Hidrológiai Közlöny, 2014 (94. évfolyam)

2014 / 5-6. különszám - LV. Hidrobiológus Napok előadásai

89

Szabó, A., Dévai, Gy., Tóthmérész, B., Horváth L., Bartalis, É. T. ben. Hidrológiai Közlöny 81: 465-467.

(2001): A Duna vízminőségének alakulása a komáromi szelvényAre the diatom ecological guilds suitable for the ecological status assessment in case of large rivers?

Szilágyi, Zs.', Szekeres, J.2, Csányi, B.2, Kiss, K. T.2, Tóth, B.2, Ács É.2

'ELTE Környezettudományi Doktori Iskola, 1117. Budapest, Pázmány P. s. 1/a;

2MTA ÖK Duna-kutató Intézet, 2131. Göd, Jávorka S. u. 14

Abstract: The diatoms have been grouped into ecological guilds mostly according to their attach strategy by Passy (2007). According to her

partition one of the guilds composes diatoms strongly attached to the surface of the substrate. This guild is favoured in nutrient-poor and high disturbance habitats. An other guild comprises diatoms with tall statures (e.g. by mucous stalked) erecting from the surface which is characteristics in nutrient-rich but low flow disturbance habitats. The third guild includes the motile species. It has been observed about this group that its proportion had increased along the nutrient gradient and decreased along the disturbance gradient. The planktic guild, as a new guild, has been introduced by Rimet & Bouchez (2012) because species belonging to this guild cannot attach to the surface, however, they are ubiquitously in the periphytic layer, sometimes in high proportion. Consequently, it has been revealed that guilds may become effective tools of ecological status assessment in the future.

Our aims were to investigate whether this method can challenge the ecological status assessment based on the diatom indices. We took samples at the same date at several sites (along cross-section) and at the same site (in the lithoral region) at more sampling dates, and studied what spatial and temporal heterogeneity the distribution of diatom ecological guilds display at Göd, in the Danube River. Though our results strenghtened the statements concerned the relationship between certain guilds and disturbance, they did not support a significant correlation between guilds and nutrient content, at least in case of such a large river as the Danube.

Keywords: diatom, guild, nutrient, disturbance, ecological status assessment