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• Clay-pit systems fishfaunistic research in the Middle-Tisza

  81-92

  Ferenc Demény

  Views:

  87

  After the regulation of the Tisza River the chance of successful fish propagation lessened. Natural spooning places in the river almost completely disappeared. The fish have to find an adequate place for their propagation in the flood plain. The period of spooning usually coincides with flooding of the river. At this time fish try to find the flooded shallow places for spooning. These parts mostly include the clay-pits beside dams, which were accidentally established during construction of the dams. At this place the fry can find the necessary food. After decreasing the flood the fingerlings and a part of the spooners are trapped inclay-pits as these latter ones are not connected with the river bed. The clay-pits usually desiccate during the summer. The trapped fish population is eaten by water birds or harvested by the local man population. This means a great loss for reproduction of some fishspecies.
  Within the framework of the Regional Rehabilitation Program at Nagykörű, supported by the “WWF Hungary” and a “SAPARD project,” these clay-pits became connected with each other in a stretch of 5 km, and they were jointed to the Tisza by a collecting channel. The water level has been regulated by a flood gate so that the water enters the holes during the flood and is released later on in to the water bed.
  Data on fish were collected from the Nagykörű Whole System, from the Anyita pond and some isolated wholes in Szandaszöllős in 2004 and 2005. First of all fish fry and fingerling were collected and the success of spooning at these places was examined. Fry was harvested by a 60 x 80 cm sized lifting net of 2x3 mm mesh size. In other cases nets used by anglers for catching prey fishes was also used. Data were also collected from local fishermen who participated in saving the fry and fishing of Anyita pond.
  Of the several thousand caught fish specimens 28 species were identified, and among them 5 protected and 5 economically important species was found. Protected fishes were as follow: gudgeon (Gobio gobio), bitterling (Rhodeus sericeus amarus), weather fish (Misgurnus fossilis), spined loach (Cobitis elongatoides) and tubenosed goby (Proterorhinus marmoratus). Among economically important fishessamples of asp (Aspius aspius), carp (Cyprinus carpio), wels (Silurus glanis), pike (Esox lucius) and pikeperch (Sander lucioperca) were

• Causes of floods and flood protection in Subcarpathia

  72-75

  György Szuhányi

  Views:

  106

  Subcarpathia is one of the richest regions in surface waters in the Ukraine. Due to its geographical, relief and climatic conditions, it belongs to the active precipitation zone, where great floods frequently occur. As a result of many years of observation, it can be concluded that the interactions of many natural factors can lead to various floods in the catchment area of the river Tisza. These are mostly hydro-meteorological factors, which can lead to great floods with the characteristics of the formed flow. Human activity also significantly influences the occurance of floods: clearing, which can accelerate the process of the runoff, ploughing in the catchment area, which can lead to erosion and the utilisation of areas endangered by floods for various economic sectors.
  A series of questions arose in recent years regarding the formation of floods: what could be the causes of floods and what actions need to be made to prevent them. The evaluation of floods made us conclude that passive protection by using dams does not always ensure protection against floods as these were constructed in different times for different water levels. Many factors can affect the whole process which cannot be foreseen, therefore the development of new solutions and new technologies is necessary in flood protection.

• The changes of the ichthiofauna of river Berettyó and tributaries

  106-112

  Sándor Wilhelm

  Views:

  68

  In the spring and summer of 2005 I made ichtiologic research on the Barcau river in the area of Nusfalau – Saniob, as well as on its affluents.
  The results obtained were compared to those of the previous research performed on the Barcau river and partially on its affluents. Wenoticed a decrease of the fish lot both from the qualitative and the quantitative point of view, although the oil industry -the main source of pollution from this area – is in a temporary regress.
  Given the fact that upstream Suplacu-de-Barcau there are construction works for a dam and an artificiallakewhichwillinfluencetheriver fauna, the current research shall allow the repeat of the research and the comparison between the results, the identification of the effects of these works on the fish population from this area.

• Examinations connected with productive life in Hungarian Holstein Friesian populations

  32-39

  Attila Berta

  Béla Béri

  Views:

  113

  In Hungary, an intensive dairy population has developed in the last few decades as the result of upgrading to Holstein-Friesian. Intensive milk production, adjusted with housing and feeding, unfavorably affected secondary traits. The number of days between two calvings has increased remarkably and productive lifetime has decreased drastically. In the interest of profitable milk production, it is important that cows should be able to stay in the herd as long as possible, in order to have great lifetime productivity.
  The aim of this paper was to compare the production and pedigree of cows with eight or more lactations to cows which were culled after their first lactation.
  It can be stated that cows with longer herd lives produced more milk in their first lactation than those which were culled after their first lactation. When analyzing the pedigree effect of sires, this could not be proven, although some bulls, mainly of Hungarian origin, appeared at a higher frequency. In the analysis of the effect of dams, it was found that many of the offspring of the cows with longer herd lives had similarly great lifetime productivity. Correlation between herdlife and milk production quantity traits was found to be mild or stronger (r>0,60), while according to our analysis, there is no correlation between herdlife and milk production quality traits.