Az Alpokalja természeti képe közlemények 12. (Praenorica - Folia historico-naturalia Szombathely, 2012)

VIZKELETY Éva - VARGA Erika: Algológiai vizsgálatok a Kis-Balaton térségében - Abstract

ALGOLÓGIAI VIZSGÁLATOK A KIS-BALATON TÉRSÉGÉBEN VIZKELETY Éva

1 - VARGA Erika

2 Algological investigations of the Kis-Balaton — The range of algae and concentration of chlorophyll-a in Stages I and II of the Kis-Balaton Water Protection System were followed from the outset with a view to learning how the waters of the Zala become standing water, about the eutrophication processes there, and about the system's effect on water quality in the Keszthely Bay (Keszthelyi-öböl) of Lake Balaton. The planktonic and filamentous algae of the still uncompleted system were examined over three periods (1985-88, 1991-1994 and 1999-2000). Under Stage I, the waters of the river Zala in the upper part of the storage system turned over one year into standing water, and in 1987 developed a strong presence of planktonic lake algae as far as the outflow. The sampling sites are shown on the sketch map and list of taxa found in Table 1.1. A total of 601 taxa were found in four years, of which diatoms dominated at the start of the storage period. In 1987, cyanobacteria caused algal blooming, which also pointed to very high concentrations of chlorophyll-a. In the second sampling period (1991-1994), we examined along with the plankton samples from close to the surface the alga groups found as a coating on water weed. The altogether 318 taxa found over the four years are listed in Table 2.1. The largest number of species (61 taxa) was found in alga coating of Ceratophyllum submersion in the Vörsi-víz. Compared with those of Stage I, the 118 taxa found included a higher proportion of diatomic algae and cyanobacteria. The major factor in the area examined was the quantity of weed and the algae coating it, rather than the planktonic algae. In the third period (1999-2000), we examined the planktonic algae and the alga coating of weed (Ceratophyllum demersum, Straloites aloides) in the submersed Zalavári-víz, where 280 taxa were identified. A detailed list appears in Table 3.1. The richest variety of species was found in the diatomic algae (genera Cymbella, Fragilaria, Gomphonema, Navicula and Nitzschia). The dominant cyanobacteria were Anabaena affinis, Lyngbya epiphytica, Lyngbya kiitzingii and Microcystis aeruginosa. The dominance relations can be seen in Figure 3.2. The most varied proved to be the coating of Ceratophyllum demersum collected in July 1999, where all the permanent taxa without exception were diatomic algae. 1 9700 Szombathely, Nádasdy Ferenc u. 14/a. Hungary vizeva@freemail.hu 2 2461 Tárnok, Egyenlőség utca 59/A. Hungary galeri76@freemail.hu