Red List habitat classification > RL - Marine habitats > RLBAL - Baltic > BAL31 Infaunal communities in Baltic infralittoral sand - bivalves

Infaunal communities in Baltic infralittoral sand - bivalves

Quick facts

Red List habitat type code BAL31
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 is a Baltic Sea benthic habitat in the photic zone where at least 90% of the substrate is sand according to the HELCOM HUB classification.  There is a lack of macrovegetation or epibenthic macrofauna but infaunal bivalves make up at least 10% of the biomass. The habitat is present in areas of high energy associated with wave action or currents. 

Six associated biotopes with different dominant species (at least 50% of the biomass of macrofauna) have been identified. Some have a restricted distribution in the Baltic. For example AB.J3L10 ‘Baltic aphotic sand dominated by multiple infaunal bivalve species: Macoma calcarea, Mya truncata, Astarte spp., Spisula spp.’  is only found at high salinities (> 18 psu) as all characteristic bivalves species are eumarine and do not tolerate lower salinities. The characteristic trait of the biotope is high species diversity. and it is encountered in the south-western Baltic Sea, from the Kiel bight to Isle of Fehmarn, and might occasionally occur from Mecklenburg Bight to Darss Sill. Where the substrate is well sorted medium to coarse sand, the large variety of interstitial space, may be inhabited by species of specialised fauna, such as the polychaetes Ophelia limacina, O. rathkei and Travisia forbesii. This fauna is restricted to the Belt Sea (sandbanks) and parts of the ‘submerged belt’ of the Arkona Basin.

 

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 determinedand applied on a location-specific basis. Diversity, abundance and biomass of fauna are potential indicators of quality.

Characteristic species
For full habitat description, please download the habitat factsheet.

Threat status

Synthesis of Red List assessment

The presence of this habitat type in the Baltic is well known but there is a lack of quantitative data on extent and quality. An overall decline in quantity is believed to have occurred over the last 50 years although there are different trends for the various associated biotopes. No signs for a decline were reported in the case of the associated biotope dominated by Baltic tellin (Macoma balthica), by cockles (Cerastoderma spp.) and by the sand gaper (Mya arenaria). In contrast the biotopes dominated by ocean quahog (Arctica islandica), by multiple infaunal bivalve species: Macoma calcarea, Mya truncata, Astarte spp., Spisula spp. and by multiple infaunal polychaete species including Ophelia spp. and Travisia forbesii are believed to have declined by 25-30% during the past 50 years in major parts of their distributional range. The quantity of Baltic photic sand dominated by multiple infaunal bivalve species: Cerastoderma spp., Mya arenaria, Astarte borealis, Arctica islandica, Macoma balthica is believed to have declined by 10% during the past 50 years in parts of their distributional range. There have also been declines in quality of some of these biotopes.
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 associated biotopes AA.J3L1, AA.J3L2, AA.J3L4 and AA.J3L9 as Least Concern (A1) and AA.J3L3, AA.J3L10 and AA.J3L11 as Near Threatened (A1). Current expert opinion is that this habitat should be assessed as Near Threatened (A1) for both the EU 28 and EU 28+ because of recent and predicted future declines.
EU
Red List Category Red List Criteria
Near Threatened A1
Europe
Red List Category Red List Criteria
Near Threatened A1

Confidence in the assessment

low
Red List of habitat categories and criteria descriptions

Pressures and threats

  • Transportation and service corridors
    • Shipping lanes, ports, marine constructions
  • 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)
    • Input of contaminants (synthetic substances, non-synthetic substances, radionuclides) - diffuse sources, point sources, acute events
  • Natural System modifications
    • Siltation rate changes, dumping, depositing of dredged deposits
    • Dumping, depositing of dredged deposits
    • Other siltation rate changes

Habitat restoration potential

The habitat forming species of one of the biotopes with the highest threat category (Near Threatened), AA.J3L3 ‘Baltic photic sand dominated by ocean quahog (Arctica islandica)’: is the most long-lived species in the world and has a long generation time (>> 50 years). It is difficult to intervene in the re-establishment. The other biotopes classified as Near Threatened AA.J3L10 Baltic photic sand dominated by multiple infaunal bivalve species: Macoma calcarea, Mya truncata, Astarte spp., Spisula spp. And AA.J3L11 Baltic photic sand dominated by multiple infaunal polychaete species including Ophelia spp. and Travisia forbesii are also dominated by bivalve species with life spans of 20 – 40 years. No information on likely recovery capacity exist for the species which dominate the other associated biotopes.

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

All actions that reduce the level of eutrophication in the Baltic Sea will benefit this habitat.These actions include measures to reduce the diffuse run off of nutrients from agriculture and tackling point source pollution by installation of waste water treatment plants. The photic sandy substrates may increasingly be utilised for mineral extraction. Restricting sand extraction will support the persistence of the habitat and it is recommended that sand extraction should be avoided in areas where biotopes AA.J3L10 (Baltic photic sand dominated by multiple infaunal bivalve species: Macoma calcarea, Mya truncata, Astarte spp., Spisula spp.) or AA.J3L11 (Baltic photic sand dominated by multiple infaunal polychaete species including Ophelia spp. and Travisia forbesii) occur.

List of conservation and management needs

  • Measures related to wetland, freshwater and coastal habitats
    • Restoring/Improving water quality
  • Measures related to spatial planning
    • Establish protected areas/sites
    • Legal protection of habitats and species
  • Measures related to hunting, taking and fishing and species management
    • Regulation/Management of fishery in marine and brackish systems
  • Measures related to special resouce use
    • Regulating/Managing exploitation of natural resources on sea

Distribution

For each habitat a distribution map was produced from a wide variety of sources indicating known and potential occurrences of the habitat in 10x10 km grids within Europe. Occurrences in grid cells were given in two classes: actual distribution from relatively reliable sources (surveys, expert knowledge), and potential distribution based on models or less reliable indicators. Please download the fact sheet to see the map.

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 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 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.
AOO = the area occupied by a habitat measured in number of 10x10 km grid cells.
EOO = the area (km2) of the envelope around all occurrences of a habitat (calculated by a minimum convex polygon).

Characteristic species

The full list of characteristic species and genus are available above from the Summary. The species available in the EUNIS database are shown here.
Invertebrates Arctica islandica
Invertebrates Macoma balthica
Invertebrates Macoma calcarea
Invertebrates Mya arenaria
Invertebrates Mya truncata
Invertebrates Ophelia limacina
Invertebrates Ophelia rathkei
Invertebrates Phaxas pellucidus
Invertebrates Travisia forbesii
Species scientific name English common name Species group
Arctica islandica Ocean quahog Invertebrates
Macoma balthica Invertebrates
Macoma calcarea Invertebrates
Mya arenaria Invertebrates
Mya truncata Invertebrates
Ophelia limacina Invertebrates
Ophelia rathkei Invertebrates
Phaxas pellucidus Invertebrates
Travisia forbesii Invertebrates

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

Not available
European Environment Agency (EEA)
Kongens Nytorv 6
1050 Copenhagen K
Denmark
Phone: +45 3336 7100