Anadromous:  Of a fish, such as salmon, migrating up rivers from the sea to spawn.

Benthics:  Organisms that live in the sediment of streams, lakes or other bodies of water.

Biodiversity: The variety of organisms living within a given area.

Current: The current was measured using a flow gauge.  The current is used to calculate the overall flow for the stream.

Ecosystem: A biological community of interacting organisms and their physical environment.

Flow: The flow is calculated using the recorded measurements for current, stream depth and stream width.  The normal flow of a stream has an impact on the types of organisms found in the aquatic environment.

Freshwater:  Scientists classify a water habitat as freshwater if it has a salinity (saltwater content) of less than .005%.  Freshwater habitats can be ponds, lakes, bogs, rivers, streams, creeks, marshes and swamps.  Even a puddle or a drainage ditch can be a source of freshwater.

Global Climate Change:  While global warming refers to the overall warming of the planet, global climate change refers to the fact that, if the warming pattern continues, it probably will not be uniform across the planet.  Some regions on Earth may become warmer while others will become cooler.  The redistribution of heat over the planet can alter rainfall patterns as well as change regional temperatures.  The combined effect of changes in precipitation and temperature could cause agricultural regions to shift or disappear completely, affecting the food supply for humans and other organisms.

Indicator:  A measurement taken at a specific site or area that can be taken alone or combined with other indicators to give an overall picture or representation of the conditions in the environment studied.

Macroinvertebrate:  An animal without a backbone that can be seen with the naked eye.

pH: pH was measured with a pH meter.  Most freshwater lakes, streams, and ponds have a natural pH in the range of 6 to 8.  Many harmful effects occur to aquatic organisms as the pH becomes more acidic, especially as the pH drops below 5.

Pollutant:  A pollutant is something that is introduced to an environment that is not native to that environment. For example, warm water introduced into a stream is called a thermal pollutant and can harm the organisms that are native to the stream and adapted to living in cool water.

Stream Depth:  Stream depth was measured using a meter stick. The depth is used to calculate the overall flow of the stream.

Stream Elevation: Stream elevation is determined using a GPS.  Different species are adapted to different gradients.  The elevation of the stream helps predict what types of species will be found in the habitat.

Stream Order:  Stream order is determined by locating the stream on a USGS map.  The types of organisms that can be found along a stream are influenced by the environment of the stream.  This environment can change as the stream grows in size.  Stream order provides information about of the relative size and strength of the stream and provides a very good indication of the number and types of organisms present in a stream of a given size.

Stream Width: Stream width was measured with a measuring tape.   The width is used to calculate the overall flow of the stream.

1. Note:  The width of a stream does not necessarily indicate the order of the stream.  Urban areas often lack sufficient vegetation near streams due to paving and other modifications.  As a result, rainwater quickly runs off these surfaces into streams.  Many urban 1st order streams have been widened to facilitate drainage during heavy rains.
   

Substrate:  The material that makes up a stream bottom such as silt, sand, gravel, rocks and woody debris.

Water Temperature: Water temperature was measured with a thermometer.  Besides current velocity, water temperature is the most relevant environmental variable for stream invertebrates. As water temperature increases, species adapted to cold water can disappear.  Other species that typically lived in warmer waters downstream may replace cold water species upstream as those waters increase in temperature.

Watershed:  A watershed includes the entire area drained by a river and its tributaries and all water run-off that travels to the same outlet.