Discharging wastewater containing heavy metals of Cu, Pb, Zn and Cd into water bodies can cause toxicity in plants and aquatic animals and some of them will be unable to survive except algae. Wastewater treatment meth...Discharging wastewater containing heavy metals of Cu, Pb, Zn and Cd into water bodies can cause toxicity in plants and aquatic animals and some of them will be unable to survive except algae. Wastewater treatment method to remove heavy metal contaminants includes chemical precipitation, ion exchange, membrane, filtration, adsorption using activated carbon. However, these methods are either expensive or have other disadvantages such as high energy consumption and inefficiencies when existing heavy metals are at trace concentration. Biosorption using algae biomass can be an alternative method to eliminate heavy metals. The objective of the project is to investigate the capability of Marine Algae (MA) and Freshwater Algae (FA) bi-omass in adsorbing heavy metals of Cu, Pb, Zn and Cd from water medium using synthetic water and industrial water. MA and FA were obtained from the eastern coast of Pulau Ubin and local fish farm respectively. After being fully washed with deionised water, dried in a furnace for 105°C, they are grinded to pass 1 mm2 of siever. MA and FA were characterised using FTIR to determine their functional groups. An industrial water was collected from industrial discharge from metal fac-tories in northern side of Singapore. Effect of adsorption time, adsorbent concentra-tion, and pH were studied. The result showed that FA and MA had a higher capability in adsorbing a total metal of about 40 ppm level from an industrial water, or 4 times than synthetic water concentration, at the same adsorbent dosage of 50 mg. In con-clusion, the presence of various functional groups, hydroxyl, carboxylic and amine groups, in all MA and FA samples had enabled the algae biomass to adsorb heavy metals of Cu, Pb, Cd and Zn from synthetic and industrial water. Due to their bio-sorptive properties and fast adsorption capability, algae could be a potential method for cleaning up surface water or post-treatment of wastewater and minimise the cost of eutrophication.展开更多
the biomass of ice algal communities in coastal sea ice off zhongshan Station, antarctica were monitored from april to december 1992. The maximum Thickness of ice cover was 1. 74 m in november/december and covered-sno...the biomass of ice algal communities in coastal sea ice off zhongshan Station, antarctica were monitored from april to december 1992. The maximum Thickness of ice cover was 1. 74 m in november/december and covered-snow was less than35 cm in depth throughout the study period. Brown layers occurred in 2~5 cm of theIce bottom in late april and november, with chlorophyll a peak values of 360. 7 and2810 mg/m3 respectively. The integrated chlorophyll a values ranged from 1. 17 to59. 7 mg/m2 with the peak occurring in november when ice algae bloomed, and theValues never exceeded 6 mg/m2 before mid october except at one site, the highest valueOccurred in april and then decreased nuctuatedly throughout the year. The biomassWas concentrated mainly in the bottom of the ice, and might be also partly concentratedIn the interior sections where autumn bloom had occurred. The dominant diatoms wereComposed of nitzschia lecointei, n. Barkleyi, n. Cylindrus in austral autumn and Amphiphiprora kjellmanii, berkeleya rutilans, nitzschia lecointei in austral spring, andShowed some difference at sites owing to the environmental conditions.展开更多
Macroalgae blooms of Ulva prolifera have occurred every summer in the southern Yellow Sea since 2007,inducing severe ecological problems and huge economic losses.Genesis and secular movement of green algae blooms have...Macroalgae blooms of Ulva prolifera have occurred every summer in the southern Yellow Sea since 2007,inducing severe ecological problems and huge economic losses.Genesis and secular movement of green algae blooms have been well monitored by using remote sensing and other methods.In this study,green algae were detected and traced by using Geostationary Ocean Color Imager(GOCI),and a novel biomass estimation model was developed from the relationship between biomass measurements and previously published satellite-derived biomass indexes.The results show that the green algae biomass can be determined most accurately with the biomass index of green algae for GOCI(BIGAG),which is calculated from the Rsurf data that had been atmospherically corrected by ENVI/QUAC method.For the first time,dynamic changes in green algae biomass were studied over an hourly scale.Short-term biomass changes were highly influenced by Photosynthetically Available Radiation(PAR)and tidal phases,but less by sea surface temperature variations on a daily timescale.A new parameter of biomass changes(PBC),calculated by the ratio of the biomass growth rate to movement velocity,could provide an effective way to assess and forecast green tide in the southern Yellow Sea and similar areas.展开更多
