scholarly journals Temperature and Water Quality-Related Patterns in Sediment-Associated Symbiodinium Communities Impact Symbiont Uptake and Fitness of Juvenile Acroporid Corals

2017 ◽  
Author(s):  
Kate M. Quigley ◽  
Line K. Bay ◽  
Bette L. Willis
Keyword(s):  
Water Quality ◽  
Environmental Gradients ◽  
Critical Role ◽  
Community Diversity ◽  
Experimental Exposure ◽  
Free Living ◽  
Sediment Samples ◽  
Juvenile Corals ◽  
Temperature Regimes ◽  
Environmental Availability

AbstractThe majority of corals acquire their photo-endosymbiont Symbiodinium from environmental sources anew each generation. Despite the critical role that environmental availability of Symbiodinium plays in the potential for corals to acclimate and adapt to changing environments, little is known about the diversity of free-living Symbiodinium communities and how variation in these communities influences uptake and in hospite communities in juvenile corals. Here we characterize Symbiodinium community diversity in sediment samples collected from eight reefs representing latitudinal and cross-shelf variation in water quality and temperature regimes. Sediment-associated Symbiodinium communities were then compared to in hospite communities acquired by A. tenuis and A. millepora juveniles following 11 – 145 days of experimental exposure to sediments from each of the reefs. Communities associated with juveniles and sediments differed substantially, with sediments harbouring four times more unique OTUs than juveniles (1125 OTUs vs. 271). Moreover, only 10.6% of these OTUs were shared between juveniles and sediments, indicating selective uptake by acroporid juveniles. The diversity and abundance of Symbiodinium types differed among sediment samples from different temperature and water quality environments. Symbiodinium communities acquired by juveniles also differed among the sediment treatments, despite juveniles having similar parentage. Moreover, Symbiodinium communities displayed different rates of infection, mortality, and photochemical efficiencies. This study demonstrates that the biogeography of free-living Symbiodinium types found within sediment reservoirs follows patterns along latitudinal and water quality environmental gradients on the Great Barrier Reef. We also demonstrate a bipartite strategy for Symbiodinium uptake by juvenile corals of two horizontally-transmitting acroporid species, whereby uptake is selective within the constraints of environmental availability.

scholarly journals Seasonal changes in water quality and macrophytes and the impact of cattle on tropical floodplain waterholes

2012 ◽  
Vol 63 (9) ◽  
pp. 788 ◽  
Author(s):  
N. E. Pettit ◽  
T. D. Jardine ◽  
S. K. Hamilton ◽  
V. Sinnamon ◽  
D. Valdez ◽  
...  
Keyword(s):  
Water Quality ◽  
Seasonal Changes ◽  
Aquatic Macrophyte ◽  
Plant Cover ◽  
Critical Role ◽  
Dry Season ◽  
Nutrient Concentrations ◽  
Wet Season ◽  
Dry Tropics ◽  
The Impact

The present study indicates the critical role of hydrologic connectivity in floodplain waterholes in the wet–dry tropics of northern Australia. These waterbodies provide dry-season refugia for plants and animals, are a hotspot of productivity, and are a critical part in the subsistence economy of many remote Aboriginal communities. We examined seasonal changes in water quality and aquatic plant cover of floodplain waterholes, and related changes to variation of waterhole depth and visitation by livestock. The waterholes showed declining water quality through the dry season, which was exacerbated by more frequent cattle usage as conditions became progressively drier, which also increased turbidity and nutrient concentrations. Aquatic macrophyte biomass was highest in the early dry season, and declined as the dry season progressed. Remaining macrophytes were flushed out by the first wet-season flows, although they quickly re-establish later during the wet season. Waterholes of greater depth were more resistant to the effects of cattle disturbance, and seasonal flushing of the waterholes with wet-season flooding homogenised the water quality and increased plant cover of previously disparate waterholes. Therefore, maintaining high levels of connectivity between the river and its floodplain is vital for the persistence of these waterholes.

