First occurrence of the eel parasite Paraquimperia tenerrima in lake Balaton, Hungary

The parasite fauna of the eel has been studied regularly since the first imported eels were introduced to Lake Balaton in 1963. Over a long period of time no important parasitic infections were recorded. However, the importance of nematode infections has increased since 1991, when the pathogenic nematode Anguillicola crassus was first detected and intensive eel mortalities started to occur. This paper reports on the first occurrence of Paraquimperia tenerrima, a small nematode infecting the gut of the eel. Paraquimperia tenerrima is a common parasite in rivers of several European countries. Due to the small size and the low prevalence of the worm its pathogenic effect upon eels seems to be negligible in Lake Balaton

Influence of weather as a changing part of landscape elements - on the touristical potentials of the Káli basin

The aim of this study is to find out the connection between the amount of sunshine hours, as changing part of landscape elements, and the touristical attractiveness and the popularity of visitors in the Káli Basin in Hungary. The data have been collected between 25 June and 13 September 1999. The analysis of the data shows that in the period from 25 June to 20 August, strong, negative correlation exists between the above mentioned two variables; and the basin is visited by those tourists, who spend their holiday in the resorts at Lake Balaton. In the studied period the touristical frequentation of the area grew on cloudy days - when the amount of direct solar radiation is decreased - , probably because this weather is not favourable for bathing. Later, between 21 August and 13 September a positive correlation was found, which presents quite well that after the end of the bathing season tourists preferred to visit this area in days characterised by sunshine, and they mostly came from the neighbouring towns and from the capital. In this period the increasing amount of sunshine hours intensified the touristical potential of the Káli Basin. The above mentioned facts suggest, that the Káli Basin belongs to the touristical attraction zone of Lake Balaton and the number of visitors in the summer season depends on the migration of visitors of Lake Balaton

Társadalmi konfliktusokat generáló ökológiai történések a Balaton életében az utóbbi néhány évtizedben : Gerinctelen állatok inváziói

Social Conflict Generating Ecological Developments in the Life of Lake Balaton in Recent Decades – Invertebrate invasions. Lake Balaton, the largest shallow lake in Central Europe, is a natural treasure of Hungary. Since the open of the Sió channel, the lake has become more vulnerable against biological invasions. Invasive aquatic alien species especially bivalves can evoke serious threats through causing dramatic changes and promoting numerous direct and indirect system-wide effects. They create or modify habitats, alter species diversity, nutrient cycling and other ecosystem processes; by these they generate several social conflict. Here we discuss our recent knowledge obtained on some exotic invasive invertebrates in Lake Balaton: the zebra mussel (Dreissena polymorpha) and the amphipod Caspian mud shrimp (Chelicorophium curvispinum), which were the first two invaders, Dikerogammarus species, and the latest (the ninth) exotic invader from the Ponto-Caspian region, the quagga mussel (Dreissena bugensis). Finally, the exotic Asiatic Chinese pond mussel (Sinanodonta woodiana) is also noticed, as the decay of its population was the most serious problem related to tourist attraction in the last years. We underline the emerging importance of studying the invasive species in order to save the original and natural ecological status of Lake Balaton

Intermittency and Correlations at LEP and at HERA

A review on recent investigations of local fluctuations and genuine correlations in electron-positron annihilations at LEP and in positron-proton collisions at HERA is given.Comment: Invited talk given at the XXXth Int. Symposium on Multiparticle Dynamics (ISMD 2000), 9-15 October 2000, Tihany, Lake Balaton, Hungar

Küszvágó csér (Sterna hirundo) előfordulások a Balaton déli partjánál, és költése az Irmapusztai-halastavakon

The Common Tern ( Sterna hirundo ) is one of the characteristic bird species of Lake Balaton. Breeding colonies were described formerly from fishponds in Fonyód and Irmapuszta. Currently, the most numerous breeding populations can be found at the Kis-Balaton reservoir. In 2007 74 breeding pairs were recorded at the fishponds at Irmapuszta, which is about 40 percent of the recognized breeding pairs at Lake Balaton and its surroundings and 6-10 percent of the total breeding pairs in Hungary

Paratenic hosts for the parasitic nematode Anguillicola crassus in Lake Balaton, Hungary

