Description of biotope or habitat type
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Littoral macrophyte-dominated sediment
Physical habitat description
| Salinity | Full (30-35 ppt), Reduced (18-30ppt), Variable (18-35 ppt) |
|---|---|
| Wave exposure | Sheltered, Very sheltered, Extremely sheltered |
| Tidal streams | |
| Substratum | Sandy or muddy sediments |
| Zone | Littoral fringe |
| Depth Band | Mid shore, Strandline, Upper shore |
| Other Features |
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'
Point data based on records in the UK Marine Recorder Snapshot.
Description
Littoral macrophyte-dominated sediment biotopes include saltmarshes on the upper shore and seagrass beds on the mid and upper shore. These higher plant-dominated communities develop mostly on sheltered shores with fine, often muddy, sediments. The character of saltmarsh communities is affected by height up the shore, resulting in a zonation pattern related to the degree or frequency of immersion in seawater. Saltmarsh and seagrass bed vegetation is generally well studied; its classification is fully covered by the UK National Vegetation Classification, where 26 types are defined (Rodwell, 2000). Users are referred to the chapter on saltmarsh communities in Rodwell (2000) (this will be a hyperlink to an electronic copy of the mentioned chapter) for details on the plant communities which characterise the different littoral macrophyte-dominated biotopes.
Situation
Saltmarshes are found on the upper shore above sheltered sand, muddy sand, and mud biotopes, generally confined to estuaries and other sheltered marine inlets. Seagrass beds are most frequently found on lower estuary and sheltered coastal muddy sands.
Temporal variation
There may be seasonal variation in the area covered by intertidal seagrass beds and saltmarshes, as plants die back during cold temperatures in winter. Intertidal seagrass beds may also be subject to heavy grazing by geese, which can reduce the extent of the plant cover significantly.
Characterising species
Characterising species data not applicable.
Similar biotopes or habitat types
Not applicable or unknown.