The Future of Sustainable Food

Investigating Aquaponics' Economic and Environmental Feasibility for Sustainable Food Production in Cities: Introductory Chapter

Growing up in Singapore, the multicultural variety of foods are endless – we have Indian curries and prata, stews and nasi padang from Malay cultures, chicken rice and noodle soups from Chinese ethnic groups, and a panoply of Western cuisine.

Yet, at home I knew that I ate beef and dairy from Australia, chicken and rice from Thailand, fruits from Malaysia, and very rarely, expensive berries from USA. Since I was young, I knew that everything I ate did not originate from the country I lived in and Singapore, as well as other cosmopolitan cities, is situated in a vulnerable position if food imports discontinue.

My research aims to find out ways in which food can be sustainable in the future, particularly investigating the economic and environmental feasibility of aquaponics as a form of food production, especially in cities. This is a critical assessment, in that the viability of aquaponics and the degree to which it is capable of being successfully brought about in cities is to some extent, dependent on whether it can have a significant impact on local food availability and security.

Enter Singapore, an island nation-state the size of 720 km2 or 278 square miles, where about 5.5 million people reside and yet has less than 1% of its land area used for agriculture[1].

However, according to the Economist Intelligence Unit’s Global Food Security Index, it manages to be the second-most food secure country in the world – based on affordability, availability, and quality and safety. This is largely due to Singapore’s high dependence on imports, buying 90% of its food from abroad, and spending approximately S$15.57 billion (US $10.9 billion) in 2014[2].

This is particularly dangerous, with the onset of increasing population, land and water constraints, changes in dietary habits, and the impact of global food production. The problem is likely to be compounded in the future by climate change. For Singapore to be so highly dependent on food exports makes it vulnerable to its major importing partners such as USA and Australia.

Aquaponics and Sustainable Food Production

However, Singapore is not the only contender for being dangerously vulnerable to climate change and its impacts on food sustainability. Today, approximately a billion people are chronically malnourished while agricultural systems are degrading land, water, biodiversity and climate on a global scale.

Godfray et al.’s (2010) review frames the urgency to generate food in the most sustainable and efficient way in order to reduce food poverty and insecurity. Godfray et al. (2010) emphasises that continuing population and consumption growth increases the global demand for food and scientists predict that there will be a 100–110% increase in global crop demand. This creates avenues for more intensive agricultural intensification and growing competition for land, water, and energy, resulting in detrimental effects to the environment: with an estimated 1 billion hectares of land cleared globally by 2050 and CO2 equivalent greenhouse gas emissions reaching about 3 gigatons per year[3]. This is further exacerbated by the effects of climate change as rising temperature and increasingly extreme natural disasters, such as flooding and droughts, negatively affect food production and poses the threat of worsening current and future access to food[4].

Furthermore, there are still several major issues that obstruct people’s human right to food, such as food insecurity, food poverty, and food waste[5]. To meet the world’s future food security and sustainability needs, food production must grow substantially while agriculture’s environmental footprint must be reduced dramatically[6]. Godfray et al. (2010) suggests a combination of solutions, including scientific and technological innovation, and the need to reduce environmental impacts.

This is the context in which I build my thesis on, as current food systems are not ideal. With the impending onset of climate change, food systems will worsen unless we propose and push for more sustainable forms of food production, such as aquaponics.

Food issues also urgently need to be addressed in cities as not only are they becoming increasingly populated and therefore receive high pressure on attending food demands, but they are also representative models of knowledge and influence. A large part of my thesis focuses on the introduction of aquaponics to cities because cities are heralded as powerful and influential hubs of knowledge and innovative solutions, informing the rest of the world – this allows aquaponics and its processes to be extended, should it be successful in city areas[7].

