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Magnetic Bacteria in Sediment - Sand Bed Aquariums

Magnetic Bacteria in Sediment - Sand Bed Aquariums

By Sam Gamble

If we want to keep and preserve living organisms, we have to read the program and follow nature's lead. We're newcomers and wannabees tryingto quickly reproduce a few million years of change for our aquariums' progress and success. I think we are improving. Mother Nature began with elemental energy and evolved through carbon, water, and light to form the complex environment we now enjoy.

Aquarists in recent history, began with a tank, biological filtration, and some lights. There were problems. Since then, we've gone to nature and read the program more closely. We've done a more detailed examination of nutrients and their subsequent involvement with energy. We've discovered how these transformations promote the success of the culture we wish to maintain. In simplest terms, our objective is tomaintain and promote the production of energy, growth, and reproduction of organisms. Also included on the program in smaller print are microorganisms, benthic ecology, energy cycles, natural equilibrium, and balance.

Most recently there have been case histories indicating the program works and is a relatively basic one, if general provisions are made. Then there are other case histories with lesser outcomes. We can learn from both hopefully.

The sand bed system with a plenum has focused attention on important aspects of benthic ecology between the aquarium water and the bottom glass of the aquarium. When all seems okay we consider equilibrium and balance as expected. When there are problems it means balance has been damaged or destroyed. Since we can't see the microorganisms and can't measure most of the interactions, we make assumptions and adjustments that are not on the program. This is changing, thanks to success and increased info exchange.

Okay, it's fine to know something interesting about a unique aspect of getting bacteria to do our handiwork. What's that got to do with a dozen corals in a 100 gallons of water? It brings us back to square one with the metabolism of nutrients and how well it gets done. Metabolism of nutrients is driven by oxygen directly or inversely by reduction. Heterotrophs for example metabolize organic carbon compounds by oxidation. Denitrification and sulfate reducers receive oxygen by reduction or stripping oxygen containing molecules like NO3, and SO4, respectively. Thus making a two way gradient possible. This gradient among other things shifts carbon back toward the environment above the sand.

Importantly the process not only produces and shifts energy, but the transition also makes CO2 avilable as a respiratory by-product. The inorganic carbon source is a big cog in the wheel of balance for influx of carbon and equilibrium of alkalinity. Some folks place this function too heavily in the processes of photosynthesis. From the standpoint of biomass and metabolic capacity, where is the greatest source of inorganic carbon in a reef tank with few plants and restrained amounts of zooxanthellae??? Bottom line, our magnetic friends yield energy and readily usable carbon sources. They make and present them to the flux of the system (energy flow through an ecological environment). It's an intricate scene, in an important act, in one of mother nature's most popular plays in life's Broadway.

It is true that in the ocean, phytoplankton out produce just about everything else in the world as a source of CO2 and oxygen. Industrial waste is catching up to phytoplankton with regard to carbon dioxide, unfortunately. However, in our reef tanks phytoplankton is of little contribution to the carbon flux. Organisms like magnetotactic bacteria do make important contributions to the carbon and energy pools. It stands to reason with the popularity of protein skimmers and their increased efficiency, that inorganic sources of carbon become more important and in some respects crucial. Answer me this; how does microbial respiration tie to calcium reactors and CO2 injectors? Hint; energy transported through equilibrium = balance. Mess it up and the stress causes imbalance and shifted equilibrium.

Stress to benthic ecology has been described as external constraints on the growth rate of organisms. In our theater of concern that would be the consortium of microbial mediators we seek and care for in the sand bed aquarium. When we think of the balance and success of our aquarium, we also need to think about stress and its possible sources. This becomes even more interesting now that we have discovered some of them are very specialized, using the earth's magnetic fields to do some of it.

In view of the concept of stress, I have a question I can't answer. Can we pose stress for the complex web of living mediators and their biogeochemical pathways, by inducing artificial magnetic fields? Motors and pumps are sources of magnetic fields greater than geomagnetism. Magnetotactic bacteria respond or orientate themselves to the natural fields of about 0.5 gauss. When 7 gauss is applied, they reverse their direction. In essence they would swim the wrong way and away from their natural behavior of following gradients into the sediment to metabolize collected nutrients. Remember, mineralization of organic matter in the sea floor proceeds via a complex and interrelated web of fermentative and respiratory microbial pathways where the oxidation of organic carbon to CO2 is balanced overall by concomitant reduction of the inorganic electron acceptors O2, NO3, oxides of Mn and Fe, and SO4. Can we add enough artificial magnetic fields to produce external constraints on the growth rate of organisms?

It could be possible, however, researchers working with the bacteria conclude external magnetic fields would not effect the ecology of the oxic-anoxic transition zone. Then again their research does not include reef tanks configured with air pumps, submersible pumps, pumps for protein skimmers, sump pumps, magnetic drive power heads, or magnetic drive supply pumps. Even the high powered lighting over the tank yields EMF magnetic fields from the ballasts. What causes the hum, hmmmmmmm?

It's important to note that the gauss level of a magnetic field from motors etc., diminishes quickly with distance away from the source. Also, the polarity of the source to the aquarium is very important. There is always a north and south pole. Which pole is positioned closest to the tank, is an important factor.

Certainly with all these factors, an effect of some sort is possible. How, what, when and where, is the question and a most difficult array of unknowns. Magnetic fields, as in geomagnetic fields of the earth, are important and have had a great influence on the world around us. Magnetotactic bacteria were first reported in 1975, but have been around for millions and millions of years. Our realization is in its early stages. Even the basic and essential water molecule has polarity with a preferred north (+) end and a south (-) end. With correctly applied magnetic force water will orientate itself and form specific clusters with specific characteristics. Water is not as simple as H-O-H in the chemistry 101 text book. It's the subject of a gigantic amount of research. In our area of concern, water and organisms ARE the subjects of magnetism.

Understanding magnetism in our aquariums is actually unheard of. But, it has actually been part of our world since the very beginning. To consider the potential for good events, and possible reactions from damaging events, is a new field. There will be more from this topic in the future.

As always, if you have questions or comments; Sam Gamble

Created by liquid
Last modified 2006-11-19 02:11