Urban Planning and Corona Spaces – Scales, Walls and COVID-19 Coincidences

This study focuses on the role and responsibility of urban planning in mitigating the COVID-19 pandemic ́s impact. The far-reaching social and economic consequences of this threat are counteracted by organisational and constructional measures to prevent lockdowns and finally illnesses and deaths. Corona spaces and voids are introduced as a consistent multi scale approach concerning the pandemics spatial implications and respective measures. These terms are operationalised for urban planning and can be used as an overarching concept to be communicated within cross-sectoral planning tasks. A comparison of Taiwan's and the USA's responses to the outbreak suggests that the coincidence at the beginning of a pandemic can be controlled by institutional precautions. On an urban scale, organisational measures (e.g. contact tracing, quarantine, and lockdown) can be supported by constructional ones concerning e.g. transport, public spaces, urban agriculture, and offices aimed at crowding reduction. If appropriate measures are applied, urban density does not seem to increase spreading the virus, whereby a regression analysis based on data of districts in Germany shows no relationship between population density and COVID-19 deaths. Lockdown prevention should be a planning goal and multifunctional approaches that integrate aspects of virus resilience should be favoured over the monothematic urban development approach (Leitbild) of a virus resilient city. Urban planning can contribute to the mitigation of future outbreaks by including pandemic preparedness in planning frameworks

Profitability of multi‐loop aquaponics: Year‐long production data, economic scenarios and a comprehensive model case

This case study examined the productivity and economic performance of a double recirculation aquaponic system in Germany with a total interior area of about 540 m2. Calculations were carried out as an ex post analysis based on one-year production data. The initial situation was not profitable; therefore, two scenarios were developed, which envisaged a significantly improved productivity of the fish as well as of the plant unit and a more than threefold enlargement of the greenhouse to make maximum use of the fish effluent. An ex ante analysis was performed and showed that the second scenario was profitable with a payback period of about 12 years. On the basis of this scenario, a simple but comprehensive model case with the complete set of economic key indicators showed that aquaponics is feasible if it exploits its potential, regardless of the high initial investment costs. The model case would cover an overall space of about 2,000 m2, which is suitable for professional aquaponics in urban and peri-urban areas with their limited space availability. Furthermore, multi-loop aquaponics with its inherent circles fits into the circular city concept and implements resource-efficient and sustainable food production into the urban fabric, which is important with increasing urbanization.Belmont Forum and the European Commission via CITYFOODINAPR

The aquaponic principle—It is all about coupling

The aquaponic principle is the coupling of animal aquaculture (e.g. fish) with plant production (e.g. vegetables) for saving resources. At present, various definitions of aquaponics exist, some bearing the risk of misinterpretation by dismissing the original meaning or being contradictory. In addition, there is no standard terminology for the aspects of coupling between the aquaponic subsystems. In this study, we addressed both issues. (1) We developed new or revised definitions that are summarised by: Aquaponic farming comprises aquaponics (which couples tank‐based animal aquaculture with hydroponics) and trans‐aquaponics, which extends aquaponics to tankless aquaculture as well as non‐hydroponics plant cultivation methods. Within our conceptual system, the term aquaponics corresponds to the definitions of FAO and EU. (2) A system analysis approach was utilised to explore different aquaponic setups aiming to better describe the way aquaponic subsystems are connected. We introduced the new terms ‘coupling type’ and ‘coupling degree’, where the former qualitatively characterises the water‐mediated connections of aquaponic subsystems. A system with on‐demand nutrient water supply for the independent operating plant cultivation is an ‘on‐demand coupled system’ and we propose to deprecate the counterintuitive term ‘decoupled system’ for this coupling type. The coupling degree comprises a set of parameters to quantitatively determine the coupling's efficiency of internal streams, for example, water and nutrients. This new framework forms a basis for improved communication, provides a uniform metric for comparing aquaponic facilities, and offers criteria for facility optimisation. In future system descriptions, it will simplify evaluation of the coupling's contribution to sustainability of aquaponics.Belmont ForumEuropean Commission via the CITYFOOD projectPeer Reviewe