Taking the pulse of Mother Ganga - Revealing the visible and invisible water pollution crisis along the Ganges River

2021 ◽  
Author(s):  
Stefan Krause ◽  
Keyword(s):  
Water Pollution ◽  
Water Quality ◽  
Land Use ◽  
Surface Water ◽  
River Network ◽  
Ganges River ◽  
Sediment Samples ◽  
Water And Sediment ◽  
The Ganges ◽  
Water And Sediment Samples

<p>It is probably hard to overestimate the significance of the River Ganges for its spiritual, cultural and religious importance. As the worlds’ most populated river basin and a major water resource for the 400 million people inhabiting its catchment, the Ganges represents one of the most complex and stressed river systems globally. This makes the understanding and management of its water quality an act of humanitarian and geopolitical relevance. Water quality along the Ganges is critically impacted by multiple stressors, including agricultural, industrial and domestic pollution inputs, a lack and failure of water and sanitation infrastructure, increasing water demands in areas of intense population growth and migration, as well as the severe implications of land use and climate change. Some aspects of water pollution are readily visualised as the river network evolves, whilst others contribute to an invisible water crisis (Worldbank, 2019) that affects the life and health of hundreds of millions of people.</p><p>We report the findings of a large collaborative study to monitor the evolution of water pollution along the 2500 km length of the Ganges river and its major tributaries that was carried out over a six-week period in Nov/Dec 2019 by three teams of more than 30 international researchers from 10 institutions. Surface water and sediment were sampled from more than 80 locations along the river and analysed for organic contaminants, nutrients, metals, pathogen indicators, microbial activity and diversity as well as microplastics, integrating in-situ fluorescence and UV absorbance optical sensor technologies with laboratory sample preparation and analyses. Water and sediment samples were analysed to identify the co-existence of pollution hotspots, quantify their spatial footprint and identify potential source areas, dilution, connectivity and thus, derive understanding of the interactions between proximal and distal of sources solute and particulate pollutants.</p><p>Our results reveal the co-existence of distinct pollution hotspots for several contaminants that can be linked to population density and land use in the proximity of sampling sites as well as the contributing catchment area. While some pollution hotspots were characterised by increased concentrations of most contaminant groups, several hotspots of specific pollutants (e.g., microplastics) were identified that could be linked to specific cultural and religious activities. Interestingly, the downstream footprint of specific pollution hotspots from contamination sources along the main stem of the Ganges or through major tributaries varied between contaminants, with generally no significant downstream accumulation emerging in water pollution levels, bearing significant implications for the spatial reach and legacy of pollution hotspots. Furthermore, the comparison of the downstream evolution of multi-pollution profiles between surface water and sediment samples support interpretations of the role of in-stream fate and transport processes in comparison to patterns of pollution source zone activations across the channel. In reporting the development of this multi-dimensional pollution dataset, we intend to stimulate a discussion on the usefulness of large river network surveys to better understand the relative contributions, footprints and impacts of variable pollution sources and how this information can be used for integrated approaches in water resources and pollution management.</p>

scholarly journals Fungal and Bacterial Diversity Patterns of Two Diversity Levels Retrieved From a Late Decaying Fagus sylvatica Under Two Temperature Regimes

2021 ◽  
Vol 11 ◽  
Author(s):  
Sarah Muszynski ◽  
Florian Maurer ◽  
Sina Henjes ◽  
Marcus A. Horn ◽  
Matthias Noll
Keyword(s):  
Species Richness ◽  
Bacterial Community ◽  
Mass Loss ◽  
Community Composition ◽  
Fagus Sylvatica ◽  
Temperature Regime ◽  
Community Diversity ◽  
Interaction Patterns ◽  
Temperature Regimes ◽  
Natural Diversity

