They are invasive pests, but they also have one of the most efficient filtering systems in the natural world. They are, of course, the much-detested zebra mussels, which have made their way from the Black Sea of Russia to the northeastern waters of North America and are still spreading. Although the eventual clarity of the waters they invade is no replacement for the harm they do, their extremely efficient filtering mechanism caught the eye of one of LSU's premier researcher teams. Harold Silverman, Tom Dietz and John Lynn, who have been studying freshwater bivalve physiology for more than 20 years, wanted to know what made this mussel such an efficient feeder. Lake Erie and Lake Michigan are much clearer since the zebra mussel took residence.
Mussels feed on algae, which are partly responsible for the cloudiness of lake water.
It was possible, he surmised, that they were not actually ingesting all the algae and other particulate matter in the lakes but doing something else with it. Bacteria grow well in pseudofeces, and Silverman thought the bacteria might be the food source that kept so many zebra mussels thriving. There was just one problem. Bacteria are thought to be far too small for the filtering system of mussels to strain efficiently. That is one piece of the period at the end of this sentence if you divide it 2,000 times.