The greater part of the Institute is involved in basic research, the results of which are published in international journals of good impact factor. At the same time much scientific research activity is carried out which helps cement the ecological protection of the Balaton.

The main topics in the field of limnology are the following:

1. the circulation of phosphorus in the lake;

2. the circulation of nitrogen in the lake;

3. the properties and ecological role of dissolved humin materials;

4. the seasonal and long-term changes of phytoplankton;

5. the ecology of pikocyanobakteria and flagellated cyanobacteria ;

6. seasonal and long-term changes in zooplankton and zoobenthos

7. feeding, metabolism, growth and population dynamics of planktonic and epilitic animals;

8. feeding relationships in the littoral zone;

9. population dynamics of fish, with special attention to early developmental stages;

10. role of fish in the regulation of water quality;

11. accumulation and effect of toxic materials in the lake.

The main topics in the field of experimental zoology (comparative neurobiology) are the following:

1. co-localization and role of signals molecules and in signal transduction;

2. neurochemistry of signal molecules and their receptors;

3. identification of neuronal networks and their role in central and peripheral regulatory processes;

4. embryogenesis of chemical specificity of neurons;

5. effects of environmental pollutants on the neural regulation of aquatic invertebrates.

Major Scientific Results

Hydrobiology

The main results of the period before the world war were the knowledge of the basic physical and chemical characteristics of the open water, benthic and littoral regions, the detailed taxonomic exploration of their biota, and the description of the living communities. These results were synthesised by Géza Entz and Olga Sebestyén in their book “A Balaton élete” (The Life of Balaton). It was published in Hungarian in 1940 and 1942, followed by an enlarged German issue in 1943. The book gives an ecological description of the lake in Thienemann’s spirit.

The long-term phytoplankton studies started in 1945. The Dinoflagellates were counted by Olga Sebestyén, all the other groups by Gizella Tamás from water samples taken monthly from the lake in front of the Institute. The biomass of the cells of the different species were calculated from their shape and microscopic dimensions. In this way the biomass of the algal species and that of the total phytoplankton could be calculated. This latter corresponded to an oligotrophic level in the forties, but surpassed the 1 mg fresh weight/liter in 1951, indicating the eutrophication of the Lake. The phytoplankton was dominated by diatoms in spring and by Ceratium hirundinella in summer. There were little cyanobacteria. Valuable research into the ecophysiology of algae was carried out by Lajos Felföldy and his colleagues at the end of the fifties and the beginning of the sixties. They used the Stemann-Nieksen’s 14C method to measure the intensity the primary production of phytoplankton as early as in 1962-1963 in a few cases. At that time no differences were found in the productivity of the four basins, the whole lake was mesotrophic.

Between 1972-1977 Sándor Herodek conducted detailed studies on the primary production of the phytoplankton in the four basins of Lake Balaton, using the 14C method. In the eastern part of the lake the water transparency depended mainly on the amount of sediment, resuspended by the waves, and the maximal photosynthesis was usually found in 1-2 m depths. In the Keszthely-basin the light extinction was highly increased by the biomass of the phytoplankton, so that here no net primary production was found even in calm periods below 2 m. The phytoplankton of the whole lake incorporated 140,000 tons of carbon into organic compounds annually. The food web of the lake is based on this material, and this amount is by one order of magnitude larger, than the production of the reeds and other macrophytes in the lake or the organic loading delivered by the tributaries. From the early 1960s to the 1970s the primary production of the phytoplankton rose to double at Tihany, triple at Szemes and eightfold at Keszthely. This proved the racing eutrophication of the lake, and brought attention to the necessity of urgent measures for the water quality protection. At the same time it demonstrated, that the water deteriorated most rapidly in the western part loaded by the Zala river and the other tributaries. It proved, that it is insufficient to deal only with the tourist region, but a comprehensive water quality protection program must cover the entire watershed.