Environmental fluctuations are a common occurrence in an ecosystem, which have an impact on organismic diversity and associated ecosystem services. The aim of this study was to investigate how a natural and a species richness-reduced wood decaying community diversity were capable of decomposing Fagus sylvatica dead wood under a constant and a fluctuating temperature regime. Therefore, microcosms with both diversity levels (natural and species richness-reduced) were prepared and incubated for 8 weeks under both temperature regimes. Relative wood mass loss, wood pH, carbon dioxide, and methane emissions, as well as fungal and bacterial community compositions in terms of Simpson‘s diversity, richness and evenness were investigated. Community interaction patterns and co-occurrence networks were calculated. Community composition was affected by temperature regime and natural diversity caused significantly higher mass loss than richness-reduced diversity. In contrast, richness-reduced diversity increased wood pH. The bacterial community composition was less affected by richness reduction and temperature regimes than the fungal community composition. Microbial interaction patterns showed more mutual exclusions in richness-reduced compared to natural diversity as the reduction mainly reduced abundant fungal species and disintegrated previous interaction patterns. Microbial communities reassembled in richness-reduced diversity with a focus on nitrate reducing and dinitrogen-fixing bacteria as connectors in the network, indicating their high relevance to reestablish ecosystem functions. Therefore, a stochastic richness reduction was followed by functional trait based reassembly to recover previous ecosystem productivity.

scholarly journals Land use influences stream bacterial communities in lowland tropical watersheds

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Karina A. Chavarria ◽  
Kristin Saltonstall ◽  
Jorge Vinda ◽  
Jorge Batista ◽  
Megan Lindmark ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Bacterial Communities ◽  
Secondary Forest ◽  
Stream Water ◽  
Community Diversity ◽  
Forested Catchments ◽  
Unifrac Distance ◽  
Cattle Pasture ◽  
The Impact

AbstractLand use is known to affect water quality yet the impact it has on aquatic microbial communities in tropical systems is poorly understood. We used 16S metabarcoding to assess the impact of land use on bacterial communities in the water column of four streams in central Panama. Each stream was influenced by a common Neotropical land use: mature forest, secondary forest, silvopasture and traditional cattle pasture. Bacterial community diversity and composition were significantly influenced by nearby land uses. Streams bordered by forests had higher phylogenetic diversity (Faith’s PD) and similar community structure (based on weighted UniFrac distance), whereas the stream surrounded by traditional cattle pasture had lower diversity and unique bacterial communities. The silvopasture stream showed strong seasonal shifts, with communities similar to forested catchments during the wet seasons and cattle pasture during dry seasons. We demonstrate that natural forest regrowth and targeted management, such as maintaining and restoring riparian corridors, benefit stream-water microbiomes in tropical landscapes and can provide a rapid and efficient approach to balancing agricultural activities and water quality protection.

scholarly journals Analysis of Antibiotic Resistance Genes, Environmental Factors, and Microbial Community From Aquaculture Farms in Five Provinces, China

2021 ◽  
Vol 12 ◽  
Author(s):  
Xu Cheng ◽  
Yitong Lu ◽  
Yanzhen Song ◽  
Ruifang Zhang ◽  
Xinyan ShangGuan ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Environmental Factors ◽  
Bacterial Community ◽  
Correlation Analysis ◽  
Resistance Genes ◽  
Environmental Risk ◽  
Antibiotic Resistance Genes ◽  
Community Diversity ◽  
Sediment Samples ◽  
Positive Correlation

