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The character of the Bódva by the composition of the fishassociations
37-44Views:96The Bódva is one of our rivers that flow outside the Hungarian borders and arrive to the country across the frontier.The Bódva is approximately 110 kilometres long, its upper course is mountaneous- like in its springfield in Slovakia and it reaches the Sajó by flowing among the lower hilly region. The river wall is ravine-like in more places, the river itself is devious, and the water basin is rather variable as in the underlay muddy segments and heavily shingly beds can also be found.
By its fish fauna and physico-chemical characteristics, the Bódva is such aliving water that-after Borne and others (Nowicki, Thienemann) river zone system- can be regarded as an almost uniform typical Barbel zone.
According to our research program (2001-2005) and literature resources we estimated the fish fauna of the Bódva on both the Slovakian and Hungarian course. From some four decades to the wide ecofaunistic examinations of the near past we surveyed the quondam and present fish species of the Bódva River. According to our survey some 40 species compose the recent fish fauna of this river.
In the fish fauna of the Bódva those fish species that presently own a tight ecospectrum, sensitive to the changes of the environment thus so called indicator species, can also be found just like the less sensitive, invasive, aggressively reproducing species. By examining the changes in the fishfauna, the complex of those biogen and abiogen processes that affect the river can be indicated well. It can be stated that the fishfauna of the Bódva is rather rich with a countrywide measure also, and maintain a lot of rare, regressive protected and worth while protection species.
In the last period of the construction, the racial and quantitive composition of the fishfauna of the upper course of the Bódva has changed significantly. Certain species (in the Hungarian course) has vanished almost totally or at least their number declined not ably. Among the vanishing species there are not only a few substantial, protected species of the fauna (e.g. Barbus pelononnesius petényi, Leucaspius delineatus, Zingel sterber, Barbatula barbatula), but the number of the once mass species also decreased appreciably (e.g. Rhodeus sericeus, Alburnoides bipunctatus, Cobitis elongatoides). With the above mentioned changes the number of other animals also decreased in the course that we examined (e.g. mussels, crabs). We examine the cause of these changes in the pollution of the river and according to that in the decrease of the food source and the negative changes of the physico-chemical parameters of the water. -
Anthropogenic effects on the fish fauna of River Hernád
21-27Views:150The fish fauna of the River Hernád was examined in 24 sampling sites in summer of 2014. As a result of the survey 31 species were detected of which eight are protected and three are highly protected by law in Hungary. The presence of the adventive tubenose goby (Proterorhinus semilunaris) in the estuary of the Hernád was observed for the first time by us. The most frequently detected species (with 100% frequency of occurrence, FO) were the chub (Squaliuscephalus), the bitterling (Rhodeusamarus) and the bleak (Alburnusalburnus), in addition the bleak was also the most dominant fish of the river. The hydraulic works have detrimental effect on the number of species and specimens and on the diversity of the fish fauna as well. The natural sections of the River Hernád have the most diverse fish assemblages.
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The fish fauna of the four rivulets of Börzsöny and Pilis mountains with together Gödöllő Hill
26-29Views:58Occurence of fish species were examined in four rivulets of Börzsöny, Pilis mountains and Gödöllő hill. Althogether 28 fish species were subject in research, of which 9 are protected.
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The changes of the ichthiofauna of river Berettyó and tributaries
106-112Views:62In 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. -
The system of faunacomponents conception and its application to qualify the degree of naturalness of fish assemblages
93-101Views:69The increase of species richness in communities of natural biogeographic regions in an anthropogenic way can be expressed as biogeographic pollution. Where there is contaminated fauna, one must investigate how this occured. I studied how the members of Hungarian fishfauna could be present resident and have managed to workout a so-called system of fauna component conception which is suitable for this requirement.
The expression of ’faunacomponent’ includes other expressions. That kind of species belong to a certain faunacomponent that reached the studied area in the same way. Species reached the studied area without an anthropogenious contribution are qualified as native fauna components. These kind of species are endemic species, occasional species and settlers. In contrast to native faunacomponents, some kind of human influence is always detectable in connection with the way reached the studied area by non-native species. Accordingly, group of non-native species includes directly or indirectly facilitated settlers, species that are introduced accidentally and those introduced intentionally. It is obvious that classifying a given species could be construed solely in connection with a certain area.
Applying Shannon diversity index I have initiated the assemblage natural index (ANI) in order to show a way how to use the system of faunacomponent conception in practice. ANI refers to the degree of naturalness of faunistical samples. If ANI > 1 it means there are not any non-native species and ANI < 1 it means there are some non-native species in the sample respectively. In the latter case ANI decreases proportionally with the number of non-native species and specimens. In that special case when only one specimen of only one non-native species can be found in the faunistical sample ANI = 1. -
Study of the Hejő brook watershed fish fauna
113-117Views:85Literature sources mention 18 fish species from the Hejő watershed. In order to learn more about the fauna, we studied the brook and its tributaries between 2003–2005. We detected a total of 32 fishspecies, 17 of which are new for the watershed. Most of these are native species (Rutilus rutilus, Leuciscus leuciscus, Leuciscus idus, Aspius aspius, Leucaspius delineatus, Gobio albipinnatus, Abramis bjoerkna, Abramis ballerus, Lota lota, Gymnocephalus cernuus, Sander lucioperca), but there are some adventive ones (Pseudorasbora parva, Carassius gibelio, Ameiurus melas, Lepomis gibbosus, Perccottus glenii) and a spontaneously immigrated species as well (Proterorhinus marmoratus).
Specific natural values of the watershed are the isolated population of minnow (Phoxinus phoxinus) in Kulcsárvölgyi Brook and the frequently occurring mudminnow (Umbra krameri) in the lower reach of Hejő Brook.