biomass productivity,high variability in nutrient removal under different trophic types,and difficulty in harvesting biomass limits the large-scale application of microalgae wastewater treatment.This study attempted to employmixotrophic microalgae biofilm to address these issues.The biomass production,microalgal activity,and nutrient removal of Chlorella pyrenoidosa biofilms with different trophic types were compared for nutrient-rich wastewater treatment.The results showed that the biomass productivity of the mixotrophic microalgal biofilm(0.215 g/(L·d))was 2.3,8.6,and 6.0 times higher than that of photoautotrophic microalgal biofilm,heterotrophic microalgal biofilm,and photoautotrophic suspended microalga,respectively.Additionally,the dehydrogenase activity(DHA),indicating microalgal activity,of the mixotrophic biofilm was 2.3 and 16.5 times higher than that of photoautotrophic and heterotrophic biofilms,respectively.Meanwhile,the mixotrophic biofilm removed 96.0%of NH_(4)^(+)-N and 99.2%of PO_(4)^(3-)-P,more efficient than that with other types of biofilms and suspended microalgae.In an open-ended air-lift photobioreactor,the mixotrophic microalgal biofilm produced biomass at 0.12 g/(L·d)and removed 90.0%of NH_(4)^(+)-N and 97.6%of PO_(4)^(3-)-P.This study suggests that the mixotrophic microalgal biofilm shows promise in treating nutrient-rich wastewater and producing microalgal biomass for value-added products.
基金the Zhejiang Provincial Natural Science Foundation of China(No.LY21D 060003)the Project of State Key Laboratory of Satellite Ocean Environment Dynamics,Second Institute of Ocean-ography,MNR(No.SOEDZZ2103)+1 种基金the National Natural Science Foundation of China(No.42076216)the Open Research Fund of the Key Laboratory of Marine Ecological Monitoring and Restoration Technologies,MNR(No.MEMRT202210)。
文摘The 2016–2022 monitoring data from three ecological buoys in the Wenzhou coastal region of Zhejiang Province and the dataset European Centre for Medium-Range Weather Forecasts were examined to clarify the elaborate relationship between variations in ecological parameters during spring algal bloom incidents and the associated changes in temperature and wind fields in this study.A long short-term memory recurrent neural network was employed,and a predictive model for spring algal bloom in this region was developed.This model integrated various inputs,including temperature,wind speed,and other pertinent variables,and chlorophyll concentration served as the primary output indicator.The model training used chlorophyll concentration data,which were supplemented by reanalysis and forecast temperature and wind field data.The model demonstrated proficiency in forecasting next-day chlorophyll concentrations and assessing the likelihood of spring algal bloom occurrences using a defined chlorophyll concentration threshold.The historical validation from 2016 to 2019 corroborated the model's accuracy with an 81.71%probability of correct prediction,which was further proven by its precise prediction of two spring algal bloom incidents in late April 2023 and early May 2023.An interpretable machine learning-based model for spring algal bloom prediction,displaying effective forecasting with limited data,was established through the detailed analysis of the spring algal bloom mechanism and the careful selection of input variables.The insights gained from this study offer valuable contributions to the development of early warning systems for spring algal bloom in the Wenzhou coastal area of Zhejiang Province.
基金Funded by the National Natural Science Foundation of China(Nos.52278269,52278268,and 52178264)the Tianjin Outstanding Young Scholars Science Fund Project(No.22JCJQJC00020)+1 种基金the Key Project of Tianjin Natural Science Foundation(No.23JCZDJC00430)the Joint Research Center of China and Foreign Countries Special Fund of Tianjin Innovation Platform(No.24PTLYHZ00240)。
文摘Concrete is subject to the synergistic effects of physical,chemical and biological processes throughout its life cycle.Among them,the corrosion of concrete by physical and chemical effects has been studied in detail.With the advance of various basic engineering facilities to the ocean,the deterioration mechanism of concrete caused by Marine fouling organisms remains to be studied.In particular,the corrosion and damage of Marine concrete by algae have rarely been reported by scholars.Therefore,combined with the current research status,we will review the mechanism of algal corrosion,the damage effect of algal adhesion on concrete and its interior,the factors affecting algal adhesion behavior,and the protection technology of algal adhesion.
