Why use bugs?
Aquatic invertebrates, a.k.a. water bugs, live in all types of aquatic habitats including springs, rivers, lakes, reservoirs, ponds, and wetlands, and they generally occur in sufficient variety and abundance that they are easy to collect. The designation "water or aquatic bugs" is somewhat deceiving. The Order Hemiptera are the only "true bugs", however, we often use the term "aquatic bugs" to refer to "aquatic invertebrates".  Aquatic invertebrates are organisms which live part or all of their lives in the water and have no internal skeletal system.  

By knowing what species or groups of bugs live in a water body, biologists are able to evaluate the ecological health and productivity of a system.  To learn about how invertebrate assemblages naturally vary or respond to land use impacts throughout a watershed, click on different stream reaches in the watershed to your right.

Surprising to many is just how many individuals and species of water bugs there are.  There can be thousands to tens of thousands of individual bugs per square meter of streambed and hundreds if not a thousand or more unique species in a healthy river reach.  Each species has specific habitat needs and so each species responds a bit differently to changes in either the chemical,

Even in healthy rivers, most of the species we find fairly rare, so we need to be very thorough when we sample.  For example, for 4200 stream riffle samples from the western United States, we found that only 4 genera occurred in more than 50% of the samples.  The 10 most common genera we have found in the western United States are Baetis, Optioservus, Simulium, Rhyacophila, Cinygmula, Epeorus, Zaitzevia, Hydropsyche, Drunella, and Paraleptophlebia.  Click on the image to the right to make readable! Most of the most common taxa we collect are habitat generalists, that is, they live just about everywhere, so their presence does not tell us much about the health of a river. It is the rarer taxa that are either particularly sensitive to pollution or extremely tolerant of pollution that provide biologists with the most telling facts about a river's health.