The occurrence of brook lamprey [Lampetra planeri (BLOCH, 1784)] in Novohradské Mountains (South Bohemia, Czech Republic)
Matěnová, V.; Matěna, Josef
2003 - Czech The occurrence of brook lamprey was studied in Novohradské Mountains during 1999-2003. Altogether 83 profiles on 22 second to fourth order brooks and streams were fished by means of electroshockers. The area investigated can be divided into three basins. Significant differences were found between basins with respect to frequency of occurrence and density of lamprey populations. The highest frequency of occurrence was in the Stropnice River basin (6 streams of 8 investigated, average abundance 2598 inds ha-1), followed by the Malše River (4 streams of 8 investigated, average abundance 844 inds ha-1). In the Černá Rivulet basin only in 1 of 6 streams investigated the brook lamprey was found at very low densities - 28 inds ha-1 on average. The lamprey contributed substantially to the whole forming more than 50 Keywords: lamprey populations; abundance; South Bohemia; povodí; kmitočet Available at various institutes of the ASCR The occurrence of brook lamprey [Lampetra planeri (BLOCH, 1784)] in Novohradské Mountains (South Bohemia, Czech Republic)

The occurrence of brook lamprey was studied in Novohradské Mountains during 1999-2003. Altogether 83 profiles on 22 second to fourth order brooks and streams were fished by means of electroshockers. ...

Matěnová, V.; Matěna, Josef
Hydrobiologický ústav, 2003

Causes of long-term increase in concentrations of dissolved organic matter in Římov Reservoir
Hejzlar, Josef; Kopáček, Jiří; Porcal, Petr; Haider, Z.
2003 - Czech The concentration of dissolved organic matter (DOM) has increased in Rimov Reservoir since the late 1980s. Two main reasons were revealed for this increase: (i) an increase of DOM concentrations in the reservoir inflow that has been caused by more frequent summer high-runoff and DOM-rich events, and (ii) an increase in temperature and surface runoff volumes during winter months. The effects of decreasing atmospheric acid deposition and changes in farmland practices in the catchment also cannot be excluded as the other sources for the increase. Byl prokázán nárůst koncentrace organických látek (DOM) v nádrži Římov od konce 80. let až do současnosti. Jako hlavní příčiny nárůstu byly identifikovány: (i) vzrůst koncentrace organických látek v přítoku do nádrže, spojený se změnou hydrologie odtoku z povodí, která se projevovala zvýšenou četností letních přívalových přítoků bohatých na DOM a (ii) zvyšování teploty, zejména v zimních měsících. Nelze vyloučit ani možné vlivy poklesu kyselé atmosférické depozice a změny v zemědělském hospodaření v povodí. Keywords: DOM; catchment hydrology; interflow; obytné budovy; povrchový odtok Available at various institutes of the ASCR Causes of long-term increase in concentrations of dissolved organic matter in Římov Reservoir

The concentration of dissolved organic matter (DOM) has increased in Rimov Reservoir since the late 1980s. Two main reasons were revealed for this increase: (i) an increase of DOM concentrations in ...

Hejzlar, Josef; Kopáček, Jiří; Porcal, Petr; Haider, Z.
Hydrobiologický ústav, 2003

Phosphorus release from sediments - a comparison of methods
Borovec, Jakub; Brzáková, Martina
2003 - Czech Phosphorus release rates from sediments were compared at two localities of Jordan Reservoir (Czech Republic) during the year. The release rates measured by incubation method were an order of magnitude higher comparing to the release rates calculated from phosphorus gradient in pore-water. A rapid decomposition of freshly settled seston at the sediment surface or just above the sediment was suggested to explain the differences. Byly srovnány rychlosti uvolňování fosforu ze sedimentů měřené v průběhu roku na dvou lokalitách v ÚN Jordán. Rychlosti uvolňování měřené inkubační metodou byly o řád vyšší ve srovnání s rychlostmi počítanými ze změn koncentrací fosforu v pórové vodě sedimentů. Rozdíl mezi oběma metodami byl vysvětlen možným rychlým rozkladem čerstvě sedimentovaného sestonu na povrchu nebo těsně nad povrchem sedimentů. Keywords: flux; peeper; sedimentation; sedimentace Available at various institutes of the ASCR Phosphorus release from sediments - a comparison of methods

Phosphorus release rates from sediments were compared at two localities of Jordan Reservoir (Czech Republic) during the year. The release rates measured by incubation method were an order of magnitude ...

