During Jan.1995 to Dec.1996, monthly investigations on the zoobenthic communities of West Lake, samples were collected from six sampling stations. A total of 26 species of macrozoobenthos were identified. The seasonal...During Jan.1995 to Dec.1996, monthly investigations on the zoobenthic communities of West Lake, samples were collected from six sampling stations. A total of 26 species of macrozoobenthos were identified. The seasonal changes in density and biomass of zoobenthos in this lake were analyzed. The annual mean densities were 980～2751 ind/m\+2 and mean biomass was 19.69-122.80 g/m\+2. The densities in winter and early spring were higher than those in summer and autumn. Comparative study of theprevious data (1982 to 1983) collected by the authors, showed that the succession of zoobenthic communities, dominated by \%Procludius choreus\% in density and \%Bellamya purificata\% in biomass, had been occurred in Xiaonan sub\|lake after Qiantang River water was drawn into it; and that the species and biomass of zoobenthos were then increased and the density was decreased. In other sub\|lakes, the dominant species were \%Limnodrilus hoffmeisteri\% and \%Tokunagayusurika akamusi \%in density and \%Branchiura sowerbyi\% and \%Tokunagayusurika akamusi \%in biomass. The water quality was bad in these sub\|lakes because these dominant species are indicators of eutrophication. According to the Margalef index and Goodnight index, West Lake is still an eutrophic lake. Only the water quality of Xiaonan sub\|lake was improved after water drawn from the Qiantang River was introduced into it.展开更多
The production of dimethylsulfoniopropionate （DMSP） and its cleavage products （DMS） are well studied in phytoplankton worldwide. However, less is known about their sources, distributions, and impacts in the coast ...The production of dimethylsulfoniopropionate （DMSP） and its cleavage products （DMS） are well studied in phytoplankton worldwide. However, less is known about their sources, distributions, and impacts in the coast of China. We examined the production of DMSP and DMS in Phaeocvstis globosa Scherffel and other benthic macroalgae from the South China coast in relation to environmental conditions. P. globosa was a harmful marine microalgal species and its bloom took place in the eutrophic waters along the South China Sea frequently. It also produced high content of DMSP at different growth stages, with the highest concentration usually observed in the stationary period. Moreover, the production of DMSP in P. globosa was significantly affected by salinity and temperature with the highest contents associated with high salinity （e.g. 40） and low temperature （e.g. 20℃）. In field benthic macroalgae, there was also a marked difference in the DMSP of various species or different samples of the same species. Chlorophyll a contents were also determined for each macroalgal species. The highest chlorophyll a （238.7 ng/g fresh weight） was recorded in Chlorophyta Ulva lactuca at Guishan Island （Zhuhai）, while the lowest value （1.5 ng/g fresh weight） was found in Rhodophyta Gracilaria tenuistipitata in Zhanjiang. Further correlation analysis indicated that there was no significant relationship between the content of DMSP and chl-a in macroalgae samples （P〉 0.05）. All the results suggested that the production of DMSP in marine algae was not only species- and stage-related, but also greatly affected by various environmental factors.展开更多
In this paper, we assessed the ecological and biodiversity status in the Bohai Sea through a quantitative survey on mac-rofaunal community at 25 stations in Laizhou Bay and adjacent waters in the autumn of 2006.We tes...In this paper, we assessed the ecological and biodiversity status in the Bohai Sea through a quantitative survey on mac-rofaunal community at 25 stations in Laizhou Bay and adjacent waters in the autumn of 2006.We tested the robustness and effectiveness of taxonomic distinctness as an ecological indictor by analyzing its correlation with species richness and natural environmental variables and by analyzing other ecological indicators (Shannon-Wiener H' and W statistics from Abundance Biomass Comparison curve).Results so obtained indicated that the benthic environment of the study waters in general is not under major impact of anthropogenic disturbance, but some stations in Laizhou Bay and along the coast of the Shandong Peninsula and even in the central Bohai Sea might be moderately disturbed and showed signs of ecological degradation.The taxonomic distinctness measures △+ and Λ+ were independent of sampling effort and natural environment factors and were compliant to other ecological indicators.Further application of the taxonomic distinctness indicator to assess marine biodiversity and ecosystem health on a larger regional scale with historical data seems promising.展开更多
