Kelp communities on Baltic infralittoral coarse sediment/shell gravel
.jpg "HELCOM RED LIST Biotope Expert Team 2013 and Baltic Sea Working Group for the European Red List of Habitats 2014 and 2015.")
.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 BAL10 |
|---|---|
| Threat status | |
| Europe | Near Threatened |
| EU | Near Threatened |
| Relation to |
|
| Source | European Red List habitat factsheet |
| European Red List of habitats reports | |
| European Red List of habitats (Excel table) |
Summary
This habitat occurs in the photic zone in areas where the more than 90% of the seabed is comprised of coarse sediments, including shell gravel and mixed substrates according to the HELCOM HUB classification. Kelp covers at least 10% of the seabed and more than other perennial attached erect groups. It is more common in areas exposed to wave action than sheltered locations and present in depths from around 0.5-10 m. Three associated biotopes have been identified. ‘Baltic photic shell gravel dominated by kelp’ (AA.E1C4), ‘Baltic photic mixed substrate dominated by kelp’ (AA.M1C4) and Baltic photic coarse sediment dominated by kelp’ (AA.I1C4) where perennial attached kelp species such as Saccharina latissima and Laminaria digitata constitute at least 50% of the biovolume of such algae.
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 the kelp is a potential indicator 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 one of the associated biotopes (kelp on shell gravel) to be Near Threatened (based on criterion B1a (ii)). Kelp on coarse sediment and kelp on mixed substrate was assessed as Least Concern. Given the scarcity of kelp habitats on shell gravel and coarse sediment in the Baltic region, continuation of known threats, and the predicted increase in pressure on this habitat associated with climate change (temperature and salinity in particular), expert opinion has been used to assess this habitat as Near Threatened for the EU 28 and EU 28+.
| EU | |
| Red List Category | Red List Criteria |
| Near Threatened | A1, A2, A3, B3 |
| Europe | |
| Red List Category | Red List Criteria |
| Near Threatened | A1, A2, A3, B3 |
Confidence in the assessment
Pressures and threats
- Biological resource use other than agriculture & forestry
- Fishing and harvesting aquatic resources
- Professional active fishing
- Benthic or demersal trawling
- Benthic dredging
- Pollution
- Pollution to surface waters (limnic, terrestrial, marine & brackish)
- Nutrient enrichment (N, P, organic matter)
- Natural System modifications
- Human induced changes in hydraulic conditions
- Siltation rate changes, dumping, depositing of dredged deposits
- Other human induced changes in hydraulic conditions
- Climate change
- Changes in abiotic conditions
- Temperature changes (e.g. rise of temperature & extremes)
- Changes in biotic conditions
- 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 |
|
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
- Measures related to marine habitats
- Other marine-related measures
- Measures related to spatial planning
- Establish protected areas/sites
- Measures related to hunting, taking and fishing and species management
- Regulation/Management of fishery in marine and brackish systems
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) |
|---|---|---|---|---|
| Belt Sea | Present | max | Unknown | Decreasing |
| The Sound | ||||
| Baltic Proper |
Extent of Occurrence, Area of Occupancy and habitat area
| Extent of Occurrence (EOO) (Km2) | Area of Occupancy (AOO) | Current estimated Total Area | Comment | |
|---|---|---|---|---|
| EU28 | max 63,250 | max 410 | max 60,000 | EOO and AOO are based on HELCOM mapping in 100 x 100km cells that were converted to 10 x 10 km cells. The values therefore represent a maximum as the habitat may not occur in all these 10 x 10 km cell |
| EU28+ | max 410 | max 60,000 | EOO and AOO are based on HELCOM mapping in 100 x 100km cells that were converted to 10 x 10 km cells. The values therefore represent a maximum as the habitat may not occur in all these 10 x 10 km cell |
EOO = the area (km2) of the envelope around all occurrences of a habitat (calculated by a minimum convex polygon).
