Making Urban Farming Scalable With Fish
Why aquaponics may be the future of urban farming, and one solution to our local food problem.
January 12, 2010
Cityscape hopes to launch its first farm in the first half of 2010. Their aquaponic greenhouses would be built in vacant lots and on rooftops. To start out, they are considering sites in San Francisco’s sunnier southern and eastern zones to capture plentiful solar energy. To monetize, Cityscape will serve as a wholesaler to local distributors and restaurants as well as operate a weekly farmers market. Yohay says there is interest from Bay Area restaurants enthusiastic about hyper-local and organic produce like strawberries and tomatoes being produced even in the off-season. That’s another advantage of hydroponic farming: the changing temperatures and seasons do not limit the indoor growing cycles.
So could this sort of farming actually work on a national level? Dr. Dickson Despommier, the Columbia professor and vertical farming guru, thinks so. He cites Cityscape’s “light weight and highly productive” structure and the speed with which food production can begin as two key indicators of potential success. One reason for this quick growth cycle involves the relationship between a plant’s environment and its energy resources. A plant traditionally expels a lot of energy sending down roots to look for water and nutrients. In an aquaponic setup,those needs are already met, which produces a shallower root systems and allows the plant to expend more energy on leafy, vertical, vegetative growth. Yohay predicts that “at Cityscape we will produce just over one hundred tons of food in twenty thousand square feet of space per year—the first year will be less as we wait for the fish to cycle up, but after that we’ll operate at regular production levels.”
A national network of urban farms is also something that Yohay envisions. “If we are going to make substantive change in our industrial model we need to look at big solutions, that means looking at the parts of the country that need this the most. We’ve been invited by cities like New York, L.A., Chicago, and even as far as the Virgin Islands. Our [model] is a completely site independent methodology—we aren’t reliant on soil testing and the perfect parcel of land; we don’t even need land. The soil in cities is often times ill-suited for agriculture because of heavy metals; we mitigate these dangers by avoiding the use of soil all together. The fact is the world is running out of quality water and soil. Look at the food riots in Asia, Latin America, and Africa. These food shortages were partially the result of the diminishing quantity and quality of soil.”
Professor Martin Schreibman says our oceans have been overfished beyond repair. If we’re going to keep eating fish and chips, tuna tartare, and all those omega-3 fatty acids, we may have to rely on aquaculture. Schreibman is working to bring those fish farms into the city. Urban aquaculture? We’ll bite.