0150578 - HBU-Z 20033065 RIV NL eng J - Článek v odborném periodiku
Hladík, Milan - Kubečka, Jan
Fish migration between a temperate reservoir and its main tributary.
Hydrobiologia. Roč. 504, - (2003), s. 251-266. ISSN 0018-8158. E-ISSN 1573-5117.
[Reservoir Limnology and Water Quality /4./. České Budějovice, 12.08.2002-16.08.2002]
Grant CEP: GA ČR GA206/02/0520; GA AV ČR IBS6017004; GA AV ČR IAA6017201; GA AV ČR KSK6005114
Výzkumný záměr: CEZ:AV0Z6017912
Klíčová slova: freshwater fish migration * reservoir-tributary ecotone * spawning
Kód oboru RIV: EH - Ekologie - společenstva
Impakt faktor: 0.720, rok: 2003

The fish migration between the Římov Reservoir and its only tributary, the Malše River (Czech Republic) was studied during seasons 2000-2002. Fish were captured by two specially constructed large fykenets (one for upstream and second one for downstream migrants). The tributary area was found as the place with high number of fish species (26 species and one hybrid). The most abundant fish species were bream Abramis brama (L.), bleak Alburnus alburnus (L.), roach Rutilus rutilus (L.), chub Leuciscus cephalus (L.), asp Aspius aspius (L.) and perch Perca fluviatilis (L.). The daily migration rate was highest during spawning migration of cyprinids and exceeded 1000 ind. per day. The succession of individual fish species during spawning period, the affinity of individual fish species to the tributary during spawning (obligatory spawners, generalist and fish spawning out of the tributary) and the importance of tributary zone for the development of fish population in whole reservoir are discussed.
Trvalý link: http://hdl.handle.net/11104/0048108

0150525 - HBU-Z 20033012 RIV DE eng J - Článek v odborném periodiku
Vašek, Mojmír - Kubečka, Jan - Seďa, Jaromír
Cyprinid predation on zooplankton along the longitudinal profile of a canyon-shaped reservoir.
Archiv für Hydrobiologie. Roč. 156, č. 4 (2003), s. 535-550. ISSN 0003-9136
Grant CEP: GA AV ČR IAA6017201; GA ČR GA206/02/0520
Grant ostatní: GA FRVŠ(CZ) 346/2000
Výzkumný záměr: CEZ:AV0Z6017912
Klíčová slova: fish predation * spatial heterogeneity * zooplankton
Kód oboru RIV: EH - Ekologie - společenstva
Impakt faktor: 1.261, rok: 2003

In the elongated Římov Reservoir, the diet composition of the three cyprinid species, as well as the fish and zooplankton distribution, were investigated at three sites along the longitudinal transect and during two months. The studied fish were roach (Rutilus rutilus), bream (Abramis brama) and bleak (Alburnus alburnus). Their diets along the entire longitudinal transect constituted almost exclusively crustacean zooplankton. Zooplankton density declined gradually downstream in the reservoir. A relatively higher total fish catch per unit effort was found at the upstream end and a decreasing size of Daphnia in zooplankton was observed towards upstream. Such results indicated stronger fish predation pressure in the upstream part of the reservoir during growing season. Moreover, lower diet overlaps within the cyprinid assemblage at the upstream end than within the cyprinid assemblages at the downstream locations suggested intense competition for food at the upstream end of the reservoir.
Trvalý link: http://hdl.handle.net/11104/0048057

0150412 - HBU-Z 20013153 RIV DE eng J - Článek v odborném periodiku
Herzig, A. - Kubečka, Jan
Fish biomass distribution in Neusiedler See (Austria): a hydroacoustic assessment of fish stock.
Verhandlungen Internationale Vereinigung für Theoretische und Angewandte Limnologie. Roč. 27, - (2001), s. 3660-3665. ISSN 0368-0770
Výzkumný záměr: CEZ:AV0Z6017912
Klíčová slova: lake * fish * biomass
Kód oboru RIV: BI - Akustika a kmity

