Physical and chemical characteristics of water help shape the nature of aquatic ecosystems. Physical characteristics include things like temperature, pH and water clarity. Chemical substances in water include ions, metals and nutrients, and can occur naturally or may be caused by human activities. Together, physical and chemical characteristics of water influence what can live in rivers and lakes.

In this chapter
A naturally occurring ion found dissolved in water
A measurement of how easily electricity flows through water
Dissolved Oxygen
The concentration of oxygen from the atmosphere dissolved in the water
The measure of dissolved minerals in water
Oxidation-Reduction Potential (ORP)
The ability of a lake or river to cleanse itself or breakdown waste products
The degree to which water is acidic or basic
Measures the saltiness of water
Secchi Depth
The depth at which a disk lowered into the water can no longer be seen from the surface
A measure of how warm or cold the water is
Total Suspended Solids (TSS) and Total Dissolved Solids (TDS)
A measure of the amount of particulate matter floating in water
A measure of water clarity