Aquatic plant communities, which largely determine the ecological state of aquatic ecosystems and the quality of their waters, are the most important components in the biological monitoring system. Lake Khadicha is a ...Aquatic plant communities, which largely determine the ecological state of aquatic ecosystems and the quality of their waters, are the most important components in the biological monitoring system. Lake Khadicha is a unique natural body of water that is used for growing commercial fish. In recent years, due to heavy loads of abiotic and anthropogenic factors, the lake water has become highly saline. This phenomenon greatly affects the biodiversity of aquatic organisms, in addition to algae. During 2019-2021, the algae flora of Lake Khadicha was studied. 216 species of algae were identified as part of the algal flora. Their relationship with external factors such as water temperature, salinity and pH was studied. The seasonal abundance and biomass of algal flora areas of the lake were determined. Quantitative indicators of the dominant species in each season and their bioecological characteristics are identified.展开更多
Most water bodies worldwide are infested with algae bloom and Lake Taihu is no exception, various techniques have been developed to harvest microalgae from Lake Taihu as part of the lake cleaning program and this resu...Most water bodies worldwide are infested with algae bloom and Lake Taihu is no exception, various techniques have been developed to harvest microalgae from Lake Taihu as part of the lake cleaning program and this results in a large algae biomass to deal with. This study made use of the algae biomass harvested as a biocolorants source for textile application and also evaluated its dyeing characteristics with mercerized and bleached cotton. The fabrics were dyed with either ultrasound or water bath method. The ultrasound method improved dye extraction yield from 17.8% for the conventional method to 26.7%, which was also enhanced to 33.2% with the addition of HCl (1 cm). The ultrasound dyeing method was effective at improving dye uptake at a reduced dyeing temperature when compared to the conventional method and also produced different shades of color after dyeing with different mordants. The dyed fabrics had good fastness properties for laundry, crocking and light. The dyed fabrics also showed a good ultraviolet protection factor. The use of algae biomass as a potential source of colorants for textile application will provide an alternate dye source that is environmentally friendly.展开更多
1 Introduction Recently the demand for fossil fuel has grown significantly with the rapid development of the Chinese economy.Renewable energy was developed to replace traditional fossil fuels,which would decrease the
Abundance, biomass and composition of the ice algal and phytoplankton communities were investigated in the southeastern Laptev Sea in spring 1999. Diatoms dominated the algal communities and pennate diatoms dominated ...Abundance, biomass and composition of the ice algal and phytoplankton communities were investigated in the southeastern Laptev Sea in spring 1999. Diatoms dominated the algal communities and pennate diatoms dominated the diatom population. 12 dominant algal species occurred within sea ice and underlying water column, including Fragilariopsis oceanica, F. cylindrus, Nitzschla frigida, N. promare, Achnanthes taeniata, Nitzschia neofrigida, Navicula pelagica , N. vanhoef fenii, N. septentrionalls, Melosiraarctica , Clindrotheca closterium and Pyramimonas sp. The algal abundance of bottom 10cm sea ice varied between 14.6 and 1562.2 × 10^4 cells 1^-1 with an average of 639.0 × 10^4 cells 1^-1 , and the algal biomass ranged from 7.89 to 2093.5μg C 1^-1 with an average of 886.9μg C1^-1 , which were generally one order of magnitude higher than those of sub-bottom ice and two orders of magnitude higher than those of underlying surface water. The integrated algal abundance and biomass of lowermost 20 cm ice column were averagely 7.7 and 12.2 times as those of upper 20 m water column, respectively, suggesting that the ice algae might play an important role in maintaining the coastal marine ecosystem before the thawing of sea ice. Ice algae influenced the phytoplankton community of the underlying water column. However, the "seeding" of ice algae for phytoplankton bloom was negligible because of the low phytoplankton biomass within the underlying water column.展开更多
