Detour around areas where you see or smell carcasses of fish or animals, or see scavengers congregated. A bear's food may be there and if the bear is nearby, it may defend the cache aggressively. Give bears plenty of room. Some bears are more tolerant than others, but every bear has a personal space - the distance within which a bear feels threatened. If you stray within that zone, a bear may react aggressively.
Bears have only about six months to build up fat reserves for their long winter hibernation.
Don't let them learn human food or garbage is an easy meal. It is both foolish and illegal to feed bears, either on purpose or by leaving food or garbage that attracts them. Cook away from your tent. Store all food away from your campsite. Hang food out of reach of bears if possible.