Management of fish communities and its impacts on the lower trophic levels in shallow ecosystems in Hungary

• Published in: Hydrobiologia Vol. 506-509; no. 1-3; pp. 489 - 496
• Main Authors: Tátrai, István, Mátyás, Kálmán, Korponai, János, Paulovits, Gábor, Pomogyi, Piroska, Pekár, Ferenc
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Nature B.V 15.11.2003
• Subjects: Biomass; Chlorophyll; Cladocera; Community structure; Cyprinidae; Ecosystems; Fish; Freshwater; Lakes; Phytoplankton; Plankton; Ponds; Trophic levels; Hungary
• ISSN: 0018-8158; 1573-5117
• DOI: 10.1023/B:HYDR.0000008616.52608.51

Issue Title: Shallow Lakes 2002 This study shows that multiyear control of phytoplankton by grazing is possible in otherwise cladoceran dominated ecosystems at low cyprinid fish stocks (around 100 kg ha^sup -1^) and where piscivore populations, following manipulation measure, can be sustained at the biomass ratio >15%. This reinforces the idea that fish community structure may be a key to the stability of trophic structures that suppress phytoplankton in ecosystems where otherwise cladoceran plankton dominates. Experimental ponds with lower fish biomass (<150-kg ha^sup -1^) had less chlorophyll-a concentration per unit TP than those with higher fish biomass. Regressions of chlorophyll-a vs. total phosphorus in the ponds and Major Lake were not significant at lower fish biomass. However, at higher fish biomass the bottom-up processes dominated across all types of ecosystems studied and the regressions were significant. The biomass of herbivorous Cladocera was significantly higher in ponds with a higher percentage of piscivores.[PUBLICATION ABSTRACT]