Sparse or no macrofaunal communities on Baltic circalittoral rock and mixed substrata (predominantly hard)
.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 BAL43 |
|---|---|
| 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
The Baltic Sea benthic habitat occurs in the aphotic zone with at least 90% coverage of rock, boulders or stones and mixed (predominantly hard) substrates according to the HELCOM HUB classification. It is typically found in depths of 20 meters or more Where sessile/semi-sessile epibenthic fauna is present they covers less than 10% of the seabed and in some cases no epibenthic vegetation or macrofauna is present. Though the habitat is more uncommon in the Northern Baltic (due to the siltation and prevalence of sand and soft bottoms) it does exist also in the Bothnian Bay where the aphotic zone starts in quite shallow water (5-10 m depth), increasing the amount of rock and hard bottom in the circalittoral zone.
Four associated biotopes have been identified: Baltic aphotic rock and boulders characterized by sparse epibenthic macrocommunity (AB.A2T); Baltic aphotic mixed substrate characterized by sparse epibenthic fauna (AB.M2T); Baltic aphotic rock and boulders characterized by no macrocommunity ( AB.A4U); and Baltic aphotic mixed substrate characterized by no macrocommunity (AB.M4U).
Indicators of quality:
Unknown.
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 three associated biotopes AB.A2T, AB.A4U and AB.M2T as Least Concern (A1). AB.M4U was not evaluated. The extent and area of this habitat is believed to have been stable over the last 50 years and no change is expected in the near future. Current expert opinion is that this habitat be assessed as Least Concern for both 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 |
|
Stable  |
Stable |
| EU28 | EU28+ |
Trends in quality |
|
Average current trend in quality |
|
| Stable |
Stable |
| EU28 | EU28+ |
Conservation and management needs
List of conservation and management needs
- No measures
- No measures needed for the conservation of the habitat/species
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 | - | Stable |
| 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. |
| EU28+ | Unknown | 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).