According to Keivani (2010), the great density of people both living and moving within cities allows for agglomeration economies and provides greater opportunities for reflexivity, information and knowledge sharing, and cultural exchanges. Due to the often close proximity to networks of political power and administration, people in cities are able to have greater opportunities to influence policies, urge for investment in certain economic activities, and pressurise for the provision of services and social activities through formal and informal partnerships[8].

Furthermore, cities are the largest contributors to greenhouse gas emissions, consuming 75% of the world’s resources and producing 80% of carbon dioxide emissions, making it critical for efforts to be made to reduce its emissions and tackle climate change[9].

Therefore, cities are subjected to respond to urgent environmental issues and will be closely observed on their approaches to these challenges. As cities are viewed as models for future solutions, these networks of relationships and information exchanges are influential to a larger extent – affecting regional, national, and even international modes of policies. This is crucial to my thesis as cities have the most potential in elevating platforms for aquaponics to be expanded on a greater scale.

There is hope and potential for solving issues in food systems through the use of aquaponics. Aquaponics systems offer a sustainable method of urban growing where the waste stream of fish is used as a source of nutrients to grow vegetables in water, combining hydroponics, or soilless growing, with aquaculture, or raising fish. This symbiotic relationship between fish and plants – fish produce waste in the water, which is filtered and converted into fertilizer for the plants.

After the plants absorb the nutrients in the water, it is filtered back into the fish tank for reuse. Through this process, the system inherently recycles water — the fish and vegetables are grown simultaneously in one controlled system, recirculating a natural and organic system that excludes hormones, fertilizers, and pesticides[10].

Aquaponics can pose as an environmental solution as it is a food-growing system that could have zero impact on the planet. Current food production requires more land, emits carbon dioxide from farm production and food transportation, methane from cattle, and discharges excess waste, pesticides, and fertilizers from its processes, creating a very unsustainable system that contributes to the worsening conditions of the environment.

Aquaponics on the other hand, requires none of these operations as it recycles all the elements involved in the production, does not produce methane as cattle do, and hardly releases any waste[11]. Aquaponics also assists in efficient water usage, by recycling fish waste that is often released into water bodies and pollutes water supplies, and utilizing only 10% of the water compared to soil-based gardening[12].

Farming fish is also one of the most resource-efficient ways to produce protein as fish convert more of the food they eat into body mass than land animals, and over a year, aquaponics will generate about 35,000 pounds of edible flesh per acre, while grass-fed beef generates about 75 pounds in the same space[13].

Furthermore, aquaponics is compact and can be easily set up in any area as it does not require fertile land for growing, making it perfect for cities which often do not have enough space, let alone fertile soil for farms[14]. Consumers can take directly from its production without having to travel; this is crucial in areas, especially cities, that import their food, as less distance is needed for transportation within the supply chain – not only would it produce fresher food, but less fuel is used and less carbon is emitted, ultimately reducing their carbon footprint[15].

However, scientists can argue that vegetarian and vegan diets are more impactful in reducing environmental degradation compared to meat diets, resulting in a 33% decrease in greenhouse gas emissions, while vegan diets have a 53% decrease in emissions[16].

I initially wanted to investigate hydroponics as a means to introduce vegetarian and vegan diets for sustainable food consumption.

Yet, it is not necessarily the consumption of meat that increases environmental degradation, but its production that is not sustainable, suggesting that the processes used in these systems require more crucial investigation and transformation, rather than on the consumer level[17].

Growing up in an Asian context where our diets and cultures include meat for nutrition or cultural expression, the vegetarian and vegan diet movement does not seem to be gaining traction as it sometimes isolates and excludes people’s diets and cultures.

I wanted to propose a solution that is inclusive to all cultures. Aquaponics is particularly beneficial to all diets – not only because it provides protein, an important nutritional source for our diets, but it also does not completely reject diets or cultures who rely heavily on meat.

Aquaponics is not only a form of introducing more sustainable means of food production, but also as a way to integrate cultures and people about its multiple benefits in providing a food source for all.

