The infaunal polychaete Perinereis aibuhitensis Grube, distributes widelyalong Asian coasts and estuaries. In this research the particle reworking function of P.aibuhitensis was investigated in Beitang Estuary, Tianji...The infaunal polychaete Perinereis aibuhitensis Grube, distributes widelyalong Asian coasts and estuaries. In this research the particle reworking function of P.aibuhitensis was investigated in Beitang Estuary, Tianjin. The result showed that P.aibuhitensis displayed significant particle mixing function, in which small grain sizesediment particles were mixed more than the large size ones. Some small grain sizesediment particles could be ingested by P. aibuhitensis and egested with fecal pellets.展开更多
Estuaries are environments where freshwater and seawater mix and they display various salinity profiles.The construction of river barrages and dams has rapidly changed these environments and has had a wide range of im...Estuaries are environments where freshwater and seawater mix and they display various salinity profiles.The construction of river barrages and dams has rapidly changed these environments and has had a wide range of impacts on plankton communities.To understand the dynamics of such communities,researchers need accurate and rapid techniques for detecting plankton species.We evaluated the diversity of eukaryotic plankton over a salinity gradient by applying a metagenomics tool at the Nakdong River estuary in Korea.Environmental samples were collected on three dates during summer and autumn of 2011 at the Eulsukdo Bridge at the mouth of that river.Amplifying the 18 S rDNA allowed us to analyze 456 clones and 122 phylotypes.Metagenomic sequences revealed various taxonomic groups and cryptic genetic variations at the intra-and inter-specific levels.By analyzing the same station at each sampling date,we observed that the phylotypes presented a salinity-related pattern of diversity in assemblages.The variety of species within freshwater samples reflected the rapid environmental changes caused by freshwater inputs.Dinophyceae phylotypes accounted for the highest proportion of overall diversity in the seawater samples.Euryhaline diatoms and dinoflagellates were observed in the freshwater,brackish and seawater samples.The biological data for species composition demonstrate the transitional state between freshwater and seawater.Therefore,this metagenomics information can serve as a biological indicator for tracking changes in aquatic environments.展开更多
The Changjiang(Yangtze)River estuary has been subject to a variety of anthropogenic pressures in recent decades.To assess the ecological health of the coastal benthic ecosystem adjacent to the estuary,three surveys we...The Changjiang(Yangtze)River estuary has been subject to a variety of anthropogenic pressures in recent decades.To assess the ecological health of the coastal benthic ecosystem adjacent to the estuary,three surveys were conducted in 2005,2009,and 2010.The AZTI's Marine Biotic Index(AMBI)and multivariate-AMBI(M-AMBI)were used to analyse the benthic ecological status of this coast.The AMBI indicate that the ecological status of the coast adjacent to the Changjiang River estuary was only slightly degraded in all 3 years.In contrast,the M-AMBI indicated that the ecological status was seriously degraded,a result that is most likely due to pollution and eutrophication induced by human activities.The assessment of the coast's ecological status by the AMBI was not in agreement with that of the M-AMBI at some stations because of lower biodiversity values at those sites.The analysis of the two indices integrated with abiotic parameters showed that the M-AMBI could be used as a suitable bio-indicator index to assess the benthic ecological status of the coast adjacent to the Changjiang River estuary.The reference conditions proposed for the coast of the Changjiang River estuary should be further evaluated in future studies.Designation of local species could also provide an important reference for Chinese waters.To improve the reliability of AMBI and M-AMBI,further research into the ecology of local species is required to understand their arrangement in ecological groups.展开更多
The Jamaica Bay ecosystem is a dichotomy. It encompasses more than 12,000 acres of coastal estuarine marshes and an ecological diversity rivaling any coastal environment in the world. It is considerably altered, and i...The Jamaica Bay ecosystem is a dichotomy. It encompasses more than 12,000 acres of coastal estuarine marshes and an ecological diversity rivaling any coastal environment in the world. It is considerably altered, and is affected by a variety of ecological insults directly related to the fact that more than 14 million people live in its vicinity. Environmental protection institutions responded to the challenge of protecting the bay, surrounding wetlands and recreational benefits by addressing the increasing load of contaminants into the ecosystem. Billions of dollars have been