All life forms require energy to grow and reproduce, and that energy must somehow be extracted from the environment. Humans, for example, breathe air and eat food. When the organic matter in the food combines chemically with the oxygen in the air, energy is released. Where did the oxygen and the organic matter come from? Both were made by other organisms, so that our survival is dependent upon the activity of other life forms. Microbial mats function in the same way as a complex food web in which each organism both depends and is depended on by other members of the community. Mats are remarkable in this regard because the organisms that live there constitute an amazing array of energy harvesting strategies. In fact, virtually every way that nature has to "make a living" occurs in microbial mats, all within a few millimeters!

This diagram (modified from Fenchel and Findlay, 1995) illustrates the basics of how a microbial mat food web works. Click here to see what role different organisms play in the overall function of the mat. (requires flash plugin)

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