The Origin of "Blue Noses"

My dictionary says bluenose is

  1. a puritanical person
  2. a person or ship from Nova Scotia

Separately, they don’t explain the term as commonly used.
Puritan’s noses aren’t blue.
Nova Scotians may have blue noses, but aren’t known to be pritanical, are they?

And there weren’t any Puritans in Nova Scotia, were there?

Isn’t the ship on the Canadian dime the Blue Nose?

Look under the term “Blue blood”.

As in people of “aristocratic” lineage who have such thin skin that their veins are visible, or have such inbred genetics that cardiac birth defects are common enough to render their blood chemistry oxygen deficient.

I’m pretty sure that it is simply coincidental that bluenose has those two separate meanings.

The aspect of being puritanical probably is drawn from the Blue Laws and is simply an insulting way to identify a person who would be willing to impose Blue Laws (no retail commerce, no movies or theaters, and no alcoholic sales on Sunday, for example) on society.

Nova Scotians get their blue noses from being out in the arctic gales along the Grand Banks fisheries.

this site offers much the same as tomndeb posted, but would offer a bit more detail.