Effects of COVID-19 lockdown on water quality, microbial extracellular enzyme activity, and sediment-P release in the Ganga River, India.

This study investigates possible improvement in water quality and ecosystem functions in the Ganga River as influenced by COVID-19 lockdown in India. A total of 132 samples were collected during summer-2020 low flow (coinciding COVID-19 lockdown) for water (sub-surface and sediment-water interface) and 132 samples separately for sediment (river bottom and land-water interface) considering 518-km main river stem including three-point sources (one releases urban sewage and the other two add metal-rich industrial effluents) and a pollution-impacted tributary. Parameters such as dissolved oxygen deficit and the concentrations of carbon, nutrients (N and P), and heavy metals were measured in water.

Integrating resilience with functional ecosystem measures: A novel paradigm for management decisions under multiple-stressor interplay in freshwater ecosystems.

Moving beyond monitoring the state of water quality to understanding how the sensitive ecosystems "respond" to complex interplay of climatic and anthropogenic perturbations, and eventually the mechanisms that underpin alterations leading to transitional shifts is crucial for managing freshwater resources. The multiple disturbance dynamics-a single disturbance as opposed to multiple disturbances for recovery and other atrocities-alter aquatic ecosystem in multiple ways, yet the global models lack representation of key processes and feedbacks, impeding potential management decisions. Here, the procedure we have embarked for what is known about the biogeochemical and ecological functions in freshwaters in context of ecosystem resilience, feedbacks, stressors synergies, and compensatory dynamics, is highly relevant for process-based ecosystem models and for developing a novel paradigm toward potential management decisions.

The skewed N:P stoichiometry resulting from anthropogenic drivers regulate production of transparent exopolymer particles (TEP) in Ganga River.

Transparent exopolymer particles (TEP), generated from excretion products of microalgae, trigger flocculation of diatoms and sinking of organic matter. Investigations along 797 km stretch of Ganga River indicated that TEP declined with increasing N:P stoichiometric ratio downstream. The TEP showed positive relationship with chlorophyll a (R(2) = 0.

The influence of DOC trends on light climate and periphyton biomass in the Ganga River, Varanasi, India.

Investigations on periphyton along an eutrophication gradient (NO(3)(-) = 0.23-0.96 mg L(-1); PO(4)(-3) = 0.