Both of my friends who have worked in Alaska were issued 12 gauge pumps with slugs, one specifically for polar bears (he was doing bowhead whale counts from a remote camp on the sea ice. He was also issued a bear alert dog trained to bark if it detected a polar bear). The other guy did bear security in grizzly country literally riding shotgun over fisheries workers doing salmon and stream survey work. If you have a guy with you I'd recommend he carry a short-barreled 12 gauge with a sling - and of course some practice with it.
The guys working protection for the fish crews practiced turning and locating a grapefruit placed randomly behind them, had to be able to consistently put a slug in the grapefruit within 1 second before they were qualified.