The Role of Fish Communities in Water Quality Management of a Large Shallow Lake

• Published in: International review of hydrobiology. Vol. 88; no. 5; pp. 498 - 507
• Main Authors: Tátrai, István, Paulovits, Gábor, Mátyás, Kálmán, Korponai, János
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.01.2003; WILEY‐VCH Verlag; Wiley-VCH
• Subjects: Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Conservation, protection and management of environment and wildlife; Environmental degradation: ecosystems survey and restoration; fish community; Fundamental and applied biological sciences. Psychology; Lake Balaton; lake management; trophic state; water quality; Hungary; Europe; Lake Balaton; Hungary, Balaton L; fish community; Water resource management; trophic state; Trophic status; Biomass; Eutrophication; Freshwater environment; Vertebrata; Fishery; Lake Balaton; lake management; Animal community; Pisces; Water quality; Water engineering; Ecological recovery; Stock
• ISSN: 1434-2944; 1522-2632
• DOI: 10.1002/iroh.200310663

Management measures of Lake Balaton such as wetland reconstruction at the main inflow to the lake along with the “unplanned” commercial fishery led to great changes in the density and biomass of fish populations. There was no significant difference in CPUE data between the two, eastern and western, basins. Biomass of total fish stock in Lake Balaton has decreased substantially, 2–3 times between 1991–1999, and ranges between 120–194 kg ha−1. Bottom‐up effects are more important than the top‐down effects due to the impact of internal nutrient load. Changes in the biomass and thus the activity of omnivorous fish in the lake lowered the intensity of various indirect effects and feedback mechanisms causing changes in the nutrient metabolism of the lake. Intensified fishery effort in Lake Balaton did not result in an increased stock of piscivores. The ratio of piscivores and omnivores remained at 5% during the whole study period. Despite this low piscivores to omnivores ratio, the water quality has improved in all basins.