The third field season has ended: the memory of alpine lakes

The first snow has fallen and our field season on the alpine lakes has come to an end. It’s time to say goodbye. The months (the years) spent on the mountains have established ties between ourselves and the places to which we dedicate so much time and so much work, and the separation has turned into a small private rite, typically ending in one last nostalgic look. All the while, the mountains keep their cool and watch our departure without returning our feelings of longing. But the alpine lakes are different!

There is something about the lakes you can fantasize about: the lakes “remember”… they have a memory that goes back thousands of years and that will still be there centuries from now, when everything that has ever been, or will ever be, known or recorded will have been erased through the passage of time. Sediment, in fact, settles at the bottom of the lakes in less than millimetric layers, which serve as a veritable historical log of ecological changes in the Alps.  Each layer retains the remnants of the small creatures that populate the high altitude lakes: fragments of bugs and crustaceans, pollen, sub-fossil algae. These remnants can be used as paleoecological indicators to work out what the Alps must have been like in ages past.  Each layer keeps track of the changes that occur, and the sediment will preserve the memory of the years spent to eradicate the alien species from the lakes of the Park and to restore the aquatic habitats to their natural state. The sediment will keep the fragments of the insects and the crustaceans that had been brought to extinction by the fish, and that now, at the end of the third season of fieldwork, have returned to populate the alpine lakes. We could fantasize about a naturalist of the future studying the lakes of Park and wondering about the changes recorded in the so called sedimentary register. And we could also fantasize about a lake that “remembers” us. But what will those memories be? It will remember that by 2015 the alien fish species had disappeared from 2 of the smaller lakes included in the BIOAQUAE project (in  Lake Nero and Lake Djouan the eradication program has been completed) and the results obtained made it possible to feel confident about completing the project in the Dres Lake and the Leynir Lake too (we have not been able to catch a fish from the Dres Lake for more than 50 days and for 30 days from the Leynir Lake… let’s keep our fingers crossed!). Thanks to the eradication or near eradication of the fish population, the lakes will remember the return of Trichoptera, Daphnias, Plecoptera, aquatic gasteropodes, Heteroptera, frogs, etc...

Now the laboratory work and data processing season begins, but the next field season will be decisive and (who knows?) will be “remembered” for ten thousand years and more!