基金jointly sponsored by the National Natural Science Foundation of China(No.41371450)the Natural Science Foundation of Henan(No.222300420418)the Postgraduate Cultivating Innovation and Quality Improvement Action Plan of Henan University(No.SYLYC2022015)。
文摘In this study,sediment organic phosphorus(OP)and organic carbon(OC)in Lake Taihu,China,as well as their relationships,were analyzed during the outbreak and decline of algal blooms(ABs)over a five-month field study.The results showed synchronous temporal changes in the sediment OP and OC contents with the development of ABs.In addition,there was a significant positive correlation between the sediment OP and OC(p<0.01),suggesting simultaneous deposition and consumption during the ABs outbreak.The sediment OP and OC contents decreased significantly at the early and last stages of the ABs outbreak and increased at the peak of the ABs outbreak and during the ABs decline.These temporal variation patterns suggest that the sediment OC and OP contents did not consistently increase during the ABs outbreak,even though algae are an important source of organic matter in sediments.The depletion or enrichment of OC and OP in sediments may also depend on the scale of the ABs outbreak.The obtained results revealed significant differences in the sediment OC and OP contents between the months(p<0.05).In addition,OP in the sediments was dominated by orthophosphate diester(phospholipids and DNA-P)and orthophosphate monoester during the ABs outbreak and decline,respectively.The active OC contents and proportions in the sediments in the ABs outbreak were significantly lower than those observed in the ABs decline period,demonstrating the significant impacts of the ABs outbreak and decline on the sediment OC and OP in Lake Taihu.
文摘Algal blooms,the spread of algae on the surface of water bodies,have adverse effects not only on aquatic ecosystems but also on human life.The adverse effects of harmful algal blooms(HABs)necessitate a convenient solution for detection and monitoring.Unmanned aerial vehicles(UAVs)have recently emerged as a tool for algal bloom detection,efficiently providing on-demand images at high spatiotemporal resolutions.This study developed an image processing method for algal bloom area estimation from the aerial images(obtained from the internet)captured using UAVs.As a remote sensing method of HAB detection,analysis,and monitoring,a combination of histogram and texture analyses was used to efficiently estimate the area of HABs.Statistical features like entropy(using the Kullback-Leibler method)were emphasized with the aid of a gray-level co-occurrence matrix.The results showed that the orthogonal images demonstrated fewer errors,and the morphological filter best detected algal blooms in real time,with a precision of 80%.This study provided efficient image processing approaches using on-board UAVs for HAB monitoring.
基金funded by Youth Fund of the National Natural Science Foundation of China,grant number 11504176,61601230.
文摘As one of the main application directions of quantum technology,underwater quantum communication is of great research significance.In order to study the influence of marine planktonic algal particles on the communication performance of underwater quantum links,based on the extinction characteristics of marine planktonic algal particles,the influence of changes in the chlorophyll concentration and particle number density of planktonic algal particles on the attenuation of underwater links is explored respectively,the influence of marine planktonic algal particles on the fidelity of underwater quantum links,the generation rate of the security key,and the utilization rate of the channel is analyzed,and simulation experiments are carried out.The results show that with the increase in chlorophyll concentration and particle density of aquatic planktonic algal particles,quantum communication channel link attenuation shows a gradually increasing trend.In addition,the security key generation rate,channel fidelity and utilization rate are gradually decreasing.Therefore,the performance of underwater quantum communication channel will be interfered by marine planktonic algal particles,and it is necessary to adjust the relevant parameter values in the quantum communication system according to different marine planktonic algal particle number density and chlorophyll concentration to improve the performance of quantum communication.
基金This study was jointly supported by the following funds awarded to Professor Danling TANG:Guangdong Natural Science Foundation(05102008 and 04001306),ChinaKey Innovation Project of Chinese Academy of Sciences(CAS)(KZCX3-SW-227-3)+3 种基金"0ne Hundred Talents Program"of CAS(Ybrjh0403)Authors are grateful to projects of South China Sea Fisheries Research Institute,Chinese Academy of Fishery Sciences(2007TS10 and 2007ZD03)High-tech Research and Development Program of China(2006AA100303)Chinese Ecosystem Research Network(http://www.cerndata.ac.cn),Dr.Guifeng WEI of Jinan University and the Key Innovation Project of CAS(KZCX3-SW-214).
