Author(s): Milinki, É., Fitala, Cs., Gere, G., Lakatos, Gy. & Andrikovics, S.
Title: Limnological conditions of Egerszalók reservoir and functional feeding guilds of aquatic birds
Year: 2008
Volume: 54
Pages: 61-74.
Abstract: The reservoir situated at the foot of the Bükk mountains was created in 1981 along the embankment of Laskó stream. it is currently used for sports, leisure, spare-time activities, and angling. The reservoir, created 22 years ago, was subject to serious contamination from Laskó stream until 1990. The operation of a goose farm established some years ago has now stopped, which accounts for an improvement in water quality. The water quality of Laskó stream changes in the reservoir: its salt, phosphorus, and nitrogen content tend to drop substantially. The improvement of water quality is especially apparent in reed beds of small size. The benthos, phyto- and zooplankton offer a rich food for the nekton and water birds. Cyanobacteria from Laskó stream are transported into the reservoir. The quality of water improved substantially after leaving the reservoir. After the goose farm was closed, the decrease in water levels caused problems for wildlife. Out of the 217 bird species documented, 97 species nest and 120 species migrate and wander in the vicinity of the reservoir. Notwithstanding the observed fluctuation of and decrease in water level, we have found 100 aquatic bird species along the largest water surface at the foot of the Bükk mountains. The reservoir is an essential feeding and resting location for groups of geese, mallards, and shorebirds. In the first years following the establishment of the reservoir, the migrating exporter-importer groups proved to be the first important functional feeding guilds of aquatic birds. During low water periods, the activity of shorebird species increased. recently, the ratio of the exporter-importer functional group has decreased. currently, decomposition-accelerators make up the majority of the avifauna. The ratio of nesting species within each guild is lower when compared to the avifauna of other reservoirs that were established earlier. The results of plankton, nekton, and water chemistry studies in evaluating the functional feeding guilds of aquatic birds show that these birds play a major role in the decomposition of organic matters contained in reservoirs. Thereby, aquatic birds contribute to the progress of natural succession processes.
Keywords: reservoir, phytoplankton, zooplankton, aquatic bird, feeding of birds
Journal: Acta Zoologica Academiae Scientiarum Hungaricae
Journal abbreviation:
ISSN: 1217-8837
Publisher: Hungarian Natural History Museum, Budapest
Editor(s): Bakonyi, G., Mahunka, S., Papp, L., Báldi, A., Csuzdi, Cs., Forró, L., Andrikovics, S. & Kerekes, J.
