We investigated food supply mechanisms to a cold-water coral (CWC) reef at 260 m depth on the Norwegian continental shelf using data from a cabled ocean observatory equipped with Acoustic Doppler Current Profilers (ADCPs), an echosounder, and sensors for chlorophyll, turbidity and hydrography in the benthic boundary layer (BBL). Tidal currents of up to tens of cm s−1 dominated BBL hydrodynamics while residual currents were weak (∼10 cm s−1), emphasizing a supply and high retention of locally produced phytodetritus within the trough. A direct connection between the reefs and surface organic matter (OM) was established by turbulent mixing and passive particle settling, but relative contributions varied seasonally. Fresh OM from a spring-bloom was quickly mixed into the BBL, but temperature stratification in summer reduced the surface-to-bottom connectivity and reduced the phytodetritus supply. A qualitative comparison among acoustic backscatter in the ADCPs (600 kHz, 190 kHz) and echosounder (70 kHz) suggests that vertically migrating zooplankton may present an alternative food source in summer. Nocturnal feeding by zooplankton in the upper water column sustains downward OM transport independent from water column mixing and may dominate as food supply pathway over sedimentation of the phytodetritus, especially during stratified conditions. In addition, it could present a concentrating mechanism for nutritional components as compensation for the deteriorating phytodetritus quality. Overall, the observed patterns suggest seasonal changes in the food supply pathways to the reef communities. The moderating role of temperature stratification in phytodetritus transport suggests stronger dependence of the cold-water corals on zooplankton for their dietary requirements with increased stratification under future climate scenarios. This study demonstrates the added value of permanent ocean observatories to research based on dedicated campaigns and regular monitoring.

The Food-Energy-Water-Waste Nexus (FEWWN) represents the interconnections between food, energy, water, and waste production systems, and it has become a key research area. Enormous quantities of agricultural and organic wastes are produced throughout the FEWWN. Often, these wastes are not treated appropriately because their true costs are rarely quantified, and usually externalized to the environment. This shortcoming is addressed from a systems perspective fused with approaches from ecological economics. A regional bioenergy production model where bioenergy may be produced from ethanol and/or agricultural wastes is constructed. Ecosystem service valuation methods are integrated into the framework, allowing for bioenergy production systems to be designed to minimize ecological damage and/or maximize ecological restoration. These values are captured within a Green Gross Domestic Product (Green GDP) objective that values both energy produced and ecosystem service values lost/gained. System profit is another objective in the multi-objective model. The framework is applied to a bioenergy production system for the U.S. state of New York, which aims to produce 10% more bioenergy compared to its current levels. Net changes in Green GDP ranged from -$16.5 M/y to $90.6 M/y, and corresponding profits ranged from $7.2 M/y to -$74.5 M/y. Corn grain ethanol was the dominant source of bioenergy in solutions with higher profits, while ethanol from corn stover and bioelectricity generated from animal manure biogas contributed more bioenergy in solutions with increasing Green GDP. Results show that there is a trade-off between promoting natural capital/ecological health and financial profit. FEWWN system design should consider these trade-offs moving forward.

Sustainable use and supply of natural resources dedicated to feeding urban life are becoming increasingly complex in a time of rapid urbanization and climate change. Sustainable governance of Water–Energy–Food (WEF) requires innovative and cross-sectorial systems of provisioning. However, practitioners have often treated WEF as separate domains, while ignoring their interconnectedness. What is missing is an ‘Urban Nexus’ perspective, which assumes that environmental flows of WEF interact and relate to one another in achieving urban sustainable development. This paper contributes to theorizing the urban nexus and to understand its emergence and governance from a more socio-material perspective. It offers a conceptual framework that helps to shed light on the social and material flows shaping connections between the sectors of WEF, and the actors facilitating these connections. The paper suggests that switchers and programmers link and configure the socio-material flows of WEF facilitating the emergence of nexus governance networks and nexus programs. In doing so, the paper provides three examples of cities to test the conceptual framework by analyzing their main challenges and examples around the nexus. It demonstrates that material and social dimensions of WEF might not play an equal role in steering synergies or trade-offs—either material or social flows and their agents can be central in facilitating a nexus or in preventing it to take shape. The paper argues that material-focused methodologies need to be complemented with a social flows analysis that pays attention to the daily practice, policies, ideologies, networks or any kind of socio-cultural meaning shaping WEF provisioning.

