Red List habitat classification > RL - Marine habitats > RLBLS - Black Sea > BLSA5.aa Pontic infralittoral sands and muddy sands with stable aggregations of perennial unattached macroalgae

Pontic infralittoral sands and muddy sands with stable aggregations of perennial unattached macroalgae

Quick facts

Red List habitat type code BLSA5.aa
Threat status
Europe Endangered
EU n/a
Relation to
Source European Red List habitat factsheet
European Red List of habitats reports
European Red List of habitats (Excel table)


This habitat occurs in infralittoral sands and muddy sands. It is most easily identified and defined by the presence of unattached forms of macroalgae, in particular the ball-like form of the red alga Phyllophora crispa var. sphaerica. The classic example of this habitat is the Small Phyllophora field (SPF) National Botanical Reserve, which lies in shallow water (less than 16 m) on sand with shells in Karkinitsky Bay, Ukraine and occupies some 300-400 km2. Smaller Phyllophora aggregations occur in shallow water (mostly 3-5 m) in Yagorlytsky, Dzharylgachsky, Tendrovsky and Yarylgachsky Bays, and near Cape Evpatoriysky.  Between 1938 and 1994, a shift in communities was observed in the SPF: the Phyllophora – oyster Ostrea edulis community was replaced by Mytilus galloprovincialis Phyllophora, and the dominant species changed. From the 1970s, the most significant pressure was eutrophication which probably caused the greatest reductions in quantity and quality. After peaking in the 1980s, eutrophication has since reduced due to tighter controls on pollution in the catchment of the Danube and other rivers which enter the north-west Black Sea as well as industrial decline after the dissolution of the Soviet Union.

Indicators of quality:

Several elements of the “quality” of Phyllophora beds have been studied, including time series data comparing 3 patches of the SPF with regard to depth of occurrence, thickness of seaweed layers, biomass, and area covered, as well as the species composition of the benthic community.

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

Threat status

Synthesis of Red List assessment

The habitat is not present in the EU. Therefore it has been classified as ‘Not Assessed’ for this region.
In the EU28+ the habitat has been assessed as Endangered under Criteria B1c and B2c due to its restricted distribution along the Ukrainian coast. Despite its restricted distribution the quality and quantity of this habitat has remained relatively stable over the last 50 years, and is expected to remain stable or increase in the near future.
Red List Category Red List Criteria
n/a -
Red List Category Red List Criteria
Endangered B1c, B2c

Confidence in the assessment

Red List of habitat categories and criteria descriptions

Pressures and threats

  • Mining, extraction of materials and energy production
    • Exploration and extraction of oil or gas
  • Biological resource use other than agriculture & forestry
    • Fishing and harvesting aquatic resources
    • Professional active fishing
    • Hunting, fishing or collecting activities not referred to above
  • Pollution
    • Nutrient enrichment (N, P, organic matter)
  • Natural System modifications
    • Siltation rate changes, dumping, depositing of dredged deposits

Habitat restoration potential

The habitat cannot recover through intervention. It can recover naturally providing pressures are relieved. The amount of time required depends on the availability of source populations. If the habitat has declined in extent but is still present at a locality then it can recover within decades. If it has collapsed and is no longer present at a locality the recovery may take longer. If source populations are not available recovery may not be possible.

Trends in extent

Average current trend in quantity

No occurrence Stable
EU28 EU28+

Trends in quality

Average current trend in quality

No occurrence Stable
EU28 EU28+

Conservation and management needs

The SPF is listed a protected area Harvesting Phyllophora crispa is prohibited Phylophorra crispa is listed in the Ukraine and Black Sea Red Data Books.

List of conservation and management needs

  • Measures related to marine habitats
    • Other marine-related measures
  • Measures related to spatial planning
    • Establish protected areas/sites
    • Legal protection of habitats and species
  • Measures related to special resouce use
    • Regulating/Managing exploitation of natural resources on sea


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)
Black Sea Present ~400 Stable Stable

Extent of Occurrence, Area of Occupancy and habitat area

Extent of Occurrence (EOO) (Km2) Area of Occupancy (AOO) Current estimated Total Area Comment
EU28 0 0 0 This habitat is only present along the coast of Ukraine therefore it does not occur in the EU 28
EU28+ 12 ~400 The current area of the habitat is approximately 400km². Due to fragmentation and difficulties in accurately estimating all patches this figure should be treated with caution.
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.
Algae Phyllophora crispa
Flowering Plants Zostera noltii
Invertebrates Bittium reticulatum
Invertebrates Harmothoe reticulata
Invertebrates Mytilus galloprovincialis
Invertebrates Nereis zonata
Invertebrates Ostrea edulis
Invertebrates Synisoma capito
Species scientific name English common name Species group
Phyllophora crispa Algae
Zostera noltii Flowering Plants
Bittium reticulatum Invertebrates
Harmothoe reticulata Invertebrates
Mytilus galloprovincialis Invertebrates
Nereis zonata Invertebrates
Ostrea edulis Flat oyster Invertebrates
Synisoma capito Invertebrates

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

Not available
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