This paper synthesizes the extent and nature of scientific information about how dredging activities potentially affect habitats and key ecological functions supporting recruitment and sustainability of estuarine and ...This paper synthesizes the extent and nature of scientific information about how dredging activities potentially affect habitats and key ecological functions supporting recruitment and sustainability of estuarine and marine environment. Fourteen samples were collected after dredging （2008） from fixed sampling stations. The impact on community was estimated at species level （Foraminifera, Protozoan, using statistical analysis）. The maximum negative effect on benthic foraminifera was reduction by 60%, for species richness and by 50% for diversity. This data were compared with the data obtained before dredging （2006） in a time services spanning 2 years. Its revealed that reestablishment of directly with in less than 3 months of the end of dredging, although affected foraminifera and of physico-chemical substrate characteristic 2 years later there was a considerable improvement of whole faunal community. Statistical treatment was given to the data sets to know the relation among parameters. Before, this type of activity is undertaken, each case should be studied regarding viability, the environmental medium where it will take place, the best time of year, and the type of dredging to be used. Small-patch dredging operations are proposed when ever possible, since they allow a quick readjustment of the initial sediment structure and benthic foraminifera. These findings will help to underpin improved planning of management strategies for dredging operations in India and other countries.展开更多
Based on detailed measurement in the field and a comprehensive analysis of carbonate microfacies,the Pennsylvanian reefal microfacies characteristic and sedimentary environment from Longjiangdong,Guangxi,China are ana...Based on detailed measurement in the field and a comprehensive analysis of carbonate microfacies,the Pennsylvanian reefal microfacies characteristic and sedimentary environment from Longjiangdong,Guangxi,China are analyzed. The twelve carbonate microfacies have been recognized including micritic / microsparitic limestone,peloidal / aggregate-grain grainstone,bioclastic wackestone / packstone,laminated mudstone,boundstone,bioclastic wackestone / packstone with single shell,coral framestone / bafflestone,bioclastic packstones /grainstones with abundant benthic foraminifera or crinoids,wackestone / mudstone with calcispheres,bioclastic packstone / grainstone,unname reef-building organism framestone and brachiopod grainstone. In addition,four facies have been identified including open platform facies,restricted platform facies,coral reefal facies and shoal facies. According to analysis of microfacies combination and facies evolution,three stages and three reef units during the reef formation process have been noted. The evolution of each stage indicates a repeating fluctuation of the sea-level,but the water energy is still relatively low overall,which represents frequent changes of paleoclimate in the early Late Carboniferous.展开更多
文摘During Jan.1995 to Dec.1996, monthly investigations on the zoobenthic communities of West Lake, samples were collected from six sampling stations. A total of 26 species of macrozoobenthos were identified. The seasonal changes in density and biomass of zoobenthos in this lake were analyzed. The annual mean densities were 980～2751 ind/m\+2 and mean biomass was 19.69-122.80 g/m\+2. The densities in winter and early spring were higher than those in summer and autumn. Comparative study of theprevious data (1982 to 1983) collected by the authors, showed that the succession of zoobenthic communities, dominated by \%Procludius choreus\% in density and \%Bellamya purificata\% in biomass, had been occurred in Xiaonan sub\|lake after Qiantang River water was drawn into it; and that the species and biomass of zoobenthos were then increased and the density was decreased. In other sub\|lakes, the dominant species were \%Limnodrilus hoffmeisteri\% and \%Tokunagayusurika akamusi \%in density and \%Branchiura sowerbyi\% and \%Tokunagayusurika akamusi \%in biomass. The water quality was bad in these sub\|lakes because these dominant species are indicators of eutrophication. According to the Margalef index and Goodnight index, West Lake is still an eutrophic lake. Only the water quality of Xiaonan sub\|lake was improved after water drawn from the Qiantang River was introduced into it.
