Lake Balaton

Lake Balaton () is a freshwater rift lake in the Transdanubian region of Hungary. It is the largest lake in Central Europe, and one of the region's foremost tourist destinations. The Zala River provides the largest inflow of water to the lake, and the canalized Sió is the only outflow.

The mountainous region of the northern shore is known both for its historic character and as a major wine region, while the flat southern shore is known for its resort towns. Balatonfüred and Hévíz developed early as resorts for the wealthy, but it was not until the late 19th century when landowners, ruined by ''Phylloxera'' attacking their grape vines, began building summer homes to rent out to the burgeoning middle class.

Name

In distinction to all other Hungarian endonyms for lakes, which universally bear the suffix ''-tó'' 'lake', Lake Balaton is referred to in Hungarian with a definite article; that is, ''a Balaton'' 'the Balaton'. It was called ''lacus Pelsodis'' or ''Pelso'' by the Romans. The name is Indo-European in origin, derived from Slavic *''bolto'' (Czech ''bláto'', Slovak ''blato'', Polish ''błoto''), meaning 'mud, swamp' (from earlier Proto-Slavic ''boltьno'', cf. , ).

In January 846, the Slavic prince Pribina began to build a fortress as his seat of power and several churches in the region of Lake Balaton, in the territory of modern Zalavár surrounded by forests and swamps along the Zala River.Bartl 2002, p. 19.Róna-Tas 1999, p. 243.Goldberg 2006, p. 85. His well-fortified castle and capital of the Lower Pannonian Principality became known as ''Blatnohrad'' or ''Moosburg'' (literally, 'Swamp Fortress'), and it served as a bulwark against both the Bulgarians and the Moravians.

The German name for the lake is '. It is unlikely it was given that name for being shallow because the adjective ' is a Greek loanword that was borrowed via French and entered general German vocabulary in the 17th century. It is also noteworthy that the average depth of Balaton () is not extraordinary for the area (cf. the average depth of the neighbouring Neusiedler See, which is roughly ).

Climate

Lake Balaton affects precipitation in the local area. The area receives approximately more precipitation than most of Hungary, resulting in more cloudy days and less extreme temperatures. The lake freezes over during winters. The microclimate around Lake Balaton has also made the region ideal for viticulture. The Mediterranean-like climate, combined with the soil (containing volcanic rock), has made the region notable for its production of wines since the Roman period 2,000 years ago.

History

It always has been an important location, both tactically and culturally(with many folk tales surrounding it). During the Ottoman wars played an important role in defending Royal Hungary where even battles were fought. While a few settlements on Lake Balaton, including Balatonfüred and Hévíz, have long been resort centres for the Hungarian aristocracy, it was only in the late 19th century that the Hungarian middle class began to visit the lake. The construction of railways in 1861 and 1909 increased tourism substantially, but the post-war boom of the 1950s was much larger.

By the turn of the 20th century, Balaton had become a center of research by Hungarian biologists, geologists, hydrologists, and other scientists, leading to the country's first biological research institute being built on its shore in 1927.

The last major German offensive of World War II, Operation Spring Awakening, was conducted in the region of Lake Balaton in March 1945, being referred to as "the Lake Balaton Offensive" in many British histories of the war. The battle was a German attack by Sepp Dietrich's Sixth Panzer Army and the Hungarian Third Army between 6 and 16 March 1945, and in the end, resulted in a Red Army victory. Several Ilyushin Il-2 wrecks have been pulled out of the lake after having been shot down during the later months of the war.

During the 1960s and 1970s, Balaton became a major tourist destination due to focused government efforts, causing the number of overnight guests in local hotels and campsites to increase from 700,000 in July 1965 to two million in July 1975. The number of weekend visitors to the region, including tens of thousands from Budapest, reached more than 600,000 by 1975. It was visited by ordinary working Hungarians, and especially for subsidised holiday excursions by National Council of Trade Union () members to exclusive hotels and small resorts () for them.
It also attracted many East Germans and other residents of the Eastern Bloc. West Germans could also visit, making Balaton a common meeting place for families and friends separated by the Berlin Wall until 1989.

Ecology

Lake Balaton, Central Europe's largest shallow lake (area ≈ 594 km²; mean depth ≈ 3.3 m), extends 77 km W–E through Transdanubia, Hungary. Because the Zala River delivers most of its inflow at the western end, the lake exhibits a persistent west-to-east trophic gradient from meso-eutrophic to oligo-mesotrophic conditions.
Balaton is polymictic: frequent wind mixing prevents stable summer stratification, although a weak diel thermocline develops in calm periods. Average residence time is ~2.3 years; alkalinity (≈ 2 meq L^-1) and pH (8.2–9.1) reflect the surrounding dolomitic catchment. Restoration measures—most notably the two-stage *Kis-Balaton Water Protection System* (KBWPS)—and upgraded wastewater treatment have reduced external phosphorus loads since the 1990 s, yet episodic internal loading still triggers cyanobacterial blooms.