The excessive use of antibiotics speeds up the dissemination and aggregation of antibiotic resistance genes (ARGs) in the environment. The ARGs have been regarded as a contaminant of serious environmental threats on a global scale. The constant increase in aquaculture production has led to extensive use of antibiotics as a means to prevent and treat bacterial infections; there is a universal concern about the environmental risk of ARGs in the aquaculture environment. In this study, a survey was conducted to evaluate the abundance and distributions of 10 ARGs, bacterial community, and environmental factors in sediment samples from aquatic farms distributed in Anhui (AP1, AP2, and AP3), Fujian (FP1, FP2, and FP3), Guangxi (GP1, GP2, and GP3), Hainan (HP1, HP2, and HP3), and Shaanxi (SP1, SP2, and SP3) Province in China. The results showed that the relative abundance of total ARGs was higher in AP1, AP2, AP3, FP3, GP3, HP1, HP2, and HP3 than that in FP1, FP2, GP1, GP2, SP1, SP2, and SP3. The sul1 and tetW genes of all sediment samples had the highest abundance. The class 1 integron (intl1) was detected in all samples, and the result of Pearson correlation analysis showed that the intl1 has a positive correlation with the sul1, sul2, sul3, blaOXA, qnrS, tetM, tetQ, and tetW genes. Correlation analysis of the bacterial community diversity and environmental factors showed that the Ca2+ concentration has a negative correlation with richness and diversity of the bacterial community in these samples. Of the identified bacterial community, Proteobacteria, Firmicutes, Chloroflexi, and Bacteroidota were the predominant phyla in these samples. Redundancy analysis showed that environmental factors (TN, TP, Cl–, and Ca2+) have a positive correlation with the bacterial community (AP1, GP1, GP2, GP3, SP1, SP2, and SP3), and the abundance of ARGs (sul1, tetW, qnrS, and intl1) has a positive correlation with the bacterial community (AP2, AP3, HP1, HP2, and HP3). Based on the network analysis, the ARGs (sul1, sul2, blaCMY, blaOXA, qnrS, tetW, tetQ, tetM, and intl1) were found to co-occur with bacterial taxa from the phyla Chloroflexi, Euryarchaeota, Firmicutes, Halobacterota, and Proteobacteria. In conclusion, this study provides an important reference for understanding the environmental risk associated with aquaculture activities in China.

Constructed wetland for water quality improvement: a case study from Taiwan

2010 ◽  
Vol 62 (10) ◽  
pp. 2408-2418 ◽  
Author(s):  
C. Y. Wu ◽  
J. K. Liu ◽  
S. H. Cheng ◽  
D. E. Surampalli ◽  
C. W. Chen ◽  
...  
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Water Reuse ◽  
Oxygen Demand ◽  
Sediment Oxygen Demand ◽  
Nucleotide Sequence Analysis ◽  
Sediment Samples ◽  
Wetland System

In Taiwan, more than 20% of the major rivers are mildly to heavily polluted by domestic, industrial, and agricultural wastewaters due to the low percentage of sewers connected to wastewater treatment plants. Thus, constructed or engineered wetlands have been adopted as the major alternatives to clean up polluted rivers. Constructed wetlands are also applied as the tertiary wastewater treatment systems for the wastewater polishment to meet water reuse standards with lower operational costs. The studied Kaoping River Rail Bridge Constructed Wetland (KRRBCW) is the largest constructed wetland in Taiwan. It is a multi-function wetland and is used for polluted creek water purification and secondary wastewater polishment before it is discharged into the Kaoping River. Although constructed wetlands are feasible for contaminated water treatment, wetland sediments are usually the sinks for organics and metals. In this study, water and sediment samples were collected from the major wetland basins in KRRBCW. The investigation results show that more than 97% of total coliforms (TC), 55% of biochemical oxygen demand (BOD), and 30% of nutrients [e.g. total nitrogen (TN), total phosphorus (TP)] were removed via the constructed wetland system. However, results from the sediment analyses show that wetland sediments contained high concentrations of metals (e.g. Cu, Fe, Zn, Cr, and Mn), organic contents (sediment oxygen demand = 1.7 to 7.6 g O2/m2 d), and nutrients (up to 18.7 g/kg of TN and 1.22 g/kg of TN). Thus, sediments should be excavated periodically to prevent the release the pollutants into the wetland system and causing the deterioration of wetland water quality. Results of polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and nucleotide sequence analysis reveal that a variation in microbial diversity in the wetland systems was observed. Results from the DGGE analysis indicate that all sediment samples contained significant amounts of microbial ribospecies, which might contribute to the carbon degradation and nitrogen removal. Gradual disappearance of E. coli was also observed along the flow courses through natural attenuation mechanisms.

Can high-frequency data enable better parameterization of water quality models and disentangling of DO processes?