The aquaponic principle : it is all about coupling

The aquaponic principle is the coupling of animal aquaculture (e.g. fish) with plant production (e.g. vegetables) for saving resources. At present, various definitions of aquaponics exist, some bearing the risk of misinterpretation by dismissing the original meaning or being contradictory. In addition, there is no standard terminology for the aspects of coupling between the aquaponic subsystems. In this study, we addressed both issues. (1) We developed new or revised definitions that are summarised by: Aquaponic farming comprises aquaponics (which couples tank-based animal aquaculture with hydroponics) and trans-aquaponics, which extends aquaponics to tankless aquaculture as well as non-hydroponics plant cultivation methods. Within our conceptual system, the term aquaponics corresponds to the definitions of FAO and EU. (2) A system analysis approach was utilised to explore different aquaponic setups aiming to better describe the way aquaponic subsystems are connected. We introduced the new terms ‘coupling type’ and ‘coupling degree’, where the former qualitatively characterises the water-mediated connections of aquaponic subsystems. A system with on-demand nutrient water supply for the independent operating plant cultivation is an ‘on-demand coupled system’ and we propose to deprecate the counterintuitive term ‘decoupled system’ for this coupling type. The coupling degree comprises a set of parameters to quantitatively determine the coupling's efficiency of internal streams, for example, water and nutrients. This new framework forms a basis for improved communication, provides a uniform metric for comparing aquaponic facilities, and offers criteria for facility optimisation. In future system descriptions, it will simplify evaluation of the coupling's contribution to sustainability of aquaponics

Comparing locomotor behaviour of the fish species Danio rerio and Leucaspius delineatus under the influence of chemical stressors

Diese Dissertation ist ein Beitrag zum Forschungsfeld der Stressökologie, im Spe-ziellen der Verhaltensökotoxikologie. Das spontane lokomotorische Verhalten der Fischarten Danio rerio und Leucaspius delineatus wurde unter sublethaler Expo-sition mit dem Cyanobakterientoxin Microcystin-LR (MC-LR) und dem Xenobio-tikums 2.4.4`-Trichlorobiphenyl (PCB 28) quantifiziert. Die Schwimmgeschwin-digkeit und Anzahl der Wendungen wurden kontinuierlich mit einem automati-schen Video-Monitoringsystem unter Laborbedingungen aufgezeichnet. In Hin-blick auf zyklische Aspekte wurden die Verhaltensanalysen mit chronobiologi-schen Methoden kombiniert. Hiermit wurde gezeigt, dass MC-LR und PCB 28 zu signifikanten Effekten in Verhalten und Aktivitätsrhythmik beider Fischarten führten. Höhere Konzentrati-onen beider Untersuchungssubstanzen verursachten eine deutliche Aktivitätsredu-zierung bei Danio rerio und Leucaspius delineatus. Einige der festgestellten Do-sis-Wirkungsbeziehungen entsprechen der Hormesistheorie, z. B. war bei geringe-ren MC-LR Konzentrationen ein Aktivitätsanstieg und bei höheren ein Aktivitäts-abfall beider Fischarten zu verzeichnen. Die Exposition mit MC-LR und PCB 28 verringerte bei beiden Testfischarten die Synchronisation der Aktivität mit dem Zeitgeber Licht. Dies führte bei beiden Fischarten zu einer Phasenverschiebung. Bei Leucaspius delineatus war unter dem Einfluss von MC-LR eine Phasenumkehr zu verzeichnen, die Fische wechselten von Tag- zu Nachtaktivität. Die Cosinor Analyse zeigte Dosis abhängige Veränderungen der circadianen Rhythmen der Schwimmaktivität (z.B. MESOR, Akrophase) unter Einfluss von MC-LR und PCB 28 an. Die Power Spektral Analyse indizierte für beide Fischar-ten unter Einwirkung von MC-LR and PCB 28 eine reduzierte Dominanz des cir-cadianen Rhythmuspeaks. Da die registrierten Unterschiede in der Reaktion beider Fischarten auf MC-LR und PCB 28 eher gering waren, sind Ergebnisse der Art Danio rerio, die häufig in Toxizitätstests verwendet wird, mit denen der einheimischen Art Leucaspius deli-neatus vergleichbar. Die Ergebnisse belegen, dass Verhaltensuntersuchungen in Kombination mit chronobiologischen Auswertemethoden eine sensitive und zuverlässige Abschät-zung des Gefährdungspotentials von Substanzen sowohl auf dem Gebiet der Öko-toxikologie als auch für Biomonitoring ermöglichen.This thesis contributes to the field of stress ecology specifically behavioural ecotoxicology. The spontaneous locomotor behavior of two fish species Danio re-rio and Leucaspius delineatus was recorded and quantified continuously under sublethal exposure to the cyanotoxin microcystin-LR (MC-LR) and the xenobioti-cum 2.4.4`-trichlorobiphenyl (PCB 28). By using an automated video-monitoring system, the swimming velocity and the number of turns were assessed under labo-ratory conditions. For analysing cyclic aspects basic behavioural analyses were combined with chronobiological procedures as cosinor analysis and power spec-tral analysis. Both MC-LR and PCB 28 acted as stressors and caused significant changes in the behaviour and circadian activity rhythms of Danio rerio as well as Leucaspius de-lineatus. So for both species elevated concentrations of the stressors led to a re-duction of their activity. Some dose-responses correspond to the hormesis theory, e.g., there was an increase of daytime activity at lower MC-LR concentrations and a decrease at elevated concentrations of MC-LR for both species. A degree of desynchronisation of activity to the zeitgeber light, which led to a phase shift was caused by the chemicals in both fish species. In Leucaspius de-lineatus this shift was so drastic that this species reversed their significant diurnal activity and became nocturnal under the influence of MC-LR. The Cosinor analysis revealed MC-LR- and PCB 28-induced, dose-dependent al-terations of the circadian rhythms of activity (e.g., MESOR, acrophase). The power spectral analysis showed that the dominance of the circadian rhythmic peak (of 24 h) was reduced under MC-LR and PCB 28 for both species. Since the observed differences in the reactions of both species to MC-LR and PCB 28 were rather small, the results of the species Danio rerio which is widely used for environmental risk assessment tests, are comparable to those of the native European species Leucaspius delineatus. The findings of this study proved that the basic behavioural analyses combined with chronobiological procedures could be valuable tools for the study of stressful or even harmful environmental factors in the field of ecotoxicology as well as for biomonitoring

