A Brief Introduction to Microbes in Aquaponics
“When you figure that a shovel-full of dirt contains a hundred times as many bacteria as we know about… well, we know about as much about microbes as we do the other side of the galaxy! I’m convinced that there are all sorts of other amazing things happening in these systems that we just have no idea of, because they're all done by microbes that we can’t culture, that we have a hard time surveying, understanding.”
Why are Microbes Important?
Hypothetical Absence of Microbes = Ammonia Accumulation
Perhaps the most obvious result of no microbes would be fish death from ammonia accumulation.
Here's how it works: As fish metabolize and perform their basic physical functions, they are producing ammonia. In fact, most animals produce ammonia at some point during their physical processes. Mammals (like us) convert ammonia to urea and get rid of it in urine, but fish don't. Instead it passively seeps through their cells through a diffusion gradient.
This means that ammonia molecules travel from an area of higher concentration (inside the fish) to an area of lower concentration (outside the fish, in the water). Without the microbes there to break it down, almost all of the ammonia from the fish sticks around, until finally, there is as much ammonia outside the fish as there is inside the fish.
At this point, the diffusion gradient (high concentration to low concentration) no longer exists. The ammonia inside the fish will not diffuse out because the concentrations inside and outside are the same. Without the different concentrations, the fish dies, poisoned by its own ammonia.
Hypothetical Absence of Microbes = Widespread Deficiencies
"Without microbes, we die. Everything dies. We tend to think of fish as being fish, and plants as being plants, and microbes as being microbes. But we should be thinking about fish and microbes being fish, plants and microbes being plants."
We need microbes to be a part of our systems as much as we need fish and plants and water. But do they need us?
We can assume that much more happens to the microbial populations in an aquaponic system than we understand, so it's hard to speculate whether or not our actions affect them significantly. What we can do is observe the results of our actions. Dr. Storey and the Bright Agrotech team have had a lot of time to do just that.
One environmental factor that continually comes up in conversations about microbes is pH. In our next post, we'll examine the role of pH in the world of microbes.