Crustose algae communities on Baltic infralittoral rock and mixed substrata
Quick facts
| Red List habitat type | code BAL5 |
|---|---|
| Threat status | |
| Europe | Least Concern |
| EU | Least Concern |
| Relation to |
|
| Source | European Red List habitat factsheet |
| European Red List of habitats reports | |
| European Red List of habitats (Excel table) |
Summary
This is a Baltic Sea benthic habitat in the photic zone , either with at least 90% coverage of rock, boulders or stones of more than 63 mm in diameter but also on mixed substrates with at least 10% coverage of rock, boulders or stones according to the HELCOM HUB classification. Soft crustose algae cover at least 10% of the seabed while all perennial attached erect groups cover less than 10%. This habitat covers the full salinity range of the Baltic Sea and is more common in areas exposed to waves and current.
Indicators of quality:
Both biotic and abiotic indicators have been used to describe marine habitat quality. These include: the presence of characteristic species as well as those which are sensitive to the pressures the habitat may face; water quality parameters; levels of exposure to particular pressure, and more integrated indices which describe habitat structure and function, such as trophic index, or successional stages of development in habitats that have a natural cycle of change over time. There are no commonly agreed indicators of quality for this habitat, although particular parameters may have been set in certain situations e.g. protected features within Natura 2000 sites, where reference values have been determined and applied on a location-specific basis.
Threat status
Synthesis of Red List assessment
The overall assessment for this EUNIS level 4 habitat has been based on the HELCOM (2013) assessments for the associated HELCOM HUB biotopes. Draft assessments were derived using a weighted approach whereby the HELCOM assessment outcomes were assigned a score. This was averaged across the relevant biotopes. The outcomes were reviewed by Baltic experts to reach a final conclusion. HELCOM (2013) assessed the two associated Baltic biotopes (AA.A1R and AA.M1R) as Least Concern (based on criterion A1). With no additional information on changes in extent or quality of this habitat, the current expert opinion is an assessment of Least Concern for the EU 28 and EU 28+.
| EU | |
| Red List Category | Red List Criteria |
| Least Concern | - |
| Europe | |
| Red List Category | Red List Criteria |
| Least Concern | - |
Confidence in the assessment
Pressures and threats
- No threats or pressures
- No threats or pressures
Habitat restoration potential
Trends in extent |
|
Average current trend in quantity |
|
Unknown  |
Unknown |
| EU28 | EU28+ |
Trends in quality |
|
Average current trend in quality |
|
| Unknown |
Unknown |
| EU28 | EU28+ |
Conservation and management needs
List of conservation and management needs
- Measures related to wetland, freshwater and coastal habitats
- Restoring/Improving water quality
Distribution
Geographic occurrence and trends
| Seas | Present or presence uncertain | Current area of habitat (Km2) | Recent trend in quantity (last 50 years) | Recent trend in quality (last 50 years) |
|---|---|---|---|---|
| Baltic Proper | Present | Unknown | Unknown | Unknown |
| Belt Sea | ||||
| Gulf of Bothnia | ||||
| Gulf of Finland | ||||
| Gulf of Riga | ||||
| The Sound |
Extent of Occurrence, Area of Occupancy and habitat area
| Extent of Occurrence (EOO) (Km2) | Area of Occupancy (AOO) | Current estimated Total Area | Comment | |
|---|---|---|---|---|
| EU28 | >50,000 | Unknown | Unknown | This habitat is present in all the Baltic sub-basins however there is insufficient information for accurate calculation of EOO and AOO. |
| EU28+ | Unknown | Unknown | This habitat is present in all the Baltic sub-basins however there is insufficient information for accurate calculation of EOO and AOO. |
EOO = the area (km2) of the envelope around all occurrences of a habitat (calculated by a minimum convex polygon).