文摘Economic development around the Daya Bay, China has profoundly affected the marine environment in the bay area in recent years, particularly since the operation of Daya Bay Nuclear Power Station （DNPS） in 1994. This study analyzed the changes of water temperature and harmful algal blooms （HABs） for two periods： 1983-1993 and 1994-2004, using in situ and satellite data. Results showed that yearly mean surface water temperature （SWT） and Chl-a concentration （Chl-a） increased by 1.1 ℃ and 1.9 mg/m^3, respectively, after 1994. The monthly occurrence of HAB was found to have increased also. HABs appeared only in spring and autumn before 1994, but occurred all the year round after 1994. SWT, Chl-a and HABs all increased significantly in May. Those changes were associated with environmental changes in this area, such as thermal discharge from the DNPS and enhancement of eutrophication from human activities around the Daya Bay.
基金supported by the HIT Environment and Ecology Innovation Special Funds (No.HSCJ201609)the Applied Technology Research and Development Program of Harbin (No.2017AB4AS035)+1 种基金the National Natural Science Foundation of China (No.51708157)Harbin Youth Talent Support Program (No.2017RAQXJ230)
文摘It was focused on the effect of different sludge concentrations on the performances of an algal-activated sludge symbiotic system in terms of wastewater treatment, algal-activated sludge characteristics and community structure. The results showed that the highest nutrient removal efficiencies were obtained in the reactor R^2 with soluble chemical oxygen demand(sC OD), ammonia nitrogen(NH_4^+-N) and phosphate(PO_4^(3-)-P) removal efficiencies of(90.6 ± 2.3)%,(97.69 ± 2.6)% and(83.81 ± 2.3)%, respectively. Further investigation exhibited that sludge concentration has a great effect on the dissolved oxygen(DO) concentration, the pH, the growth of algae and the extracellular polymeric substance(EPS) production, which resulted in influencing the settleability and the performance of symbiotic system. The denaturing gradient gel electrophoresis(DGGE) analysis demonstrated that the sludge concentration had a selective power for particular members of algae. Meantime, the stimulated algal population would selectively excite the members of bacteria benefited for the formation of algal-bacterial consortia.The variation of microbial compositions, which was influenced by the different sludge concentrations, might be ultimately responsible for the different treatment performances.
基金supported by the National Natural Science Foundation of China(No.51808531)the Major Science and Technology Program for Water Pollution Control and Treatment(No.2018YFE0204101)。
文摘Water transfer is becoming a popular method for solving the problems of water quality deterioration and water level drawdown in lakes. However, the principle of choosing water sources for water transfer projects has mainly been based on the effects on water quality, which neglects the influence in the variation of phytoplankton community and the risk of algal blooms. In this study, algal growth potential(AGP) test was applied to predict changes in the phytoplankton community caused by water transfer projects. The feasibility of proposed water transfer sources(Baqing River and Jinsha River) was assessed through the changes in both water quality and phytoplankton community in Chenghai Lake, Southwest China. The results showed that the concentration of total nitrogen(TN) and total phosphorus(TP) in Chenghai Lake could be decreased to 0.52 mg/L and 0.02 mg/L respectively with the simulated water transfer source of Jinsha River. The algal cell density could be reduced by 60%, and the phytoplankton community would become relatively stable with the Jinsha River water transfer project, and the dominant species of Anabaena cylindrica evolved into Anabaenopsis arnoldii due to the species competition. However, the risk of algal blooms would be increased after the Baqing River water transfer project even with the improved water quality. Algae gained faster proliferation with the same dominant species in water transfer source. Therefore, water transfer projects should be assessed from not only the variation of water quality but also the risk of algal blooms.
