Aquatic moss communities on Baltic infralittoral coarse sediment

This habitat occurs on Baltic bottoms in the photic zone where the seabed substrate is at least 90% coarse sediment according to the HELCOM HUB classification.  Aquatic moss covers at least 10% of the seabed and more than any other perennial attached erect groups. In some places the mosses form extensive underwater meadows which provide shelter and food for benthic animals. This habitat occurs where salinity is typically  <5 psu and in all exposure ranges although more common in areas exposed to wave action. It occupies the photic zone typically between 1 to 7 meters.

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 depth zone occupied and amount of epiphytic ephemeral filamentous algae are potential indicators of quality of this habitat.

Synthesis of Red List assessment

Confidence in the assessment

Pressures and threats