With the onset of climate change where environmental conditions are already under threat, current food production needs to be reconstructed in order to meet the needs of the people while reducing its negative impacts on the environment – all of which aquaponics provides.

I will also investigate the economic feasibility of aquaponics and its capability of being brought about successfully as a form of sustainable food production in terms of being able to sustain itself economically in the long-term.

No city can be self-sufficient as food security depends on domestic production and imports, effective distribution, diversification, partnerships, and good long-term planning. Moreover, the large capital needed to start and maintain the operations combined with often high rental prices in cities, makes it difficult for aquaponics to be replicated and create large-scale food production to provide for respective populations.

However, my research posits that while aquaponics may not be economically thriving in urban areas, it is particularly valuable due to their positioning in cities, which are cultural and knowledge centres and permeate information due to its high-density and influential power.

Using case studies of aquaponics farms in Singapore, New York City, and London as examples to inform my research, the thesis addresses the economic and political structures that challenge the feasibility of aquaponics, but also urges the need for aquaponics in cities as a way to promote the local farm-to-table movement, as powerful locales for education, as forms of experimentation and technological improvement, and as modelling for other sustainable agricultural projects.

Literature Review

There is currently extensive research on urban agriculture, aquaculture and its potential in cities, such as Ackerman et al.’s research of the potential of urban agriculture in New York City, and Dickson Despommier’s analysis of vertical farming, a method that produces food and medicine in vertically stacked layers and requires less energy and produces less pollution[18].

Although it concludes that NYC cannot be self-sufficient on urban agriculture, urban agriculture still addresses multiple challenges of food insecurity, obesity, and food poverty – ultimately catalysing a larger food system change[19]. This brings hope to the feasibility of aquaponics in cities. The key concept of cities as sources of knowledge and innovation could elevate aquaponics into other contexts and address the challenges of food insecurity and poverty on a larger scale.

However, Ackerman et al.’s (2014) findings are unique to NYC because of its high level of awareness to sustainability, infrastructure, and access to investment capital, allowing for the processes of urban agriculture to develop efficiently. This is a weakness due to the study’s inability to address whether it can be replicated in other cities or places who have different contextual factors. Furthermore, the study focuses on urban agriculture, and not aquaponics specifically, which may have its own individual benefits and potential to be expanded on a larger scale and there is not a lot of information on the scalability and feasibility of aquaponics in a city-wide and even nation-wide context.

Furthermore, while it is a common traditional method used in China, it is currently evolving into new formats with the improvement of technology and availability of modern techniques. Whether this combination of modern technology and traditional food production can be scaled up economically and sustainably, and be resilient to the effects of climate change, is a topic worth discussing in order to feed the increasing demand for food.

Furthermore, geographical literature on the concept of political ecology reports that the relations between nature and society is analysed through the struggle of access and control over resources, power, and knowledge[20]. Lawhon and Murphy’s (2012) research focuses on the potential contributions which political ecologists can make into socio-technical transition studies to achieve more just and sustainable outcomes by considering the roles of knowledge, diversity, power, geography, and non-material circumstances[21].

This is particularly important to my thesis as it emphasizes the need to acknowledge all these factors when considering aquaponics in attempts to a more sustainable food system.

Swyngedouw and Heynen’s (2004) addresses how these transitions are carried out on an urban scale. Their research highlights urban political ecology and posits that produced environments, such as cities, are results of dense networks of socially mediated natural processes which constantly shift between groups of actors and scales[22].

They emphasise the need for historical and geographical insights in order to strategize equitable distribution of social power and environmental production. This is important as although aquaponics can be a method for equitable food production and distribution in cities, it is necessary to understand the power relations and different social actors that define who will have access to or control over its resources, particularly in urban contexts. Through the case studies in different cities, the essay aims to inform how each city has different dialectics that allow or restrain aquaponics within their varying contexts.