Unfortunately, the predictions of a racing eutrophication proved true. The long-term phytoplankton monitoring after the death of Gizella Tamás in 1975 was continued by Lajos Vörös and later by Judit Padisák. They found already regular blooms of N₂-fixing filamentous blue green algae in the western basins in the summers of the 1970s, which gradually spread eastwards. The water quality was the worst on particularly hot summers, when Cylindrospermopsis raciborskii, a N₂-fixing cyanobacterium of subtropical origin invaded the whole lake, endangering even the bathing.

It was demonstrated by Sándor Herodek, Vera Istvánovics and János Zlinszky, using chemical measurements, studies into the phosphorus uptake kinetics of phytoplankton, fertilization experiments in small ponds isolated from the lake by plastic cylinders, that the increase of the phytoplankton productions in lake Balaton results basically from the increased phosphorus, and the external phosphorus load must be reduced in order to improve the water quality.

Eutrophication models try to answer the question how the lakes will react to nutrient load reductions. The development of the Balaton Eutrophication Model started in 1976 as a cooperation of the BLRI and the biomathematical group headed by János Fisher in of the Institute of A Computer and Automation of the Has. From the limnologists Sándor Herodek, from the biomathermaticeans Tibor Kutas and Péter Csáki took part most actively in this work. Based to the results of this study the International Institute of Applied System Analysis selected Lake Balaton as study area for modeling shallow lakes eutrophication. The Balaton eutrophication model is a system of differential equations describing the mass transfer processes in the water and sediment of the lake, which are regarded to be the most important in the eutrophication. The four basins of the lake are connected by a hydrological submodel. The internal variables are the different groups of the phytoplankton, the bacterioplankton, the detritus, the dissolved inorganic phosphorus and nitrogen compounds in the water, the organic matter and exchangeable phosphorus in the sediment. The external variables are the light and temperature and the biologically available phosphorus and nitrogen loads of the lake. Model runs demonstrated, that a stable but high external loading, corresponding to that of the late 1970s, does not guarantee an unchanged water quality, because the phosphorus accumulation in the sediment increases the internal loading. Significant reduction of the external loading decreases the phytoplankton biomass, but the improvement is delayed by the accumulated phosphorus.

The modelling helped to understand the behaviour of the ecosystem, and to specify the problems that need further studies. In the last decade Vera Istvánovics used a modell, based on thermodynamic considerations, to describe the phosphorus uptake of the phyto- and bacterioplankton, characterised the different phosphorus forms in the sediment, studied the transformations of the organic and inorganic fractions and demonstrated strong positive feed-backs in the internal loading processes, that can lead to abrupt changes in water quality. Mátyás Présing, in his ¹⁵N studies found a strong ammonium preference in the nitrogen uptake of the phytoplankton. Urea is the second, nitrate only the third important nitrogen source for algae in this lake. The blue-greens have an even higher affinity for ammonium than the other algae, and they change for N2 fixation only after a nearly complete exhaustion of this compound. Most of the nitrate used by the phytoplankton originates from the nitrification within the lake. Lajos Vörös discovered that blue-green algae of bacterial size known earlier mainly in the oceans, occur in high number in Lake Balaton. Sometimes this picoplankton is responsible for half of the primary production. He demonstrated a light adaptation in the pigment composition of these algae. He studied with his colleagues the ecology of Cylindrospermopsis raciborskii. This is a filamentous N₂ fixing species that causes the strongest water blooms. Its temperature optimum proved to be high, its demand on light low. This explains why canicular weeks are needed for the development of the water blooms, and why other species are outcompeted by increased selfshading of the phytoplankton. Judit Padisák’s detailed phytoplankton studies demonstrated an increase of the biodiversity by moderate disturbances of environmental factors. Katalin V.-Balogh determined chemical characteristics and ecological effects of the humic substances and other dissolved organic compounds in lake water. Viktor Tóth measured the light compensation point of several submerged macrophytes and conducted ecophysiological studies into the causes of the reed die-back.