A 1 yr study was conducted to determine which fish species may play a role in the life cycle of Anguillicola crassus in various habitats of Lake Balaton, Hungary. The prevalence and intensity of the larval infection of fish species acting as paratenic hosts was studied, and observations were made on the types of paratenic host reactions against larvae. With the exception of 1 species, all 20 fish species were infected by A. crassus larvae; however, the prevalence and intensity of infection varied widely. Six species (asp, white bream, Chinese rasbora, pike, river goby, European catfish), hitherto unreported as paratenic hosts, also proved to be infected by larvae in Lake Balaton. Of the 13 fish species examined in large numbers, ruffe and European catfish showed the highest prevalence of infection (100 %), followed by river goby (83 %), white bream (79 %) and bleak (68 %). Of these 13 fish species, ruffe showed the highest intensity of infection by live larvae (mean intensity: 39.3 3rd stage larvae, L3), followed by European catfish (mean number of live larvae: 26.9) and river goby (mean number of live larvae: 9.1). The mean number of live L3 in bleak, a species regarded as the principal food source for eels, was 4.1. Specimens containing only dead or both dead and live larvae were much more common in cyprinid fishes than in species belonging to other taxonomical entities. In these fish, the process of encapsulation and subsequent necrosis of live larvae could also be observed. With knowledge of the feeding habits of eels, it appears that bleak play the most important role in the transmission of anguillicolosis. Other intensively infected fish species (e.g. ruffe) may also contribute to massive infection of individual eels, even if they have a lower share in the eels' food structure

Life history patterns of Procladius choreus, Tanypus punctipennis and Chironomus balatonicus in Lake Balaton

Life history patterns of the three most abundant chironomids were analysed in Lake Balaton by monitoring the population dynamics of larvae and the presence of pupal exuviae. Procladius choreus had two generations per year with at least two parallel cohorts during 1996-1999. Tanypus punctipennis had a trivoltine life cycle with occasional parallel cohorts, overlapping generations and long, interrupted emergence periods between 1997 and 1999. At Tihany, Chironomus balatonicus had only one detectable generation between 1995 and 2002. Meanwhile at Keszthely, the abundance of C. balatonicus larvae peaked from autumn to the beginning of summer in 1996/1997, 1998/1999 and 2000/2001, and it was continuously high from August 2001 to October 2002. However, between these abundance peaks there were long periods when larvae could not be found at all. The C extreme population dynamics of C. balatonicus suggests that living conditions may fluctuate around the limit of this species in Lake Balaton. Although C. balatonicus larvae practically were not found at both sampling sites from July 1997 to August 1998. and from July 1999 to August 2000, sporadic occurrence of exuviae during these periods proves that refuge areas should exist within the lake. Possible background of the uncommon population dynamics of C. balatonicus is discussed

Társadalmi konfliktusokat generáló ökológiai történések a Balaton életében az utóbbi néhány évtizedben – A halfogás csökkenése

Social Conflict Generating Ecological Developments in the Life of Lake Balaton in Recent Decades – Decreasing Fish Catches The fisheries sector was the chief utilizer of fish stocks living in the Lake Balaton for centuries, however with recreational use in the forefront the importance of angling has considerably increased in the last sixty years. Due to the diminishing of spawning areas of native fish species, the unadvised stocking of non native ones (silver carp, eel), and the ongoing oligotrophication during the last fifteen years the fish stock size and composition of the lake has changed significantly. Decreasing fish catches and contrasting intrests generate numerous conflicts between fishermen and recreational anglers.Social Conflict Generating Ecological Developments in the Life of Lake Balaton in Recent Decades – Decreasing Fish Catches The fisheries sector was the chief utilizer of fish stocks living in the Lake Balaton for centuries, however with recreational use in the forefront the importance of angling has considerably increased in the last sixty years. Due to the diminishing of spawning areas of native fish species, the unadvised stocking of non native ones (silver carp, eel), and the ongoing oligotrophication during the last fifteen years the fish stock size and composition of the lake has changed significantly. Decreasing fish catches and contrasting intrests generate numerous conflicts between fishermen and recreational anglers

Concepts for waterfront developments, focusing on Siofok, Hungary

The paper shows a general introduction about the connection of cities, particularly Siófok, the ‘capital’ of Lake Balaton and water surfaces through three topics: the first part deals with the past and present of waterfronts, by exploring the most important principles in their design, then describes the significant tools and methods of the Hungarian cities around Lake Balaton, the most important water surface of Hungary, related to the areas adjacent to the water. Finally, it reveals a complex design work by the authors for refurbishing the waterfront in Siófok, based on a national competition