You need to have a work permit(?) or be a permanent resident/citizen of Canada to qualify to take the exams conducted by Transport Canada - Marine. You can't work in Canada without one or the other. Once you are in Canada (if you aren't already) go to the nearest TC marine office with your documents and they will advise you. Since you have a 1st Class licence, you will probably only need to take the EK general and motor exams and the oral exam; but again TC are the ones who will decide. Once you pass your exams you will receive a Canadian ticket and CDC.
For a shore job as a mechanical engineer, you need to contact Professional Engineers of Ontario (PEO) (other provinces have similar governing bodies) to find out what you need to do to get your degree recognised in Canada. Generally, degrees from most countries are not recognised in Canada. It will probably take you a couple of years of exams and apprenticeships to get qualified; but that's just a guess, I don't have too much info about it.
Another option is to get a Stationary Engineer licence from TSSA. They will assess you on the basis of your work on boilers and power generation and let you know what exams you can take to qualify. A Stationary Engineer keeps a watch on power plants and manufacturing facilities ashore, also hotels, hospitals, etc. You need to have your watch-keeping certificates showing boiler capacities.
You could find a Superintendent job in Canada; best places to look for one would be Montreal, Halifax, St. Johns and Vancouver. Check the job postings on this site as well as www.indeed.ca
Right now, I don't believe there's any shortage of engineers due to the current economic situation in Canada but things can change very quickly.