Borovec, Jakub; Brzáková, Martina
Hydrobiologický ústav, 2003

New records of Chironomus MEIGEN species (Diptera, Chironomidae) in the Novohradské Mountains (South Bohemia)
Matěna, Josef; Matěnová, V.
2003 - Czech C. longistylus Goetghebuer and C. sp. South Bohemia were found as new species for the Czech Republic. Karyotype of the new species is presented together with preliminary mapping of chromosomal arms A, C, D, E, F. C. cingulatus, melanescens, nuditarsis, uliginosus and C. (Camptochironomus) palidivittatus are recorded for the first time from Novohradské Mountains. Notes about distribution and ecology of these species are given. C. longistylus Goetghebuer a C. sp. South Bohemia byly nalezeny jako nové druhy pro Českou republiku. Je prezentován karyotyp nového druhu spolu s předběžným zmapováním chromosomálních ramen A, C, D, E, F. C. cingulatus, melanescens, nuditarsis, uliginosus a C. (Camptochironomus) palidivittatus byly zjištěny poprvé na území Novohradských hor. Jsou uvedeny poznámky o rozšíření a ekologii těchto druhů. Keywords: macrozoobenthos; faunistics; cytotaxonomy; druhy; hory Available at various institutes of the ASCR New records of Chironomus MEIGEN species (Diptera, Chironomidae) in the Novohradské Mountains (South Bohemia)

C. longistylus Goetghebuer and C. sp. South Bohemia were found as new species for the Czech Republic. Karyotype of the new species is presented together with preliminary mapping of chromosomal arms A, ...

Matěna, Josef; Matěnová, V.
Hydrobiologický ústav, 2003

Use of genetic probes to study bacterioplankton of Římov reservoir
Horňák, K.; Mašín, M.; Nedoma, Jiří; Šimek, Karel
2002 - Czech Keywords: bacterial community composition; genetic probes; bacterioplankton; průzkumy; vodárenské nádrže Available at various institutes of the ASCR Use of genetic probes to study bacterioplankton of Římov reservoir

Horňák, K.; Mašín, M.; Nedoma, Jiří; Šimek, Karel
Hydrobiologický ústav, 2002

Recovery of the Jordán reservoir from eutrophication: nutrient sources and retention in the catchment
Hejzlar, Josef; Borovec, Jakub; Porcal, Petr; Žaloudík, Jiří; Porcalová, P.
2002 - Czech Keywords: reservoir; eutrophication; catchment; zdroje; nádrže Available at various institutes of the ASCR Recovery of the Jordán reservoir from eutrophication: nutrient sources and retention in the catchment

Hejzlar, Josef; Borovec, Jakub; Porcal, Petr; Žaloudík, Jiří; Porcalová, P.
Hydrobiologický ústav, 2002

Indicators of fecal and organic pollution in reservoirs and their inflows
Straškrábová, Viera; Hartman, Petr; Marhanová, K.
2002 - Czech Keywords: fecal indicators; organic pollution; reservoir; údolní nádrže; indikátory Available at various institutes of the ASCR Indicators of fecal and organic pollution in reservoirs and their inflows