Urban Rooftop Uses: Competition and Potentials from the Perspective of Farming and Aquaponics – a Berlin Case Study

Accelerating urbanisation is profoundly changing our world, making it necessary to rethink - inter alia - the way cities distribute and provide food. Agriculture is an emerging urban use that can play an important role in these processes, supporting circular economy and resilience, but competes with other uses for limited space. One option to address this spatial problem in relation to urban food production is to exploit rooftops. For evaluation, we investigated the use, competition and potential of urban roofscapes, using the city of Berlin as an example. An overview of current roofscape uses in Berlin is given, plans and initiatives for further expansion are presented, rooftop potential studies are compared, and important boundary conditions of rooftop uses are discussed. Berlin’s roofscape of 97.3 km² (excluding 4.5 km² underground garages) already has a wide range of roof uses, with green roofs (11.8 km²) and solar roofs (0.7 km²) being the most common ones. As on the ground, commercial urban farming competes for space in the roofscape. We highlight rooftop aquaponics as a possibility to save resources by coupling fish and crop production and producing animal protein with a low environmental footprint compared to other animal farming systems. Freestanding single-storey aquaponic systems in inner cities should be avoided and in Berlin, approximately 800 buildings of appropriate using type exist with more than 2000 m² roof area as a precondition to host commercial rooftop aquaponics. The selection of specific sites should consider the availability of urban resources and requirements of an urban situation for the roofscape under existing as well as future competitive conditions. Further research efforts are required to adapt building regulations and planning laws, determine circular city locations for rooftop aquaponics, and evaluate the potential of peri-urban versus urban rooftop food production

Site Resource Inventories – a Missing Link in the Circular City's Information Flow