In his 1897 work “A Balaton faunája” (Fauna of the Balaton), Géza Entz mentions 462 species of animals from the lake. The book was considered modern for its time, investigating the fish fauna, benthic and planktonic organisms. A significant biological event, the invasion of zebra mussel in the Balaton, was also described at this time by Géza Entz and Olga Sebestyén. By the 1940s, nearly 1000 species of invertebrates had been listed, a number that between 1991-1998 had risen to 3000 as a result of Jenő Ponyi’s taxonomical studies on the fauna of the lake. Investigations in the 1950s clarified the spatial, diel and seasonal variations of the zooplankton, as well as the distribution of crustaceans, chironomid larvae and other inhabitants of the sediment (Sebestyén, Ponyi). Ichthyological studies in the 1950s and 1960s aimed at the feeding, growth, distribution and competition between different fish species (Elek Woynárovich, István Tölg, Ferenc Lukacsovics, Béla Entz). The artificial fertilization of fish, most important from the economic point of view, have been elaborated, including the carp and pikeperch, which was the primary force to control the fish population of the lake.

At the turn of the 1980s that there were almost ten times as many planktonic rotifera in the different trophic areas of the lake as in the oligotrophic-mezotrophic areas (Nóra P. Zánkai). Crustacean plankton represent the largest group from a point of view of the most detailed analysis. It has been shown that in the course of the 1980s the quality and composition of crustacean plankton has changed as a result of higher phytoplancton production. Investigations on amphipods, including estimations of the biomass and average number of eggs laid by a female Corophium curvispinum (Ilona B.-Muskó). On the basis of the growth of mussels in the Balaton, their biomass for the entire lake was estimated (Jenő Ponyi). At the beginning of the 1990s, the density of Chironomidae larvae varied considerably along the longitudinal axis of the lake. As a result of the cyanobakteria bloom in 1994, the biomass of the phyto-detritiphagous chironomidae larvae far exceeded that of previous years. Since 1996, as a result of the improving water quality carnivorous species became dominant, producing low total biomass (András Specziár). The amount of inorganic nitrogen released into the water column by Chironomidae was also estimated (István Tátrai).

Investigations on the nutrition biology of filtering zooplankton, has shown that the majority of the intestinal content of the summer plankton feeding upon algae consists of small mineral drops that retard the time of development and production of eggs (László G.-Tóth). When fed with glass beads, it was found that the food uptake of later larval stages of Eudiaptomus gracilis consume 5-7 times more food than the younger larvae of copepodite stages (Nóra P.-Zánkai). In the periphyton of the reeds the activity of the electron transport system (ETS) in spring is low, almost reaching the value of the sediment in summer, and on green reeds the ETS value exceeds that measured on the rancid reeds (Péter Bíró, László G.-Tóth, Ilona B.-Muskó).

Simulated eutrophication in limnocorals proved that the most turbid water, as well as that containing the highest level of phosphorus and ammonium, was that stocked with bream. At the beginning of the experiment fish had a positive effect on the density and production of algae, while decreased the density of the crustacean plankton (István Tátrai, Vera Istánovics).

Publications up to the present day list 47 different species of fish, this number being decreased in recent years to 31. A few fish supposed to have become extinct (the eurasian perch, large mouth bass) have reappeared, disappearing from the lake itself, they formed self-supporting populations in the refuge areas of the tributary mouths south and west of the lake and in the Kis-Balaton (Péter Bíró, István Tátrai, Gábor Paulovits). Over the last 20 years, the density and biomass of the fish population has more or less followed the trophic gradient along the lake. The general fluctuations and a decrease in ratio of the native species is characteristic, in contrast to the stocked species such as the eel and the silver carp or the immigrated gibel. The altered dynamics parameters of the populations of pikeperch, bream, asp, razor-fish and bleak indicate marked changes (Péter Bíró, András Specziár, László Tölg, Miklós Perényi).

Studies on the population dynamics of fish has provided quantitative estimations of the main parameters (density of population, growth, biomass, production, P/B ratio, mortality rate) of the pikeperch, bream, razor-fish, asp, bleak, eel, silver carp, monkey goby, carp, roach, rudd and white bream populations, as well as the relationship between the breeding population and natural recruitment, their equilibrium state, and the processes controlling their population densities (Péter Bíró, András Specziár, László Tölg). A close relationship was found between the biomass of bream and primary production, but this relationship was much looser in the case of the predatory pikeperch (Péter Bíró, Lajos Vörös). In the course of describing the relationship between the quantity and quality of the complicated feeding network, a special emphases was put upon competition, niches, overlapping niches, segregation and emigration (biotop saturation). Feeding interactions among five coexisting cyprinid species were described with discriminant competition analyses and resource partitioning among species in some cases lead to interactive niche segregation (András Specziár).