Straškrábová, Viera; Hartman, Petr; Marhanová, K.
Hydrobiologický ústav, 2002

The diet of larval and juvenile pikeperch (.i.Stizostedion lucioperca./i.)(L.)), comparative study of fishponds and a reservoir
Peterka, Jiří; Matěna, Josef; Lipka, J.
2002 - English Diet of larval and juvenile pikeperch (.i.S. lucioperca./i.) reared in ponds was investigated and compared with the diet of pikeperch from a reservoir. Numbers of rotifers were found low in the diet of pikeperch larvae in fishponds and they were soonreplaced by nauplii of cyclopoid copepods. .i.Daphnia./i. spp. were consumed from the onset of exogenous feeding. Another smaller cladoceran .i.Bosmina./i. longirostris did not contribute to the diet significantly. In the reservoir, rotifers were not found in the diet of pikeperch larvae. Dominant food items were nauplii and 1st copepodite instar of .i.Eudiaptomus gracilis./i. and .i.Cyclops./i. spp. .i.Daphnia galeata./i. and to a lesser extent .i.Diaphanosoma brachyurum./i. appeared in the pikeperch diet at a length of about 10 mm. A shift towards larger prey, especially .i.Leptodora kindtii./i., could be recognised in pikeperch at a length of 20 mm. Growth of pikeperch was found faster in nursing ponds than in the reservoir. Keywords: diet composition; food selection; growth; růst Available at various institutes of the ASCR The diet of larval and juvenile pikeperch (.i.Stizostedion lucioperca./i.)(L.)), comparative study of fishponds and a reservoir

Diet of larval and juvenile pikeperch (.i.S. lucioperca./i.) reared in ponds was investigated and compared with the diet of pikeperch from a reservoir. Numbers of rotifers were found low in the diet ...

Peterka, Jiří; Matěna, Josef; Lipka, J.
Hydrobiologický ústav, 2002

The genus .i.Chironomus./i. MEIGEN (Diptera, Chironomidae) in the Novohradské Mountains (South Bohemia)
Matěna, Josef; Matěnová, V.
2002 - Czech The occurrence of Chironomus species was investigated in Novohradské Mountains during 1999-2001. Fishponds, running waters and small standing waters of both permanent and astatic characters were included. Larvae were identified cytotaxonomically according to polytene chromosomes of salivary glands. Ch. annularius occurred more regularly in fishponds without fishery management, further species were found only in some of these habitats - Ch. balatonicus, bernensis, obtusidens, parathummi, plumosus, sp. - near muratensis and Ch. (C.) tentans. Organically polluted stretches of running waters were characterized by mass occurrence of Ch. riparius. Ch. luridus and Ch. melanotus were the dominant species of small permanent water bodies, further species found in these habitats were Ch. aberratus, commutatus, dorsalis, holomelas, piger and pseudothummi. Astatic habitats - rainpools were inhabited almost exclusively by Ch. dorsalis. Výskyt druhů rodu .i.Chironomus./i. byl sledován v Novohradských horách během let 1999-2001. Zahrnuty byly následující biotopy - rybníky, tekoucí vody a malé stojaté vody permanentního i astatického charakteru. Materiál byl determinován cytotaxonomickými metodami podle chromosomů slinných žláz. V rybnících bez rybářského obhospodařování se pravidelněji vyskytoval .i.Ch. annularius./i.. Ostatní druhy .i.Ch. balatonicus./i., .i.bernensis./i., .i.obtusidens./i., .i.parathummi./i., .i.plumosus./i., sp. - near .i.muratensis./i. a .i.Ch. (C.) tentans./i. byly nalézány pouze v určitých lokalitách. Organicky znečištěné úseky potoků byly charakteristické masovým výskytem druhu .i.Ch. riparius. Ch. luridus./i. a .i.melanotus./i. byly dominantními druhy malých permanentních stojatých vod, dále byly v těchto biotopech nalezeny druhy .i.Ch. aberratus./i., .i.commutatus./i., .i.dorsalis./i., .i.holomelas./i., .i.piger./i. a .i.pseudothumm./i.. Astatické biotopy obývá především .i.Ch. dorsalis./i.. Keywords: chironomus; macrozoobenthos; ecology; ekologie Available at various institutes of the ASCR The genus .i.Chironomus./i. MEIGEN (Diptera, Chironomidae) in the Novohradské Mountains (South Bohemia)

The occurrence of Chironomus species was investigated in Novohradské Mountains during 1999-2001. Fishponds, running waters and small standing waters of both permanent and astatic characters were ...

Matěna, Josef; Matěnová, V.
Hydrobiologický ústav, 2002

The possible reasons for the dissappearence of water-bloom from the surface of Slapy reservoir
Hrbáček, Jaroslav
2002 - Czech Keywords: reservoir; water-bloom; cianophyta; voda; nádrže Available at various institutes of the ASCR The possible reasons for the dissappearence of water-bloom from the surface of Slapy reservoir

Hrbáček, Jaroslav
Hydrobiologický ústav, 2002