When the authorities in Quebec heard news of ships arriving with sick passengers, they quickly set up Grosse Île as a port of entry and quarantine station at which all ships were required to dock before moving on to the mainland. The island had dealt with epidemics before. In 1830, about 30,000 immigrants arrived in Quebec, and two-thirds were Irish. These huge waves of immigration were concurrent with cholera epidemics in Great Britain and Europe. Areas in the west of Ireland – mostly Mayo, Donegal and Galway – were also experiencing potato crop failure. In fact, the crop failed to various degrees all over the country throughout the 1830s, though no one is sure exactly when the blight that caused the successive crop failures of 1845-49 arrived in Ireland.