The global metabolism within the lake’s fauna was described using a multivariate ECOPATH II model (Péter Bíró), which displays the matter flow among the four main energy levels of the lake. Recently the effect of global climatic changes and the duration of ice cover of the lake were analyzed on the aquatic life, and connections were established between the biomasses of algae and Chironomidae, the fish yield and the El Nino phenomenon (Péter Bíró).

Experimental zoology (comparative neurobiology)

In the experimental zoological studies three periods can be divided since the institute’s foundation 72 years ago. The first, 1927-1942, was the period of general physiological studies; the second, 1945-1962, a period of transition from the traditional to modern experimental physiological research; and the third, that of comparative neurobiological studies on the nervous system of invertebrate animals (bivalves, snails, insects).

1. Data from the early zoological research of the Institute are connected with the basic aspects of stimuli transmission, showing the role of certain chemical substances and metal ions in the nervous system and the function of the muscle cells (Frigyes Verzár, Sándor Müller, György Ludány, Lóránd Jendrassik).The electrocardiogram (EKG) of the crayfish’s cardiac muscles was described (Verzár and Ludány). The comparative approach that has been applied to tackle the same question on different species was remarkable in its day. For instance, they examined the effect of chemical compounds affecting the activity of the heart of fish, frogs and turtles. In the 1930s Eszter Kokas and György Ludány demonstrated that villiquinine, the hormone regulating motility of microvilli, is not only to be found in mammals but also in vertebrates of lower orders, including fish. Gyula Méhes and Sándor Wolsky examined the stimulatory and inhibitory effects of various biologically active materials (atropine, pilocarpine, physostigmine, muscarine, nicotine, adrenaline, papaverine, and acetylcholine) upon the intestinal musculature of the tench. Ambrus Ábrahám, using the Ábrahám-Bielschowsky silver impregnation method, described the intestinal nervous system, and the innervation of the respiratory organ and heart in lower vertebrates (fish, frogs, turtles). Albert Szent-Györgyi investigated the chemical characteristics of the Nissl-granules in the brain of the guinea-pig. Sándor Wolsky proved on frog embryos that one of the compounds still applied nowadays in biological research, colchicine has a strong effect upon the early division of cells, on the morphogenetic processes of ontogenesis and the maturation of the nervous system.
   In recognition of the physiological research carried out at the Institute, the Hungarian Physiological Society was founded within its walls in 1931.

2. In the second phase of research, following Gyula Méhes’s experiments on osmoregulation and regulation of blood sugar levels, Aladár Beznák, Margit Beznák and Arisztid Kovách studied the blood circulation, and sugar and vitamin metabolism in vertebrates. István Konok demonstrated that moulting in insects is essentially the result of endogenously regulated processes, and isolated various hormone-producing materials from the central nervous system of insects.

3. Since 1962, when the third phase began, the aim of the comparative neurobiological investigations initiated by János Salánki, has been the complex (neuroanatomical, neurochemical, microelectrophysiological) analysis of the nervous systems of invertebrates. The significance of such research is that the function and structure of the nerve cells in a so-called simpler, lower order organism is essentially similar to that in a higher-order vertebrate with a highly developed, complicated nervous system. At the same time, it is much easier to approach and perform experiments upon the neurons of certain invertebrate species, first of all because of their relatively small number and large size.