2021 ◽  
Author(s):  
Jingshui Huang ◽  
Pablo Merchan-Rivera ◽  
Gabriele Chiogna ◽  
Markus Disse ◽  
Michael Rode
Keyword(s):  
Water Quality ◽  
High Frequency ◽  
Critical Role ◽  
Measurement Data ◽  
High Frequency Data ◽  
Model Parameters ◽  
Frequency Data ◽  
Quality Models ◽  
Model Parameter ◽  
Water Quality Models

<p>Water quality models offer to study dissolved oxygen (DO) dynamics and resulting DO balances. However, the infrequent temporal resolution of measurement data commonly limits the reliability of disentangling and quantifying instream DO process fluxes using models. These limitations of the temporal data resolution can result in the equifinality of model parameter sets. In this study, we aim to quantify the effect of the combination of emerging high-frequency monitoring techniques and water quality modelling for 1) improving the estimation of the model parameters and 2) reducing the forward uncertainty of the continuous quantification of instream DO balance pathways.</p><p>To this end, synthetic measurements for calibration with a given series of frequencies are used to estimate the model parameters of a conceptual water quality model of an agricultural river in Germany. The frequencies vary from the 15-min interval, daily, weekly, to monthly. A Bayesian inference approach using the DREAM algorithm is adopted to perform the uncertainty analysis of DO simulation. Furthermore, the propagated uncertainties in daily fluxes of different DO processes, including reaeration, phytoplankton metabolism, benthic algae metabolism, nitrification, and organic matter deoxygenation, are quantified.</p><p>We hypothesize that the uncertainty will be larger when the measurement frequency of calibrated data was limited. We also expect that the high-frequency measurements significantly reduce the uncertainty of flux estimations of different DO balance components. This study highlights the critical role of high-frequency data supporting model parameter estimation and its significant value in disentangling DO processes.</p>

scholarly journals Linkages between Macrophyte Functional Traits and Water Quality: Insights from a Study in Freshwater Lakes of Greece

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1047 ◽  
Author(s):  
Konstantinos Stefanidis ◽  
Eva Papastergiadou
Keyword(s):  
Water Quality ◽  
Cluster Analysis ◽  
Functional Traits ◽  
Environmental Gradients ◽  
Hierarchical Cluster ◽  
Environmental Drivers ◽  
Secchi Disk ◽  
Secchi Disk Depth ◽  
Freshwater Lakes ◽  
Functional Characteristics

Freshwater ecologists have shown increased interest in assessing biotic responses to environmental change using functional community characteristics. With this article, we investigate the potential of using functional traits of the aquatic plants to assess eutrophication in freshwater lakes. To this end we collected macrophyte and physicochemical data from thirteen lakes in Greece and we applied a trait-based analysis to first identify discrete groups of macrophytes that share common functional traits and then to assess preliminary responses of these groups to water quality gradients. We allocated 11 traits that cover mostly growth form and morphological characteristics to a total of 33 macrophyte species. RLQ and fourth corner analysis were employed to explore potential relationships between species, trait composition and environmental gradients. In addition, a hierarchical cluster analysis was conducted to discriminate groups of plants that share common trait characteristics and then the position of the groups along the environmental gradients was assessed. The results showed total phosphorus, chlorophyll-a, conductivity, pH and Secchi disk depth as main drivers of the environmental gradients. Hierarchical cluster analysis showed a clear separation of macrophyte assemblages with discrete functional characteristics that appeared to associate with different environmental drivers. Thus, rooted submerged plants were related with higher Secchi disk depth, conductivity and alkalinity whereas rooted floating-leaved plants showed a preference for enriched waters with phosphorus and nitrogen. In addition, free-floating plants were related positively with nitrogen and increased pH. Although we did not identify specific trait patterns with environmental drivers, our findings indicate a differentiation of macrophytes based on their functional characteristics along water quality gradients. Overall, the presented results are encouraging for conducting future monitoring studies in lakes focused on the functional plant trait composition, as expanding the current approach to additional lakes and using quantifiable functional characteristics will provide more insight about the potential of trait-based approaches as ecological assessment systems.

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