WATER

Glossary

biological indicator: A living thing whose presence or absence tells something about the quality of the environment.

erosion: The wearing away of any part of the earth's surface by weathering, corrosion, dissolution or abrasion.

food web: The complex association of plants and animals in nature whereby organisms are interconnected because they are sources of food for one another. At the base of the wood web are green plants and bacteria which supply food for small animals. Larger animals eat smaller animals as well as plants. Detritovores recycle nutrients by breaking down decaying plants and animals.

habitat: The specific environment or area in which a creature lives. For example, the habitat for a stonefly nymph is the cool riffle of a stream.

habitat requirements: Environmental conditions necessary for survival of a given species.

macroinvertebrates: Animals without backbones that are large enough to be seen without a microscope.

nymph: The immature form of certain insects such as stoneflies, mayflies and true bugs. Nymphs go through incomplete metamorphosis to become adults.

run-off: The increase in water flow of rivers and streams caused by the melting of mountain snow or extra flow of water into a creek during and after rain storms:

silt: Fine particles of sand and soil deposited by water.

watershed: The area around a stream that drain into the stream.