The most important results of these studies have been the following. It has been proven that two chemical signal molecules, serotonin (excitatory) and dopamine (inhibitory) are responsible for the regulation of the rhythmic activity of the shells of the freshwater mussel; furthermore, that the chemical specificity of the system regulating the movement of the shells of the mussel larvae will be changed in the course of the ontogenetic development (László Hiripi, Elemér Lábos, János Salánki). Applying retrograde staining and multi-electrode recording on so-called semi-intact preparations (central nervous system – peripheral nerve – target organ), central nerve cells of snails were successfully identified, which are responsible for the regulation of heart activity and the function of the entire visceral organ system. The pharmacological map of the central nervous system of the edible (garden) snail, Helix pomatia, has been described. In the edible snail, Helix pomatia, and the pond snail, Lymanea stagnalis, it has been proven that the function of excitable membranes (nerve cells and cardiac muscle cells) varies, according to the sensitivity to different chemical substances, or according to responses given to synaptic input (István Kiss, Tibor Kiss, Katalin S.-Rózsa, János Salánki). The presence different signal molecules, such as serotonin and dopamine, has been demonstrated in the nervous system of molluscs (mussels, snails), and the biochemical processes have been described by which these messengers are synthesized and their effect upon nerve cells are eliminated. Using 3H-labeled signal molecules, it has been shown that the nerve cells of molluscs, similarly to those of vertebrates, are capable of eliminating the effect of the released transmitter molecules by their re-uptake (Károly Elekes, László Hiripi, Imre Zs.-Nagy). Some neuropeptides, such as the FMRFamide and opiates, were shown to modify the “learning capability” of the nerve cells in snails, resulting in the sensitization or habituation of cellular responses evoked by different transmitters or stimuli (Katalin S.-Rózsa). A role of excitatory amino acids in the snail CNS was proved by demonstrating the glutamate sensitivity of and the presence of NMDA-like receptors on neurons (János Győri, János Salánki). It has also been proven that a third group of messengers, the immune signals molecules (interleukins) exert a specific effect onto the snail neurons, by changing the function of potassium and calcium channels in them (Katalin S.-Rózsa, Attila Szűcs). Following electrophysiological and electron microscopical analysis, identified multifunctional snail neurons were shown to fulfil both information processing and efferent functions (Károly Elekes, Katalin S.-Rózsa, János Salánki, Ágnes Vehovszky). Applying false transmitter (5,6-dihydroxytrypamine), serotonergic neurons were identified in the snail central nervous system, followed by the identification of their intercellular connections and role in certain behaviours, such as feeding and locomotion (László Hernádi, György Kemenes, Katalin S.-Rózsa, Ágnes Vehovszky). Distribution of different signal molecules (monoamines and myoactive neuropeptides) has been mapped in the snail nervous system, using immunocytochemistry (Károly Elekes, László Hernádi, György Kemenes). Occurrence of nerve endings containing different signal molecules (serotonin, endogenous neuropeptides) at both synaptic, modulatory and neurohormonal levels has been demonstrated (Károly Elekes). The effect of tachykinins and Mytilus inhibitory peptides on potassium and calcium channels in identified snail neurons was described (Tibor Kiss). Applying double-labelling technique (retrograde cobalt/nickel staining and immunocytochemistry), the somatotopic arrangement of neurons which are responsible for the innervation of the different head regions (mouth, lip, tentacles) could be demonstrated in the snail brain (László Hernádi). Octopamine, a modulatory substance in invertebrates, was shown to be present in high concentrations and possessing specific receptors in the nervous system of both insects (locust) and snails. Octopaminergic neurons were identified immunocytochemically in the snail CNS and their role in the feeding behaviour was proven (Károly Elekes, László Hiripi, Ágnes Vehovszky). It has also been demonstrated by ligand-binding experiments that similarly to the nervous system vertebrates, several types of serotonin and dopamine receptors are present in the CNS of invertebrates (locust, garden snail, pond snail), possessing species specific pharmacological and affinity characteristics (László Hiripi). Studying the embryogenesis of the pond snail, Lymnaea stagnalis, both transmitter systems (serotonin, neuropeptides) showing continuous development from the early embryonic stages, and others (octopamine, dopamine, nitrogen monoxide) appearing only right before hatching were described, the latter are suggested to have a specific role in the maturation of adult-like, free-living behaviours, such as feeding, locomotion and respiration (Károly Elekes, László Hiripi). In the course of the electrophysiological (voltage- and patch-clamp) investigation of the effects of environmental pollutants (heavy metals) it was found that low concentrations of cadmium, tin, mercury and copper influence the conductivity of the nerve cell membrane and open new channels in the CNS of different snail species. Heavy metals are capable of modifying voltage-dependent calcium, potassium and sodium currents evoked by different signal molecules (acetylcholine, glutamate, GABA). The rhythmic activity of the adductor muscles in bivalves is damaged by heavy metals (János Győri, Tibor Kiss, Katalin S.-Rózsa, János Salánki, Attila Szűcs). The mosquito killer, deltamethrine has a target point in the nerve cell membrane of molluscan neurons, different from vertebrates; it decreases the strength of potassium and acetylcholine activated membrane currents (Tibor Kiss, János Salánki).

