Phytoplankton from Las Tablas de Daimiel National Park. I. The Euglenophytes.

Abstract

Las Tablas de Daimiel is one of the most important wetlands in the Iberian Península. The increase of water contamination is producing obvious eutrophication. Monthly water samples were taken during 1996 and 1997 at five places - both from channels and shallow water (tablas). 18 taxa of Euglenophyta were found, two of them had been found before in Las Tablas de Daimiel (Astasia sp. and Euglena acus). Nine species are new records for this wetland (E. acilis, E. polymorpha, Lepocinclis ovum var. dimidio-minor. Phacus brevicaudatus, P. pyrum, P. skujae, Trachelomonas armata, T. abrupta and T. volvocinopsis); six species are new records for Spain (E. agilis var. piriformis, E. clara, E. oxyuris var. oxyuris, E. splendens, L. ovum var. globula, and P. brachykentron), and one species is new record for Europe (T. sculpta). The richness of Euglenophyta has increased conspicuously (1 species in 1975, 8 species in 1992-1993 and 18 species in 1996-1997). Moreover, the increasing water level from 19% has reduced the Euglenophyta density and these populations have simultaneously spread throughout the whole Park. The fluctuation seen in the Euglenophyte populations of the Tablas de Daimiel is not a response to contamination events, but the result of a the long eutrophication process endured by these wetlands.