THE RIVER: the first 10 kilometres of the lower reaches of Ticino are devided in two sectors thanks to the presence of three dams (Miorina’s dam, Porto della Torre’s dam, Panperduto’s dam). By the regulation of such dams you can modify the river capacity, feeding in case of need, a serie of other lateral canals, well-watered and industrial.
All these things are necessary to manage the floods of Lake Maggiore, the lake from which the Ticino lower reaches come out. Lake Maggiore, which has a variable surface between 210 and 250 kilometres squared, counts 33 tributary rivers and only one emissary river, Ticino lower reaches. During the Alps snow melting, and under strong and prolonged rains, those 33 rivers get floods and the lake level could rise even more than 1 metre and a half per hour; think about what happened in the past when those three dams were not there yet.
There were destroying Ticino overflows, with some cases of tens of thousands of victims. This dams and canals system allows to manage the level of the whole Lake Maggiore, and has allowed to keep in safety the whole area near the river, making the overlooking lands bearable and cultivable.
The Lombard bank on the side between the second and the third dam hangs on my domicile municipality, Somma Lombardo. My studies and my researches about Ticino flora and fauna are usually carried on that side, a part of river which sometimes seems to be as static as a lake, and other times flows fast, with level sudden changes which could even reach lots of metres during only one day.
Since 2002 the Ticino lower reaches entered in the program MAB (Man and the biosphere) of the UNESCO.
For videos and photos visit my blogs www.ticino-underwater.blogspot.it and www.ticinoriverpark.blogspot.it.
THE FISH: The Rhodeus amarus is a small fish of the Family Cyprinidae, from the river Danube, in Central Europe, but since two decades is widely present in almost all the Northern Italy river systems. In the Ticino lower reaches its presence became so invasive to provoke the quite entire disappearance of almost all local species of small size, for example the Alborella (Scientific name: Alburnus arborella).
Rhodeus amarus is an omnivorous specie, but which feeds itself especially with covering riverweeds of micro-invertebrates and stones which live in there. It prefers quiet waters, with a good presence of water plants. It especially stays near the river floor and it reproduces incubating its eggs in the bivalves, in particular of Unio and Corbicula, with who it shares in the Ticino the same habitat.
THE AQUARIUM: with this setting I tried to represent in 1 : 1 scale, a portion of the river bank floor, with a small free and beached space among the stones, good for the placement of bivalves. I wanted to demonstrate what happens during the periods when the river level decreases a lot, for example in the end of the summer, with long-stemmed plants which start to get entangled creating formless masses, ugly to see, but full of micro-life.
Everything in the aquarium (floor, sand, stones, some wooden objects, plants, sleeves, fishes, invertebrates and water) has been taken from the river, directly from the Rhodeus amarus habitat, which I’ve been studying for two years.
Twice a month I take 10 litres of new water from the river, together with some floor mud and some drifts, which I suddenly put in my aquarium during the partial changing.
I apologize for the use of invasive species in this tank, but the situation of the lower Ticino is this, since I was a child. Many native species have disappeared, or very very rare, or too large to display them in a home aquarium. I preferred to show the truth.
Rhodeus amarus habitat in river Ticino
Lagarosiphon major, Vallisneria sp. 'Italia'
10 Rhodeus amarus, some small Corbicula fluminea, 1 Unio sp., some small snails (Bithynia tentaculata, Physella acuta, Gyraulus acronicus, Lymnaea auricularia, Theodoxus fluviatilis, Helisoma sp.), larvae of Potamophylax sp.