Fish Farming and Aquaponics
When I was back in Wisconsin for the holidays, I spent some time with my friend Joe Kaye, who has been doing research and experimentation in the area of aquaponics, and making a fish farm.
Aquaponics is the symbiotic cultivation of plants and aquatic animals in a re-circulating system. In a greenhouse setting, Kaye has been growing perch and using cattails, irises, and other native WI plants to filter the water. The water needs to be filtered since fish excrete ammonia, which turns to nitrogen. The nitrogen needs to be removed or it kills the fish. Usually this is done by filtering the water through a bed of gravel, then to the plants, which remove the nitrates, and then back to the fish.
In Kaye’s greenhouse, the perch are in an insulated tank and are heated by day from the sun and light, and at night from a small heater. Kaye chose perch to grow, since they are the favorite fish fry fish, are currently are selling at $17 a pound, and are supposed to be easy to grow.
Today Kaye has 100 perch growing. Perch will grow to full-size in 2-3 years when outdoors, and indoors in one year. Keeping the water warm, and feeding them as much as they can eat will increase their growth.
Years ago in Milwaukee, people used to fish in lake Michigan, and within an afternoon fill up a 5-gallon bucket with fish. They would then bring the fish to their local church – and the popular Friday night tradition was founded. Statewide, at a fish fry battered or deep-fried fish is accompanied by potato (baked, mashed, French fries, etc.) and coleslaw. This became popularity due to the tradition of meatless Fridays among German Catholics and Wisconsin’s proximity to Great Lakes.
Perch used to be widely available. According to population estimates, the number of perch in the Wisconsin waters of Lake Michigan has declined from 24.6 million in 1990, to 2.6 million in 2000, to 316,210 in 2009. There are several efforts occurring in Wisconsin and other states to support improving water quality, and in increasing the fish population in the lake.
Milwaukee is location for fish farm and aquaculture. Recently at the University of Wisconsin, Milwaukee, a new School of Freshwater Science was created which includes research and education in the area of filtering water, aquaculture and other water issues.
At the forefront of aquaculture, a national non-profit organization called Growing Power that supports access to healthy, high-quality, safe and affordable food and is at the forefront of acquaulture. Their fish farms use plants such as basil and with the use of compost – other vegetable plants like tomatoes are grown while also filtering the water for the fish. It was started by Will Allen, a former professional basketball player who bought the Milwaukee farm in 1993. He was awarded a MacArthur Foundation “Genius Grant” in 2008 for his work on urban farming, sustainable food production, and with Growing Power.
Next time I am in Wisconsin, I plan to visit Growing Power, and also to check in and see how Kaye’s fish are doing.