Fish stock of large shallow lake (Neusiedlersee, South East Austria, average depth 1.2m, area 321 kmsup2/sup) was estimated by the scientific echosounder (Simrad EY 500, 120 KHz). The echosounder beam was used in horizontal dirrection and current survey may be the most extensive survey reported so far by this method. Open areas of the lake were relatively poor with the fish biomass ranging between 5 and 30 kg/ha. Much higher values were estimated for protected areas, western shore (protected from prevailing North-Western winds, fish biomass usually 100-200 kg/ha) and National park on the South end of the lake (more structured area with biomass ranging between 200 and 400 kg/ha). Areas with higher fish abundance and biomass corresponded to the regions with highest benthos and macrophyte occurrence.
Trvalý link: http://hdl.handle.net/11104/0047946

0150344 - HBU-Z 20013055 RIV DE eng J - Článek v odborném periodiku
Duncan, A. - Kubečka, Jan - Kett, S. - Hanna, N. - Skeldon, J.
Habitats of 0+ fry in an English lowland river.
Large Rivers. Roč. 12, 2-4 (2001), s. 153-171. ISSN 0945-3784
Výzkumný záměr: CEZ:AV0Z6017912
Klíčová slova: 0+ fish communities * lowland river * connected backwater
Kód oboru RIV: DA - Hydrologie a limnologie

The fish fry communities of the upper River Thames and a connected backwater were sampled quantitatively by a fry seine. The following main habitat types were samled: (1) clumps of channel plants at the water edge of the littoral vegetation and (2) deep erosion banks without plants. A third characteristic habitat in this river were (3) shallow organically-rich sandy-gravel beaches produced by watering cattle. The most species-rich and abundant fry communities were found in habitats with a plant cover and in the shallow beaches because they offered both a good food resource and protection from predation. Neither of these was available in the deep erosion banks where few 0+ fish occurred. No 0+ fry occupied the plantless sites in the backwater which were subject to high velocities. Roach was the predominant species in the abundant fry communities and its relative abundance explained differences in community structure estimated by Simpson's and Shannon Diversity Indices.
Trvalý link: http://hdl.handle.net/11104/0047882

0150321 - HBU-Z 20003028 RIV FR eng J - Článek v odborném periodiku
Kubečka, Jan - Frouzová, Jaroslava - Čech, Martin - Peterka, Jiří - Ketelaars, H. A. M. - Wagenwoort, J. - Papáček, M.
Hydroacoustic assessment of pelagic stages of freshwater insects.
Aquatic Living Resources. Roč. 13, č. 13 (2000), s. 361-366. ISSN 0990-7440. E-ISSN 1765-2952
Grant CEP: GA AV ČR IAA6017901; GA ČR GA206/97/0072; GA ČR GA206/99/0405
Výzkumný záměr: CEZ:MSM 123100004
Kód oboru RIV: DA - Hydrologie a limnologie
Impakt faktor: 0.942, rok: 2000

Two independent surveys showed that aquatic insects can generate echoes comparable with the echoes of small fish. In the open water of two fishless mountain acidic waters of the Czech Republic, a very distinct population of well defined single targets resembling fish (target strength -66 to -50 dB at 120 kHz) was discovered. These targets were found in the depth range of 5-7 m during the day (June-July 1997). At night, most targets were recorded by horizontal beaming (depth < 3m). Towing of ichthyoplankton nets in these horizons revealed the presence of water bugs - Corixidae (Heteroptera), mostly genus Glenocorisa. Target strengths of water bugs was also verified by direct observations in an experimental tank, where it was possible to track side, dorsal and ventral aspects. In three Dutch reservoirs, Petrusplaat, Honderd-en-Dertig and De Gijster the targets of ascending dipteran pupae (Chironomidae, Procladius signatus) with target strength of -74 to -65 dB were observed by vertical beaming.
Trvalý link: http://hdl.handle.net/11104/0047859