Sea-ice algae are a paramount feature of polar marine ecosystems and ice algal standing stocks are characterized by a high spatio-temporal variability. Traditional sampling techniques, e.g., ice coring, are laborinte...Sea-ice algae are a paramount feature of polar marine ecosystems and ice algal standing stocks are characterized by a high spatio-temporal variability. Traditional sampling techniques, e.g., ice coring, are laborintensive, spatially limited and invasive, thereby limiting our understanding of ice algal biomass variability patterns. Thishas consequences for quantifying ice-associated algal biomass distribution, primary production, and detecting responses to changing environmental conditions. Close-range under-ice optical remote sensing techniques have emerged as a capable alternative providing non-invasive estimates of ice algal biomass and its spatial variability. In this review we first summarize observational studies, using both classical and new methods that aim to capture biomass variability at multiple spatial scales and identify the environmental drivers. We introduce the complex multi-disciplinary nature of under-ice spectral radiation profiling techniquesand discuss relevant concepts of sea-ice radiative transfer and bio-optics. In addition, we tabulate and discuss advances and limitations of different statistical approaches used to correlate biomass and under-ice light spectral composition. We also explore theoretical and technical aspects of using Unmanned Underwater Vehicles (UUV), and Hyperspectral Imaging (HI) technology in an under-ice remote sensing context. The review concludes with an outlook and way forward to combine platforms and optical sensors to quantify ice algal spatial variability and establish relationships with its environmental drivers.展开更多
Surging oil, feed and fertilizer costs have impacted farmers particularly hard. Farm-based, local sources of renewable energy could help reduce energy costs for farmers and help develop rural-based processing and manu...Surging oil, feed and fertilizer costs have impacted farmers particularly hard. Farm-based, local sources of renewable energy could help reduce energy costs for farmers and help develop rural-based processing and manufacturing of biofuel to bolster rural economies. At the same time, nutrient contamination and eutrophication from farming operations have become national problems. Algal-based bioprocessors have the potential to address these problems simultaneously. At Appalachian State University (Appstate) we set out to design, build and test a system that uses algae to capture wastewater nutrients as well as excreted pharmaceuticals, while simultaneously sequestering CO2, producing oil for conversion to biodiesel and feed for livestock. There are a number of problems with current algae growth systems. Algae grown in an open pond or raceway system are suspended in the water in the presence of soluble and suspended waste making most of the current harvest techniques problematic and expensive. Appstate designed algae troughs in which the algae are immobilized on a solid substrate. The laboratory-scale prototype was constructed of three-sided square plastic pipe open at the top. Inside the pipe, there was a series of cloth filters supported by rigid flow-through baffles. Preliminary results observed an average percent reduction of nitrate and phosphorous of 40 and 43, respectively, from different initial nutrient concentrations. Near complete removal (~96%) of estrogen was observed in 2-day trial experiments. In addition, effective increases in algal biomass which can serve as both biofuel feedstock and livestock feed were observed.展开更多
