Bacteria and Bio-Dredging


Bacteria is the most widely distributed and abundant organism on the Earth. They are adapted to live nearly everywhere on the planet from the deepest darkest reaches of the ocean to the surface of your skin.  Bacteria often gets a bad rap in the news because of potential human health hazards, (MRSA, listeria, etc.)  but the fact is that they are very important members in a properly functioning, healthy ecosystem.  This is especially true in aquatic environments.  Without bacteria, organic muck would accumulate and nothing would decompose--causing the ponds to fill to the brim with dead organic material.  Thankfully, because of the trillions of bacterial cells present in the water and sediment, this does not happen.  Bacteria break down dead matter and through specialized chemical processes, make the nutrients available to enter back into the food web.

There are two different ways that bacteria can break down and recycle nutrients—aerobic (with oxygen) and anaerobic (without oxygen). We can distinguish between bad and good bacteria by the process they use.  “Bad” bacteria typically will digest muck anaerobically.  They are considered “bad” bacteria because anaerobic digestion produces compounds that are foul smelling, toxic to fish and potentially humans.  Also, it is a very slow way of breaking down organic material causing muck to build up in the bottom of the pond.  On the other side of the coin is “good” bacteria.  They will typically break down muck aerobically.   This is a much faster process that does not produce foul smelling odors and converts toxins into safe, beneficial compounds.  Proper aeration is one of the most important factors when it comes to the health of a body of water.  When the water is properly aerated it allows the aerobic (Good) bacteria to thrive both reducing number of anaerobic (bad) bacteria and accelerating the breakdown of muck, increasing the quality of the water. 

Scientists have formulated methods for culturing “good” bacteria for introduction into lakes and ponds.  Typically, a very large initial dose of bacteria is added to establish a large population, followed by periodic “booster” applications.  Different formulations contain different blends of bacteria and additives to accomplish different goals.  Some are designed to increase water clarity, some degrade surface films, others are specifically designed for muck degradation or Bio-dredging.  “Bio-dredging” (biological dredging) is a process where beneficial bacteria are added into the water in conjunction with specific enzymes and bio-stimulants (additives that increase the efficacy of the microbes in the water). While bio-dredging does nothing for the removal of inorganic material, (sand, metals, etc.) it has potential to be a non-invasive, economically friendly alternative to conventional dredging for the removal of large amounts of organic sediment.