Flow and water quality of rivers are highly dynamic. Water quantity and quality are subjected to simultaneous physical, chemical and biological processes making it difficult to accurately assess lotic ecosystems. Our study investigated net ecosystem production (NEP) relying on high-frequency data of hydrology, hydrodynamics and water quality. The Kanawha River, West Virginia was investigated along 52.8 km to estimate NEP. Water quality data were collected along the river using three distributed multiprobe sondes that measured water temperature, dissolved oxygen, dissolved oxygen saturation, specific conductance, turbidity and ORP hourly for 71 days. Flows along the river were predicted by means of the hydrologic and hydrodynamic models in Hydrologic Simulation Program in Fortran (HSPF). It was found that urban local inflows were correlated with NEP. However, under hypoxic conditions, local inflows were correlated with specific conductance. Thus, our approach represents an effort for the systematic integration of data derived from models and field measurements with the aim of providing an improved assessment of lotic ecosystems.

We sequenced two metagenomes from upper sediment layers (0 to 5 and 6 to 10 cm) from the Kanawha River, West Virginia. The watershed includes inputs from the forested Appalachian Mountains, surface coal mining, municipal residues, and extensive chemical manufacturing. The dominant bacterial phyla were Proteobacteria, Bacteriodetes, Firmicutes, Actinobacteria, and Chloroflexi. Xenobiotic degradation pathways were present.

We sequenced the metagenome of a pilot-scale thermophilic digester with long-term, stable performance on poultry litter feedstock which has a very low C/N ratio, a high ammonia level, and high lignocellulose content. Firmicutes were the dominant phylum (68.9%).

Rainstorms rapidly change catchment conditions which can alter river flow and water constituents due to the transport and fate of suspended and dissolved solids and the river water chemistry. To understand river water chemistry changes, this investigation relies on field data collected during a winter season. The Kanawha River in West Virginia was monitored using grab water samples and continuous readings from two water quality stations (Q1 and Q2) separated by 23.5 km. Water samples allowed the identification of water chemistry, whereas the two stations retrieved hourly measurements of temperature, turbidity, NO3−, Cl− and pH to capture transient rainstorm responses. It was found through the Piper diagram that water type was mainly calcium-chloride, whereas the Gibbs diagram identified that the dominant geochemical process was rock weathering. On the other hand, during transient rainstorms responses, we found that concentrations of HCO3−, NO3− and Cl− changed from bicarbonate type to no dominant type. Furthermore, hysteretic effects of rainstorms were influenced by the soil moisture of the catchment area. Additionally, HCO3− and NO3− had different hysteretic loop directions between Q1 and Q2. This approach proved that river water chemistry adjustments caused by rainstorms were successfully identified by relying on grab water samples and continuous measurements.

IntroductionContinental hydrothermal systems (CHSs) are geochemically complex, and they support microbial communities that vary across substrates. However, our understanding of these variations across the complete range of substrates in CHS is limited because many previous studies have focused predominantly on aqueous settings.MethodsHere we used metagenomes in the context of their environmental geochemistry to investigate the ecology of different substrates (i.e., water, mud and fumarolic deposits) from Solfatara and Pisciarelli.Results and DiscussionResults indicate that both locations are lithologically similar with distinct fluid geochemistry. In particular, all substrates from Solfatara have similar chemistry whereas Pisciarelli substrates have varying chemistry; with water and mud from bubbling pools exhibiting high SO42− and NH4+ concentrations. Species alpha diversity was found to be different between locations but not across substrates, and pH was shown to be the most important driver of both diversity and microbial community composition. Based on cluster analysis, microbial community structure differed significantly between Pisciarelli substrates but not between Solfatara substrates. Pisciarelli mud pools, were dominated by (hyper)thermophilic archaea, and on average, bacteria dominated Pisciarelli fumarolic deposits and all investigated Solfatara environments. Carbon fixation and sulfur oxidation were the most important metabolic pathways fueled by volcanic outgassing at both locations. Together, results demonstrate that ecological differences across substrates are not a widespread phenomenon but specific to the system. Therefore, this study demonstrates the importance of analyzing different substrates of a CHS to understand the full range of microbial ecology to avoid biased ecological assessments.