Great Lakes Water Institute & 10,000 Yellow Perch to Growing Power

TOP: A few of the 10,000 yellow perch raised
at the WATER Institute and released at
Growing Power.

BOTTOM:Two levels of plants and gravel sit atop
a fish-filled trench in Growing Power’s
fish-farming system. Fish waste provides
nutrients for the plants, and the plants
clean the water for the fish.

WATER Institute researchers arrived earlier this month at Growing
Power, an urban farm on Milwaukee’s north side, with a special
delivery: 10,000 young yellow perch.

Born and raised at the WATER Institute’s Great
Lakes Aquaculture Center, the three-month old fish will help test the
waters, so to speak, of a new indoor fish-farming system that aims to
prove itself functional as well as environmentally friendly and
affordable.

Developed by Growing Power, the system
features an 8,000-gallon trench built into the floor of a greenhouse
and topped with two levels of edible plants, including watercress and
dandelion greens. Pumps circulate water from the trench to the system’s
upper levels, where gravel filters out solids from fish waste and the
plants absorb nutrients, using them to grow. The cleansed water then
returns to the fish and the cycle begins again.

“It’s a system that closely replicates
nature,” says Will Allen, Growing Power’s CEO and founder. “In this
instance there is a symbiotic relationship between the fish and the
plants,” he says, with waste from the fish providing nutrients for the
plants, and the plants cleaning the water for the fish.

The materials to build the system cost around
$1,500—about one tenth the amount of conventional commercial systems
that use chemical processes to clean their water, says Richard Mueller,
Growing Power’s aquaponics manager.

A future for fish farming

The 10,000-fish trial is a follow-up to a
successful smaller trial that last year produced 800 plate-size perch.
Allen hopes Growing Power’s approach to raising fish can one day be
applied on a more widespread scale in rural Wisconsin, where fish
farming—also known as aquaculture—could fill gaps left by a declining
dairy farming industry and make use of vacant barn space.

WATER Institute scientist Fred Binkowski sees
great potential for such systems in more populated areas as well.
“There’s a trend going on now where people are growing their own food,
better food, and safer food,” he says. “What we want to do is show that
you can grow fish in an urban area, and put the food at the center of
consumer demand.” Urban fish farming can also cut shipping costs, fill
vacant buildings, and create jobs in economically deprived communities.

There is also a more global reason to develop
the area’s rural and urban fish-farming industry. As the world’s
population grows, worldwide demand for seafood will exceed the
sustainable supply from the wild—meaning fish farming will have to meet
the remaining demand.

What’s more, according to the U.S. Department
of Agriculture, the United States imports more than 40 percent of its
seafood—making the U.S. trade deficit for seafood the second largest in
dollars, after petroleum, of any natural product. About $1 billion of
this imported seafood is farm raised; meanwhile, the United States
ranks only tenth in the world in farm-raised food fish production.

That leaves room for growth of the industry at
home, a point well understood by WATER Institute researchers and
Growing Power staff, as well as Leon Todd and Jon Bales, Milwaukee
business partners who hope to launch an urban aquaculture center that
will utilize the Growing Power model. Through collaborative efforts,
the three groups hope to build a strong foundation for fish farming in
the Milwaukee area and help establish the city as a national leader in
the industry.

In the meantime, Binkowski and his staff will
keep a close eye on the perch at Growing Power. Over the next year,
they will perform weekly water quality tests and regularly monitor the
survival and growth of the fish.

And if the system works successfully? “A year
from now,” says Binkowski, “these fish will probably be part of a
Friday night fish fry.”

–Jennifer Yauck