基金financially supported by the Major Science and Technology Program forWater Pollution Control and Treatment(2018ZX07208-009)the National Natural Science Foundation of China(21677122 and 21876148)+4 种基金the open fund of the Key Laboratory of Marine Eco-monitoring and Remediation Technology,Ministry of Natural Resources(MATHAB201809)the open fund of the Key Laboratory of Marine Ecosystem Dynamics,Second Institute of Oceanography,Ministry of Natural Resources(LMEB201709)Key Projects of Philosophy and Social Sciences Research,Ministry of Education(18JZD059)Fundamental Research Funds for the Central Universities(2019QNA4051)the China Scholarship Council(201806325035).
文摘The use of agricultural straw for algal bloom control has been studied for more than 30 years.In this article,we have reviewed the promising potentials of using agricultural straw as source of anti-algal agents,including the effectiveness of each major straw type so far used in this regard,and the investigated algal species.Various pre-treatment methods have also been widely reviewed.Significant progress has been made in natural product chemistry and molecular biology with regards to agricultural straw,especially in relation to the extraction of antialgal allelochemicals,degradation processes of agricultural straws and the mechanisms through which these inhibitions occur.The development of biotechnologies using agricultural straw to successfully inhibit growth of bloom forming algae has been generally accepted as environmentally friendly.The current research status and that of the future should include isolation and discovery of antialgal allelochemicals,development of models that would illustrate the sequence of physiologic events that match the species-specific inhibitor phenomenon,and products fit in the field applications.
基金supported by the Faculty Research Grant(FRG1/08-09/056, FRG1/09-10/047, Faculty of Science of Hong Kong Baptist University) awarded to Y.Liang
文摘Six common algal fatty acids （FAs） with different numbers of double bonds, lipophilic fractions and proteins extracted from the diatom Navicula pelliculosa and algal ceils were chlorinated to evaluate their potential in generating disinfection by-products （DBPs）. The result showed that the more double bonds in the FAs, the higher the amounts of chloroform and dichloroacetic acid （DCAA） produced, but such a pattern was not observed for trichloroacetic acid （TCAA）. Based on the previously reported composition of fatty acids in algal lipids, the DBP generation potentials of algal lipids were calculated. These predicted values were much lower than those measured in the chlorinated algal lipophilic fraction, suggesting unknown lipophilic fraction（s） served as potent DBPs precursors. Another calculation attempted to predict DBP production in algal cells based on algal lipid and protein composition, given quantified measured DBP production per unit algal lipid and proteins. The analysis showed that the observed DBP production was similar to that predicted （〈 35% difference）, suggesting that algal biochemical compositions may serve as a bioindicator for preliminary estimation of chloroform, DCAA and TCAA formation upon chlorinating algae.
基金supported by Universiti Kebangsaan Malaysia [Grant No.DIP-2016-031]CRIM(Center for Research and Instrumentation Management,UKM)for sponsoring the postgraduate study of W.C.Chong via Research University Zamalah Scheme and the technical supports in this work.
文摘Microalgae cultivation has gained tremendous attention in recent years due to its great potential in green biofuel production and wastewater treatment application. Membrane technology is a great solution in separating the microalgae biomass while producing high quality of permeate for recycling. The main objective of this study was to investigate the filtration performance of Ag/GO-PVDF(silver/graphene oxide-polyvinylidene fluoride) membrane in an algalmembrane photoreactor(A-MPR) by benchmarking with a commercial PVDF(com-PVDF) membrane. In this study, Chlorella vulgaris microalgae was cultivated in synthetic wastewater in an A-MPR for ammoniacal-nitrogen and phosphorus recovery and the wastewater was further filtered using Ag/GO-PVDF and com-PVDF membranes to obtain high quality water. Spectrophotometer was used to analyze the chemical oxidation demand(COD), ammoniacal nitrogen(NH3-N) and phosphate(PO43-). The concentration of proteins and carbohydrates was measured using Bradford method and phenol-sulfuric acid method, respectively. The COD of the synthetic wastewater was reduced from(180.5 ± 5.6) ppm to(82 ± 2.6) ppm due to nutrient uptake by microalgae. Then, the Ag/GO-PVDF membrane was used to further purify the microalgae cultivated wastewater, resulting in a low COD permeate of(31 ± 4.6) ppm. The high removal rate of proteins(100%) and carbohydrates(86.6%) as the major foulant in microalgae filtration, with low membrane fouling propensity of Ag/GO-PVDF membrane is advantageous for the sustainable development of the microalgae production. Hence, the integrated A-MPR system is highly recommended as a promising approach for microalgae cultivation and wastewater polishing treatment.
