In order to investigate the aggregation mechanism of green macroalgae (Enteromorpha prolifera) on the Qingdao coastline,the macroalgal drift characteristics in the Yellow Sea during June and July in 2008 and 2010 were...In order to investigate the aggregation mechanism of green macroalgae (Enteromorpha prolifera) on the Qingdao coastline,the macroalgal drift characteristics in the Yellow Sea during June and July in 2008 and 2010 were simulated using a three-dimensional wave-tide-circulation coupled model.In June 2008,the monthly-mean surface current flowed onshore and its direction was almost perpendicular to the Qingdao coastline,which was identified as the main reason for a huge accumulation of algae in the coastal waters off Qingdao.The current became parallel to the coastline in July 2008;this shift in current direction led to little accumulation of algae near Qingdao and thus relieved the environmental pressure on the Olympic sailing events.By using the coupled model,we predicted that there would be no serious algal accumulation at Qingdao in late June 2010,which was later confirmed by observations.This study demonstrated that the drift path of macroalgae near Qingdao is mainly controlled by the surface current,which is primarily driven by wind.Regional climate change is therefore one of the means by which physical processes affect marine ecosystems.展开更多
Marine photosynthesis drives the oceanic biological CO2 pump to absorb CO2 from the atmosphere, which sinks more than one third of the industry-originated CO2 into the ocean. The increasing atmos-pheric CO2 and subseq...Marine photosynthesis drives the oceanic biological CO2 pump to absorb CO2 from the atmosphere, which sinks more than one third of the industry-originated CO2 into the ocean. The increasing atmos-pheric CO2 and subsequent rise of pCO2 in seawater, which alters the carbonate system and related chemical reactions and results in lower pH and higher HCO3- concentration, affect photosynthetic CO2 fixation processes of phytoplanktonic and macroalgal species in direct and/or indirect ways. Although many unicellular and multicellular species can operate CO2-concentrating mechanisms (CCMs) to util-ize the large HCO3- pool in seawater, enriched CO2 up to several times the present atmospheric level has been shown to enhance photosynthesis and growth of both phytoplanktonic and macro-species that have less capacity of CCMs. Even for species that operate active CCMs and those whose photo-synthesis is not limited by CO2 in seawater, increased CO2 levels can down-regulate their CCMs and therefore enhance their growth under light-limiting conditions (at higher CO2 levels, less light energy is required to drive CCM). Altered physiological performances under high-CO2 conditions may cause genetic alteration in view of adaptation over long time scale. Marine algae may adapt to a high CO2 oceanic environment so that the evolved communities in future are likely to be genetically different from the contemporary communities. However, most of the previous studies have been carried out under indoor conditions without considering the acidifying effects on seawater by increased CO2 and other interacting environmental factors, and little has been documented so far to explain how physi-ology of marine primary producers performs in a high-CO2 and low-pH ocean.展开更多
文中首次报导贵州寒武系黔东统都匀阶"清虚洞组"(或乌训组)宏观藻类,计2属2种:环圈螺旋抚仙藻Fuxianospira gyrata Chen and Zhou,1997和云南中华细丝藻Sinocylindra yunnanensis Chen and Erdtmann,1991,它们是澄江生物群最...文中首次报导贵州寒武系黔东统都匀阶"清虚洞组"(或乌训组)宏观藻类,计2属2种:环圈螺旋抚仙藻Fuxianospira gyrata Chen and Zhou,1997和云南中华细丝藻Sinocylindra yunnanensis Chen and Erdtmann,1991,它们是澄江生物群最常见的两类宏观藻类具有澄江生物群宏观藻类的组合特征。"清虚洞组"位于黔东统上部,介于杷榔组和凯里组之间,该组宏观藻类的发现,为寒武纪宏观藻类演化链的完整研究提供了有价值的资料。展开更多
Arsenobetaine（AB） and thio-arsenoribosides were measured in common macroalgae species（8 phaeophyta, 4 rhodophyta and 2 chlorphyta）, along the Australian south east coast line. As well, arsenic species profiles wer...Arsenobetaine（AB） and thio-arsenoribosides were measured in common macroalgae species（8 phaeophyta, 4 rhodophyta and 2 chlorphyta）, along the Australian south east coast line. As well, arsenic species profiles were measured for two common marine herbivores, the sea urchin Centrostephanus rodgersii and the fish Odax cyanomelas that graze on these macroalgae to understand if trophic transfer of these species would account for their presence in marine herbivores. AB was found in seven of the fourteen macroalgae species investigated but does not contributed significantly to any of the macroalgae arsenic content（0.01-1.2 μg/g）. AB was found in only two of the brown macroalgae and all the red and green macroalgae（with the exception of Corallina officinalis）. Thio-arsenic species were found sporadically, but not in high concentrations in any of the macroalgae investigated.AB present in macroalgae is likely to be associated with epiphytic organisms while thio-arsenoribosides are likely to be produced by decaying parts of damaged macroalgae.A laboratory feeding experiment in which the herbivorous gastropod, Austrocochlea constricta, was fed macroalgae containing thio-arsenoribosides for a 24 hr period every three days showed that these are readily accumulated over a short period. Thio-arsenoribosides in herbivores are therefore probably obtained through trophic transfer. Some AB is also obtained through trophic transfer; however, the presence of trimethylated arsonioribosides,a hypothesized precursor of AB formation in herbivores, suggests that some AB is produced within herbivores from the transformation of arsenoribosides accumulated from their diet.展开更多
基金supported by the National 908 Project of China (908-02-01-04)the National Key Technology R&D Special Program (2008 BAC49B02)
文摘In order to investigate the aggregation mechanism of green macroalgae (Enteromorpha prolifera) on the Qingdao coastline,the macroalgal drift characteristics in the Yellow Sea during June and July in 2008 and 2010 were simulated using a three-dimensional wave-tide-circulation coupled model.In June 2008,the monthly-mean surface current flowed onshore and its direction was almost perpendicular to the Qingdao coastline,which was identified as the main reason for a huge accumulation of algae in the coastal waters off Qingdao.The current became parallel to the coastline in July 2008;this shift in current direction led to little accumulation of algae near Qingdao and thus relieved the environmental pressure on the Olympic sailing events.By using the coupled model,we predicted that there would be no serious algal accumulation at Qingdao in late June 2010,which was later confirmed by observations.This study demonstrated that the drift path of macroalgae near Qingdao is mainly controlled by the surface current,which is primarily driven by wind.Regional climate change is therefore one of the means by which physical processes affect marine ecosystems.
