Content of the Volume 25.
Waijandt, J.: Water quality of the Tisza river at Szolnok in the period 1970-1988.
Bodrogközy, Gy.: Hydroecological relations of littoral marsh meadow associations at Bodrogzug.
Harka, A.: Growth of different forms of carp (Cyprinus carpio L.) in Kisköre storage-lake.
Molnár, Gy.: On food composition of four heron species.
Bodrogközy, Gy.: Tisza-research conference XX (1989).
Waijandt, J. (1990): Water quality of the Tisza river at Szolnok in the period 1970-1988. – Tiscia 25, 3-13.
A process of water purification
is characteristic for the second biggest Hungarian river in the
stretch between the mouth of the Sajó river and Szolnok. Because
of the considerable water consumption of Szolnok for industrial
purposes and drinking-water supply, the water quality and its
long-term changes are of outmost importance. Our analysis is
based on the evaluation of results obtained in the studies of
water samples collected weekly from the Tisza reach at Szolnok
(335,4 river km) in the period 1970-1988. In order to obtain
sufficiently detailed information on the water quality the most
important 27 water quality parameters have been considered in
the present study.
The changes observed in the annual maximal, minimal and mean
values of several parameters in the period between 1970 and 1988
are shown in certain figures. The changes in the water quality
reflected by the mean values of the quality parameters were not
considerable, altogether deterioration of water quality was
observed, which is proven by the increase in the average
concentrations in most of the parameters.
The direction and extent of the changes were determined for the
periods 1970-1978 and 1979-1988 by means of regression analysis.
It was found that a considerable deterioration of water quality
took place in the 70s. Among the parameters studied 52% showed
an improved or unchanged water quality, 22% indicated slight and
22% - considerable deterioration between 1979 and 1988.
The quality of water in the Tisza met the I. class requirements
when used for industrial and irrigation purposes during the
whole period studied. From 1976 on it corresponded only to II.
class in covering the needs of fishery or drinking-water supply,
and in this field a further deterioration of water quality is to
be expected.
(full text)
Gajin, S., Petrovic, O., Matavulj, M., Gantar, M. and Radnovic, D. (1990): Vertretung der erdöl- und phenolabbauenden Bakterien im Theisswasser. – Tiscia 25, 15-19.
Die Belastung der oberflächlichen Gewässer mit Erdöl und Phenol
stellt ein bedeutendes Problem der Gegenwart dar. Da durch die
methabolische Aktivität der Mikroorganismen die
Selbstreinigungsprozesse von sämtlichen orgaqischen
Belastungsstoffen stattfinden, war unsere Absicht, mit dieser
Arbeit das Auftreten dieser Bakteriengruppe im Theisswasser, die
bedeutend für den mikrobiellen Abbau des Erdöls und Phenols ist,
darzustellen.
Die zweijährigen Untersuchungen der Erdöl- und Phenolabbauenden
Bakterien im Theisswasser zeigten das zeitweise oder dauernde
Auftreten dieser Bakteriengruppen an allen untersuchten
Probeentnahmestellen.
Der Anteil diser Bakteriengruppe an der heterotrophen Population
war sehr groß (38-128% für ölabbauende ond 0.8-1,6 für
phenolabbauende Bakterien). Das Auftreten diser Bakterien im
Theisswasser spricht über die zeitweise oder dauernde
Anwesenheit von Erdöl und Phenol als Belastungsstoffe aber auch
über die methabolische Aktivität der Mikroflora, die gute
Möglichkeit für Selbstreinigunsprozesse im Theiss darbietet.
(full text)
Hegedűs, M., Fodré, Zs. and Dobler, E. (1990): Bacteriological quality of the fresh waters in the region of the lower Tisza in the period 1977-1986. – Tiscia 25, 21-29.
The quality of water in the rivers Tisza, Hármas-Körös and Maros
was characterized on the basis of bacteriological investigations
carried out by the authors in the period between 1977 and 1986.
The changes of the bacteriological parameters in the course of
the years are shown in the figures. Quality of water at
different sampling points was evaluated by cluster and centroid
analysis. On the basis of the results obtained in the
bacteriological studies the following conclusions have been
reached:
- The quality of water in the river Tisza has been gradually
deteriorating during the last ten years in all the four sampling
points. The water was particularly polluted and contaminated in
the sections at Mindszent and Tiszasziget.
- The bacteriological quality of water in the Hármas-Körös was
the most favourable above its influx into the Tisza, though even
at this sampling point temporary deterioration of water quality
was observed.
- The water quality in the tributary Maros has deteriorated
significantly during the period under investigation. Since 1980
pollution and contamination have been registerd at both sampling
points.
(full text)
Bodrogközy, Gy. (1990): Hydroecological relations of littoral marsh meadow associations at Bodrogzug. – Tiscia 25, 31-57.