While Swyngedouw and Heynen’s (2003) research draws attention to the constantly shifting networks, actors, and systems, they also need to acknowledge the concept of neoliberalism in cities and the economic challenges in instituting aquaponics. According to Miró (2011), neoliberalism is a political ideology that advocates the withdrawal of state intervention, which allows for privatization of resources and open, competitive, and unregulated free markets that are deemed to be the best method for socioeconomic development[23].

In recent years, urbanization plays a very important role in this global expansion and accumulation of capital, giving rise to neoliberal urbanism, in which urbanism is subject to the capitalist system and powerful actors compete in elevating their urban spaces – cities – to higher ranks within the global capitalist network.

Therefore, cities are identified as centres of neoliberalism due to increasing engagement in competition to attract high accumulation of capital flows and subsequent power, often accelerating uneven development and spatial, social, and power relations[24].

The concept of neoliberalism in the entrepreneurial city, cities’ powerful influence on national and international policies, and the role of the state within these spaces also greatly influence and shape these processes, with some cities having more decisions determined by the government. This is particularly potent as neoliberalism contributes to the global, industrial, and corporate drive of current food systems, resulting in unequal food distribution and high food insecurity, especially in cities despite their high capital base. As a result, aquaponics in cities play a key role in their engagement with these processes, not only whether they will be able to compete and be economically feasible within neoliberal forces, but also if they will further contribute to these ideals.

Joassart-Marcelli and Bosco (2014) contend that dissatisfaction with the corporate food system arising from neoliberal urbanism has resulted in the emergence of alternative food systems that foster health, justice, and sustainability. Alternative developments, such as farmers markets and community gardens, act as forms of resistance and localized solutions against the capitalist pressures straining current food systems[25].

However, other researchers provide evidence that these have become increasingly popular among affluent and white urban residents and may not foster the democracy and justice that it claims to do.

Furthermore, despite being alternatives to neoliberalism, these “local” organizations may be contributing to the capitalist cycle but under the guise of being sustainable alternatives. Therefore, it is crucial to investigate if urban aquaponics are prone to capitalist processes.

However, while neoliberalism is a good critique of how capitalism contributes to uneven development and inequitable distribution of food, the accumulation of capital does not always have negative consequences. There are ways in which capital can be used to balance food insecurity and reduce food poverty.

Furthermore, Joassart-Marcelli and Bosco (2014) argue that it is the actors involved and their individual agendas that determine whether food systems are just, democratic, or sustainable, – with some operations as non-profits who are trying to break even, while others want to be large-scale agricultural businesses with significant returns[26].

It may also be possible for the government to be highly involved in aquaponics. Currently the U.S. Department of Agriculture’s Federal-State Marketing Improvement Program (FSMIP), Natural Resources Conservation Service, and Aquaponics Association has awarded grants to aquaponics projects to improve long-term efficiency and sustainability of American agriculture and increase public awareness and understanding of aquaponics[27].

Therefore, although aquaponics can be situated in food systems as ideal methods for sustainable food production, it is dependent on the key actors involved, their embedded series of networks, and the way they shape aquaponics into different spaces and consequent social, political and economic relations. I hope to analyse and highlight any common specific conditions of power and relationships between nature and society that require aquaponics to be feasible in these areas, adding to the literature of whether aquaponics is scalable in other contexts.

Methods and Chapter Organization

The methodology will include archival research and journal articles on aquaponics and urban agriculture. Furthermore, qualitative interviews of people involved in aquaponics farms in Singapore, New York City, and London, and on-site observation will be taken in New York City and Singapore to inform the contemporary issues of aquaponics and its sustainability.

An economic framework of a cost-benefit analysis will be used to analyse the sustainable profitability of aquaponics, such as including the monetary costs and rate of technological progress.

According to a John Hopkins University research, 70% of the respondents did not have commercial aquaponics as their primary source of income and higher profits were due to their diversity in their revenue stream by including non-food products, services, or educational trainings[28].

