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Advisor(s)
Abstract(s)
The trends in zooplankton community were assessed in response to variations
in the trophic state and water quality, occurring in a shallow reservoir subjected to
seasonal water level fluctuations. Concomitantly, various ratios were calculated:
(1) the ratio of crustacean abundance to rotifer abundance (NCrust/NRot); (2) the
ratio of large (>10 μg) cladoceran abundance to total cladoceran group abundance
(NLarge-Clad/NClad); (3) The trophic state indices of rotifer abundance. The
reservoir’s hydrological cycle was characterized by three regimes. The maximum
level phase lasted from January to the beginning of June, the emptying phase
existed between mid-June to the beginning of September and the minimum level
phase lasted from mid-September to the beginning of the first autumn/winter
rain events. The highest values of total phosphorus, soluble reactive phosphorus,
nitrate, and ‘chlorophyll a’ were found during the minimum level phase. Rotifera
was the most abundant taxa, except in summer and in autumn where Cladocera
and Copepoda were dominant. Redundancy analysis (RDA) revealed a strong
contribution of temperature, chlorophyll a, soluble reactive phosphorous and total
phosphorous to the observed significant associations between the zooplankton
assemblage and environmental variables. The ordination space defined by the
first two RDA axes accounted for 84.2% of species–environment relations and
represented 25.4% of the variation in species data. The ratio NCrust/NRot showed
the higher role of rotifers in the zooplankton community in the low level phase;
the ratio NLargeClad/NClad showed a decreasing trend in the abundance of largesized
cladocerans for the same mentioned period. Therefore, these indices seem
suitable to be used in reservoir management as rapid tools to evaluate the effects
of environmental disturbances to reservoir ecological integrity.
Description
Keywords
Seasonal water level fluctuations Zooplankton community Environmental indicator Shallow reservoir
Pedagogical Context
Citation
Geraldes, Ana Maria; Pasupuleti, Rajeev (2016). Zooplankton: a valuable environmental indicator tool in reservoir ecology management? In International Zoological Congress of “Grigore Antipa” Museum. Bucharest. ISSN 2457-9777