Beitrag
Changes in the chironomid communities in Lake Geneva in relation with eutrophication, over a period of 60 years
Lods-Crozet, Brigitte; Lachavanne, Jean-Bernard
Archiv für Hydrobiologie Volume 130 Number 4 (1994), p. 453 - 471
59 Literaturangaben
veröffentlicht: Jun 23, 1994
DOI: 10.1127/archiv-hydrobiol/130/1994/453
ArtNo. ESP141013004004, Preis: 29.00 €
Abstract
Chironomid larvae were collected by different authors, between 1958 and 1985 in Lake Geneva, from the shore to the deepest part of the lake (310 m). Their bathymetric distribution is described. Littoral and sublittoral communities were dominated by Procladius, Cricotopus sylvestris, Chironomus, Cryptochironomus, Dicrotendipes, Polypedilum nubeculosum and Cladotanytarsus mancus group. The profundal zone (> 50 m) was only colonized by a few taxa such as Macropelopia, Sergentia coracina, Micropsectra and Tanytarsus lugens/gregarius gr., taxa characteristic of deep-lake fauna. During the period 1958-63, some chironomid larvae were found even in the deepest part of the lake (310 m), whereas in 1978 and after, they were rarely observed and not below 290 m. Changes in the trophic level of the lake are described by the profundal communities according to Saether's (1979) trophic classification. The results confirm those of Lang (1984) and the assumption that the communities have changed in 10 years from an ξ-oligotrophic (1958) to a θ-mesotrophic (1978) chironomid community, thus reflecting the eutrophication of the lake. The importance of dissolved oxygen as a limiting factor in the bathymetric distribution of profundal chironomid communities is discussed.
Schlagworte
chironomid • larvae • profundal zone • bathymetric • Lake Geneva