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Anthropogenic Substrate (Substrate Origin)

Component: Substrate

Unique Identifier: 362

Substrate Origin Anthropogenic Substrate
Substrate Class Anthropogenic Rock
Anthropogenic Wood
Construction Materials
Metal
Trash


Description
Definition Substrates where percent cover of Anthropogenic Substrate exceeds percent cover of both Geologic Substrate and Biogenic Substrates, considered separately. Anthropogenic Substrates are classified at the higher levels by composition, and at the lower levels by median particle size, using the units Reef Substrate (= 4,096 millimeters), Rubble (64 millimeters to < 4,096 millimeters), Hash (2 millimeters to < 64 millimeters), Sand (0.0625 millimeters to < 2 millimeters), and Mud (< 0.0625 millimeters). These units are derived from Wentworth (1922), and can be broken down into Wentworth grain size classes for greater precision if desired. Shape for this substrate origin is covered in the GC, but practitioners may choose to add further descriptors in a comment or notes field. Anthropogenic Substrate classifications may be based on percent weight (e.g., for retrieved samples); percent cover (e.g., for plan-view images); and visual percent composition (for other approaches). The terms "dominant" and "primarily" in the Anthropogenic Substrate Origin describe the substrate type that is present in the greatest percent cover, greatest percent weight, or greatest visual percent composition. When two Anthropogenic Substrate types are present, "dominant" and "primarily" are equivalent to "> 50%". When three or more types exist, the dominant type may occur at a lower percent-of-total value. When Anthropogenic Substrate is present, but does not constitute the dominant substrate, it should be included as a Co-occurring Element Modifier.