Lake Garda Algae Monitoring to Address Macrophyte Spread in 2023
For the first time, this year the Regione Lombardia will conduct a monitoring study on the algae and submerged macrophytes phenomenon in Lake Garda. The Directorate-General of Health informed the relevant districts of the ASL about this, explaining that the checks will be carried out alongside the usual sampling procedures used to assess water quality, which are also used to verify bathing conditions.
The macrophyte phenomenon, involving aquatic plants that at a certain point in their life cycle detach from the lakebed in large quantities to reach the surface (and decompose), began around five years ago in the Benaco. So far, the problem has been confined to the southern area of the lake, characterized by extremely shallow depths; however, the possibility that it could spread to nearby areas is not entirely ruled out. Despite numerous proclamations made over the past years, the issue has yet to be addressed with proper decisiveness.
Cause and Responsibility of the Problem
The primary cause lies in the shifting of responsibility and competencies among state agencies, provinces, and municipalities. It is important to note that the competence for interventions falls under the Autorità di bacino del Po, to which Lake Garda is functionally connected. However, due to limited available funds and likely slow (or incompetent) decision-making processes, the algae issue has remained practically stagnant: no significant progress has been made, despite continuous and pressing requests mainly from the mayors of Peschiera and Sirmione.
These two municipalities have been the most affected by the appearance of aquatic weeds. In recent years, aside from 2000, tons of plants detached from the lakebed would end up on beaches and in ports, rotting under the hot summer sun. Hundreds of millions of euros have been spent by the two local administrations to curb the phenomenon and prevent the coastlines from being covered by a mountain of foul-smelling vegetation.
Initiatives and Future Perspectives
Later, after yet another summit with the Autorità di bacino, with managers of the provinces of Brescia and Verona, the ASL, the Garda Community, and municipal administrations, it was decided to establish a scientific committee to clarify the causes behind the proliferation of macrophytes. There was also talk of a weed-cutting boat, but nothing has been heard of that project either.
