According to CRA for immigrants:http://www.cra-arc.gc.ca/newcomers/#whtr
For the part of the tax year that you WERE NOT a resident of Canada
You have to report the following amounts:
- income from employment in Canada or from a business carried on in Canada;
- taxable capital gains from disposing of taxable Canadian property; and
- taxable part of scholarships, bursaries, fellowships, and research grants you received from Canadian sources.
You report world income only after you become a resident of Canada
As you received all the pension before becoming a resident of Canada, you do not report it so it should not affect your net income
