Lake Pollution at Spiaggia degli Olivi Linked to Bird Waste, Not Boating
While awaiting the new inspections by the Azienda sanitaria (which will allow the restoration of bathing safety only after finding acceptable coliform bacteria levels for four consecutive surveys), Riva and the lake are questioning the potential causes of organic pollution at the Spiaggia degli Olivi. Today we share the considerations and hypotheses of Giancarlo Angelini.
“In announcing that the samples taken by the Azienda sanitaria in the area of the Spiaggia degli Olivi tested positive for bacteria in the water, one of the suggested causes for this phenomenon has also been attributed to ‘the bad habit of some boat owners to clean, and perhaps even discharge toilets onboard, into the lake near the shore’.” Furthermore, there was an hope expressed for “a civil correction from unruly navigators”.
Clarifications about the presence of toilets and responsibility
It is important to clarify immediately that boats do not have onboard toilets. The larger vessels have a toilet, but with direct discharge into the water, hence there are no toilets on board. But, at this point, to prevent unjust blame on those with no fault, let me be as clear as possible.
Recreational boating, in our area, is conducted with daily outings, making it unlikely that those setting sail around 9–10 in the morning would be doing their business on the boat, as by that time, they are already “settled”. When necessary, urination occurs offshore, and upon returning to the port, visitors use the new, much more comfortable facilities of the Circolo, which include sinks, showers, and, of course, toilets. It is not credible that they would do so onboard just to then discharge in the lake.
Even the rare tourists who arrive at our small port and stay overnight are provided, at the time of docking, with keys to a dedicated sanitation facility specifically built for port visitors, equipped with all comforts, including sinks, showers, and toilets. It is implausible that they defecate onboard only to discharge into the lake.
The increase in bacteria, if anything, is due to the dense bird population that inhabits the calm waters of the natural pool at the Spiaggia. Ducks, geese, and swans excrete significant quantities directly into those few centimeters of water that remain.
This water, due to the lowered levels, is unable to benefit from lake currents and self-purification. This phenomenon has been observed in the past and is linked to the large population of waterfowl, which find it easy to stay in these spots because, despite an ordinance prohibiting it for several years, some people still bring bread bags.
Responsibility and bird movement
The birds, finding it easy to stay, do not migrate in search of new habitats: thus, they turn the channels of Rocca and the area of the Spiaggia into a genuine poultry farm.
The Municipality also bears responsibility. Because, in addition to the ordinance, there should be multilingual signs to make the ordinance publicly known and to facilitate intervention by the town police (who know well the few people who sell bread) to curb this phenomenon, which is fueled by a misguided sense of animal welfare.
Furthermore, there is another phenomenon to be monitored. It concerns the sewer outlet that flows into the Gulf of Lido, on the left side of the external slipway of the Fraglia. During heavy rains, all sorts of matter, including, apparently, dark, foul-smelling sewer waste, is discharged, then carried by the wind and currents into the port and the Spiaggia degli Olivi.
What could this be? It would be advisable to investigate!