Perennial algal communities (excluding kelp) on Baltic infralittoral coarse sediment
_on_Baltic_infralittoral_coarse_sediment_(1).jpg "HELCOM RED LIST Biotope Expert Team 2013 and Baltic Sea Working Group for the European Red List of Habitats 2014 and 2015.")
_on_Baltic_infralittoral_coarse_sediment_(2).jpg "HELCOM RED LIST Biotope Expert Team 2013 and Baltic Sea Working Group for the European Red List of Habitats 2014 and 2015.")
Quick facts
| Red List habitat type | code BAL11 |
|---|---|
| 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 habitat is distributed on Baltic bottomsin the photic zone with at least 90% coverage of coarse sediment according to the HELCOM HUB classification. Perennial attached algae such as Fucus spp., or perennial red algae cover at least 10% of the seabed and more than other perennial attached erect groups. It is most common in areas moderately exposed to wave action and in depths of up to 10 m.
Four associated biotopes with different dominant species of algae and some differences in depth and salnity preferences, resulting in variations in their geographical occurrence in the Baltic Sea have been described by HELCOM. These are: ‘Baltic photic coarse sediment dominated by Fucus spp.’ (AA.I1C1) such as Fucus radicans, F. serratus or F. vesiculosus: ‘Baltic photic coarse sediment dominated by perennial non-filamentous corticated red algae’ (AA.I1C2) such as Furcellaria lumbricalis; ‘Baltic photic coarse sediment dominated by perennial foliose red algae’ (AA.I1C3) such as Coccotylus spp., Phyllophora spp. and Delesseria spp. and ‘Baltic photic coarse sediment dominated by perennial filamentous algae’ (AA.I1C5) such as Polysiphonia spp, Aegagrophila linnaei, Cladophora rupestris.
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. The lower depth limit of algae, especially Fucus spp. where applicable, and the amount of epiphytic algae are potential indicators of quality of this habitat.
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 four relevant Baltic biotopes (AA.I1C1, AA.I1C2, AA.I1C3, AA.I1C5) to be Least Concern (A1). With no additional information on changes in extent or quality of this habitat, a wide geographical distribution in the Baltic and less than a 25% decline in quantity over the last 50 years, the current expert opinion is that this habitat should be assessed as 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
- Pollution
- Pollution to surface waters (limnic, terrestrial, marine & brackish)
- Nutrient enrichment (N, P, organic matter)
- Input of contaminants (synthetic substances, non-synthetic substances, radionuclides) - diffuse sources, point sources, acute events
- Natural System modifications
- Human induced changes in hydraulic conditions
- Siltation rate changes, dumping, depositing of dredged deposits
- Climate change
- Temperature changes (e.g. rise of temperature & extremes)
- Habitat shifting and alteration
Habitat restoration potential
Trends in extent |
|
Average current trend in quantity |
|
Decreasing  |
Decreasing |
| EU28 | EU28+ |
Trends in quality |
|
Average current trend in quality |
|
| Decreasing |
Decreasing |
| EU28 | EU28+ |
Conservation and management needs
List of conservation and management needs
- Measures related to wetland, freshwater and coastal habitats
- Restoring/Improving water quality
- Measures related to marine habitats
- Other marine-related measures
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 | 670 | Decreasing | Decreasing |
| 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 | >50 | Unknown | This habitat is present in all the Baltic sub-basins. |
| EU28+ | >50 | Unknown | This habitat is present in all the Baltic sub-basins |
EOO = the area (km2) of the envelope around all occurrences of a habitat (calculated by a minimum convex polygon).