Respondents views on A) aquaponics-related income, B) profit in the previous 12 months, and projections for C) profit the next 12 months and D) 36 months

GIS (Geographic Information Systems) will also be utilised to visualise the potentiality of aquaponics farms in those locations, and the specific conditions that aid in its development, such as the level of capital, rental costs, weather and climate, governmental involvement, and technology availability and access.

This thesis framework aims to guide the process of the feasibility of aquaponics in cities through analysis of each case study. Chapter 2 will cover the unsustainable issues concerning agriculture and food production and the impact of climate change on current conditions. It will also include other environmental food issues such as food waste, food consumption, and food insecurity.

Chapter 3 will investigate a case study of Oko Farms, one of the few aquaponics farms in New York City, highlighting its individual benefits, challenges, economic framework, involvement of different actors, and aspects needed for its feasibility.

It is the largest outdoor aquaponics farm in New York City, and is distinct as not only does it raise commonly used tilapia fish, but it also experiments with different types of fish, such as catfish, and ornamental fish like koi and goldfish, as tilapia’s short maturity cycle are unsuitable for the cold climates of New York City[29].

Oko Farms had to work with several different actors, such as GreenThumb, part of New York City Parks Department, in order to acquire affordable land for their farm, and gained grants from the Brooklyn Economic Development Corporation and the Awesome Foundation[30].

Oko Farms is particularly significant not only because of its large scale operations, but also because of its experimentation with other fishes, and is therefore a hotbed of research for future improvements in aquaponics and sustainable food production.

Furthermore, Oko Farms’ opens up the importance of functioning within a neoliberal urban framework by navigating between different actors within New York City. These are all elements that aid in providing valuable knowledge on the feasibility of aquaponics in a contextual setting of New York City and how it has managed to flourish and enact change, even though it may not be as successful in large scale sustainable food production.

Chapter 4 will follow the same research, except through the lens of Singapore’s aquaponics farm by architectural design team Woha, using its office rooftop as a test bed with more than 100 species of edible plants, which are shared among the staff. Other than providing food, it is also a scenic place for staff to relax and destress. Members of the firm’s gardening club gather every week tending to the plants and a gardening workstation for potting and propagation, experiments with different urban farming systems, and a large tank that collects rainwater to water the plants. The office also makes its own compost from food scraps, and there may even be potential of rearing chickens and quails[31]. The office has also installed solar panels on the rooftop that supplies around 7% of the power consumed by the office[32].

As a result, its goals and purposes are distinctly different from New York City and London as it is not for commercial large-scale production or for a larger audience. Instead, it serves as a space for recreation, learning, and aims to involve a whole network of urban farming and community building within the firm.

Although it does not provide a great amount of information about aquaponics as a form of sustainable food production, it is still informative in the way that it shows the alternative purposes of aquaponics, especially how it can be used for further education and cultivation of agriculture within the space of a professional workplace.

London’s GrowUp Box will be utilised as a case study in Chapter 5 and is unique as compared to European aquaponics farms that use purpose-built greenhouses, it fits out empty urban buildings, uses no chemicals, employs LED lights, sources 100% renewable energy.

London School of Economics (LSE) students from the Sustainable Futures Society visiting the GrowUp Box in 2017. (All pictures are mine)

Furthermore, GrowUp aims to reduce limits to food access as it is based within five miles of its customer base in a dense urban area, allowing for various customers to have access to its healthy food. Not only does GrowUp aim to reduce food spoilage from transportation, it also aims to fill in the gaps of downsizing supermarkets whose stocks are empty due to increased online shopping.

Moreover, the “field to fork” freshness also meets a key customer demand, and maintains a partnership with Farm Drop, a London grocery-box delivery scheme specialising in local produce.

GrowUp also hopes to develop its business model where they could include growing micro herbs for restaurants, which would subsidise growing mixed salad for supermarkets.

