All living things need water. In the Chesapeake Bay region, waterways support more than 3000 species of plants and animals. Monitoring changes to the Bay's waterways is important, and the data that is collected can help scientists make determinations about water quality. Many factors help to paint a picture of whether a waterway is healthy. Information on sediment is collected in both types of waters, but in different ways.
Scientists also examine data on water temperature, salinity and dissolved oxygen.
Healthy water contains a balanced amount of nutrients and normal fluctuations in salinity and temperature. It also has plenty of oxygen and little sediment so that underwater living resources can breathe or receive enough sunlight to grow. Stressed waters have an overabundance of nutrients and sediment, along with a lack of enough oxygen and clarity.