Today most of the seal hunting in Canada is done commercially and while the traditional hunt still goes on with the aboriginal people but make up smaller number. Modern commercial seal hunting is done with high powered rifles with approved ammunition and a club called hakapik. This commercial hunt mostly happens in Newfoundland and Labrador, with harp seals making the majority of seals hunted and the remaining numbers are mostly made up of grey seals. The Canadian government asserts that these seal hunts are substantial employers in the rural community and make up a considerable part of their yearly income.
http://i.cbc.ca/1.2468739.1438550507!/cpImage/httpImage/image.jpg_gen/derivatives/16x9_620/arctic-seals.jpg
Seal clubbing generally refers to the act of using a hakapik to strike and kill a seal by crushing its skull and its brain. Seal cubs are generally targeted as they have the most valuable coat (though white coats are now banned in Canada more on this later).
Source; http://www.unmaskingchoice.ca/sites/default/files/imagecache/original/images/sr-8.jpg