Sustainable Agriculture / Aquaponics

Sustainable Agriculture / Aquaponics

Aquaponics is a sustainable food production system that combines a traditional aquaculture (raising aquatic animals such as snails, fish, crayfish or prawns in tanks) with hydroponics (cultivating plants in water) in a symbiotic environment. In aquaculture, effluents accumulate in the water, increasing toxicity for the fish. This water is led to a hydroponic system where the by-products from the aquaculture are filtered out by the plants as vital nutrients, after which the cleansed water is recirculated back to the animals. The term aquaponics is a portmanteau of the terms aquaculture and hydroponic.

Aquaponic systems vary in size from small indoor or outdoor units to large commercial units, using the same technology. The systems usually contain fresh water, but salt water systems are plausible depending on the type of aquatic animal and which plants. Aquaponic science may still be considered to be at an early stage, relative to other sciences.


Aquaponics Resources

For complex systems like aquaponics, videos are some of the best resources to start with since they illustrate real world applications in action.

Our fist pick was "Backyard Aquaponics" because it demonstrates an operation which is small enough to be affordable for hobbyists, but also high tech enough to be scalable for larger operations.

Your state university extension service will always be a vital resource for anything having to do with agriculture, so we included a video below from Purdue University to show the information they provide for larger scale operations. The primary value from aquaponics comes from the plants, so the smaller scale systems often use inedible fish stocks like goldfish. This video shows several larger operations which include edible fish.

We liked "Internet of Food," since the author has done an excellent job with his aquaponics systems (his fish and plants appear to be in great condition). With a background in robotics he's developed some impressive prototypes, and he does a good job of explaining aquaponics.

One of the more well known experts in the aquaponics industry is Murray Hallam, so we've included one of his videos showing an example of a commercial aquaponics operation.


Pros & Cons of Aquaponics

The unique advantages of aquaponic systems are:

  • Conservation through constant water reuse and recycling.
  • Organic fertilization of plants with natural fish emulsion.
  • The elimination of solid waste disposal from intensive aquaculture.
  • The reduction of needed cropland to produce crops.
  • The overall reduction of the environmental footprint of crop production.
  • Building small efficient commercial installations near markets reduces food miles.
  • Reduction of pathogens that often plague aquaculture production systems.
  • Reduction of erosion by eliminating the need to plough the soil.

Some conceivable disadvantages with aquaponics are:

  • Initial expenses for housing, tank, plumbing, pumps, and grow beds.
  • The infinite number of ways in which a system can be configured lends itself to equally varying results, conflicting research, and successes or failures.
  • Some aquaponic installations rely heavily on man-made energy, technological solutions, and environmental control to achieve recirculation and water/ambient temperatures. However, if a system is designed with energy conservation in mind, using alternative energy and a reduced number of pumps by letting the water flow downwards as much as possible, it can be highly energy efficient.
  • While careful design can minimize the risk, aquaponics systems can have multiple 'single points of failure' where problems such as an electrical failure or a pipe blockage can lead to a complete loss of fish stock.
  • Like all aquaculture based systems, stock feed usually consists of fish meal derived from lower value species. Ongoing depletion of wild fish stocks makes this practice unsustainable. Organic fish feeds may prove to be a viable alternative that negates this concern. Other alternatives include growing duckweed with an aquaponics system that feeds the same fish grown on the system, excess worms grown from vermiculture composting, using prepared kitchen scraps, as well as growing black soldier fly larvae to feed to the fish using composting grub growers.

Work Sited
Aquaponics. (2013, January 2). In Wikipedia, The Free Encyclopedia. Retrieved 06:35, January 5, 2013, from http://en.wikipedia.org/w/index.php?title=Aquaponics&oldid=530904331