Benthic diatoms of the southern coast of the Gulf of Finland (Lebyazhiy nature reserve)

Abstract

The benthic diatom flora of the southern coast of the Gulf of Finland (Lebyazhiy nature reserve) was studied. Species and varieties of diatoms were identifi ed based on their morphological features using light and electron microscopy. A total of 154 diatom taxa were identified, including several varieties. They are centric diatoms, araphid diatoms, monoraphid diatoms, symmetrical biraphid diatoms, asymmetrical biraphid diatoms. Most of them belongs to symmetrical biraphid diatoms but the most abundant are araphid diatoms. An assemblage composed of epipelic, epiphytic, epilitic, epipsammic and planktonic species have been found. Salinity was the important factor that determined the composition of diatoms. The diatom community contains freshwater, freshwater-brackish, brackish and marine taxa. The diatom assemblage included taxa (58%) widely distributed in the Baltic Sea. Nine species are recorded for the fi rst time in the Gulf of Finland, twelve species — in the Baltic Sea. This first comprehensive checklist of the diatoms in the study area compiled with an account of earlier published works and with an account of modern nomenclature changes is presented. Refs 32. Figs 2.