Stream Bed

Information on this page has been adapted from the Streamkeepers Handbook and Modules

Different kinds of streambed material influence plant and animal life in a stream. This material ranges in size from "fines" like silt, sand, and clay, to large boulders and bedrock. Although variety in material size is desirable, a streambed comprised primarily of fine sediment is less stable than one comprised primarily of boulder, cobble, and gravel. Larger material also provides better quality fish and aquatic invertebrate habitat.

Size Categories of Streambed Material
Bedrock Solid Slab of Rock
Boulder > 25 cm diameter
Cobble 5 - 25 cm diameter
Gravel 0.2 - 5 cm diameter
Fines 0.2 cm diameter

Salmon Eggs
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