基金Supported by the Science&Technology Basic Resources Investigation Program of China(No.2018FY100200)the Key Deployment Project of Centre for Ocean Mega-Research of Science,Chinese Academy of Science(No.COMS2019Q05)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA23050302)the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2018SDKJ0504)the Sino-Australian Centre for Healthy Coasts(No.2016YFE0101500)。
文摘Harmful algal blooms(HABs)in the Southern Yellow Sea(SYS)have shown a trend of increasing diversity and detrimental ef fects.While the Bohai Sea,East China Sea,and South China Sea have experienced a high incidence of HABs since the 1980s,the Yellow Sea provides a relatively healthy ecological environment in which fewer HABs have been documented before the 21s t century.Yet largescale blooms of the green macroalga Ulva prolifera(so-called“green tides”)have occurred annually since 2007 in the Yellow Sea.Six people were poisoned and one person died in Lianyungang in 2008 due to ingestion of algal toxins.Moreover,the Yellow Sea experienced co-occurrence of harmful red tides,green tides,and golden tides in 2017.This combination of events,rare worldwide,indicates the potential for further deterioration of the marine environment in the Yellow Sea,which may be related to climate change,aquaculture,and other human activities.Using the SYS as an example,we collected data of the frequency and scale of HABs over the years,as well as that of marine algal toxins,and analyzed the trend in the diversity of HABs in the SYS,to explore the causes and impacts of HABs,as well as the interrelationships among dif ferent types of HABs,including harmful red tides,green tides,and golden tides.We also attempted to improve our understanding of HAB evolution under the influence of global climate change and intensified human activities.
基金Funded by the Natural Science Foundation of China (No.50178070)the Natural Science Foundation of Chongqing (Nos. 8091 and 7136)
文摘To understand the potential impact of the Three Gorges Reservoir on the aquatic ecosystem after the damming of the Yangtze River,we studied the community composition and temporal abundance distribution of algae in two types of water bodies:a segment of the Jialing River near its confluence with the Yangtze River as an example of the river-lake type,and Shuanglong Lake in Chongqing as an example of the lake type.In total,107 species belonging to 58 genera of 7 phyla were identified in the study area of the Jialing River,dominated by three groups with 49.5% diatoms,29.0% chlorophytes,and 11.4% cyanobacteria in the community composition.There were 122 species belonging to 66 genera of 8 phyla in Shuanglong Lake,dominated by the same three groups with 19.7% diatoms,48.4% chlorophytes,and 22.2% cyanobacteria.The densities of total algae and individual dominant groups were all much higher in the lake.More species of diatoms were found in the river-lake segment;whereas more chlorophyte species and cyanobacteriaum species were in the lake.There were 17 dominant species including 8 diatoms,4 chlorophytes,3 cyanobacteria and 2 cryptophytes in the river-lake segment,and 21 species in the lake,including 2 diatoms,9 chlorophytes,6 cyanobacteria,3 cryptophytes and a dinoflagellate.In eutrophic conditions,chlorophytes and cyanobacteria may proliferate in a lake-type area and diatoms may cause algal bloom in a relatively faster-flow lake-river type area.
