B. Papp szerk.: Studia Botanica Hungarica 32. 2001 (Budapest, 2001)
Buczkó, Krisztina, Reskóné Nagy, Mária , Vinogradova, Oxana N.; Kiss, Gábor: The occurence of Aphanothece stagnina (Spreng.) A. Br. in Lake Velence, Western Hungary
Studia bot. hung. 32, pp. 33-38, 2001 THE OCCURRENCE OF APHANOTHECE STAGNINA (SPRENG.) A. BR. IN LAKE VELENCE, WESTERN HUNGARY K. BUCZKO 1 , M. RESKÓNÉ-NAGY 2 , O. M. VINOGRADOV A 3 and G. KISS 2 'Department of Botany, Hungarian Natural History Museum H1476 Budapest, Pf. 222, Hungary; E-mail: buczko@bot.nhmus.hu 2 Central Danubian Environmental Protection Inspectorate H-8000 Székesfehérvár, Balatoni út 6, Hungary 3 Department of Spore Plants, N. G. Kholodny institute of Botany National Academy of Sciences of Ukraine Tereshchenkivska st. 2, 01601 Kyiv, Ukraine This report discusses the occurrence of the cyanobacterium species Aphanothece stagnina in Lake Velence. Besides the report summarised here, earlier occurrences of this species in Hungary are also presented in this article. Easily observed and well visible to the naked eye, this cyanobacterium was found in the sediments of "Lángi-" and "Német-tisztás" as well as in the phytoplankton of "Német-tisztás". It has probably lived in the lake for decades but only appears from time to time. Observations on its presence and occurrence have been a contribution to the assessment of the biological diversity of the mosaic-like Lake Velence. Although the sediment of the lake has been well studied from 1989, this species was only detected in 1997. Its multiplication and growing distribution may well be connected with the growing biological uniformity of the lake. Further studies of Aphanothece stagnina in the lake may be an ideal tool for the biomonitoring of this precious lake. Key words: Aphanothece stagnina, biomonitoring, cyanobacteria, Lake Velence INTRODUCTION In the summer of 1997, during the collection of sediment samples from Lake Velence for the Central Danubian Environmental Protection Inspectorate, we observed some peculiar, bean-sized, vivid green colonies of algae in the upper layers of the sediment near "Németh-tisztás". In August of the same year, while collecting algae around the so called "black-brown waters" of the lake, we again noticed larger, peanut- or walnut-sized pieces of mucilaginous colonies of brownish, greenish or sometimes yellowish colour. We paid special attention to this fact as such phenomenon had never been observed in the lake before. Some habitat characteristics of Lake Velence With its reeds, floating islands and open water surfaces of varying size, the lake, environmentally and conservation-wise, is one of the most remarkable and diverse natural landscapes of Hungary. Its surface totals at 24.5 km 2 , with a waterStudia Botanka Hungarica 32, 2001 Hungarian Natural History Museum, Budapest
