LIMNOLOGICAL STUDIES ON LAKE MAGGIORE FUNDED BY THE CIPAIS

(International Commission for the Protection of Waters between Italy and Switzerland) (Link: http://www.cipais.org/)

The International Commission for the Protection of Waters between Italy and Switzerland has been established in 1978 (Italian Law n: 527). Its major aim is the protection of surface and underground waters shared between the two countries (Lakes Maggiore and Lugano) from pollution, by promoting research programmes. The long-term studies performed on the two lakes and their watershed since many decades integrate the monitoring and control activities run by local institutions. As to limnological studies, the on-going programme (2019-21) includes regular limnological campaigns performed by the CNR ISE to assess physical, chemical and biological aspects. Results of these campaigns are published in annual reports. (last report)

The research on water chemistry evaluates the seasonal and long-term evolution of the main chemical features of the lakes and its tributaries. Recent results highlighted a condition of limited mixing depth at the end of the limnological winter (late February-early March) due to mild weather condition. The persistence of this situation since several years is promoting an increasing stability of the water column and a limited interchange between surface and deep water, with consequences on water chemistry i.e. decrease of dissolved oxygen and accumulation of nutrients in deep water. Meteo-climatic variables also affect nutrient load from the tributaries, which show a great interannual variability related to hydrology. Long-term research on Lake Maggiore overall demonstrate the relevant role played by meteo-climate drivers in the evolution of lake chemistry and water quality and confirm the need for long-term, possibly high frequency investigations.