基金Supported by the National Natural Science Foundation of China (No. 41006092)Natural Science Foundation of Guangdong Province (No. 1015030101000002)
文摘The production of dimethylsulfoniopropionate （DMSP） and its cleavage products （DMS） are well studied in phytoplankton worldwide. However, less is known about their sources, distributions, and impacts in the coast of China. We examined the production of DMSP and DMS in Phaeocvstis globosa Scherffel and other benthic macroalgae from the South China coast in relation to environmental conditions. P. globosa was a harmful marine microalgal species and its bloom took place in the eutrophic waters along the South China Sea frequently. It also produced high content of DMSP at different growth stages, with the highest concentration usually observed in the stationary period. Moreover, the production of DMSP in P. globosa was significantly affected by salinity and temperature with the highest contents associated with high salinity （e.g. 40） and low temperature （e.g. 20℃）. In field benthic macroalgae, there was also a marked difference in the DMSP of various species or different samples of the same species. Chlorophyll a contents were also determined for each macroalgal species. The highest chlorophyll a （238.7 ng/g fresh weight） was recorded in Chlorophyta Ulva lactuca at Guishan Island （Zhuhai）, while the lowest value （1.5 ng/g fresh weight） was found in Rhodophyta Gracilaria tenuistipitata in Zhanjiang. Further correlation analysis indicated that there was no significant relationship between the content of DMSP and chl-a in macroalgae samples （P〉 0.05）. All the results suggested that the production of DMSP in marine algae was not only species- and stage-related, but also greatly affected by various environmental factors.
基金funded by the National Natural Science Foundation of China (Grant Nos.40730847,40906063 and 41076090)
文摘In this paper, we assessed the ecological and biodiversity status in the Bohai Sea through a quantitative survey on mac-rofaunal community at 25 stations in Laizhou Bay and adjacent waters in the autumn of 2006.We tested the robustness and effectiveness of taxonomic distinctness as an ecological indictor by analyzing its correlation with species richness and natural environmental variables and by analyzing other ecological indicators (Shannon-Wiener H' and W statistics from Abundance Biomass Comparison curve).Results so obtained indicated that the benthic environment of the study waters in general is not under major impact of anthropogenic disturbance, but some stations in Laizhou Bay and along the coast of the Shandong Peninsula and even in the central Bohai Sea might be moderately disturbed and showed signs of ecological degradation.The taxonomic distinctness measures △+ and Λ+ were independent of sampling effort and natural environment factors and were compliant to other ecological indicators.Further application of the taxonomic distinctness indicator to assess marine biodiversity and ecosystem health on a larger regional scale with historical data seems promising.
文摘This paper synthesizes the extent and nature of scientific information about how dredging activities potentially affect habitats and key ecological functions supporting recruitment and sustainability of estuarine and marine environment. Fourteen samples were collected after dredging （2008） from fixed sampling stations. The impact on community was estimated at species level （Foraminifera, Protozoan, using statistical analysis）. The maximum negative effect on benthic foraminifera was reduction by 60%, for species richness and by 50% for diversity. This data were compared with the data obtained before dredging （2006） in a time services spanning 2 years. Its revealed that reestablishment of directly with in less than 3 months of the end of dredging, although affected foraminifera and of physico-chemical substrate characteristic 2 years later there was a considerable improvement of whole faunal community. Statistical treatment was given to the data sets to know the relation among parameters. Before, this type of activity is undertaken, each case should be studied regarding viability, the environmental medium where it will take place, the best time of year, and the type of dredging to be used. Small-patch dredging operations are proposed when ever possible, since they allow a quick readjustment of the initial sediment structure and benthic foraminifera. These findings will help to underpin improved planning of management strategies for dredging operations in India and other countries.
基金supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20120042110027,20110042120043)the National Natural Science Foundation of China(No.41202018)
文摘Based on detailed measurement in the field and a comprehensive analysis of carbonate microfacies,the Pennsylvanian reefal microfacies characteristic and sedimentary environment from Longjiangdong,Guangxi,China are analyzed. The twelve carbonate microfacies have been recognized including micritic / microsparitic limestone,peloidal / aggregate-grain grainstone,bioclastic wackestone / packstone,laminated mudstone,boundstone,bioclastic wackestone / packstone with single shell,coral framestone / bafflestone,bioclastic packstones /grainstones with abundant benthic foraminifera or crinoids,wackestone / mudstone with calcispheres,bioclastic packstone / grainstone,unname reef-building organism framestone and brachiopod grainstone. In addition,four facies have been identified including open platform facies,restricted platform facies,coral reefal facies and shoal facies. According to analysis of microfacies combination and facies evolution,three stages and three reef units during the reef formation process have been noted. The evolution of each stage indicates a repeating fluctuation of the sea-level,but the water energy is still relatively low overall,which represents frequent changes of paleoclimate in the early Late Carboniferous.