The ice algal and phytoplankton assemblages were studied from Nella Fjord near Zhongshan Station, East Antarctica from April 12 to December 30, 1992. Algal blooms occurred about 3 cm thick on the bottom of sea ice in ...The ice algal and phytoplankton assemblages were studied from Nella Fjord near Zhongshan Station, East Antarctica from April 12 to December 30, 1992. Algal blooms occurred about 3 cm thick on the bottom of sea ice in late April and mid November to early December respectively, and a phytoplankton bloom appeared in the underlying surface water in mid December following the spring ice algal bloom. The biomass in ice bottom was 1 to 3 orders of magnitude higher than that of surface water. Amphiprora kjellmanii, Berkeleya sp., Navicula glaciei, Nitzschia barkelyi, N. cylindrus /N. curta, N. lecointei and Nitzschia sp. were common in the sea ice temporarily or throughout the study period. The biomass in a certain ice segment was decreased gradually and the dominant species were usually succeeded as the season went on. Nitzschia sublineata and Dactyliosolen antarctica were two seasonal dominant species only observed in underlying water column. The assemblages between bottom of ice and underlying surface water were different except when spring ice algae bloomed. The evidence shows that the ice algal blooms occurred mainly by in situ growth of ice algae, and the phytoplankton bloom was mostly caused by the release of ice algae.展开更多
In the coastal ecosystems of the Black Sea,macrophytobenthos and,in particular,the association of Cystoseira crinite,C.barbara,Cladostephus verticillatus,and Corallina mediterranea,with its thick vegetative canopy(VC)...In the coastal ecosystems of the Black Sea,macrophytobenthos and,in particular,the association of Cystoseira crinite,C.barbara,Cladostephus verticillatus,and Corallina mediterranea,with its thick vegetative canopy(VC),is the key contributor to primary production(PP).Though the vertical structure of the canopy,formed by the algal association,is of principal importance to the PP level,this subject has been long-neglected by researchers.The goal of our work was to compare vertical structures of the vegetative canopy of Cystoseira brown algae under diverse hydrodynamical conditions of the Crimean Peninsula coast.Samples were collected using the 50 cm×50 cm counting frame at eight stations positioned in shallow(55-60 cm deep)sites of Sevastopol Bay(Crimean Peninsula).Dry weight biomass of the VC was determined for all algae assemblage and for each algal species individually,per horizontal surface unit,at each height(Z).The study shows that:1)the VC is characterized by unimodal vertical distribution of biomass,with maximum estimate in the lower part,where the biomass increases to 85%of the total biomass;2)a series of single-peaked curves reliably describes the unimodal distribution of the biomass;thalli of different age groups are found along the canopy profile;and 3)algae found in epiphytic synusia prefer inhabiting the upper part of the VC.The role of environmental factors(seawater turbulence and solar radiation)is discussed in reference to the formation of the vertical structure,made up of the associations of the brown algae Cystoseira.展开更多
文摘Discharging wastewater containing heavy metals of Cu, Pb, Zn and Cd into water bodies can cause toxicity in plants and aquatic animals and some of them will be unable to survive except algae. Wastewater treatment method to remove heavy metal contaminants includes chemical precipitation, ion exchange, membrane, filtration, adsorption using activated carbon. However, these methods are either expensive or have other disadvantages such as high energy consumption and inefficiencies when existing heavy metals are at trace concentration. Biosorption using algae biomass can be an alternative method to eliminate heavy metals. The objective of the project is to investigate the capability of Marine Algae (MA) and Freshwater Algae (FA) bi-omass in adsorbing heavy metals of Cu, Pb, Zn and Cd from water medium using synthetic water and industrial water. MA and FA were obtained from the eastern coast of Pulau Ubin and local fish farm respectively. After being fully washed with deionised water, dried in a furnace for 105°C, they are grinded to pass 1 mm2 of siever. MA and FA were characterised using FTIR to determine their functional groups. An industrial water was collected from industrial discharge from metal fac-tories in northern side of Singapore. Effect of adsorption time, adsorbent concentra-tion, and pH were studied. The result showed that FA and MA had a higher capability in adsorbing a total metal of about 40 ppm level from an industrial water, or 4 times than synthetic water concentration, at the same adsorbent dosage of 50 mg. In con-clusion, the presence of various functional groups, hydroxyl, carboxylic and amine groups, in all MA and FA samples had enabled the algae biomass to adsorb heavy metals of Cu, Pb, Cd and Zn from synthetic and industrial water. Due to their bio-sorptive properties and fast adsorption capability, algae could be a potential method for cleaning up surface water or post-treatment of wastewater and minimise the cost of eutrophication.
