Polar bears appear particularly disturbed by snowmobiles and boats and often show avoidance behavior long before people see the bear. Given the relative safety of approaching a polar bear from vehicles of all sorts, it is common for people to approach to get a better look. The impact of this type of harassment is unknown. However, in one case, a mother was chased so long that she was separated from her cub that was caught and photographed. In another case in Svalbard, two people chased a polar bear for an extended period. However, the event was recorded on video and charges were laid that resulted in a substantial fine. Chronic harassment may result in polar bears abandoning preferred habitats with long-term implications for the population.
Other problems occur as well. Photographers are notorious for wanting the “full-frame” photograph and to obtain this, some resort to baiting polar bears or following them from snowmobiles. This type of harassment can occur with amateur and professional photographers and filmmakers. In one situation, a film crew followed a female polar bear with new-born cubs for a week and were surprised that she had not yet killed a seal. It was likely that the persistent harassment was affected her hunting success. It is difficult to assess the potential impact of this type of activity but after emerging from a maternity den, a female must soon begin feeding again to replenish her fat stores so she can continue to nurse her cubs. Failure could mean the death of her young.
Some tour operators have baited polar bears into tourist vehicles so passengers can see and photograph the bears close up. Such situations can cause problems when mothers with young venture into areas that they would normally avoid: specifically, areas with lots of other bears that may kill their young. Juvenile polar bears have been killed by adult males when their mothers have been baited into tourist vehicles.
In many areas, polar bears have been killed at cabins or remote stations when they arrive to investigate food smells. Habituation of polar bears to humans leads results in polar bear that are more likely to seek out humans. Polar bears are fast to learn that human settlements may provide food. Habituated polar bears are often killed when they approach settlements or camps.
Other human-based threats to polar bears do exist. These can include garbage dumps. In Churchill, Manitoba, several polar bears have died from eating items as diverse as sardine cans and lead acid batteries. Improved management of bears near the garbage dump in Churchill has greatly reduced this problem. In Alaska, a polar bear was killed when it ingested anti-freeze mixed with dye to mark an aircraft runway on the ice. In another case, a polar bear drank several litres of hydraulic fluid with unknown consequences.
All-in-all, polar bears are curious and not particularly selective in their diet. This combination leads them into conflict with humans and as human activities increase in the Arctic, it is likely that polar bears will be more affected. However, relative to other threats, the impacts of tourism and related activities are minor and with good management, the impacts can be controlled.