spent during the past five decades on restoration attempts, including upgrading wastewater treatment plantsand the closure of three major sanitary landfills. Even with the curtailment of untreated wastewater release and ending periodic dredging and filling programs, all activities that are necessary processes in maintaining an urban harbor, the Jamaica Bay ecosystem has reached a point where many believe it to be unrecoverable, requiring massive infusions of restoration dollars. This categorization has been perpetuated based on questionable data (the "myths") that, when investigated in rigorous scientific detail, prove to be unsubstantiated. In this paper, the origin of these myths and the scientific investigation that dispel them are discussed.展开更多
For successful conservation and restoration of biodiversity,it is important to understand how diversity is regulated.In the ecological research community,a current topic of interest is how much of the variation in pla...For successful conservation and restoration of biodiversity,it is important to understand how diversity is regulated.In the ecological research community,a current topic of interest is how much of the variation in plant species richness and composition is explained by environmental variation(niche-based model),relative to spatial processes(neutral theory).The Yellow River Estuary(YRE) is a newly formed and fragile wetland ecosystem influenced by both the Yellow River and Bohai Bay.Here,we applied variance partitioning techniques to assess the relative effects of spatial and environmental variables on species richness and composition in the YRE.We also conducted a species indicator analysis to identify characteristic species for three subestuaries within the YRE.Partial redundancy analysis showed that the variations in species richness and composition were explained by both environmental and spatial factors.The majority of explained variation in species richness and composition was attributable to local environmental factors.Among the environmental variables,soil salinity made the greatest contribution to species abundance and composition.Soil salinity was the most important factor in the Diaokou subestuary,while soil moisture was the most important factor influencing species richness in the Qingshui and Chahe subestuaries.The combined effects of soil salinity and moisture determined species richness and composition in the wetlands.These results increase our understanding of the organization and assembly of estuarine plant communities.展开更多
基金supported by the Chinese Natural Science Foundation(Funding Numbers:41303070,21307045)
文摘The infaunal polychaete Perinereis aibuhitensis Grube, distributes widelyalong Asian coasts and estuaries. In this research the particle reworking function of P.aibuhitensis was investigated in Beitang Estuary, Tianjin. The result showed that P.aibuhitensis displayed significant particle mixing function, in which small grain sizesediment particles were mixed more than the large size ones. Some small grain sizesediment particles could be ingested by P. aibuhitensis and egested with fecal pellets.
基金Supported by the East Asian Seas Time Series-I(No.EAST-I)the Ministry of Oceans and Fisheries,Korea,the"Development of Microbial Metagenomic Techniques for a Fine-Scale Seawater Mass Analysis"through the Ministry of Education of the Republic of Koreathe National Research Foundation of Korea(No.NRF-2013R1A1A2006915)
文摘Estuaries are environments where freshwater and seawater mix and they display various salinity profiles.The construction of river barrages and dams has rapidly changed these environments and has had a wide range of impacts on plankton communities.To understand the dynamics of such communities,researchers need accurate and rapid techniques for detecting plankton species.We evaluated the diversity of eukaryotic plankton over a salinity gradient by applying a metagenomics tool at the Nakdong River estuary in Korea.Environmental samples were collected on three dates during summer and autumn of 2011 at the Eulsukdo Bridge at the mouth of that river.Amplifying the 18 S rDNA allowed us to analyze 456 clones and 122 phylotypes.Metagenomic sequences revealed various taxonomic groups and cryptic genetic variations at the intra-and inter-specific levels.By analyzing the same station at each sampling date,we observed that the phylotypes presented a salinity-related pattern of diversity in assemblages.The variety of species within freshwater samples reflected the rapid environmental changes caused by freshwater inputs.Dinophyceae phylotypes accounted for the highest proportion of overall diversity in the seawater samples.Euryhaline diatoms and dinoflagellates were observed in the freshwater,brackish and seawater samples.The biological data for species composition demonstrate the transitional state between freshwater and seawater.Therefore,this metagenomics information can serve as a biological indicator for tracking changes in aquatic environments.
