Zingel asper and spined loach which are both endangered species of fish. But the silting and the lack of oxygen has greatly reduced the number of trout. The European brook lamprey has been seen in recent times but it may have disappeared since. History The Durance played a very important part in the history of Provence, and largely contributed to the economic growth and population of the Marseilles area, after having been an obstacle for centuries. From Antiquity until the 19th century, the Durance was famous for the difficulty of crossing it, its massive floods and an inconstant flow. The width of its bed, the force and depth of its current, and the changes of course after the floods hindered crossing by ford. The only durable fords are those of Mirabeau and Pertuis, obviously unusable in periods of floods. The changes in the flow also limited river navigation (in spite of size of the river in periods with a high flow. It sometimes needed several ferries to cross the various arms or channels. The unstable and sometimes steep banks prevented easy access to ferries. In more recent times even suspension bridges often had to be re-built after floods. Prehistory Twelve million years ago, the Durance flowed directly into the Mediterranean. During the Riss glaciation, the source of the Durance was at Sisteron, where the icecap finished. As the ice-cap receded, the Durance course changed towards the west, between Luberon and Alpilles, and flowed into the Rhône. Antiquity In pre-Roman times, the Durance was the border between various Celto-Ligurian people established along its course, such as the Cavares (Cavaillon) and the Salyes (Bouches-du-Rhône). The valley of the Durance is a route through the Alps, used by the Via Domitia. A statue of Janus was erected at Montgenèvre, the only passage between Cisalpine Gaul and Gallia NarbonensisStrabon (1st century) reported that a ferry was established in Cavaillon, The great Roman way from Spain to Italy only crossed the Durance at Cavaillon and Sisteron. The existence of a bridge at Sisteron was recorded. At other places there were ferries, in particular at Pertuis, whose name is based on it ferry. Although it was difficult to cross, except in Sisteron, the Durance was nevertheless navigable. The bas-reliefs at Cabrières-d'Aigues depict the river being used for the transport of various liquid food products such as wine and olive oil. Gallo-Romans used the towpaths () and