Effects+of+pollution


 * Pollution** has a very broad definition: releasing substances produced by humans or as the result of [[image:http://www.paranormalknowledge.com/wp-content/uploads/2010/01/water-pollution.jpg width="311" height="303" align="right"]]human activities into the environment that have the potential of harming other organisms.

In the case of Puritan tiger beetles, which require a brackish water source nearby, substances that affect the water quality, including its salinity can have a negative effect on their health. In fact, closely related species of of tiger beetles have been placed on endangered lists after increasing fresh water runoff changed the composition of their water sources (25). Fresh water runoff is increased as humans move into places where they previously did not live, and increase the amount of ground that is paved with concrete and asphalt. These surfaces do not let water through, and instead of soaking into the ground, it is channelled into other water sources. It may surpise you that the change in runoff can result in a condition where fresh water, in the wrong concentration or in the wrong place, is a pollutant!

In the Chesapeake Bay, as in many estuaries, the salinity of the water is increasing, which will affect organisms living there (34).

Other pollutants are more expected. When humans overuse insecticides, the excess is washed away duing rains. These chemicals often make their way into rivers and streams, which flow into larger bodies of water like the Chesapeake Bay. Depending on the concentration and biological effect, pesticides in runoff can harm organisms for which they were not intended, like the Puritan tiger beetle.