Spatial distribution of the diatoms <i>Dactyliosolen fragilissimus</i> and <i>Cerataulina pelagica</i> in the autumn phytoplankton of the South-Eastern Baltic in 2020–2021

Abstract

The mass development of diatom Dactyliosolen fragilissimus and Cerataulina pelagica, which are atypical of the South-East Baltic Sea water area, were registered along the Sambia peninsula coastline in the mid of October 2020. Both species were found in the coastal zone of the western and northern coast of the Sambia peninsula to a depth of 32 m, from the Baltic Strait to port Pionerskiy. In early November 2021 a mass vegetation of C. pelagica was recorded –both in the shallow coastal zone of the northern coast of the Sambia peninsula and in the deep water zone of the South-Eastern Baltic Sea. The biomass of this species reached 2.8 g/m3. Both diatom species were abundant within the entire Russian Exclusive Economic Zone. The prevailing hydrological situation during the study period probably facilitated penetration of the species into the study area by surface transport from the Arkona Basin.