It expects a turnover of over £500,000 a year, ultimately hoping to build bigger aquaponics farms and the ability to be replicated in any warehouse near any city[33]. Although the GrowUp Box has its purposes of education, it has the most business-like model for aquaponics through its aims to expand its processes and provide sustainable food.

Chapter 6 will consolidate the findings from the case studies and provide the GIS maps on overall discoveries. It will also aim to project the feasibility of aquaponics on a larger scale in other cities or regions and emphasise certain conditions and requirements that might be needed for it to be feasible in other areas.

Chapter 7 will conclude with a summary of the findings, and extrapolate if aquaponics is a feasible solution to sustainable food production in the future, or if other methods are more suitable.

The conclusion posits that although aquaponics easily fits into a local and regional food system model as it can be practiced in or near large population centres, it is not enough for cities to be self-sufficient[34]. However, aquaponics remains valuable, particularly in cities, due to its influential impacts on informing sustainable agricultural models to the rest of the world.

Works Cited

Abdolhamidi, Shervin. “Inside Oko Farms: A Farming Oasis Powered by Fish in Bushwick, Brooklyn.” Untapped Cities, 2016. https://untappedcities.com/2016/10/10/inside-oko-farms-a-farming-oasis-powered-by-fish-in-bushwick-brooklyn/

Ackerman et al. “Sustainable Food Systems for Future Cities: The Potential of Urban Agriculture”. The Economic and Social Review, vol. 45, no. 2, 2014, pp. 189–206.

Agrilyst, “State of Indoor Farming Report”, 2016.

The Aquaponic Source, “What is Aquaponics?” 2017. https://www.theaquaponicsource.com/what-is-aquaponics/

Bernstein, Sylvia, “The Way of the Future: Aquaponics vs. Traditional Agriculture”, Edited from Aquaponic Gardening: A Step-By-Step Guide to Raising Vegetables and Fish Together, New Society Publishers, 2011.

Despommier, Dickson. “The Rise of Vertical Farms”. Scientific American, vol. 30, no. 5, 2009, pp. 60–67.

Foley, Jonathan A., et al. “Solutions for a Cultivated Planet.” Nature, vol. 478, 2011, pp. 337-342.

Godfray et al. “Food Security: The Challenge of Feeding 9 Billion People”. Science, vol. 327, no. 5967, 2010, pp. 812-818.

Joassart-Marcelli, Pascale and Bosco, Fernando J. “Alternative Food Projects, Localization and Neoliberal Urban Development.” Métropoles, vol. 15, 2014.

Keivani, Ramin. “A Review of the Main Challenges to Urban Sustainability.” International Journal of Urban Sustainable Development, vol. 1, no. 1-2, 2010, pp. 5-16.

Lawhon, Mary & Murphy, James T. “Socio-technical regimes and sustainability transitions: Insights from Political Ecology”. Progress in Human Geography, vol. 36, no. 3, 2012, pp. 354-378.

Love, David C., Fry, Jillian P., Li, Ximin, Hill, Elizabeth S., Genello, Laura, Semmens, Ken, Thompson, Richard E. “Commercial aquaponics production and profitability: Findings from an international survey.” Aquaculture, vol. 435, 2015, pp. 67-74.

Madel, Robin. “Oko Farms in Bushwick, Brooklyn: Little (Fish) Farm in the Big City.” Grace Communications Foundation, 2016. http://www.gracelinks.org/blog/7174/oko-farms-in-bushwick-brooklyn-little-fish-farm-in-the-big-

Miró, Sònia Vives. “Producing a “Successful City”: Neoliberal Urbanism and Gentrification in the Tourist City—The Case of Palma (Majorca).” Urban Studies Research, vol. 2011, Article ID 989676, 2011, 13.

