Present Ecological Status of the Main Benthic Habitats from the Romanian Black Sea Shelf

Abstract

Benthic fauna on sedimentary habitats has been analysed on 133 samples collected in 43 stations between 2015 and 2018 from the national monitoring network at depths ranging from 5 to 100m. The aim of the analysis was the identification of the main communities inhabiting sandy, muddy and mixed habitats and the assessment of their ecological status. In the above-mentioned period, 113 zoobenthic species have been identified; also, distinct communities have been evinced at 5-10, 20-30, 35-57 and 70-100m, dominated by Ampelisca sarsi (Chevreux, 1888) (at 5-10m), Melinna palmata (Grube, 1870) and various bivalves such as Chamelea gallina (Linnaeus, 1758), Abra prismatica (Montagu, 1808), Spisula subtruncata (da Costa, 1778), Anadara kagoshimensis (Tokunaga, 1906) (at 20-30m), Mytilus galloprovincialis (Lamarck, 1819) and its associated fauna (at 35-57m) and Modiolula phaseolina (Philippi, 1844) (at 70-100m). For the environmental status assessment of sedimentary habitats based on zoobenthic communities, abundance values were used to calculate the species’ richness, Shannon diversity index, AMBI index, and its five ecological groups, and multimetric index M-AMBI*(n). By applying the principle “One Out All Out” set out by the WFD, the sedimentary habitats on the Romanian shelf were assessed as non-GES. In shallow waters (0-3m), in the Romanian southern area, from Navodari to Vama Veche (eleven sampling stations), benthic habitats dominated by key species (Zostera noltei Hornemann, 1832, Cystoseira barbata (Stackhouse) C.Agardh, 1820) and various macrophytes have been analysed in the same period (2015-2018) based on the Ecological Index (EI) while the ecological status of benthic habitats dominated by macrophytes and marine phanerogams were assessed.