The International Commission on Irrigation and Drainage (ICID) has organized its 23ʳᵈ International Congress in Mexico City during the period 08–‐14 October 2017. Its overall theme was: Modernizing Irrigation and Drainage for a new Green Revolution. Two Questions 60 and 61 were addressed and concerned respectively the following issues: Question 60 on Water Productivity: Revisiting the concepts in light of water, energy and food nexus, and Question 61 on State of knowledge of irrigation techniques and practicalities within given socio‐economic settings. The present paper aims at giving a summary of the main axis covered by the various contributions on Question 60. In fact, 91 contributions from 27 countries analyzed and discussed the three following sub themes related to Question 60, namely: i) Emerging issues and challenges of water saving, including impact of transferring water out of agriculture; ii) Understanding water productivity, water and energy use efficiency and water footprint of crops; iii) Water security for growth and development. A summary of the main ideas and findings emerged, for each sub theme mentioned above, are herein presented. Majors conclusions and recommendations are also included at the end of this paper. © 2019 John Wiley & Sons, Ltd.

Captação de água de chuva in situ é uma maneira de preparar o solo para o plantio de culturas, principalmente anuas, como milho, feijão, mandioca, exploradas em condições dependentes de chuva.

The main limiting factor impeding the operationalisation of the WEF nexus has been lack of metrics and tools to translate the concept into a fully-fledged operational framework to support policy and decision-making. This study developed a WEF nexus model by (i) defining WEF nexus sustainability indicators, and (ii) calculating composite indices for those indicators to establish numerical relationships among WEF nexus resources using South Africa as a case study. The composite indices show WEF nexus performance as well as monitoring and evaluation of WEF resources management. The indicators were integrated through the Analytic Hierarchy Process (AHP) in a multicriteria decision-making (MCDM). The established quantitative relationships indicate resource utilisation, management and performance through a spider graph to illustrate WEF nexus performance, providing a general overview of the level of interactions, interrelationships and inter-connectedness of resources. The shape of the spider graph is determined by the level of the interdependencies and interactions among the WEF nexus sectors, whose management is viewed either as sustainable or unsustainable depending on the classification of the developed integrated index. The spider graph for South Africa showed an over-emphasis on food self-sufficiency and water productivity at the expense of other sectors. The deformed shape of the spider graph is a demonstration of the sectoral or “silo” approach in resource management. The calculated integrated WEF nexus index of 0.203 for South Africa classified the country under the low sustainability category. The developed model is a decision support tool that provides evidence for interventions in priority areas. The model demonstrates the capabilities of the WEF nexus to evaluate synergies and trade-offs in a systematic and integrated way to increases efficiency and productivity in resource management for sustainable development.

Rapid development of food factories in both developed and developing countries, owing to continued growth in the world population, plays a critical role in the food supply chain, including environmental issues such as pollution, emissions, energy and water consumption, and thus food system sustainability. The objective of this study was to briefly review various environmental aspects of food processing operations, including aquatic, atmospheric, and solid waste generation, and also to discuss several strategies that many companies are using to reduce these negative impacts as well as to improve water and energy efficiency. To obtain higher energy efficiencies in food processing factories, two key operations can play critical roles: non-thermal processing (e.g., high pressure processing) and membrane processes. For higher water efficiency, reconditioning treatments resulting in water reuse for other purposes can be conducted through chemical and/or physical treatments. With regards to reducing volumes of processing food waste, two approaches include value-added by-product applications (e.g., animal feed) and/or utilization of food waste for energy production. Finally, we present trends for lowering operational costs in food processing.