Morgan, Scott. “Grants for Aquaponics Farms.” Career Trend, 2017. https://careertrend.com/info-12105775-grants-aquaponic-farms.html

Neal, Arthur. “Hooked on Aquaponics.” United States Department of Agriculture, 2013. https://www.usda.gov/media/blog/2013/11/8/hooked-aquaponics

National Oceanic and Atmospheric Administration Fisheries. 2017. http://www.nmfs.noaa.gov/aquaculture/faqs/faq_aq_101.html

Pang, Amelia. “New York City Might Be Able to Mass Produce Its Own Food With Aquaponics.” Epoch Times, 2015. https://www.theepochtimes.com/new-york-city-might-be-able-to-mass-produce-its-own-food-with-aquaponics_1273946.html

Pang, Amelia. “New York City Might Be Able to Mass Produce Its Own Food With Aquaponics.” Epoch Times, 2015. https://www.theepochtimes.com/new-york-city-might-be-able-to-mass-produce-its-own-food-with-aquaponics_1273946.html

Park, Hans. “The Power of Cities.” UNHCR, The UN Refugee Agency, 2016. http://www.unhcr.org/innovation/the-power-of-cities/

Schiller, Lindsey. “Can a Commercial Aquaponics Greenhouse Be Profitable?” Ceres Greenhouse Solutions, 2017. https://www.ceresgs.com/can-a-commercial-aquaponic-greenhouse-be-profitable/

Singapore Department of Statistics. “Population & Land Area (Mid-Year Estimates)”. Singapore Statistics, 2014. http://www.singstat.gov.sg/statistics/latest-data#14

Smedley, Tim. “Aquaponics: The Future of food?” The Financial Times, 2015. https://www.ft.com/content/d264ab16-a435-11e5-873f-68411a84f346

Swyngedouw, Erik & Heynen, Nikolas C. “Urban Political Ecology, Justice and the Politics of Scale”. Antipode, vol. 35, no. 5, 2003, pp. 898-918.

Tay, Suan Chiang. “Championing the Green Cause.” Business Times, 2017. http://www.businesstimes.com.sg/lifestyle/feature/championing-the-green-cause

Terry, Dr. Leon A., Mena, Dr. Carlos., Williams, Dr. Adrian., Jenney, Nigel, and Whitehead, Dr. Peter. “Fruit and Vegetable Resource Maps.” WRAP, 2011. http://www.wrap.org.uk/sites/files/wrap/Resource_Map_Fruit_and_Veg_final_6_june_2011.fc479c40.10854.pdf

Tilman, David, Balzer, Christian, Hill, Jason, and Befort, Belinda L. “Global food demand and the Sustainable Intensification of Agriculture.” Proceedings of the National Academy of Sciences of the United States of America, vol. 108, no. 50, 2011, pp. 20260-20264.

Tortajada, Cecilia and Paramasilvam, Thinesh Kumar S/O. “Singapore’s Impressive Food Security.” The Diplomat, 2015. https://thediplomat.com/2015/09/singapores-impressive-food-security/

UN-Habitat, “Financing urban shelter: global report on human settlements,” London: Earthscan, 2005.

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Beyond the Alternative Complex. The London Urban Food Strategy and Neoliberal Governance. https://metropoles.revues.org/5147

[1] Singapore Department of Statistics, “Population & Land Area (Mid-Year Estimates)”. Singapore Statistics, 2014; Cecilia Tortajada and Thinesh Kumar S/O Paramasilvam. “Singapore’s Impressive Food Security.” The Diplomat, 2015.

[2] Ibid.

[3] David Tilman, Christian Balzer, Jason Hill, and Belinda L. Befort. “Global food demand and the Sustainable Intensification of Agriculture.” Proceedings of the National Academy of Sciences of the United States of America, vol. 108, no. 50, 2011, pp. 20260-20264.

[4] Godfray et al, “Food Security: The Challenge of Feeding 9 Billion People,” Science Mag 327 (2010): 812-818.

