Water–Energy–Food Nexus Narratives and Resource Securities: A Global South Perspective provides a knowledge synthesis on the water–energy–food (WEF) nexus, focusing primarily on the global south. By presenting concepts, analytical tools, and case studies, the book serves as a practical resource for researchers, policymakers, and practitioners in sustainability and functional roles across all three sectors. It addresses key issues related to data availability, tools, indices, metrics, and application across multiple scales, beginning with a summary of existing knowledge. Finally, it examines the WEF nexus, presents global insights, and discusses future considerations and implications. This book presents an overview of existing knowledge on the WEF nexus and examines how such research aligns with emerging global WEF nexus perspectives, making it ideal for professionals, government entities, private industry, and the general public.

Vaca Muerta is the major region in South America where horizontal drilling and hydraulic fracturing techniques are used to extract unconventional shale oil and gas. Despite the growing interest in the Vaca Muerta resources, there is only a limited understanding of the impacts that their extraction could have on local water resources. This study uses a water balance model to investigate the hydrological implication of unconventional oil and gas extraction in this region. We find that, with current rates of extraction, water scarcity is observed for four months a year. We also find that water consumption per fractured well increased 2.5 times in the period 2012–2016 and produced water from unconventional shale formation sharply increased from roughly zero to 1.15 × 10⁶ m³ y⁻¹ in the 2009–2017 period. Our projections estimate that in this region future water consumption for unconventional oil and gas extraction will increase 2.2 times in the 2017–2024 period reaching 7.40 × 10⁶ m³ y⁻¹. The consequent exacerbation of current water scarcity will likely lead to competition with irrigated agriculture, the greatest water consumer in this semiarid region. Produced water recycling, domestic wastewater reuse, brackish groundwater use, and waterless unconventional oil and gas extraction technologies are some of the strategies that could be adopted to meet future additional water demand. Our results estimate the likely range of water consumption and production from hydraulic fracturing operations in the Vaca Muerta region under current and future conditions. These results could be used to make informed decisions for the sustainable water management in this semiarid region of Argentina.

Pejerrey, Odontesthes bonariensis, is an euryhaline fish of commercial importance in Argentina. This work aimed to determine if water salinity affects the expression of genes involved in somatic growth (gh; ghr-I; ghr-II; igf-I), lipid metabolism (Δ6-desaturase) and food intake (nucb2/nesfatin-1). First, we identified the full-length cDNA sequences of Δ6-desaturase (involved in lipid metabolism) and nesfatin-1 (an anorexigen). Then, pejerrey juveniles were reared during 8weeks in three different water salinity conditions: 2.5g/L (S2.5), 15g/L (S15) and 30g/L (S30) of NaCl. Brain, pituitary, liver and muscle samples were collected in order to analyze mRNA expression. The expression of gh and ghr-II mRNAs increased in the pituitary of fish reared at S2.5 and S30 compared with the S15 group. The expression of ghr-I was higher in the liver of S30 group compared to S2.5 and S15. Igf-I mRNA expression in liver increased with the increment of water salinity, while it decreased in the muscle of S15 and S30 groups. Δ6-desaturase expression increased in S2.5 group compared to S15 in both liver and muscle. S30 caused a decrease in the Δ6-desaturase expression in liver compared to S15. The S30 treatment produced an increase in nucb2/nesfatin-1 mRNA expression in the brain and liver compared to S2.5 and S15. The changes in gene expression observed could help pejerrey perform better during salinity challenges. The S30 condition would likely promote pejerrey somatic growth in the long term.

Riparian areas of riverine plains develop extensive floodable areas named riverine wetlands, which are essential to the water cycle balance and ecosystem dynamics. In this study, we contrasted the hydrological and physicochemical variables of riverine wetlands of both peri-urban areas impacted by intensive farming and those of rural areas with the indicators of the biotic structure (taxonomic richness, Shannon diversity and total density) of benthic diatoms, phytoplankton, zooplankton, macroinvertebrates, chironomids, fishes, turtles, and birds. The study was performed on riverine waters of the Pampean plain, Argentina, with four seasonal samplings conducted in 2017–2018. Our results showed that the significant deepening of the groundwater level caused by aquifer overexploitation in peri-urban areas, as well as the declining surface water quality with higher phosphorus and total nitrogen concentrations, affected the taxonomic richness, diversity, and total density of the biotic assemblages of riverine wetlands. The taxonomic richness of birds, turtles, phytoplankton, chironomids, and fishes was the most sensitive to land use. Phytoplankton, chironomid, and fish diversity showed the greatest differences between rural and peri-urban riverine waters, while the total density of chironomids and birds showed the greatest differences according to land use. The results suggest that the socioeconomic development in those riverine wetlands that still maintain conditions close to the natural ones needs to be subject to guidelines derived from integrated basin management and sustainable urban planning.

Water from La Pampa, Argentina, was used for washing and cooking rice to examine the in-situ impact of using naturally-contaminated water for food preparation on the elemental dietary intake. Whilst washing with the control tap water (28 μg/L As) reduced the concentration of As in rice by 23%, the use of different well waters (281–1144 μg/L) increased As levels significantly (48–227%) in comparison with the original concentration in the rice (0.056 µg/g). Cooking the rice at a low water-to-rice ratio (2:1) using modern methods increased the levels of As in the cooked samples by 2–3 orders of magnitude for both pre-washed and un-washed rice. Similar trends were observed for vanadium. Although the levels of manganese, iron, copper, zinc and molybdenum in rice were reduced during washing and cooking for most water samples, the molybdenum concentration in the cooked rice doubled (2.2–2.9 µg/g) when using water containing >1 mg/L Mo.

Con el propósito de conocer cualitativamente la alimentación y la conducta alimentaria de la almeja de agua dulce Diplodon chilensis, se analizó mediante estudios de laboratorio y de campo el comportamiento alimentario y el contenido digestivo de especímenes procedentes de sustratos areno-pedregosos y arenosos del Lago Panguipulli y se relacionó con la oferta ambiental existente en el sustrato (fitobentos) y en el agua (fito-plancton). El análisis del contenido digestivo de los especímenes y los resultados experimentales, indican que Diplodon chilensis tiene una alimentación mixta en base a fitoplancton, fitobentos y materia orgánica existente en el plancton y en el bentos<br>To determine qualitatively, feeding and alimentary behavior of the freshwater mussel, Diplodon chilensis, it was studied by means of field and laboratory studies the alimentary behavior and the digestive content of specimens inhabiting sand-gravel and sandy substrates of Lake Panguipulli; the digestive content of D. chilensis specimens was correlated to the environmental food offer existing in the substrate (phytobenthos) and in the water (phytoplankton). The digestive content analysis of the specimens and the experimental results show that D. chilensis has a mixed feeding based on phytoplankton, phytobenthos and organic matter existent in the plankton and benthos