基金Supported by National Natural Science Foundation of China (Grant Nos. 90411018, and 40676063)National Basic Research Program of China (Grant No. 2009CB 421207)Ministry of Education of China for Key Profect (Grant No. 308015)
文摘Marine photosynthesis drives the oceanic biological CO2 pump to absorb CO2 from the atmosphere, which sinks more than one third of the industry-originated CO2 into the ocean. The increasing atmos-pheric CO2 and subsequent rise of pCO2 in seawater, which alters the carbonate system and related chemical reactions and results in lower pH and higher HCO3- concentration, affect photosynthetic CO2 fixation processes of phytoplanktonic and macroalgal species in direct and/or indirect ways. Although many unicellular and multicellular species can operate CO2-concentrating mechanisms (CCMs) to util-ize the large HCO3- pool in seawater, enriched CO2 up to several times the present atmospheric level has been shown to enhance photosynthesis and growth of both phytoplanktonic and macro-species that have less capacity of CCMs. Even for species that operate active CCMs and those whose photo-synthesis is not limited by CO2 in seawater, increased CO2 levels can down-regulate their CCMs and therefore enhance their growth under light-limiting conditions (at higher CO2 levels, less light energy is required to drive CCM). Altered physiological performances under high-CO2 conditions may cause genetic alteration in view of adaptation over long time scale. Marine algae may adapt to a high CO2 oceanic environment so that the evolved communities in future are likely to be genetically different from the contemporary communities. However, most of the previous studies have been carried out under indoor conditions without considering the acidifying effects on seawater by increased CO2 and other interacting environmental factors, and little has been documented so far to explain how physi-ology of marine primary producers performs in a high-CO2 and low-pH ocean.
文摘文中首次报导贵州寒武系黔东统都匀阶"清虚洞组"(或乌训组)宏观藻类,计2属2种:环圈螺旋抚仙藻Fuxianospira gyrata Chen and Zhou,1997和云南中华细丝藻Sinocylindra yunnanensis Chen and Erdtmann,1991,它们是澄江生物群最常见的两类宏观藻类具有澄江生物群宏观藻类的组合特征。"清虚洞组"位于黔东统上部,介于杷榔组和凯里组之间,该组宏观藻类的发现,为寒武纪宏观藻类演化链的完整研究提供了有价值的资料。
文摘Arsenobetaine（AB） and thio-arsenoribosides were measured in common macroalgae species（8 phaeophyta, 4 rhodophyta and 2 chlorphyta）, along the Australian south east coast line. As well, arsenic species profiles were measured for two common marine herbivores, the sea urchin Centrostephanus rodgersii and the fish Odax cyanomelas that graze on these macroalgae to understand if trophic transfer of these species would account for their presence in marine herbivores. AB was found in seven of the fourteen macroalgae species investigated but does not contributed significantly to any of the macroalgae arsenic content（0.01-1.2 μg/g）. AB was found in only two of the brown macroalgae and all the red and green macroalgae（with the exception of Corallina officinalis）. Thio-arsenic species were found sporadically, but not in high concentrations in any of the macroalgae investigated.AB present in macroalgae is likely to be associated with epiphytic organisms while thio-arsenoribosides are likely to be produced by decaying parts of damaged macroalgae.A laboratory feeding experiment in which the herbivorous gastropod, Austrocochlea constricta, was fed macroalgae containing thio-arsenoribosides for a 24 hr period every three days showed that these are readily accumulated over a short period. Thio-arsenoribosides in herbivores are therefore probably obtained through trophic transfer. Some AB is also obtained through trophic transfer; however, the presence of trimethylated arsonioribosides,a hypothesized precursor of AB formation in herbivores, suggests that some AB is produced within herbivores from the transformation of arsenoribosides accumulated from their diet.