文摘the biomass of ice algal communities in coastal sea ice off zhongshan Station, antarctica were monitored from april to december 1992. The maximum Thickness of ice cover was 1. 74 m in november/december and covered-snow was less than35 cm in depth throughout the study period. Brown layers occurred in 2~5 cm of theIce bottom in late april and november, with chlorophyll a peak values of 360. 7 and2810 mg/m3 respectively. The integrated chlorophyll a values ranged from 1. 17 to59. 7 mg/m2 with the peak occurring in november when ice algae bloomed, and theValues never exceeded 6 mg/m2 before mid october except at one site, the highest valueOccurred in april and then decreased nuctuatedly throughout the year. The biomassWas concentrated mainly in the bottom of the ice, and might be also partly concentratedIn the interior sections where autumn bloom had occurred. The dominant diatoms wereComposed of nitzschia lecointei, n. Barkleyi, n. Cylindrus in austral autumn and Amphiphiprora kjellmanii, berkeleya rutilans, nitzschia lecointei in austral spring, andShowed some difference at sites owing to the environmental conditions.
基金the National Natural Science Foundation of China(Nos.41776052,41476031)the Research Fund of State Key Laboratory of Marine Geology(No.MG20190104)the China Scholarship Council(No.CSC201906260052).
文摘Macroalgae blooms of Ulva prolifera have occurred every summer in the southern Yellow Sea since 2007,inducing severe ecological problems and huge economic losses.Genesis and secular movement of green algae blooms have been well monitored by using remote sensing and other methods.In this study,green algae were detected and traced by using Geostationary Ocean Color Imager(GOCI),and a novel biomass estimation model was developed from the relationship between biomass measurements and previously published satellite-derived biomass indexes.The results show that the green algae biomass can be determined most accurately with the biomass index of green algae for GOCI(BIGAG),which is calculated from the Rsurf data that had been atmospherically corrected by ENVI/QUAC method.For the first time,dynamic changes in green algae biomass were studied over an hourly scale.Short-term biomass changes were highly influenced by Photosynthetically Available Radiation(PAR)and tidal phases,but less by sea surface temperature variations on a daily timescale.A new parameter of biomass changes(PBC),calculated by the ratio of the biomass growth rate to movement velocity,could provide an effective way to assess and forecast green tide in the southern Yellow Sea and similar areas.
文摘Aquatic plant communities, which largely determine the ecological state of aquatic ecosystems and the quality of their waters, are the most important components in the biological monitoring system. Lake Khadicha is a unique natural body of water that is used for growing commercial fish. In recent years, due to heavy loads of abiotic and anthropogenic factors, the lake water has become highly saline. This phenomenon greatly affects the biodiversity of aquatic organisms, in addition to algae. During 2019-2021, the algae flora of Lake Khadicha was studied. 216 species of algae were identified as part of the algal flora. Their relationship with external factors such as water temperature, salinity and pH was studied. The seasonal abundance and biomass of algal flora areas of the lake were determined. Quantitative indicators of the dominant species in each season and their bioecological characteristics are identified.
文摘Most water bodies worldwide are infested with algae bloom and Lake Taihu is no exception, various techniques have been developed to harvest microalgae from Lake Taihu as part of the lake cleaning program and this results in a large algae biomass to deal with. This study made use of the algae biomass harvested as a biocolorants source for textile application and also evaluated its dyeing characteristics with mercerized and bleached cotton. The fabrics were dyed with either ultrasound or water bath method. The ultrasound method improved dye extraction yield from 17.8% for the conventional method to 26.7%, which was also enhanced to 33.2% with the addition of HCl (1 cm). The ultrasound dyeing method was effective at improving dye uptake at a reduced dyeing temperature when compared to the conventional method and also produced different shades of color after dyeing with different mordants. The dyed fabrics had good fastness properties for laundry, crocking and light. The dyed fabrics also showed a good ultraviolet protection factor. The use of algae biomass as a potential source of colorants for textile application will provide an alternate dye source that is environmentally friendly.
