Evolution of water quality of Lake Balaton

Abstract

Lake Balaton, a large shallow lake with some 600 km2 surface area, with its 3.5 m average depth, is among the shallowest lakes in the World and one of the most important lakes in Europe in terms of ecological, economic and cultural aspects. Intervention in the natural environment of lakes, especially shallow ones of high vulnerability and low resilience may result in detrimental and often irreversible changes. In case of Lake Balaton, irreversible changes include the reduction of lake level and subsequent construction directly on the lakeshore as well as introduction of foreign species such as eel and silver carp. Reasons for the negative results/impacts of the introduced interventions are: insufficient level of technical or scientific knowledge at the time of planning and implementation; poor decision support systems and mechanisms; insufficient consultation with local people and experts of other fields; lack of integrated approach, both in terms of territorial and interdisciplinary aspects; and pursuing of short term economic or political benefits. Compared to the situation one and a half centuries ago, many of the reasons leading to adverse effects can be eliminated because technical and scientific knowledge is increasing with high speed and huge amount of monitoring, etc. data are becoming available; decision support systems and mechanisms are getting faster and are improving in complexity; consultation with, participation, and empowerment of local people, stakeholders and a diverse choice of experts are becoming basic requirements in environmental and spatial development policy; integrated approaches both in terms of territorial and interdisciplinary aspects are gathering momentum. It would be of great importance to stop pursuing short term economic gains and political benefits when significant interventions into lake environments are considered.