[5] Dr. Leon A. Terry, Dr. Carlos Mena, Dr. Adrian Williams, Mr. Nigel Jenney, and Dr. Peter Whitehead. “Fruit and Vegetable Resource Maps.” WRAP, 2011.

[6] Jonathan A. Foley, et al. “Solutions for a Cultivated Planet.” Nature, vol. 478, 2011, pp. 337-342.

[7] Hans Park. “The Power of Cities.” UNHCR, The UN Refugee Agency, 2016.

[8] Ramin Keivani, “A review of the main challenges to urban sustainability,” International Journal of Urban Sustainable Development1 (2010): 5-16.

[9] UN-Habitat, “Financing urban shelter: global report on human settlements,” (London: Earthscan, 2005).

[10] Amelia, Pang, “New York City Might Be Able to Mass Produce Its Own Food With Aquaponics.” Epoch Times, 2015.

[11] Sylvia Bernstein, “The Way of the Future: Aquaponics vs. Traditional Agriculture,” in Aquaponic Gardening: A Step-By-Step Guide to Raising Vegetables and Fish Together, 2011.

[12] The Aquaponic Source, “What is Aquaponics?” 2017.

[13] National Oceanic and Atmospheric Administration Fisheries. 2017; Bernstein, Sylvia, 2011.

[14] Bernstein, Sylvia, 2011.

[15] Agrilyst, “State of Indoor Farming”, 2016.

[16] Dockrill, Peter, “Vegetarian And ‘Healthy’ Diets May Actually Be Worse For The Environment, Study Finds,” 2015, Science Alert.

[17] Berstein, 2011.

[18] Ackerman et al. “Sustainable Food Systems for Future Cities: The Potential of Urban Agriculture”. The Economic and Social Review, vol. 45, no. 2, 2014, pp. 189–206; Despommier, Dickson. “The Rise of Vertical Farms”. Scientific American, vol. 30, no. 5, 2009, pp. 60–67.

[19] Ackerman et al. “Sustainable Food Systems for Future Cities: The Potential of Urban Agriculture”. The Economic and Social Review 45, (2014): 189–206.

[20] Mary Lawhon & James T. Murphy, “Socio-technical Regimes and Sustainability Transitions: Insights from Political Ecology,” Progress in Human Geography 36, (2012): 354.

[21] Lawhon & Murphy, 354-378.

[22] Erik Swyngedouw & Nikolas C Heynen, “Urban Political Ecology, Justice and the Politics of Scale,” Antipode 35, (2003): 898-918.

[23] Sònia Vives Miró, “Producing a “Successful City”: Neoliberal Urbanism and Gentrification in the Tourist City—The Case of Palma (Majorca),” Urban Studies Research 2011, (2011).

[24] Miró, 2011.

[25] Pascale Joassart-Marcelli and Fernando J. Bosco, “Alternative Food Projects, Localization and Neoliberal Urban Development,” Métropoles 15, (2014).

[26] Pascale and Bosco, 2014; Schiller, Lindsey. “Can a Commercial Aquaponics Greenhouse Be Profitable?” Ceres Greenhouse Solutions, 2017

[27] Neal, Arthur. “Hooked on Aquaponics.” United States Department of Agriculture, 2013; Morgan, Scott. “Grants for Aquaponics Farms.” Career Trend, 2017.

[28] David C. Love, Jillian P.Fry, Ximin Li, Elizabeth S. Hill, Laura Genello, Ken Semmens, Richard E. Thompson. “Commercial aquaponics production and profitability: Findings from an international survey.” Aquaculture, vol. 435, 2015, pp. 67-74.

[29] Shervin, Abdolhamidi, “Inside Oko Farms: A Farming Oasis Powered by Fish in Bushwick, Brooklyn.” Untapped Cities, 2016

[30] Robin, Madel, “Oko Farms in Bushwick, Brooklyn: Little (Fish) Farm in the Big City.” Grace Communications Foundation, 2016

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