Red List habitat classification > RL - Marine habitats > RLNEA - Atlantic > NEAA3.33 Macaronesian submerged fucoids, green or red seaweeds on full salinity infralittoral rock

Macaronesian submerged fucoids, green or red seaweeds on full salinity infralittoral rock

Quick facts

Red List habitat type code NEAA3.33
Threat status
Europe Data Deficient
EU Data Deficient
Relation to
Source European Red List habitat factsheet
European Red List of habitats reports
European Red List of habitats (Excel table)


This habitat is found throughout the Macaronesian islands in rocky infralittoral areas and is characterised by the presence of many photophilic algae.

In shallow waters 2-3m around the Azores the habitat is dominated by Codium fragile although in places the invasive species Cfragile spp. tomentosoides has also become established.  In the southern Macaronesian archipelagos of Madeira, Selvagen and the Canaries other Codium  spp. are characteristic elements of this habitat either as conspicuous narrow belt of crustose species (C. intertextum, C. adhaerens) in the infralittoral fringe, globlose to subglobose, somewhat flattened specimens of C. elisabethiae / C. bursa, or frondose and large specimens in crevices and overhangs (C. taylorii) or attached to pebbles (C. decorticatum).

In shallow sublittoral rocks, it is also possible to find the biotope of the green macroalgae Dasycladus vermicularis - Halimeda discoidea -Acetabularia acetabulum  with the gasteropod Elysia timida.  Where there is some organic matter sedimentation the red algae Halopithys incurva, Digenea simplex, Rytiphlaea tinctoria and Alsidium corallinum are more common.

The fucoids Cystoseira mauritanica, C. tamariscifolia  and sometimes, C. abies-marina and c. foeniculacea, Sargassum vulgare - S. desfontainesii - S. furcatum are the main elements of other biotopes, with many marine invertebrates associated (copepods, amphipods, hydrozoans, etc.). A seasonal biotope during spring – summer months is characterized by Sporochnus spp.

In deeper waters with low light intensity the associated biotopes include those characterised by the red macroalgae Botryocladia, Halymenia, Sebdenia and less frequently Kallymenia.  In some detritic sediments, the introduced tropical green seaweed Caulerpa racemosa  var. cylindracea  could be observed between 10 - 50 m. depth. Associated species are the polychaete Ditrupa arietina, decapods such as Paromola cuvieri and Cancer bellianus, bryozoans of the genus Cupuladria and the sea urchins Cidaris cidaris and Genocidaris maculata.

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.

Characteristic species:

In the Canary Islands, common associated species are the anthozoan Palythoa canariensis and the bivalve Spondylus senegalensis as well as the red macroalgae Nemastoma canariensis and the esponges Aplysina aerophoba e Ircinia spp. The Azores archipelago is the southwestern limit of distribution of Codium fragile ssp. atlanticum but the invasive species C. fragile ssp. tomentosoides has also established successful populations in the archipelago.  

The biodiversity of these biotopes is high, with the dominant macroalgal species associated with other macroalgae, such as the perennial species Halopteris scoparia  Cladostephus spongiosus and Padina pavonica or the annual  green macroalgae Acetabularia acetabulum. Among these species it is possible to observe turf species, such as Ellisondia elongata  Jania rubens, Jania corniculata or Haliptilon virgatum, Amphiroa rigida, erect species such as Liagora distenta, Hypnea musciformis, H. cervicornis, or epiphytes as Falkenbergia rufolanosa. Among gastropod molluscs, Haliotis tuberculata, Gibbula  spp., Rissoa  spp., Aplysia  spp., Elysia timida, Ocenebra erinacea, Ocinebrina edwardsi, Stramonita haemastoma and Nassarius incrassatus are observed. The most common echinoderms are Sphaerechinus granularis, Paracentrotus lividus and Arbacia lixula (sometimes also the long spined sea urchin Diadema africanum) and the seastar Echinaster sepositus. The icthyofauna is diverse and common species are Sparus aurata, Sciaena umbra, Ephinephelus marginatus and Hippocampus hipppocampus.

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

Threat status

Synthesis of Red List assessment

There is insufficient information to determine historical, current or future trends in quantity or quality of this habitat although it is considered likely to decline in the future if conservation measures are not introduced.
This habitat has a large EOO and AOO, and therefore qualifies as Least Concern under criterion B. However the habitat is assessed as Data Deficient both at the EU 28 and EU 28+ levels given the lack of information on its trends in quantity and quality and the fact that its overall distribution is unknown.
Red List Category Red List Criteria
Data Deficient -
Red List Category Red List Criteria
Data Deficient -

Confidence in the assessment

Red List of habitat categories and criteria descriptions

Pressures and threats

  • Urbanisation, residential and commercial development
    • Urbanised areas, human habitation
    • Discharges
  • Biological resource use other than agriculture & forestry
    • Fishing and harvesting aquatic resources
  • Pollution
    • Pollution to surface waters (limnic, terrestrial, marine & brackish)
    • Nutrient enrichment (N, P, organic matter)
    • Marine water pollution
  • Invasive, other problematic species and genes
    • Invasive non-native species

Habitat restoration potential

There is insufficient information to determine whether this habitat retains the capacity to recover when severely damaged.

Trends in extent

Average current trend in quantity

Unknown Unknown
EU28 EU28+

Trends in quality

Average current trend in quality

Unknown Unknown
EU28 EU28+

Conservation and management needs

This habitat is included within some Marine Protected Areas where there are associated management measures, regulations and codes of conduct but not necessarily targetting this specific habitat. Regulation of coastal development and discharges to the marine environment and control of activities that might lead to the introduction of invasive species are other measures that could benefit this habitat.

List of conservation and management needs

  • Measures related to wetland, freshwater and coastal habitats
    • Restoring/Improving water quality
  • Measures related to spatial planning
    • Other marine-related measures
    • Establish protected areas/sites
  • Measures related to urban areas, industry, energy and transport
    • Urban and industrial waste management
    • Managing marine traffic


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)
Macaronesia Present Unknown Unknown Unknown

Extent of Occurrence, Area of Occupancy and habitat area

Extent of Occurrence (EOO) (Km2) Area of Occupancy (AOO) Current estimated Total Area Comment
EU28 718,914 173 Unknown EOO and AOO have been calculated on the available data. Although this data set is known to be incomplete the figures exceed the thresholds for threatened status.
EU28+ 173 Unknown This habitat does not occur outside the EU28
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

Not available

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

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