Sandi Smith Educational Technology Specialist, Helena, MT 59601
Revised March 13, 2001.
Background courtesy of
| Substrate-
Mineral (rock) or organic (plant) material at the bottom of a stream. The order of the following substrate types is from the smallest particles in the stream, to the largest particles. Sand- Substrate particle between 0.062 and 2 mm in size. Gravel- Substrate particles between 2 and 64 mm in size, good for spawning. Cobble- Substrate particles between 64 and 128 mm in size, good for spawning. Boulder- Substrate particles greater than 25 cm in size. |
Sandi Smith Educational
Technology Specialist, Helena, MT 59601
Revised March 13, 2001.
Background courtesy of