THE QUALITATIVE AND QUANTITATIVE CHARACTERISTICS OF THE BENTHIC DIATOMS NEAR KAZANTIP CAPE OF THE SEA OF AZOV

The qualitative and quantitative characteristics of the benthic diatoms near Kazantip Cape of the Sea of Azov

Larisa I. Ryabushko, Antanov V. Bondarenko

A.O. Kovalevsky Institute of Marine Biological Researches RAS, Sevastopol, RUSSIA

Abstract

This is the first record of species composition and quantitative characteristics of diatom communities on epiphyton and epilithon present near Kazantip Cape, including Kazantip Nature Reserve, located in the Crimean coast of the Sea of Azov for several periods between 2005 and 2014 (2005, 2006, 2008, 2010, 2011, 2014). Ninety-two taxa of Bacillariophyta were found, belonging to three classes, Сoscinodiscophyceae, Fragilariophyceae and Bacillariophyceae (9, 19 and 64 taxa, respectively), 18 orders, 26 families, 41 genera. 17 new species were indicated for the Sea of Azov. The number of species found varied seasonally: 12 diatoms were seen in winter, 54 in spring, 41 in summer and 45 in autumn. The epiphyton of macrophytes contained 79 taxa and showed spring maximal number of 52 species, and the epilithon – 44, with the autumn maximum of 25 species. Applied to diatoms from the two ecotopes, Czekanowski-Sörensen index of species similarity was estimated 52%. Quantitative analysis for two ecotopes of diatoms was carried out; the epiphyton abundance (N = 1171, 5·103 cells·cm-2) was largest in September (19.3°С) and the biomass (B = 0.142 mg·cm-2) in April (10°С) in 2006. For epilithon the maximum abundance and biomass were evaluated as N = 72.6·103 cells·cm-2 in April and B = 0,008 mg·cm-2 in September. Epiphyton diatoms showed the averages of minimal and maximal abundance 2.4 and 16 times larger than in the epilithon.

Keywords: Biomonitoring, diatoms, microphytobenthos, Crimean coast, Kazantip Cape, Kazantip Nature Reserve, the Sea of Azov