Per i pescatori professionisti è una catasfrofe. Nelle loro reti non abbondano più i pesci, ma le conchiglie. Le loro entrate sono fortemente diminuite negli ultimi anni a causa del proliferarsi della Dreissena rostriformis, comunemente chiamata: “cozza quagga”.
Ed è un problema anche per l’azienda dell’acqua potabile. Questo organismo altamente invasivo, a differenza delle specie locali, lo si trova anche a 200 metri di profondità. Si aggrappa alle pareti delle condutture. Per evitarne l’ostruzione la manutenzione si è intensificata, passando da un’ispezione ogni 10 anni a due controlli all’anno.
Al momento non vi sono ancora soluzioni per contrastare l’avanzata di questa specie altamente invasiva, che crea problemi anche in altri specchi d’acqua svizzeri, dal Bodanico al lago di Bienne.
MarJa
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