Faunal crusts on wave-surged littoral cave walls

English name: Faunal crusts on wave-surged littoral cave walls

Description (English)

The inner walls of caves, predominantly in the mid shore in wave-surged conditions dominated by barnacles Semibalanus balanoides, and Verruca stroemia, with patches of encrusting sponges such as Halichondria panicea and Grantia compressa and occasional patches of the mussel Mytilus edulis. Increased moisture allows a denser faunal population than unit A1.449 to develop within the cave. The limpet Patella vulgata and spirorbid tube-forming polychaetes can be present. The hydroid Dynamena pumila and anemones such as Metridium senile and Actinia equina may occur towards the lower reaches of the cave. Where a dense faunal turf of barnacles or bryozoan crusts covers the cave walls, the biotope can also extend to cover the ceiling and may be accompanied by the bryozoan Alcyonidium diaphanum. Variations of this biotope may occur in mid and lower shore scoured caves in south Wales the rock is dominated by dense Sabellaria alveolata. In south-west England the rock can be completely covered by the barnacle Balanus perforatus. There may be a variation in the species composition from cave to cave, depending on local conditions.
Situation: This biotope usually occurs above the sand/pebble scoured A1.449 zone and may extend to the ceilings of the caves.

Source: EUNIS habitat classification

Quick facts

EUNIS habitat type code A1.448
Bern Convention Included in a Resolution 4 habitat type at a higher level (A1.44)

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Invertebrates Actinia equina
Invertebrates Alcyonidium diaphanum
Invertebrates Balanus perforatus
Invertebrates Dynamena pumila
Invertebrates Grantia compressa
Invertebrates Halichondria panicea
Invertebrates Metridium senile
Invertebrates Mytilus edulis
Invertebrates Patella vulgata
Invertebrates Sabellaria alveolata
Invertebrates Semibalanus balanoides
Invertebrates Verruca stroemia
Species scientific name English common name Species group
Actinia equina Invertebrates
Alcyonidium diaphanum Invertebrates
Balanus perforatus Invertebrates
Dynamena pumila Invertebrates
Grantia compressa Invertebrates
Halichondria panicea Invertebrates
Metridium senile Invertebrates
Mytilus edulis Invertebrates
Patella vulgata Invertebrates
Sabellaria alveolata Invertebrates
Semibalanus balanoides Invertebrates
Verruca stroemia Invertebrates

Other classifications

Classification Code Habitat type name Relationship type
Marine Habitat Classification Britain/Ireland 0405 LR.FLR.CvOv.FaCr Faunal crusts on wave-surged littoral cave walls source
For relation to plant communities (syntaxa), see Vegetation types

History

Classification Code Habitat type name Relationship type
EUNIS Habitat Classification 200410 A1.448 Faunal crusts on wave-surged littoral cave walls same
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