Description of biotope or habitat type
Green seaweeds (Ulva spp. and Cladophora spp.) in shallow upper shore rockpools
Physical habitat description
|Salinity||Full (30-35 ppt), Variable (18-35 ppt)|
|Wave exposure||Very exposed, Exposed, Moderately exposed, Sheltered|
|Zone||Eulittoral - upper, Littoral fringe|
|Depth Band||Upper shore|
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- 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'
Point data based on records in the UK Marine Recorder Snapshot.
Rockpools in the littoral fringe or upper eulittoral zone subject to widely fluctuating temperatures and salinity are characterised by ephemeral green alga of the genus Ulva, along with Cladophora spp. and Ulva lactuca. Due to the physical stress imposed on these upper shore pools, grazing molluscs such as the limpet Patella vulgata and the winkles Littorina littorea and Littorina saxatilis are generally in lower abundance than eulittoral pools, allowing the green seaweeds to proliferate under reduced grazing pressures. The bright orange copepod Tigriopus fulvus is tolerant of large salinity fluctuations and may occur in large numbers in these upper shore pools, along with gammarid amphipods.
Rockpools throughout the upper eulittoral and lower littoral fringe in bedrock.
Fluctuations especially in the abundance of the green seaweeds will occur due to marked changes in salinity and temperature during the year. Enteromorpha intestinalis can often be bleached during the summer.
|Taxon||Relative importance of taxon for defining this community (%)||Typical abundance - SACFOR scale||% of core records where taxon was recorded|
Similar biotopes or habitat types
Classification history of this biotope or habitat type