Unfortunately we are on a lake not the ocean so we do not have any whales nearby. There are boat cruises on the lake but there is not much wildlife to see.
No, the best you'll get is a ferry ride to Toronto Island, which is worth it. There are harbour cruises, mostly showing off Toronto skyline. We are fresh water, so there are no interesting animals or fish to see.
Make the time to take the Transit to the zoo. You won't regret the trip. Get there early though.. Most animals take big snoozes by lunch, especially since it has been so hot lately.
If you want ocean wildlife......head to the east cost. Not much to see on/in Lake Ontario.