MathBench > Environmental Science

What's in your Watershed?

Muddying the waters

There are many ways of measuring water quality in the Chesapeake Bay (or anywhere else).  For example, measuring the clarity of the water is an obvious way to figure out, very roughly, how much “stuff” is in it.  For the last 150 years, people have been doing this with the help of a “secchi disk”, You lower this black and white disk into the water and  measure the depth at which the disk can no longer be distinguished.

bernieA secchi disk is decidedly low tech,  although recently a Chesapeake Bay activist named Bernie suggested an even more intuitive measure called “Bernie’s toes” – the depth at which he could no longer see his own feet.

Another way to measure water quality is to take bay water and mix in particular chemicals which will react with specific pollutants such as excess nitrogen (fertilizer).  This allows you to measure levels of specific pollutants and possibly guess where the pollution is coming from.