MA623 Seagrass beds on Atlantic littoral mud
Description
Beds of dwarf eelgrass colonising estuarine muds (‘slikke’) exposed by the low tide only for a few hours.
Protection
Protected under the code 1140 ("Mudflats and sandflats not covered by seawater at low tide") by the EU Habitat Directive.Floristic Composition
Frequent species
Nanozostera noltei 100%,
Zostera marina 8%
Indicator species
Nanozostera noltei 1,
Zostera marina 0.08
Phytosociology
- Zosteretum noltii
Relations with other habitat types
In the outer margin of tide channels, these communities transition towards MA225. Though still unrepresented in our phytosociological dataset, the unit MB522 (“Seagrass beds on Atlantic infralittoral sand") should be recognised to accomodate infralittoral, virtually permanently submersed sandy or muddy substrates colonised by Zostera marina in the more constantly saline, open to the sea areas, and by Ruppia maritima in ponds or lagoons with partial, either spatial or temporal isolation from the sea and whose waters fluctuate from brackish to hypersaline.
Regional distribution
Known occurrences and potential area of occupancy of the habitat type in the study region.