Abstract. In the flood-plain of
the Hungarian Upper-Tisza stretch, at the junction of the Tisza
and Bodrog, the composition of vegetation cover of Bodrogzug,
formed in the Tokaj-region differs significantly from that found
in other locations of the Tisza flood-plain. This can be
attributed in the first place to the mountain effect, and to the
diversity of soil and hydroecological conditions. The southern
region of the flood-plain converted into a nature conservation
area is under environmental stress effect of damming. As a
consequence large areas became occupied by Scirpo-Phragmitetum
at the expense of other cenoses. In the middle and lower
stretches due to mineralogen and biogen filling up the
river-beds of dead-arms have been occupied by
Sparganio-Sagittarietum, Rorippo-Oenanthetum, at places by
Glycerietum maximae replacing hydatophyton associations.
Propagation of Caricetum gracilis subassociation units
was observed as well.
In degraded moist habitats mud vegetation of
Eleocharito-Schoenoplectetum supini could be found.
In the middle and upper regions of Bodrogzug vast marshy green
field developed. At another places of higher moisture content
Carici melanostachyae-Alopecuretum pratensis, on higher
reliefs Lythro virgatae-Alopecuretum played a subordinate
role as compared to other locations of the Tisza flood-plain. In
drier places Poo angustifoliae-Alopecuretum vegetation
has been plough up. In moist places used for intensive grazing
Lolio-Potentilletum anserinae, at places
Lolio-Alopecuretum pratensis pastures developed.
(full text)
Harka, A. (1990): Growth of different forms of carp (Cyprinus carpio L.) in Kisköre storage-lake. – Tiscia 25, 59-64.
Abstract. Carps in Kisköre
storage-lake (newly called the Tisza-lake) can be classified in
three groups Non the basis of their profile index (Pi:
ratio of body length to body hight). The most widespread form is
the usual wild carp characterized by a medium hight spine arch
(Pi: 2,8-3,5), but beside it the low spine arch rangy
carp (Pi > 3,5) and the markedly high spine arch
culture-carp (Pi < 2,8) can be found as well.
No significant differences have been found in the longitudinal
growth of the three forms. However, the wild forms are lagging
behind in gain of weight as compared to the culture ones.
Irrespective of this in natural waters the maintenance of wild
forms in the first place seems to be justified, on the one hand
because of their excellent sport characteristics (when hooked
they struggle vigorously and persistantly), and on the other
hand because they preserve the genetic diversity of the species.
Supplementing or increasing of the carp population in the
storage-lake is to be solved in the future preferably by
pjopagation of wild carps in it and not by introducing culture
ones as practiced formerly.
(full text)
Harka, A. and Pintér, K. (1990): Systematic status of Hungarian bullhead pout: Ictalurus nebulosus pannonicus ssp. n. – Tiscia 25, 65-73.
Abstract. Morphological studies have been carried out by the authors on 337 specimens of bullhead pout (Ictalurus nebulosus) caught in Hungarian waters, and the results were compared with the data available from the literature. Taking into consideration the differences observed in the number of anal rays and in the pectorial spine, it is justified to distinguish the population of bullhead pout in Hungary and bordering regions showing the same characteristics as a separate subspecies under the name Ictalurus nebulosus pannonicus (ssp. n.). The formation of the new species can be attributed to the introgressive hybridization during the introduction of the species in Europe, as well as to the adaptation to the new, differrent environmental conditions.
(full text)
Molnár, Gy. (1990): On food composition of four heron species. – Tiscia 25, 75-82.
Abstract. The wet weight and the
maximum length of the aliment animal organisms found in the food
samples obtained by the neck collar method in nestíings of
Purple Heron (Ardea purpurea). Night Heron (Nycticorax
nycticorax), Little Egret (Egretta garzetta) and
Squacco Heron (Ardeola ralloides) have been studied by
the author between 1985 and 1989. In all of the four heron
species a significant consumption of fish and frogs was
observed. Night Heron and Purple Heron tended to capture big
fish in smaller numbers. The proportion of insects, fish and
frogs was found to be best balanced in the food of Squacco
Heron. The overlap inrespect to the body weight of the aliment
animal organisms was strikingly high between Little Egret and
Squacco Heron. The overlap in size exceeded 50% between Night
Heron, Little Egret and Squacco Heron.
The food composition of Purnle Heron and Night Heron shows the
highest diversity. Consumption of small manumals was observed
only in Purple Heron and Night Heron in 1989, when a definite
mouse gradation occurred. On the basis of the obtained data the
biomass consumption of the nestlings of an average heron colony
can be calculated.
(full text)
Dózsa, J. (1990): From the life of Tisza-research working committee, which has become international. Dr. István Kiss 1910-1990. – Tiscia 25 , 83-86.
Bodrogközy, Gy. (1990): Tisza-research conference XX (1989). – Tiscia 25, 87-92.