Attached Sea Urchins (Biotic Group)

Component: Biotic

Unique Identifier: 1219

Biotic Setting	Benthic/Attached Biota
Biotic Class	Faunal Bed
Biotic Subclass	Attached Fauna
Biotic Group	Attached Sea Urchins
Biotic Community	Attached Strongylocentrotus purpurata Attached Strongylocentrotus droebachiensis

Description

Definition

Hard or mixed substrate areas dominated by mobile sea urchins. Many sea urchins are omnivorous, consuming algae, debris, sessile invertebrates, and other foods. In some situations, sea urchins will occur in great numbers, clearly constituting the dominant Biotic Group. These fauna may be associated with another Biotic Group (upon which they are feeding) and may be considered as Co-occurring Elements if the "forage" group occurs in greater percent cover, or dominates biomass.