Academicians and Professors of the Institute

From among the researchers at the Institute the following were or became members of the Hungarian Academy of Sciences: Frigyes Verzár, Scherffel Aladár, Géza Entz jnr. Rezső Soó, Sándor Wolsky, István Krompecher, Endre Dudich, Dániel Fehére, János Salánki, Tibor Farkas and Péter Bíró.

The following Institute researchers were or became the doctor of sciences (D. Sc.): Olga Sebestyén, Barna Győrffy, Elek Woynarovich, Gábor Uherkovich, Katalin S.-Rózsa, Imre Zsolnai-Nagy, Elemér Lábos, István Benedeczky, Jenő Ponyi, János Oláh, Péter Bíró, Sándor Herodek, Ferenc Máté, János Nemcsók, Károly Elekes, György Kemenes, Judit Padisák, Vera Istvánovics, Lajos Vörös and G. Tóth László.

The following research groups and scientists, respectively, have received Academic Prize: in 1972, Elemér Lábos, Katalin S .-Rózsa, János Salánki and Imre Zsolnai-Nagy; in 1988, Péter Bíró, Sándor Herodek, Nóra P.-Zánkai, Jenő Ponyi, István Tátrai and Lajos Vörös; in 2000, Károly Elekes.

Applied Scientific Results

The Balaton is one of Europe’s most frequented lakes and responsible for one-third of Hungary’s income from tourism. Tourism and water quality are closely related. Early on, the Institute observed the deterioration in the water quality, brought attention to it and determined the reasons for it. Its researchers have worked alongside the government in the elaboration of resolutions which over the last 15 years have significantly reduced the phosphorus load in the lake. At the First International Conference on Lake Preservation, the UNEP Secretary, in highlighting one lake from each continent, raised the Balaton out of all European lakes as being a model for appropriate lake preservation. (As a result, it was our Institute which played host to the 3rd International Conference on Lake Preservation.) Perhaps more important than the honor conferred is the fact that over the past five years the water in the West-Basin of the Lake has improved from hypertrophic to eutrophic, and in the eastern half has improved from eutrophic to mezotrophic.

The artificial breeding of carp first carried out at Tihany by Woynarovich has spread to every continent, and has proved to be of great assistance in solving the nutrition problems of a number of developing countries.

Studying fishes and the other aquatic species of lower level which compose their food has laid the ecological basis for a fish-management in the Lake.

The Role of the Institute in University Education

According to Klebelsberg, the Hungarian Biological Research Institute was the first research center in the country the primary function of which was research, and which was independent of the universities. However, a number of the researchers have given courses as university lecturers parallel with their Institute work. During decades, several scientists have eventually left the Institute in order to join university departments. Tihany’s main contribution to higher education has lain in its provision of university teachers with outstanding research experience. Twenty-eight researchers from the institute were or became university professor: Béla Hankó, Frigyes Verzár, Rezső Soó, Lajos Csík, Piusz Koller, Sndor Müller, Gyula Méhes, Géza Entz, István Krompecher, Aladár Beznák, Endre Dudich, Dániel Fehér, Lajos Varga, András Krámli, Lajos Felföldi, Gábor Uherkovich, Gyula Fábián, János Horváth, Elek Woynarovich, Miklós Udvardy, János Salánki, Katalin S.-Rózsa, Imre Zsolnai-Nagy, Jenő Ponyi, István Benedeczky, Ferenc Máté, János Nemcsók, Károly Elekes, Péter Bíró.