Flora

Emergent and riparian vegetation

A nearly continuous reed (*''Phragmites australis''*) belt—locally mixed with cattail (*''Typha latifolia''*) and bulrush (*''Schoenoplectus lacustris''*)—fringes > 100 km of shoreline, providing spawning substrate, wave attenuation and nutrient sequestration.

Submerged macrophytes

Species richness peaks in protected embayments where Secchi depth exceeds 1.5 m. Dominant taxa include *''Potamogeton perfoliatus''*, *''P. pectinatus''*, *''Myriophyllum spicatum''*, *''Ceratophyllum demersum''* and charophytes such as *''Chara tomentosa''*.
Satellite-derived phenological metrics demonstrate that these macrophyte stands create pronounced spatio-temporal complexity in primary production dynamics and habitat structure.

Phytoplankton

Community composition fluctuates between diatom-dominated spring assemblages (*Cyclotella*, *Aulacoseira*) and summer cyanobacterial blooms (notably *Dolichospermum lemmermannii*, *Microcystis aeruginosa*) in the western basins, whereas chlorophytes and cryptophytes prevail farther east. In 2019 Balaton experienced a record-setting bloom with chlorophyll-a > 200 μg L^-1, attributed to climate-driven sediment P release.

Fauna

Fish

About fifty of Hungary's seventy-six native freshwater fish species occur. The littoral reed belt shelters cyprinids (common bream *''Abramis brama''*, bleak *''Alburnus alburnus''*), predator nurseries for pike-perch (*''Sander lucioperca''*) and northern pike (*''Esox lucius''*), and native endemics such as weather loach (*''Misgurnus fossilis''*). Feeding studies show cyprinids shift from zooplankton to benthic prey as they move inshore during summer.
Commercial fishing has been banned since 2013; invasive gobiids (*''Neogobius melanostomus''*) and Prussian carp (*''Carassius gibelio''*) are increasingly targeted by recreational harvest regulations.

Zooplankton

Rotifers (*Brachionus*, *Keratella*), cladocerans (*Daphnia cucullata*, *Bosmina longirostris*) and copepods (*Eudiaptomus gracilis*) dominate pelagic communities; densities reach 200–400 ind. L^-1 in Basin I but rarely exceed 100 ind. L^-1 eastward.

Benthic macroinvertebrates

Soft sediments host oligochaetes, chironomids and the invasive Asian clam (*''Corbicula fluminea''*). A 2024 lake-wide survey documented limited native recolonisation despite improved water quality, while alien taxa increased in rip-rap habitats.

Microbiota

Complementary 16S rRNA amplicon surveys show pronounced habitat and basin heterogeneity in the lake. A cross-lake transect in June 2017 revealed that planktonic communities are dominated by Proteobacteria (35–45 %) and Actinobacteria (20–30 %), whereas benthic sediments harbour proportionally more Proteobacteria (40–60 %), Bacteroidota and Firmicutes; Shannon diversity in sediments exceeded plankton by ≈ 25 %. The Zala River mouth contained distinct Betaproteobacterial (*Limnohabitans*) and Acidobacterial lineages, indicating the inflow as a hotspot of diversity.
Higher-depth sequencing, detected 951 OTUs distributed across 26 phyla, including rare Verrucomicrobiota, Patescibacteria (candidate division CPR) and Parcubacteria that were previously overlooked by lower-resolution surveys, underscoring a substantial "rare biosphere" component in Balaton. Viral metagenomes further indicate high cyanophage richness, suggesting top-down control of bloom-forming cyanobacteria.
High-resolution long-read sequencing of full-length 16S-rRNA genes on an Oxford Nanopore R10.4 flow cell, applied to water samples taken at 33 pelagic and littoral sites spanning all four basins, recovered > 6 000 high-quality amplicon-sequence variants (ASVs). While some bacterial families, such as Methylophilaceae and Cryomorphaceae, are evenly distributed throughout the lake, others like Comamonadaceae and Burkholderiaceae show localized abundance, being prevalent in certain areas and scarce in others. The use of the long-read Oxford Nanopore Technologies (ONT) sequencing has provided unprecedented insights into the genetic diversity and distribution of bacterioplankton across the lake. The high degree of shared taxa across all basins (209 taxa, 83%) suggests the presence of a core microbiome essential for the lake's ecosystem functioning. This core microbiome likely plays a vital role in maintaining ecological processes such as nutrient cycling and organic matter decomposition, which are crucial for the lake's health and stability. At the same time, the different groups identified between basins in lake water suggest a complex microbial ecosystem and highlight the need for ongoing monitoring to assess potential health risks and ecological change.