基金National Natural Science Foundation of China (41572326) for the support of this study
文摘1 Introduction Recently the demand for fossil fuel has grown significantly with the rapid development of the Chinese economy.Renewable energy was developed to replace traditional fossil fuels,which would decrease the
基金supported by the National Nature Science Foundation of China(30270112,40006010)the Basic Research Special Project of Chinese Science and Technology Administration(2003DEB5J057)Oceanic Science Foundation of State 0ceanic Administration of China(2003122).
文摘Abundance, biomass and composition of the ice algal and phytoplankton communities were investigated in the southeastern Laptev Sea in spring 1999. Diatoms dominated the algal communities and pennate diatoms dominated the diatom population. 12 dominant algal species occurred within sea ice and underlying water column, including Fragilariopsis oceanica, F. cylindrus, Nitzschla frigida, N. promare, Achnanthes taeniata, Nitzschia neofrigida, Navicula pelagica , N. vanhoef fenii, N. septentrionalls, Melosiraarctica , Clindrotheca closterium and Pyramimonas sp. The algal abundance of bottom 10cm sea ice varied between 14.6 and 1562.2 × 10^4 cells 1^-1 with an average of 639.0 × 10^4 cells 1^-1 , and the algal biomass ranged from 7.89 to 2093.5μg C 1^-1 with an average of 886.9μg C1^-1 , which were generally one order of magnitude higher than those of sub-bottom ice and two orders of magnitude higher than those of underlying surface water. The integrated algal abundance and biomass of lowermost 20 cm ice column were averagely 7.7 and 12.2 times as those of upper 20 m water column, respectively, suggesting that the ice algae might play an important role in maintaining the coastal marine ecosystem before the thawing of sea ice. Ice algae influenced the phytoplankton community of the underlying water column. However, the "seeding" of ice algae for phytoplankton bloom was negligible because of the low phytoplankton biomass within the underlying water column.
基金supported by the Australian Research Council’s Special Research Initiative for Antarctic Gateway Partnership (Project ID SR140300001)EC was supported by the Antarctic Gateway Partnership+3 种基金the University of Tasmania’s Institute for Marine and Ph.D. programKMMs contribution to this work was supported by the Australian Governments Cooperative Research Centres Program through the Antarctic Climate and Ecosystems Cooperative Research Centre, through Australian Antarctic Science project #4298 and through a fellowship at the Hanse-Wissenschaftskolleg (Delmenhorst, Germany)LCLH’s contribution to the work was supported by AUFF (Aarhus University Research Foundation) grant nr. 20858. (Delmenhorst, Germany)LCLH’s contribution to the work was supported by AUFF (Aarhus University Research Foundation) grant nr. 20858
文摘Sea-ice algae are a paramount feature of polar marine ecosystems and ice algal standing stocks are characterized by a high spatio-temporal variability. Traditional sampling techniques, e.g., ice coring, are laborintensive, spatially limited and invasive, thereby limiting our understanding of ice algal biomass variability patterns. Thishas consequences for quantifying ice-associated algal biomass distribution, primary production, and detecting responses to changing environmental conditions. Close-range under-ice optical remote sensing techniques have emerged as a capable alternative providing non-invasive estimates of ice algal biomass and its spatial variability. In this review we first summarize observational studies, using both classical and new methods that aim to capture biomass variability at multiple spatial scales and identify the environmental drivers. We introduce the complex multi-disciplinary nature of under-ice spectral radiation profiling techniquesand discuss relevant concepts of sea-ice radiative transfer and bio-optics. In addition, we tabulate and discuss advances and limitations of different statistical approaches used to correlate biomass and under-ice light spectral composition. We also explore theoretical and technical aspects of using Unmanned Underwater Vehicles (UUV), and Hyperspectral Imaging (HI) technology in an under-ice remote sensing context. The review concludes with an outlook and way forward to combine platforms and optical sensors to quantify ice algal spatial variability and establish relationships with its environmental drivers.
