The assessment of the ecosystem health of urban rivers and lakes is the scientific basis for their management and ecological restoration.This study developed a three-level indicator system for its assessment.The resul...The assessment of the ecosystem health of urban rivers and lakes is the scientific basis for their management and ecological restoration.This study developed a three-level indicator system for its assessment.The results indicated that:Zhonghai and Nanhai are in the state of transition from unhealthy to critical state and all the other lakes are in unhealthy states.Water environmental quality,structure and function of the aquatic ecosystem,and the structure of waterfront areas were the constraints.Nanhai was ranked as poor and the others were all ranked as very poor.However,the ecological environment of Zhonghai and Nanhai were better than the others,the sums of the degree of membership to the healthy state and critical state were all close to 0.6.and the restorations of these lakes were moderate.The sums of the degree of membership to the healthy state and critical state of the other lakes were under 0.3,as it was difficult to restore these lakes.Some suggestions on scientific management and ecological restoration of the six lakes were proposed:①To control non-point pollution and to improve the water quality of six lakes and the water entering into these lakes;②To improve the hydrological conditions of six lakes;③To rehabilitate the aquatic ecosystem and waterfront areas.展开更多
This research was conducted to generate a primary database on ichthyofauna,distribution and diversities in the upstream and downstream segments of Sittaung River in Bago Region of Myanmar.This study contributes to the...This research was conducted to generate a primary database on ichthyofauna,distribution and diversities in the upstream and downstream segments of Sittaung River in Bago Region of Myanmar.This study contributes to the information needed on the distribution of river fish in Myanmar.Fish diversities are assessed by calculating the various diversities indices between December,2018 and November,2019.A total of 65 fish species belonging to 9 orders,23 families and 49 genera were recorded.All 65 fish species were found in upstream segment but only 60 species of them were found in downstream segment of the river.In all study sites,Shannon diversity index had value above 3 indicating that the structure of habitat was stable and balanced.Simpson’s index values were close to 1 in all sites indicating that the species richness in the region was satisfactory.The abundance all of above 5%of total catch of Mystus vittatus,M.pulcher,M.cavasius and Erethistes pusillus in their feeding habitat suggested that their upstream and downstream habitats provided suitable feeding conditions.Anguilla bengalensis,Tenualosa ilisha,Mystus gulio,Rita rita and Silonia silondia were least abundant all below 0.1%of total catch showing they could be impacted by unwise anthropogenic activities.Assessing fish species diversity is thus very important to conserve and manage and promote the health of river ecosystem that is necessary for the migration of fish species.展开更多
基金This study was supported by the National Basic Research Program of China(Grant No.2006CB403403)Key Program of the National Natural Science Foundation of China(Grant No.50238020)。
文摘The assessment of the ecosystem health of urban rivers and lakes is the scientific basis for their management and ecological restoration.This study developed a three-level indicator system for its assessment.The results indicated that:Zhonghai and Nanhai are in the state of transition from unhealthy to critical state and all the other lakes are in unhealthy states.Water environmental quality,structure and function of the aquatic ecosystem,and the structure of waterfront areas were the constraints.Nanhai was ranked as poor and the others were all ranked as very poor.However,the ecological environment of Zhonghai and Nanhai were better than the others,the sums of the degree of membership to the healthy state and critical state were all close to 0.6.and the restorations of these lakes were moderate.The sums of the degree of membership to the healthy state and critical state of the other lakes were under 0.3,as it was difficult to restore these lakes.Some suggestions on scientific management and ecological restoration of the six lakes were proposed:①To control non-point pollution and to improve the water quality of six lakes and the water entering into these lakes;②To improve the hydrological conditions of six lakes;③To rehabilitate the aquatic ecosystem and waterfront areas.
文摘This research was conducted to generate a primary database on ichthyofauna,distribution and diversities in the upstream and downstream segments of Sittaung River in Bago Region of Myanmar.This study contributes to the information needed on the distribution of river fish in Myanmar.Fish diversities are assessed by calculating the various diversities indices between December,2018 and November,2019.A total of 65 fish species belonging to 9 orders,23 families and 49 genera were recorded.All 65 fish species were found in upstream segment but only 60 species of them were found in downstream segment of the river.In all study sites,Shannon diversity index had value above 3 indicating that the structure of habitat was stable and balanced.Simpson’s index values were close to 1 in all sites indicating that the species richness in the region was satisfactory.The abundance all of above 5%of total catch of Mystus vittatus,M.pulcher,M.cavasius and Erethistes pusillus in their feeding habitat suggested that their upstream and downstream habitats provided suitable feeding conditions.Anguilla bengalensis,Tenualosa ilisha,Mystus gulio,Rita rita and Silonia silondia were least abundant all below 0.1%of total catch showing they could be impacted by unwise anthropogenic activities.Assessing fish species diversity is thus very important to conserve and manage and promote the health of river ecosystem that is necessary for the migration of fish species.
