Summary

Estimated observations of the biotopes AA.E1F1 and AB.E1F1 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes.

Description

Baltic photic or aphotic shell gravel dominated by vase tunicate (Ciona intestinalis)The HELCOM Red List of Baltic Sea underwater biotopes, habitats and biotope complexes (2013) is an updated and improved version of the Red List assessment of marine and coastal biotopes and biotope complexes published in 1998. The classification of the report follows the proposed International Union for Conservation of Nature (IUCN) criteria and assessment principals but with some modifications for the Baltic Sea.Altogether, the HELCOM Underwater Biotope and habitat classification (HELCOM HUB) includes 209 biotopes of which 59 were red-listed. Many of the red-listed biotopes are located in deep areas of the Baltic Sea due to oxygen-free nature as well as in the southwestern Baltic Sea due to the salinity restricted distribution of species in certain biotope. The HELCOM assessment relies heavily on expert judgment and inference, and the questionnaire data represents the estimated presence-absence data not in-situ measured data. This must be taken in account when observing the map presentation. The biotopes are shown on the map using the EEA 100 km grid. This dataset displays estimated presence of AA.E1F1 and AB.E1F1 according to HELCOM RED LIST assessment experts:The biotopes are known from German waters in the Baltic Sea, but may also occur in other areas in the southwestern Baltic Sea where the vase tunicate (Ciona intestinalis) occurs. The distribution map indicates the area in the 100 x 100 km grid where biotopes are known to occur. The biotopes may potentially occur in other areas with high salinity on shell gravel covered bottoms, but are currently not known from other locations.(Data (expert judgements) collected in HELCOM RED LIST project, released in May 2013)