Conservation and management

Key measures include the KBWPS wetland complex, a 150-km² reed-management zone, a ban on commercial fisheries (2013) and riparian buffer restoration. Recent Sentinel-2 analyses reveal strong functional connectivity between KBWPS and the western basins, mediating turbidity and chlorophyll pulses. Persistent challenges include sediment-mediated internal P release, shoreline hardening that favours alien macroinvertebrates, and climate-driven bloom intensification.

Tourism

The major resorts around the lake are Siófok, Keszthely, and Balatonfüred. Zamárdi, another resort town on the southern shore, has been the site of Balaton Sound, a notable electronic music festival since 2007. Balatonkenese has hosted numerous traditional gastronomic events. Siófok is known for attracting young people to it because of its large clubs. Keszthely is the site of the Festetics Palace and Balatonfüred is a historical bathing town which hosts the annual Anna Ball.

The peak tourist season extends from June until the end of August. The average water temperature during the summer is , which makes bathing and swimming popular on the lake. Most of the beaches consist of either grass, rocks, or the silty sand that also makes up most of the bottom of the lake. Many resorts have artificial sandy beaches and all beaches have step access to the water. Other tourist attractions include sailing, fishing, and other water sports, as well as visiting the countryside and hills, wineries on the north coast, and nightlife on the south shore. The Tihany Peninsula is a historical district. Badacsony is a volcanic mountain and wine-growing region as well as a lakeside resort. The lake is almost completely surrounded by separated bike lanes to facilitate bicycle tourism. Although the peak season at the lake is the summer, Balaton is also frequented during the winter, when visitors go ice-fishing or even skate, sledge, or ice-sail on the lake if it freezes over.

Sármellék International Airport provides air service to Balaton (although most service is only seasonal).

Other resort towns include Balatonalmádi, Balatonboglár, Balatonlelle, Fonyód, and Vonyarcvashegy.

Sport

The annual Lake Balaton Crossing swim takes place in July. The race starts at Révfülöp and finishes at Balatonboglár for a total distance of 5.2 kilometres.

Towns and villages

North shore

From east to west:

Balatonfőkajár - Balatonakarattya - Balatonkenese - Balatonfűzfő - Balatonalmádi - Alsóörs - Paloznak - Csopak - Balatonarács - Balatonfüred - Tihany - Aszófő - Örvényes - Balatonudvari - Fövenyes - Balatonakali - Zánka - Balatonszepezd - Szepezdfürdő - Révfülöp - Pálköve - Ábrahámhegy - Balatonrendes - Badacsonytomaj - Badacsony - Badacsonytördemic - Szigliget - Balatonederics - Balatongyörök - Vonyarcvashegy - Gyenesdiás - Keszthely

South shore

From east to west:

Balatonakarattya - Balatonaliga - Balatonvilágos - Sóstó - Szabadifürdő - Siófok - Széplak - Zamárdi - Szántód - Balatonföldvár - Balatonszárszó - Balatonszemes - Balatonlelle - Balatonboglár - Fonyód - Fonyód–Alsóbélatelep - Bélatelep - Balatonfenyves - Balatonmáriafürdő - Balatonkeresztúr - Balatonberény - Fenékpuszta

Gallery

File:Balatonmáriafürdő, Hungary.jpg, Badacsony
File:Balatonalmadi06szept0005.jpg, Balatonalmádi
File:ShipsBalatonfüred.jpg, Balatonfüred
File:Zala estuary.jpg, The estuary of Zala river
File:Heart-shaped tombstones in Balatonudvari.jpg, Balatonudvari
File:Balaton in winter (1).jpg, Balaton in Winter
File:Fonyód.jpg, Fonyód
File:Balaton as seen from Alsórét szabadstrand.jpg, Balaton as seen from Alsórét, Balatonkenese
File:Kőröshegy catholic church.JPG, Kőröshegy
File:Balaton Hungary 2005 033.jpg, Siófok
File:Szigliget, vár 2.JPG, Castle at Szigliget
File:Benedictine Abbey on Tihany Peninsula - july 2007.jpg, Tihany
File:A tihanyi apátság.jpg, Benedictine Abbey on Tihany Peninsula
File:Zamárdi kilátás Kőhegyről.jpg, Zamárdi
File:A tihanyi félszigeten.jpg, On Tihany Peninsula
File:Naplemente a Balatonnál.jpg, Sunset at the lake
File:Balatoni látkép.jpg, A view of the lake
File:Balaton lake.jpg, View to lake Balaton from the Fonyod city

See also

* Balaton Principality
* Balaton Uplands National Park
* Geography of Hungary
* Kis-Balaton
* Transdanubian Mountains
* List of lakes by area

References

External links

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{{Authority control

Balaton
Ramsar sites in Hungary