At present our researchers are lecturing in six Hungarian universities: at Budapest, Pécs, Debrecen, Keszthely, Gödöllő and Veszprém. Three of them have been awarded Széchenyi Professor Fellowship. Each year, the Institute plays host for a month to a group of twenty university students on summer practicals.

International Relationships

It was the inspiration of Klebelsberg that, borrowing the example of the Zoological Station in Neaples, the Institute should provide accommodation and laboratory opportunities to visiting scientists, thereby providing a constant supply of fresh ideas. Between 1927 and 1942, 158 visiting scientists spent spells of various length at Tihany, among them the two Nobel Prize-winners Otto Loewi and Paul Weiss. During the war and the following decade foreign connections were severely restricted; however, from the 1960s onwards they began to flourish again. Over the last thirty years, 6-8 foreign researchers have visited Tihany annually, the same number of Hungarians visiting foreign institutes. Over the past few years the most significant cooperation has been with the Norwegian Water Research Institute of Oslo, the Research Institute for Freshwater Ecology and Fishing of Berlin, the Limnological Institute of Uppsala University, the Hydrobiological Institute at Pallanza, the Institute of Developmental Biology of the Russian Academy of Sciences (Moscow), the Zoological Institute of Stockholm University, the Department of General Zoology and Animal Physiology (Jena), and the New York University Faculty of Public Health.

The Institute’s own scientists regularly attend international events, often as plenary speakers, as well as organizing conferences at the Institute itself. Among the many the following should be mentioned: The International Symposium on Paleolimnology, 1967; Limnology of Shallow Lakes, 1975; Human Impacts on Life in Fresh Waters, 1977; International Symposium on Trophic Relationships in Inland Waters, 1987; Third International Conference on the Conservation and Management of Lakes, “Balaton ‘88”, Keszthely, 1988; EIFAC/FAO Workshop on Fish Farm Effluents, 1991; ILEC/UNEP International Training Course on Limnological Bases of Lake Management, 1993; and the IUBS International Workshop on Freshwater Biodiversity, Balatonfüred, 1996. Since 1967 the Institute has played host every four years to the Symposium of the International Society for Invertebrate Neurobiology, whose seat is at the Institute.

A Short Evaluation of the Activities of the Institute

For 72 years the Institute has been considered one of the main centers for limnological research, providing important contributions to the international development in limnology, and making the Balaton one of the Earth’s best-investigated lakes. Deterioration of the water quality of the lake was realized in time by the researchers of the Institute, the reasons for this were identified and successful advice was given regarding the preservation of the lake.

In the first 35 years of its history the Institute provided a home for the various branches of experimental biological research, earning international reputation in biology, biochemistry, histology, microbiology and genetics. From 1962 research began to specialize in the neurobiology of invertebrate animals, creating unique results domestically and earning recognition on the international scene.

Conferences, Symposia

Every year in October, the "Days of Hidrobiology" were held in the Institute, organized by the Hungarian Hydrological Society, the Regional Committee of HAS, Veszprém, and the Institute. (Péter Bíró, organizer)

Furthermore:

IBRO-CEER Summer School, 2000, "Functional anatomy and evolution of complex integrative centers of the CNS: approaches and facts". (Károly Elekes, co-organizer)

IBRO-CEER Summer School 2001, "Neuronal transmission: microphysiology of synaptic currents and receptor function". (Károly Elekes, co-organizer)

"Shallow Lakes 2002", International Conference on Limnology of Shallow Lakes, 2002, (Scientific Committee: Sándor Herodek, Péter Bíró, Ellen van Donk, Alois Herzig, Anna Hillbricht-Ilkowska, Vera Istvánovics, Erik Jeppensen, Stephen Maberly, Luigi Naselli-Flores, Judit Padisák. Organizing Committee: Judit Padisák, László G. Tóth, István Tátrai, Lajos Vörös). 269 participants from 39 country.