Benthic diatoms species richness at Dvuyakornaya Bay and other coastal sites of Crimea (the Black Sea) under various environments

Abstract

First-time research of the pristine water area of Dvuyakornaya Bay (South-Eastern Crimea, Black Sea) revealed high taxonomic richness of benthic diatoms (Bacillariophyta). Altogether, 304 species, 78 genera, 37 families and 20 orders were identified. Among them 68 newly-found species for the Black Sea were marked. The largest species number was marked in the genera Navicula (41 species), Nitzschia (29), Amphora (25), Cocconeis (20), Diploneis (16), Lyrella, Fallacia and Planothidium (10 species respectively). Inter-regional comparative analysis of diatom species richness was carried out using Bray-Curtis similarity coefficient and Venn diagrams. Diatom taxocene of Dvuyakornaya Bay (DB) was compared with Bacillariophyta flora from several Crimean coastal sites under different level of anthropogenic impact, i.e. relatively pristine water area near Cape Fiolent (CF) and heavy polluted Sevastopol Bay (SB) and Balaklava Bay (BB). The highest similarity of species composition (58%) was registered between intact biotopes (DB vs CF) and between heavy polluted water areas (SB vs BB), despite the geographical remoteness of the compared areas, differences in hydrological-hydrochemical conditions and in bottom substrates patterns. The lowest species similarity of diatom taxocenes was observed between SB and CF (32.3%) and between SB and DB (36.5%). It was concluded that the content of technogenic pollutants (trace metals, PCBs, PAHs and pesticides) in the bottom sediments, as well as the heterogeneity of microbiotopes are represent major factors influencing on the species composition of benthic Bacillariophyta in the investigated coastal water areas.

New Records of Diatoms (Bacillariales, Rhopalodiales & Surirellales) with ultrastructure details from the Black Sea Coast of Turkey

“…In the Aegean Sea coasts, common species were Campylodiscus scalaris, Epithemia guettingeri, Nitzschia amabilis, N. liebethruthii, N. inconspicua (Louvrou, 2007). Similarly, species numbers were higher in the lower saline waters of the Black Sea (Nevrova & Petrov, 2019). While marine diatom ecology has been given less attention, and limited data is present on the autecology of the species, in Campylodiscus scalaris an example which was described from the South African coasts, our findings in the Black Sea expanded the biogeographic range of the species in lower saline waters of the Black Sea.…”

“…Amongst the species, several of them were formerly reported from the Black Sea, including Cylindrotheca closterium, Nitzschia liebethruthii, N. inconspicua, N. liebethruthii, Psammodictyon panduriforme var. continuum, Surirella fastuosa, Tryblionella compressa and T. coarctata (Nevrova, 2016;Nevrova & Petrov, 2019). In the Aegean Sea coasts, common species were Campylodiscus scalaris, Epithemia guettingeri, Nitzschia amabilis, N. liebethruthii, N. inconspicua (Louvrou, 2007).…”

“…Recently benthic diatom communities in the Black Sea have become intensively studied in the north due to observing the diatoms' adaptation to environmental changes. On the other hand, Black Sea flora consisted mostly of the presented taxa, particularly in the Northern Black Sea (Petrov & Nevrova, 2007;Nevrova & Petrov, 2019) showed the high biodiversity presence of Bacillariaceae. Although diatom biodiversity of diatoms from the Turkish coasts has not been studied in depth before, some of the previous studies (Baytut & Gönülol, 2016;Kaleli et al, 2017) devoted to benthic diatom flora found that biodiversity could be even higher than that which has been investigated so far on the Black Sea coasts.…”

“…According to some authors, certain environmental parameters (e.g., salinity, temperature) are necessary to identify the taxa. Ultrastructural studies can contribute to the knowledge of the diatom structure in the observed area, even though data is lacking in the Black Sea apart from a few studies in the north (Witkowski, Kulikovskiy, Nevrova, Lange-Bertalot & Gogorev, 2010;Nevrova et al, 2013;Nevrova & Petrov, 2019). When compared to the illustrated fine structure of the freshwater diatoms, marine diatoms have slightly less available data.…”

Checklist of marine diatoms from the Turkish coastal waters with updated nomenclature

“…mostly in the Black Sea coasts (Soylu et al, 2011;Baytut et al, 2016). It might be related to the freshwater inputs e.g., two major rivers; Kızılırmak and Yeşilırmak, where relatively lower salinity might be a factor to detect the freshwater diatoms in the Black Sea and yielded favourable conditions for the taxa to survive; however, it was observed that marine taxa could dominate in these coastal waters (Kaleli et al, 2017) as well as in the northern Black Sea coasts (Nevrova and Petrov, 2019). Many taxa reported in the list have no documentation or sufficient data on geographical distribution.…”