Description of biotope or habitat type
Ascophyllum nodosum with epiphytic sponges and ascidians on variable salinity infralittoral rock
Habitat (physical) description
|Salinity||Variable (18-35 ppt)|
|Wave exposure||Extremely sheltered|
|Tidal streams||Weak (>1 kn), Very weak (negligible)|
|Substratum||Bedrock; boulders and cobbles|
|Depth Band||0-5 m|
Download comparative physical and biological data. The comparative tables enable a rapid comparison of the species composition and principal physical characteristics between a given set of biotopes.
- Records used to define the biotope (core records)
- Other records assigned to this biotope, marked as 'certain'
- Other records assigned to this biotope, marked as 'uncertain'
- Predicted extent of the level 3 (for sublittoral rock & deep sea) or 4 (for sublittoral sediment) habitat
Dense subtidal stands of Ascophyllum nodosum, heavily epiphytised by sponges and ascidians in lagoon-like habitats. The wracks Fucus vesiculosus and Fucus serratus can be present along with the brown seaweed Chorda filum and the red seaweed Polyides rotundus. The crab Carcinus maenas can be present between the A. nodosum holdfasts along with the shrimps Mysidae.
Nearby rock often supports similar biotopes of submerged fucoids and green seaweeds (FChoG). Slightly deeper rock often supports Laminaria saccharina (Lsac.Ft), usually surrounded by more extensive areas of sediment. Seagrass beds thrive well in the muddy sand of these lagoons and often cover large areas. They include both Ruppia maritima and Zostera marina (Rup and Zmar).
|Taxon||Relative importance of taxon for defining this community (%)||Typical abundance - SACFOR scale||% of core records where taxon was recorded|
|Carcinus maenas||21||Occasional||81-100 %|
|Polyides rotundus||7||Frequent||41-60 %|
|Chorda filum||4||Frequent||41-60 %|
|Ascophyllum nodosum||40||Frequent||81-100 %|
|Fucus serratus||4||Frequent||41-60 %|
|Fucus vesiculosus||4||Frequent||61-80 %|
Not applicable or unknown.