By Brian FilipowichLong travel distances for our food lead to excessive carbon use, energy use for refrigeration, food spoilage, nutrient depletion, and poorer food security.Aquaponics - and other controlled-environment growing techniques like hydroponics and aeroponics - can greatly reduce the distance food travels from farm to plate.For the first time ever, researchers recently attempted to map out the entire U.S. food supply chain. The resulting map, above, shows an intricate web of food moving across the country. The full report is public and can be found here: Food flows between counties of the United States (Lin, 2019)The map illustrates that our food travels long distances before it reaches our plate. "Food miles" is the measurement that tracks the actual distance food travels from farm to plate."Studies estimate that processed food in the United States travels over 1,300 miles, and fresh produce travels over 1,500 miles, before being consumed." (ATTRA, 2008)One reason for high food miles is because most food requires a large amount of open land and arable soil, and requires a specific climate to be grown at a large scale. Only certain parts of the country meet this criteria, and these areas must transport food long distances to reach all U.S. consumers. The map to the right shows the nine counties in the U.S. (highlighted in red) from which most food originates.But aquaponics - and other modern growing methods like hydroponics and aeroponics - are water-based and do not require large amounts of arable soil. Also, these modern growing methods are usually practiced in "controlled-environments" like greenhouses that maintain ideal growing environments for plants throughout the entire year.Aquaponic systems that raise edible fish can further reduce food miles by cutting down on the distance needed to transport the animal protein in our diets. The demand for animal protein is expected to rise along with world population growth. But farms that raise beef, pork, and poultry need large tracts of land far from population centers. Conversely, aquaponics and other recirculating aquaculture operations can raise fish in urban or suburban areas. And, because fish have a much more efficient feed conversion ratio than land animals, less feed stock needs to be grown and shipped, further increasing efficiency.To read more about food miles, see Food Miles, Background and Marketing from ATTRA.One often-overlooked benefit of local food is greater food security. Our complex web of food is susceptible to systemic shocks such as weather or disaster events. In extreme cases, disruptions could make it difficult to get enough food to a certain population. A greater proportion of local food allows areas to be better-prepared in cases of unexpected events.But, before we assume that all food miles are bad, more research is needed to measure the tradeoffs between local and long-distance. For instance, studies show that it's often more efficient to import fruits from distant warmer climates than to heat a local greenhouse in the winter.More needs to be done to evaluate, quantify, and account for the hidden costs of our food system, including food miles. Analytic tools such as True Cost Accounting, Cost-Benefit Analysis, and Life Cycle Assessment (LCA) create a more complete picture of the true cost of a product. LCA takes into account the costs of a product's entire life cycle: production, processing, packaging, transport, use, and final disposal. LCA uses indicators not traditionally captured in a product's market price, such as resource depletion, air and water pollution, biodiversity loss, human health impacts, and waste generation.Analytic tools like LCA can uncover the true cost of shipping foods long distances and incentivize local agriculture. Aquaponic and hydroponic growers will benefit because - without the need for soil - they can get as close to consumers as possible. The result will be fresher food, less strain on the planet, and local economic growth!