文摘Surging oil, feed and fertilizer costs have impacted farmers particularly hard. Farm-based, local sources of renewable energy could help reduce energy costs for farmers and help develop rural-based processing and manufacturing of biofuel to bolster rural economies. At the same time, nutrient contamination and eutrophication from farming operations have become national problems. Algal-based bioprocessors have the potential to address these problems simultaneously. At Appalachian State University (Appstate) we set out to design, build and test a system that uses algae to capture wastewater nutrients as well as excreted pharmaceuticals, while simultaneously sequestering CO2, producing oil for conversion to biodiesel and feed for livestock. There are a number of problems with current algae growth systems. Algae grown in an open pond or raceway system are suspended in the water in the presence of soluble and suspended waste making most of the current harvest techniques problematic and expensive. Appstate designed algae troughs in which the algae are immobilized on a solid substrate. The laboratory-scale prototype was constructed of three-sided square plastic pipe open at the top. Inside the pipe, there was a series of cloth filters supported by rigid flow-through baffles. Preliminary results observed an average percent reduction of nitrate and phosphorous of 40 and 43, respectively, from different initial nutrient concentrations. Near complete removal (~96%) of estrogen was observed in 2-day trial experiments. In addition, effective increases in algal biomass which can serve as both biofuel feedstock and livestock feed were observed.
文摘The ice algal and phytoplankton assemblages were studied from Nella Fjord near Zhongshan Station, East Antarctica from April 12 to December 30, 1992. Algal blooms occurred about 3 cm thick on the bottom of sea ice in late April and mid November to early December respectively, and a phytoplankton bloom appeared in the underlying surface water in mid December following the spring ice algal bloom. The biomass in ice bottom was 1 to 3 orders of magnitude higher than that of surface water. Amphiprora kjellmanii, Berkeleya sp., Navicula glaciei, Nitzschia barkelyi, N. cylindrus /N. curta, N. lecointei and Nitzschia sp. were common in the sea ice temporarily or throughout the study period. The biomass in a certain ice segment was decreased gradually and the dominant species were usually succeeded as the season went on. Nitzschia sublineata and Dactyliosolen antarctica were two seasonal dominant species only observed in underlying water column. The assemblages between bottom of ice and underlying surface water were different except when spring ice algae bloomed. The evidence shows that the ice algal blooms occurred mainly by in situ growth of ice algae, and the phytoplankton bloom was mostly caused by the release of ice algae.
文摘In the coastal ecosystems of the Black Sea,macrophytobenthos and,in particular,the association of Cystoseira crinite,C.barbara,Cladostephus verticillatus,and Corallina mediterranea,with its thick vegetative canopy(VC),is the key contributor to primary production(PP).Though the vertical structure of the canopy,formed by the algal association,is of principal importance to the PP level,this subject has been long-neglected by researchers.The goal of our work was to compare vertical structures of the vegetative canopy of Cystoseira brown algae under diverse hydrodynamical conditions of the Crimean Peninsula coast.Samples were collected using the 50 cm×50 cm counting frame at eight stations positioned in shallow(55-60 cm deep)sites of Sevastopol Bay(Crimean Peninsula).Dry weight biomass of the VC was determined for all algae assemblage and for each algal species individually,per horizontal surface unit,at each height(Z).The study shows that:1)the VC is characterized by unimodal vertical distribution of biomass,with maximum estimate in the lower part,where the biomass increases to 85%of the total biomass;2)a series of single-peaked curves reliably describes the unimodal distribution of the biomass;thalli of different age groups are found along the canopy profile;and 3)algae found in epiphytic synusia prefer inhabiting the upper part of the VC.The role of environmental factors(seawater turbulence and solar radiation)is discussed in reference to the formation of the vertical structure,made up of the associations of the brown algae Cystoseira.