A circular city builds upon the principles of circular economy, which key concepts of reduce, reuse, recycle, and recover lead to a coupling of resources: products and by-products of one production process become the input of another one, often in local vicinity. However, sources, types and available quantities of underutilised resources in cities are currently not well documented. Therefore, there is a missing link in the information flow of the circular city between potential users and site-specific data. To close this gap, this study introduces the concept of a site resource inventory in conjunction with a new information model that can manage the data needed for advancing the circular city. A core taxonomy of terms is established as the foundation for the information model: the circular economy is defined as a network of circular economy entities which are regarded as black boxes and connected by their material and energy inputs and outputs. This study proposes a site resource inventory, which is a collection of infrastructural and building-specific parameters that assess the suitability of urban sites for a specific circular economy entity. An information model is developed to manage the data that allows the entities to effectively organise the allocation and use of resources within the circular city and its material and energy flows. The application of this information model was demonstrated by comparing the demand and availability of required alternative resources (e.g. greywater) at a hypothetical site comprising a commercial aquaponic facility (synergistic coupling of fish and vegetables production) and a residential building. For the implementation of the information model a proposal is made which uses the publicly available geodata infrastructure of OpenStreetMap and adopts its tag system to operationalise the integration of circular economy data by introducing new tags. A site resource inventory has the potential to bring together information needs and it is thus intended to support companies when making their business location decisions or to support local authorities in the planning process

CITYFOOD - Upscaled Urban Aquaponics and the Food-Water-Energy Nexus

To address the most pressing global problems of sustainable development, the UN formulated 17 goals in 2015 (UN, 2015). The current review shows that while progress has been made, efforts need to be significantly increased to achieve the sustainable development goals (SDGs) (UN, 2020) and therefore a “Decade of Action” was proclaimed to fulfil the 2030 Agenda (UN, 2021). This call by the United Nations was taken up by the German Federal Government through the revision of its sustainability strategy, which now contains six transformation areas, including the circular economy as well as sustainable agricultural and food systems (BReg, 2021). One food production technology that belongs to these two transformation areas is aquaponics, the coupled production of fish and plants (Naegel, 1977; Baganz et al., 2021a). Given the rising importance of urban agriculture (Lohrberg et al., 2015), the project CITYFOOD posed the question of whether and to what extent it makes sense to bring aquaponics into cities (Baganz et al., 2020; Proksch & Baganz, 2020) The urban Food-Water-Energy (FWE) Nexus describes the interlinkages and interdependencies between food, water and energy in coupled systems in an urban context, whereas all three sectors have also strong impacts on climate, environment and land use (Lehmann, 2018). Within the FWE-Nexus concept, we applied a food-centric approach to reduce the complexity of the connections between these three resource sectors, taking Berlin as a case study. Food. The starting point is Berlin’s demand: with a population of about 3.75 million in 2020, approximately 21 kilotonnes (kt) of freshwater fish and fish products, 108 kt of fresh tomatoes and tomato products, and 27 kt of lettuce are needed per year to cover the demand, including the non-marketable portion, e.g. waste from fish processing. To estimate the environmental footprint, we used the results of a work conducted as part of the CITYFOOD project, which modelled aquaponic facilities with a greenhouse size of 5000 m² and year-round vegetable production for a life cycle assessment (LCA) (Körner et al., 2021). The gross area for the entire facility of about 6000 m² results from increasing the sum of the aquaculture and greenhouse net areas by 10%. Different combinations of fish (tilapia, catfish) and plants (tomato, lettuce) were studied, resulting in four variants of aquaponic facilities that differ considerably in production parameters, e.g. fish stocking density. To enforce the aquaponic principle for the total demand of the city and balance the fish production with the vegetable production so that there is no excess production or unnecessary effluent on either side, the following proportion of preselected aquaponic combinations have been calculated: Catfish/Tomato 56%, Catfish/Lettuce 13%, Tilapia/Tomato 31%, and Tilapia/Lettuce 0%. This makes it possible to achieve the required annual yield with 370 facilities on a total area of 224 hectares (Baganz et al., 2021b). Water. A key feature of aquaponics is the dual use of water, which is used first to raise the fish and then to irrigate and – at least in part – for plant nutrition (Kloas et al., 2015). Compared to the water footprint of the German market mix for fresh tomatoes and lettuce (LCA impact category water consumption), aquaponic production of both vegetables for Berlin would save about 2.0 billion cubic metres of water. In terms of the LCA impact category of water scarcity, about 1.4 billion cubic metres of water would be saved, especially as a significant proportion of the tomatoes consumed in Berlin are produced in the Spanish region of Almeria, where the rapid development of greenhouse agriculture has affected the availability of groundwater resources (Castro et al., 2019). Energy. The LCA has shown that the energetic disadvantages of greenhouse production in Berlin, especially in winter, compared to southern European cultivation areas can be compensated by e.g. thermal coupling of rooftop aquaponics with the waste heat of a supermarket’s cooling system. But even then, the energy savings from upscaled urban aquaponics are not particularly high. Conclusion. It could be shown that aquaponics can make a relevant contribution to sustainability in Berlin. An essential prerequisite for this year-round scenario is building integration for thermal coupling needed in the cool season and the heating demand can be significantly reduced by the application of low-energy greenhouses. We identified significant aquaponic variables which influence the three sectors of the FWE nexus directly or via causal chains and which thus are useful for a designer or operator of an AP to control its environmental impacts. We further discussed the impacts of production-location, dietary shifts, and trade-offs on the FWE nexus

