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Biogenic Substrate (Substrate Origin)

Component: Substrate

Unique Identifier: 301

Substrate Origin Biogenic Substrate
Substrate Class Algal Substrate
Coral Substrate
Organic Substrate
Ooze Substrate
Shell Substrate
Worm Substrate


Description
Definition Substrates where percent cover of non-living Biogenic Substrate exceeds percent cover of both Geologic Substrate and Anthropogenic Substrates, when all are considered separately. Biogenic substrates are classified at the higher levels by taxonomy, 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), and Sand (0.0625 millimeters to < 2 millimeters). These units are derived from Wentworth (1922), and they can be broken down into Wentworth grain size classes for greater precision, if desired. Biogenic 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 Biogenic Substrate Origin describe the substrate type that is present in the greatest percent cover, greatest percent weight, or greatest visual percent composition. When two Biogenic 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. Biogenic Substrate types that are present, but do not constitute the dominant feature, may be included as a Co-occurring Element modifier (see Section 10).