Why did Japanese canadians get evacuated during world war 1?

In Canada, they were interned at Hastings Park (where the Pacific National Exhibition is), because of a few reasons. Firstly, it was a chance for the population to get back at the Japanese (and Asian community), because the mentality of the public was that Canada should be a "white man's land", without any outside influences. In addition, they feared that the Japanese-Canadians would lead the Japanese submarines along the coast in their fishing-boats, and were secretly acting as spies.

Although this public hysteria was uncalled for, as determined by the RCMP and the government, the internment of the Japanese was demanded by the public. Many were sent to labour camps, else sent to the interior provinces, where they were far away from the coast. Their possessions were auctioned off, and they never were paid for the profit.