Ábrahám Levente: Biomonitoring a Dráva folyó magyarországi szakasza mentén 2000-2004 - Natura Somogyiensis 7. (Kaposvár, 2005)

Héra, Zoltán: On experiences in monitoring molluscs (Mollusca) in the area of Duna-DrávanNational Park - A Duna-Dráva Nemzeti Park térségében végzett puhatestű (Mollusca) monitoring tapasztalatai

Natura Somogyiensis 7 25-34 Kaposvár, 2005 On experiences in monitoring molluscs (Mollusca) in the area of Duna-Dráva National Park HÉRA ZOLTÁN Toldi Secundary Grammer School, H-7400 Kaposvár Tamási Áron str. 9. Hungary; e-mail: heraz65@msn.com HÉRA Z.: On experiences in monitoring molluscs (Mollusca) in the area of Duna-Dráva National Park. Abstract: Researching Mollusc fauna forms part of biomonitoring investigation in the Duna-Dráva National Park aiming study of protected and invasive species, water and terrestrial fauna. As a result of this investigation, the occurance of new protected species Vertigo angustior Jeffreys, 1830, Vertigo moulinsiana Dupuy, 1840 or their accurate habitat in this area have become known. Recording frequency circumstances of basic fauna and expansion of newly introduced species Potamopyrgus antipodarum (Gray, 1843), Arion lusitanicus Mabille, 1868, Anodonta woodiana (Lea, 1834) - is repeated every year. Keywords: protected molluscs, invasive molluscs, biomonitoring Introduction Due to the coordination of DDNP started in 2000, biomonitoring investigation began in the river Dráva. 22 sampling sites were marked between Ortilos and Felsőszentmárton. The sampling sites are 5-50 m

2 in size. Investigations were implemented in the following projects: 1. protected species, 2. invasive species, 3. monitoring water fauna, 4. monitoring terrestrial fauna. According to literature data (VARGA and UHERKOVICH 1998) the number of terrestrial and water Gastropods found in the areas along the Dráva is estimated to be about 100, out of which 90 species were identified during monitoring investigation. An average of 9000 individuals are entered in the database of the national park. Material and method 1. Sampling applied in the project of protected species Theodoxus danubialis, Amphimelania holandri - underwater counts of individuals in 10 sites (50x50 cm quadrates) twice a year. Pomatias elegáns, Ena montana - placing artificial hiding - place quadrate (5x1 m

2 surface covered with corrugated cardboard), twice a year and checkings after a month. Cepaea hortensis - study of its absence by single individual sampling. Helix pomatia - single individual sampling at an even pace for 20 minutes. Unio crassus - sweep-netting the riverbed with a 0.5 wide scraping net of 1mm meshes and along a 2 m stretch, five times.