基金Supported by the National Special Research Fund for Non-profit Sector(Environmental Protection)(No.2008467041)the National Natural Science Foundation of China(No.40976086)
文摘The Changjiang(Yangtze)River estuary has been subject to a variety of anthropogenic pressures in recent decades.To assess the ecological health of the coastal benthic ecosystem adjacent to the estuary,three surveys were conducted in 2005,2009,and 2010.The AZTI's Marine Biotic Index(AMBI)and multivariate-AMBI(M-AMBI)were used to analyse the benthic ecological status of this coast.The AMBI indicate that the ecological status of the coast adjacent to the Changjiang River estuary was only slightly degraded in all 3 years.In contrast,the M-AMBI indicated that the ecological status was seriously degraded,a result that is most likely due to pollution and eutrophication induced by human activities.The assessment of the coast's ecological status by the AMBI was not in agreement with that of the M-AMBI at some stations because of lower biodiversity values at those sites.The analysis of the two indices integrated with abiotic parameters showed that the M-AMBI could be used as a suitable bio-indicator index to assess the benthic ecological status of the coast adjacent to the Changjiang River estuary.The reference conditions proposed for the coast of the Changjiang River estuary should be further evaluated in future studies.Designation of local species could also provide an important reference for Chinese waters.To improve the reliability of AMBI and M-AMBI,further research into the ecology of local species is required to understand their arrangement in ecological groups.
文摘The Jamaica Bay ecosystem is a dichotomy. It encompasses more than 12,000 acres of coastal estuarine marshes and an ecological diversity rivaling any coastal environment in the world. It is considerably altered, and is affected by a variety of ecological insults directly related to the fact that more than 14 million people live in its vicinity. Environmental protection institutions responded to the challenge of protecting the bay, surrounding wetlands and recreational benefits by addressing the increasing load of contaminants into the ecosystem. Billions of dollars have been spent during the past five decades on restoration attempts, including upgrading wastewater treatment plantsand the closure of three major sanitary landfills. Even with the curtailment of untreated wastewater release and ending periodic dredging and filling programs, all activities that are necessary processes in maintaining an urban harbor, the Jamaica Bay ecosystem has reached a point where many believe it to be unrecoverable, requiring massive infusions of restoration dollars. This categorization has been perpetuated based on questionable data (the "myths") that, when investigated in rigorous scientific detail, prove to be unsubstantiated. In this paper, the origin of these myths and the scientific investigation that dispel them are discussed.
基金supported by National Science & Technology Pillar in the 11th Five-Year Program(Grant No.2006BAC01A13)
文摘For successful conservation and restoration of biodiversity,it is important to understand how diversity is regulated.In the ecological research community,a current topic of interest is how much of the variation in plant species richness and composition is explained by environmental variation(niche-based model),relative to spatial processes(neutral theory).The Yellow River Estuary(YRE) is a newly formed and fragile wetland ecosystem influenced by both the Yellow River and Bohai Bay.Here,we applied variance partitioning techniques to assess the relative effects of spatial and environmental variables on species richness and composition in the YRE.We also conducted a species indicator analysis to identify characteristic species for three subestuaries within the YRE.Partial redundancy analysis showed that the variations in species richness and composition were explained by both environmental and spatial factors.The majority of explained variation in species richness and composition was attributable to local environmental factors.Among the environmental variables,soil salinity made the greatest contribution to species abundance and composition.Soil salinity was the most important factor in the Diaokou subestuary,while soil moisture was the most important factor influencing species richness in the Qingshui and Chahe subestuaries.The combined effects of soil salinity and moisture determined species richness and composition in the wetlands.These results increase our understanding of the organization and assembly of estuarine plant communities.