Hidrológiai Közlöny 2010 (90. évfolyam)

6. szám - LI: Hidrobiológus Napok: „Új módszerek és eljárások a hidrobiológiában” Tihany, 2009. szeptember 30–október 2.

83 A O

.i 0,5 1.0§ 1'5O) S 2,0•05 2 2,53,03,54,0 imav ÍSS3LO 253X3 msm> CZ1 Egyéb 0,5 1,0 1.5 F 2,0 2,0 >2,5 3,0 3,0 3.5 4,0 Biomassza (mg/L) p 5 10 15 20 0 SI Egyéb ÍS2210 LEJv MP EEH3A Biomassza (mg/L) 20 40 60 80 Biomassza (mg/L) 5 10 Biomassza (mg/L) 5 10 15 20 25 30 Biomassza (mg/L) 12 3 4 4. ábra. A főbb kodonok vertikális eloszlása A) május, B) június, C) július, D) augusztus, E) szeptember, F) október, G) december Vertical distribution of phytoplankton in a shallow oxbow Krasznai E., Borics G., Várbíró G., Deák Cs., Abonyi A., Tóthmérész B., Padisák J. Abstract The stability of the stratification and its impact on the vertical distribution of phytoplankton were investigated in a shallow oxbow in East-Hungary in 2007. The oxbow was characterised by stable stratification from May to late August. In late spring, phytoplankton was dominated by L

0/X3/MP/Y assemblages. In June and July, Lo/Sl coda were significant. In July a huge cyanobacterial bloom developed in the epilimnion caused by Limnothrix redekei

, while hypolinmion was dominated by the sulfur bacteria, Thiopedia rosea. From September, when mixing started, Sl/MP/Y coda were dominating. The oxbow was partially mixed in December, when A/L

0 coda were significant. Our results showed that in case of shallow oxbows the thermal stratification can be consistent from month to month in the growing season. Keywords: oxbow, stratification, functional groups.