基金supported by the National Natural Science Foundation of China (No.30870452)the National Chaohu Lake Special Project of China (No.2008ZX07103-005)
文摘^ 15N isotope tracer techniques and ecological modeling were adopted to investigate the fractionation of nitrogen, its uptake and transformation in algae and snail （Bellamya aeruginosa Reeve）. Different algal species were found to differ in their uptake of nitrogen isotopes. Microcystis aeruginisa Ktitz. demonstrated the greatest ^15N accumulation capacity, with the natural variation in isotopic ratio （δ^15N） and the isotope fractionation factor （ε,‰） being the highest among the species investigated. The transformation and utilization of ^15N by snails differed depending on the specific algae consumed （highest for Chlorella pyrenoidosa Chick., lowest for M. aeruginisa）. When snails was seeded in the experimental pond, the algae population structure changed significantly, and total algal biomass as well as the concentration of all nitrogen species decreased, causing an increase in water transparency. A model, incorporating several chemical and biological parameters, was developed to predict algal biomass in an aquatic system when snails was present. The data collected during this investigation indicated that the gastropods such as snails could significantly impact biological community and water quality of small water bodies, suggesting a role for biological control of noxious algal blooms associated with eutrophication.
基金supported by the Major Projects on Control and Rectification of Water Body Pollution of China (No. 2009ZX07317-006)the National Natural Science Foundation of China (No. 41001347, 40971259)+3 种基金the China Postdoctoral Science Foundation (No. 20100470759)the Shanghai Postdoctoral Scientific Program (No. 10R21412300)the Program of Shanghai Subject Chief Scientist (No. 10XD1401600)the International Cooperation Program of Ministry Science and Technology Development of Sino-Germany (No. 2007DFA90510)
文摘To explore eutrophication and algal bloom mechanisms in channel type reservoirs, a novel enclosure experiment was conducted by changing light intensity （LI） in the Daning River of the Three Gorges Reservoir （TGR）. Square enclosures （side 5.0 m） were covered on the surface with shading materials of different thickness, and with their bases open to the river. Changes and characteristics of the main eutrophication factors under the same water quality and hydrodynamic conditions but different LI were evaluated. All experimental water samples were neutral and alkalescent, with high nitrogen and phosphate concentrations, low potassium permanganate index, stable water quality, and different LI. At the same water depth, LI decreased with increasing shade material, while dissolved oxygen and water temperature were both stable. The growth peak of phytoplankton was with light of 345-4390 lux underwater or 558-7450 lux above the water surface, and water temperature of 25.6--26.5℃. Algae were observed in all water samples, accounting for 6 phylum and 57 species, with algal density changing frequently. The results showed that significantly strong or weak light was unfavorable for phytoplankton growth and the function together with suitable temperature and LI and ample sunshine encouraged algal blooms under the same water quality and hydrodynamic conditions. Correlation analysis indicated that algae reduced gradually lengthwise along water depth in the same enclosure while pH became high. The power exponent relationship between chlorophyll a （Chl-a） and LI was found by curve fitting, that is Chl-a = K（LI）n.
基金supported by the State Technology Major Special Project on Water Pollution Control(No.2008ZX07101-009,2009ZX07101-015)the National Natural Science Foundation of China(No. 90510009)
文摘To study how global warming and eutrophication affect water ecosystems, a multiplicative growth Monod model, modified by incorporating the Arrhenius equation, was applied to Lake Taihu to quantitatively study the relationships between algal biomass and both nutrients and temperature using long-term data. To qualitatively assess which factor was a limitation of the improved model, temperature variables were calculated using annual mean air temperature （AT）, water temperature （WT）, and their average temperature （ST）, while substrate variables were calculated using annual mean total nitrogen （TN）, total phosphorus （TP）, and their weighted aggregate （R）, respectively. The nine fitted curves showed that TN and AT were two important factors influencing algal growth; AT limited growth as algal photosynthesis is mainly carried out near the water surface; N leakage of phytoplankton and internal phosphorus load from sediment explains why TN was the best predictor of peak biomass using the Monod model. The fitted results suggest that annual mean algal biomass increased by 0.145 times when annual mean AT increased by 1.0℃. Results also showed that the more eutrophic the lake, the greater the effect AT had on algal growth. Subsequently, the long-term joint effect of annual temperature increase and eutrophication to water ecosystems can be quantitatively assessed and predicted.
