Coralline crusts and crustaceans on Atlantic littoral mobile boulders or cobbles in surge gullies

Description (English)

Highly mobile and scoured boulders and cobbles found on cave and gully floors and which often appear bare. Where there is sufficient light and stability, however, the boulders are encrusted by coralline algal crusts. Barnacles Balanus crenatus and keelworms Pomatoceros triqueter may survive in areas protected from severe abrasion. Crabs such as Cancer pagurus and Carcinus maenas may occur, often beneath and between the rocks, along with the gastropod Calliostoma zizyphinum. The anemone Actinia equina may be present in low numbers.
Situation: The slightly less-scoured walls often found above this biotope in caves and gullies are generally characterised by a similar, but richer community of scour-tolerant Balanus crenatus, Pomatoceros triqueter, coralline crusts and spirorbid worms (MB1-2761). This impoverished biotope may form an intermediate between barren gravel and slightly more stable larger pebbles and cobbles which are covered by algae that are often found in the mouths of caves (unit MB1-271).
Temporal variation: Winter storms periodically mobilise the boulders and cobbles, causing abrasion to any seasonal biota that may have developed over the calmer summer months.

Source: EUNIS habitat classification

Quick facts

EUNIS habitat type code MB12762
Relation to Resolution 4 habitat type (used for designation of Emerald sites)

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Invertebrates Actinia equina
Invertebrates Balanus crenatus
Invertebrates Calliostoma zizyphinum
Invertebrates Cancer pagurus
Invertebrates Carcinus maenas
Invertebrates Pomatoceros triqueter
Species scientific name English common name Species group
Actinia equina Invertebrates
Balanus crenatus Invertebrates
Calliostoma zizyphinum Invertebrates
Cancer pagurus Invertebrates
Carcinus maenas Invertebrates
Pomatoceros triqueter Invertebrates

Other classifications

Classification Code Habitat type name Relationship type
EUNIS Habitat Classification 2007 (revised descriptions 2012) A3.7162 Coralline crusts and crustaceans on mobile boulders or cobbles in surge gullies same
For relation to plant communities (syntaxa), see Vegetation types

History

Classification Code Habitat type name Relationship type Comment
EUNIS Habitat Classification 200410 A3.7162 Coralline crusts and crustaceans on mobile boulders or cobbles in surge gullies same
EUNIS Habitat Classification 200308 A3.4152 Coralline crusts and crustaceans on mobile boulders in surge gullies same
EUNIS Habitat Classification 200202 A3.4152 Coralline crusts and crustaceans on mobile boulders in surge gullies same
EUNIS Habitat Classification 199910 A3.4152 Coralline crusts and crustaceans on mobile boulders in surge gullies same
MNCR BioMar 97.06 (Britain & Ireland) EIR.SG.CC.Mob Coralline crusts and crustaceans on mobile boulders in surge gullies same
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