Hungary’s Lake Balaton will no longer be the largest freshwater lake in Central Europe?

As we all know, Lake Balaton is Central Europe’s largest freshwater lake. However, the water of the Hungarian Sea is going through a significant change due to human intervention. Lake Balaton is getting saltier and saltier which is a danger to its wildlife.

VEOL asked an expert to answer questions surrounding the changes in Lake Balaton’s water composition. Lajos Vörös, a member of the Balaton Limnological Research Institute, talked about the lake’s future. He said:

Up until the middle of the last century, Lake Balaton was the largest freshwater lake in Central Europe, but that has changed. The water of Lake Balaton is no longer fresh water but is now also called “fresh-salty transitional water” in the local terminology.

According to the internationally accepted classification, the upper limit of total salinity in freshwater is 500 milligrams per litre. Lake Balaton was under this limit until the mid-twentieth century. Today, the salinity of the lake is around 700mg/litre.

Why is the water so soft and silky?

According to Lajos Vörös, the water of Lake Balaton is slightly alkaline, which makes it soft and silky. On the pH scale, water with a pH of 7 is neutral, however, the “Hungarian Sea” has a pH level of 8.5. The expert says:

The waters in our area and in our rocky shelf have three main mineral components: calcium, magnesium, and bicarbonate. Calcium and bicarbonate dissolve from limestone, and magnesium from dolomite. The waters flowing into the lake contain a lot of carbon dioxide.

As the water settles in the bed of Lake Balaton, the dissolved carbon dioxide slowly equilibrates with that in the air. Calcium carbonate (limestone) forms because of chemical reactions. Therefore, calcium might be the dominant element in the inflowing water, but magnesium is the dominant element in the water of Lake Balaton.