Last weekend, Marisa and I decided to take a little field trip to the great lakes region. I was recently contracted for the design of an advanced Aquaponics system. For those who are not in the know, an Aquaponics system combines the best elements of classical aquaculture(Fish Farming) and modern hydroponic gardening. In effect, animal waste is fed to fish. And the waste of the fish is then fed in solution form to garden plants through a hydroponics setup. The plant remains of those hydroponic crops are then fed to a variety of herbivore fish called Carp. The entire system is a closed loop operating within an environment the size of a large green house, talking in animal manure and turning out delicious fish and vegetables. There was only one problem, Carp has a notorious reputation as an invasive species. Thus, I consigned myself and my girlfriend to an investigative trip to the great lakes region. The source of the Aquaponics revolution and well as the epicenter of the Invasive Carp outbreak in the U.S.
So with that, we took off. Flying across a continental landmass always held a fascinating obsession with me. It seems all too miraculous that human beings can be lifted a mile into the air and shuttled near the speed of sound across hundreds of miles, yet there we were flying to Chicago. Of course any reasonable man would think it all rather sordid that we would burn a hundred million years worth of collected fossil fuels for just a mere century of near-magical capabilities such as intra-continental flight, but whoever said humanity was at all reasonable? :P
So in any case, we flew across a long stretch of Lake Michigan to land in the Fair city of Chicago. The waters were shimmering shades of turquoise phasing here and there into patches of emerald due to the presence of water-borne algae. Of course, we were unable to see any carp from inside the airplane. Once in Chicago, we were stunned by the scale of this city. Clearly this metropolis was not designed to be walkable. The streets were broad and straight, the neighborhoods were spread out to achieve minimal urban density.
At once we got to our investigations. It appeared that Carp was first introduced to the midwest by fish farmers as a cheap source of protein feed for other animals. Carp is an incredibly hardy and prolific species, selectively bred by Asians to survive in highly variable watery environments. They eat pretty much any kind of aquatic vegetation. They can survive water temperatures as low as 10 degrees Celsius. Their flesh is tough and very unpleasant tasting(I know from past experiences). This type of fish is so effective, that they were selected by the early pioneers of Aquaponics systems such as
Growing Power for disposing of plant waste.
During the 80s, a serious of floods allowed some of the carp to escape into the Mississippi and Missouri rivers. And since then these invasive fish have been making their way up the river to reach the Great Lakes region. The situation has gotten so bad that the government has put a huge electric fence to block the migration of these fish into the Great Lakes. However, due to the high pain tolerance threshhold of these fish, some of the Carp have been making their way through these screens. We saw several of the carp swimming the waters of Lake Michigan on our trip.
The take-away of this weekend investigation is that using Carp is risky way of cleaning scrap vegetation from an aquaponics operation. However, it is the single most efficient species of the task at hand. Thus if one's aquaponics facility is located relatively far away from any flowing body of water(Lake, Rivers, Streams) the chance of Carp escaping can be brought down to very manageable levels.