基金supported by the Major State Basic Research Development Program of China(No. 2008CB418105)
文摘It is important to assess the effect on zooplankton when perform the environmental protection or restoration technology, especially removing algal blooms, because algae were the major primary producer in algal lakes. The influence on zooplankton community after half a year of algal blooms removed by chitosan-modified soils in Taihu Lake was assessed and the rationality of carrying out the process semiannually was evaluated in the present study. Morphological composition and genetic diversity of zooplankton community were investigated by microscope checkup and polymerase chain reaction-denatured gradient gel electrophoresis （PCR-DGGE）. A total of 44 zooplankton taxa （23 protozoa, 17 rotifers, 3 copepoda and 1 cladocera） were detected by microscope checkup, and a total of 91 bands （28 bands amplified by primers F1427-GC and R1616, 63 bands amplified by primers Fung-GC and NS1） were detected by PCR-DGGE. The results of cluster analysis or detrended correspondence analysis indicated that there was no considerable difference in morphological composition of zooplankton and DGGE profiles between experimental and control sites, and DGGE profiles could represent the biologic diversity. The study showed that zooplankton community could recover original condition after half year of algal blooms removed by chitosan-modified soils and it was acceptable to apply this process semiannually. In addition, the results revealed that PCR-DCJGE could be applied to investigate the impacts of the environmental protection or restoration engineering on zooplankton community diversity.
基金Supported by the National Natural Science Foundation of China(NSFC)(Nos.41576159,U1133003)the National High Technology Research and Development Program of China(863 Program)(No.2013AA065805)
文摘Blooms of Phaeocystis globosa have been frequently reported in Chinese coastal waters, causing serious damage to marine ecosystems. To better understand the ecological characteristics of P. globosa in Chinese coastal waters that facilitate its rapid expansion, the effects of temperature, salinity and irradiance on the growth of P. globosa from the South China Sea were examined in the laboratory. The saturating irradiance for the growth ofP. globosa （Is） was 60 μmol/（m^2·s）, which was lower than those of other harmful algal species （70-114μmol/（m^2·s））. A moderate growth rate of 0.22/d was observed at 2 μmol/（m^2·s） （the minimum irradiance in the experiment）, and photo-inhibition did not occur at 230 μmol/（m^2·s） （the maximum irradiance in the experiment）. Exposed to 42 different combinations of temperatures （10- 31 ℃） and salinities （10-40） under saturating irradiance, P. globosa exhibited its maximum specific growth rate of 0.80/d at the combinations of 24℃ and 35, and 27℃ and 40. The optimum growth rates （〉0.80/d） were observed at temperatures ranging from 24 to 27℃ and salinities from 35 to 40. While P. globosa was able to grow well at temperatures from 20℃ to 31℃ and salinities from 20 to 40, it could not grow at temperatures lower than 15℃ or salinities lower than 15. Factorial analysis revealed that temperature and salinity has similar influences on the growth of this species. This strain ofP. globosa not only prefers higher temperatures and higher salinity, but also possesses a flexible nutrient competing strategy, adapted to lower irradiance. Therefore, the P. globosa population from South China Sea should belong to a new ecotype. There is also a potentially high risk of blooms developing in this area throughout the year.
基金the National Natural Science Foundation of China(No.51978561)the International Science and Technology Cooperation Program in Shaanxi Province(No.2018kw-011)Shaanxi Provincial Key Research and Development Projects(Nos.2019ZDLSF06-01 and 2019ZDLSF06-02).
文摘Urban lake ecosystems are significant for social development,but currently we know little about the geographical distribution of algal community in urban lakes at a large-scale.In this study,we investigated the algal community structure in different areas of urban lakes in China and evaluated the influence of water quality parameters and geographical location on the algal community.The results showed that obvious differences in water quality and algal communities were observed among urban lakes in different geographical areas.Chlorophyta was the dominant phylum,followed by cyanobacteria in all areas.The network analysis indicated that algal community composition in urban lakes of the western and southern area showed more variations than the eastern and northern areas,respectively.Redundancy analysis and structural equation model revealed that nutrients and p H were dominant environmental factors that affected the algal community,and they showed higher influence than that of iron,manganese and COD Mn concentration.Importantly,algal community and density exhibited longitude and latitude relationship.In general,these results provided an ecological insight into large-scale geographical distributions of algal community in urban lakes,thereby having potential applications for management of the lakes.
