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The fluorescence assay of aminopeptidase activity as an alterantive indicator of water quality?
Vrba, Jaroslav ; Svoboda, J. ; Fuksa, J. K.
Recent water quality/pollution control uses standard chemical, biological or microbiological indicators that provide information on water status with a delay of several days. Though they characterise direct impact of released compounds on water quality in a recipient, they do not well reflect consequent reaction of the ecosystem on increased pollution. Following the Water Framework Directive 2000/60/EC we focused on such alternative microbial indicators that would allow for instant evaluation of ecological status of running waters and ongoing in-stream processes. Recently, activities of different extracellular enzymes have been suggested as indicators of both trophic status of lakes and organic or faecal pollution of streams. This contribution evaluates an indication potential of the extracellular aminopeptidase assay.
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Distribution and diversity of fish fry in different habitats of the Slapy reservoir
Kratochvíl, M. ; Kubečka, Jan ; Matěna, Josef
The fish fry assemblages of the Slapy reservoir (Czech Republic) were studied in May and June 2002. The aim of this study was to estimate diversity and distribution of fish fry in three habitats – epipelagic (depth 0 – 4 m), bathypelagic (depth 10 – 16 m) and littoral areas. Percids were present both in epipelagic and bathypelagic areas, while cyprinids preferred living in upper layers of the water column. During the dusk, bathypelagic fish started migration towards surface layers, throughout the dawn they returned back to the deeper layers. The highest densities of fish fry were observed in epipelagic zone during nighttime. Perch was revealed as the dominant fry species in Slapy reservoir, pikeperch was also abundant in the open water. Both during day and night, perch was usually the most common species in all habitats, cyprinids were most abundant in the littoral zone in May, only.
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Effect of catastrophic flooding on the composition of the fish stock of the Římov reservoir
Kubečka, Jan ; Prchalová, Marie ; Hladík, Milan ; Vašek, Mojmír ; Říha, Milan
In 2002, great flood occurred in the Římov reservoir. Fish stock of the reservoir was sampled before and after the flood by night beach seinings, pelagic and benthic gillnets, traps and electrofishing of spawning shoals of common bream. The fluctuations of most species (roach, bream and their hybrid, perch, ruffe, bleak, white bream, asp, pikeperch, eel, catfish) were random and can be attributed to interhabitat migrations rather to the effect of flooding. The share of certain species (carp, tench, goldfish, trout, dace, gudgeon) increased as they were flushed from ponds and fishing grounds in the catchment. Increased share of these species was detected in the spring 2003, while during August, the share of flooded fish decreased near to the usual level. The ‘climax’ cyprinid dominated fish stock proved itself to be very resistant to the extreme flood.
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Sedimenty jako dynamická zásoba fosforu ve stratifikované nádrži
Borovec, Jakub ; Hejzlar, Josef ; Brzáková, Martina ; Jan, J.
The ecosystem of the small, dimictic, and hypertrophic reservoir (Jordan Reservoir, Czech Republic) was studied from March 2001 till March 2004 to evaluate rates at selected pathways in the P-cycle. The rates were inferred from measurement of P mass-balance, sedimentation of seston, and P-release from sediments. A shift between seasonal changes of inflow and outflow P concentrations caused by P accumulation in the hypolimnion and the sediments was demonstrated. An important amount of P was temporally retained at the sediment surface during the summer stratification but a part of it was released back to water during the autumnal mixing, due to pore water „flushing out” and fast organic matter decomposition.
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Modelování hydrodynamiky a kvality vody v dimiktické nádrži – nádrž Jordán, Česká republika
Hejzlar, Josef ; Jarošík, Jiří ; Borovec, Jakub ; Růžička, Martin
The two-dimensional, dynamic model CE-QUAL-W2 was used to model water quality of a small, highly eutrophic reservoir with intensive nutrient cycling between the water column and bottom sediment. The model was calibrated and evaluated for a 4-year, hydrologically variable period and used in a scenario simulation study to analyse effects of the changing external and internal phosphorus loading and depth of outflow to trophic conditions and water quality. The reservoir hydrodynamics were simulated with good precision in all parts of the seasonal cycle and during the whole period. Water quality and nutrient cycling could be calibrated and simulated with satisfactory results for individual years, however, an extrapolation of model to conditions with different nutrient loading was problematic. It spite of this partial limitation, the model was found appropriate for water quality evaluation and prediction in Jordan Reservoir.
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