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Adam, Stefan; Pawert, Michael; Lehmann, Reinhold; Roth, Barbara J.; Müller, Ewald F; Triebskorn, Rita

doi:10.1023/a:1012924825380

Cited by 23 publications

(1 citation statement)

References 20 publications

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“…Whilst an unsteady fluctuation, particularly high values of N-NH4 + at observed sites as S2, S3, S8, S10, S14, S17, and S18 compared to other sites, occurred along with the river courses in the rest of the season. It was due to the impacts of wastewater sources induced by the aquaculture practices, containing excretion and decomposition of aquatic organisms and differing also the number of pollutant outputs at the influenced sites, were responsible for high N-NH4 + concentrations [235,236]. In overall, the results illustrated relatively high contents in the seasons, but still met the allowable standard for water quality.…”

Section: Framework Of Methodologymentioning

confidence: 99%

Changes in surface water and sediment quality at a complex tidal-influenced river: a case study of Ganh Hao river, Mekong delta, Vietnam

Van

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The research was carried out to determine the extent of surface water and sediment pollution using the physicochemical parameters and heavy metal concentrations. The surface water and sediment samples were obtained from 25 sites along the river on March 22 and September 5, 2019 at the main river influenced by the complex tidal regime and aquaculture practices in Ca Mau peninsular in the Vietnamese Mekong Delta. The water quality was compared with international and national standards, while the sediment quality was compared with Vietnamese standards and pollution indices (geo-accumulation index, contamination factor, and pollution load index). Principal component analysis (PCA) was employed to explain the main factors responsible for the observed levels of water pollution. The dependence of water quality parameters and variations in water quality due to tidal regimes and seasonality were also evaluated by statistical comparisons. Based on the logistic regression models, the temporal variability of selected water quality parameters was visualized using QGIS. The Delft 3D model was used to evaluate changes in hydraulic characteristics based on actual fieldwork. The concentrations of nutrients and organic compounds exceeded 2-3 times greater than the standard for surface water quality. The contents of heavy metals were below the standard for sediment quality and consistent with the background levels. The influence of the tidal regime and seasonality caused significant changes in water quality and its association with various flow regimes (P<0.05). Three components based on the PCA accounted for approx. 79.84% of the total variance in water quality characteristics of which the first, second, third component explained for 53.64%, 18.43%, and 7.77% of total variance related to physicochemical properties and organic matter pollution, suspended solids and nutrients, and DO consumption, respectively. Water quality maps indicated pollution hotspots, and the extensive and improved extensive shrimp culture practices were identified in connection to the changes in water quality. Changes in the river's hydraulic characteristics were influenced remarkably by the tidal regime as well as geomorphological changes. The results of the research addressed the gaps from the previous studies were to identify degradation of surface water quality was associated primarily with extensive and improved extensive shrimp culture. Seasonal factors and tidal regimes influenced significantly changes in water quality parameters. Pollution sources were specified by the principal component analysis. Spatiotemporal distribution maps of selected water quality parameters highlighted pollution hotspot. Changes in the river hydraulic characteristics were caused mainly by the tidal regimes as well as geomorphological changes. The selected water quality parameters responded as well as depended diversely to various flow regimes. The results could be useful not only to local policymakers in developing water management strategies but also to other rivers beyond the geographical regions. �

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Section: Framework Of Methodologymentioning

confidence: 99%

Changes in surface water and sediment quality at a complex tidal-influenced river: a case study of Ganh Hao river, Mekong delta, Vietnam

Van

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Endocrine Effects in Gammarus fossarum (Amphipoda): Influence of Wastewater Effluents, Temporal Variability, and Spatial Aspects on Natural Populations

Schirling

Jungmann

Ladewig

et al. 2005

Arch Environ Contam Toxicol

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In a field study, individuals of autochthounous populations of the amphipod Gammarus fossarum were examined for their maturity status, oocyte development, and biochemical parameters associated with their reproductive cycle. Variability in these parameters was related to abiotic exposure parameters varying in accordance to wastewater discharges, stream identity, and time. Patterns of all investigated parameters showed predominantly seasonal rather than spatial influence for both exposure and biologic effects. Single selected-effect parameters, however--such as the maturity index, late vitellogenic oocyte size and atresia, and the hsp90 level--responded to a sewage treatment plant discharge showing an estrogenic potential and also correlated significantly with the concentration of potential xenoestrogens at the different locations.

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Population Structure and Dynamics of Gammarus fossarum (Amphipoda) Upstream and Downstream from Effluents of Sewage Treatment Plants

Ladewig

Jungmann

Köhler

et al. 2005

Arch Environ Contam Toxicol

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Two streams in Germany (Körsch and Lockwitzbach), each with two sampling sites above and below a sewage treatment plant (STP) discharging effluent, were investigated. Sampling sites were characterized, and exposure monitoring for chemicals with known or assumed endocrine disrupting potential was carried out. Both the population structure and the population dynamics of Gammarus fossarum were examined. The physicochemical parameters measured at the sampling sites of the Lockwitzbach and Körsch streams were found not to reach levels having an acute toxic impact on the development of gammarids. The calculated estrogenic potential in the stream water was 22- to 35-fold higher at the downstream site of the Körsch compared with the other sampling sites, mainly because of the concentrations of 17alpha-ethinylestradiol on two sampling dates. At both streams, an influence of the respective STP effluent on the sex ratio of G. fossarum was not observed. Moreover, intersexuality was not induced by these effluents. Differences in the structure and dynamics of G. fossarum populations were more pronounced at the Körsch than at the Lockwitzbach. At the downstream sampling site at the Körsch, gammarids reached their highest abundances. Particularly at the downstream sampling site of the Körsch, the proportion of breeding female gammarids and the proportion of juvenile gammarids in the smallest body length class were decreased compared with upstream. Adult gammarids were larger from the Lockwitzbach downstream site, but they were smaller from the Körsch downstream site compared with the respective upstream site. At the Körsch, the earlier onset of the autumnal reproductive resting period could be caused by the influence of the STP effluent.

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Untitled

Cited by 23 publications

References 20 publications

Changes in surface water and sediment quality at a complex tidal-influenced river: a case study of Ganh Hao river, Mekong delta, Vietnam

Changes in surface water and sediment quality at a complex tidal-influenced river: a case study of Ganh Hao river, Mekong delta, Vietnam

Endocrine Effects in Gammarus fossarum (Amphipoda): Influence of Wastewater Effluents, Temporal Variability, and Spatial Aspects on Natural Populations

Population Structure and Dynamics of Gammarus fossarum (Amphipoda) Upstream and Downstream from Effluents of Sewage Treatment Plants

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