Insect-based fish feed in decoupled aquaponic systems: Effect on lettuce production and resource use.

The utilisation of insect meal-based fish feed as a substitute for conventional fish meal-based fish feed is considered as a promising innovative alternative to boost circularity in aquaculture and aquaponics. Basic research on its use in aquaponics is limited. So far, no reports on the effects of fish waste water, derived from a recirculating aquaculture system using Black Soldier Fly (BSF) meal-based diets, were available on the growth performance of lettuce. Therefore, this study aimed to compare the effect of reusing fish waste water from tilapia culture (as a base for the nutrient solution) fed with a fish meal-based diet (FM) and a BSF meal-based diet on resource use and lettuce growth in decoupled aquaponic systems. A conventional hydroponics nutrient solution (HP) served as control, and inorganic fertilisers were added to all nutrient solutions to reach comparable target concentrations. The experiment was conducted in a controlled climate chamber in nine separate hydroponics units, three per treatment. Lettuce fresh and dry weight, number of leaves, relative leaf chlorophyll concentration, water consumption, and the usage of inorganic fertilisers were measured. Micro- and macronutrients in the nutrient solutions were monitored in time series. Similar lettuce yield was seen in all treatments, with no significant effects on fresh and dry weight, the number of leaves, and relative chlorophyll values. Water use per plant was also similar between treatments, while the amount of total inorganic fertiliser required was 32% lower in FM and BSF compared to HP. Higher sodium concentrations were found in the FM nutrient solutions compared to BSF and HP. The results confirm that BSF-based diet is a promising alternative to FM-based diet in aquaponics with no negative effects on lettuce growth. Additionally, BSF-based diet might be beneficial in intensive, professional aquaponics applications due to the lower sodium concentration in the nutrient solution

Environmental impact assessment of local decoupled multi-loop aquaponics in an urban context

Fresh vegetables available on Northern European markets usually originate from a high number of sources. Environmental impacts for these goods typically arise from the resources used in production and the long-distance transport in air-conditioned trucks. As such, environmental impacts are mainly attributed to direct energy consumption, water use and nutrient supply. The aim of this paper was therefore to investigate and evaluate possible solutions to reduce the environmental impacts of vegetables available on urban markets in Northern Europe. We hypothesise that for the production of lettuce and tomatoes in Northern Europe, a 4-step solution, i.e. 1) local production, 2) climate-controlled efficient greenhouses, 3) decoupled aquaponics, and 4) combined building architecture with waste heat and green waste reuse, will enable a low environmental impact. We defined the metropole Berlin as case example, and used simulation results from a proven greenhouse simulator as input to a comparing life cycle assessment of fresh lettuce and tomato. The assessment included a list of 12 midpoint environmental impact categories, e.g. global warming potential with 100 year horizon (GWP100; kg CO2 eq.), depletion of fossil fuel reserves (FRS; kg oil eq.), and water use (WCO; m3 water). Most impact categories decreased systematically when increasing the complexity of the local vegetable production. Compared to the mix of vegetables from different locations available on the market, the complete 4-step solution reduced WCO from water consumption to water saving: i.e. from 14.2 L or 3.3 L to −10.1 L or −0.21 L per package of 500 g tomatoes or 150 g lettuce, respectively. GWP100 and FRS were below the values of the available market mix, e.g. GWP100 decreased with 8.7% in tomatoes and 49.9% in lettuce. In conclusion, with the right set-up, local vegetable productions in urban regions can surpass the imported mix on environmental performance in Northern Europe.</p