 The effect of European colonization was a 40 to 80 percent Aboriginal population decrease post-contact.This is attributed to various factors, including repeated outbreaks of European infectious diseases such as influenza, measles and smallpox (to which they had not developed immunity), inter-nation conflicts over the fur trade, conflicts with colonial authorities and settlers and loss of land and a subsequent loss of nation self-suffiency.For example, during the late 1630s, smallpox killed more than half of the Huron, who controlled most of the early fur trade in what became Canada.