Do the long-term changes in zooplankton biomass indicate changes in fish stock?

0150585 - HBU-Z 20033072 RIV NL eng J - Journal Article
Hrbáček, Jaroslav - Brandl, Zdeněk - Straškraba, M.
Do the long-term changes in zooplankton biomass indicate changes in fish stock?
Hydrobiologia. Roč. 504, - (2003), s. 203-213. ISSN 0018-8158. E-ISSN 1573-5117.
[Reservoir Limnology and Water Quality /4./. České Budějovice, 12.08.2002-16.08.2002]
R&D Projects: GA ČR GA206/01/1113
Institutional research plan: CEZ:AV0Z6017912
Keywords : zooplankton biomass * long term changes * seasonal cycles
Subject RIV: EG - Zoology
Impact factor: 0.720, year: 2003

In the narrow and deep Slapy reservoir in years 1964 - 2001. The chlorophyll-a increased relatively more than total phosphorus concentration. The relative increase of the biomass of crustaceoplankton larger than 0.2 mm was in-between. The biomass of copepods nearly equals that of cladocerans. The percentage of cladocerans larger than 0.71 mm (%LCl) determined in the period 1985 - 2001 decreased. and indicates an increase fraction of small fish. In the course of the year there are two subsequent high values of %LCl in spring, the relation of which differs in different years, and are probably due to the spawning activities of two groups of fish probably percids and cyprinids. The low %LCl in autumn can be connected with the increasing size and therefore increased feeding activity of the yearlings in the period of decreasing biomass of zooplankton. The later mild increase can be connected to the decreased activity of cyprinids in the period of decreasing temperature.
Permanent Link: http://hdl.handle.net/11104/0048115