Polar bears retreat into dens under the snow in order to have their cubs. Until recently this was an entirely sensible thing to do as these stems would survive very effectively until warm enough for the bear’s to emerge.
What changed recently? Well, the trump government has given permission for oil exploration to occur in this protected area. The vehicles that use are heavy enough to squash the snowdens- this is known and the oil exploration experts have scanners that tell them when there are bears under the snow. However analysis has shown that these are only about 45% successful.
Given that the destruction then often leads to the death of the cub it is critical for the survival of the polar bears in this important area. In a greater number of cases, the noise simply disturbs the mother bears making them emerge to early- still often leading to the death of their cub.
There is little that can be done about this, oil extraction in this area is essentially impossible without significant damage to the environment of the ecosystem within it. Pressure must be put on the oil companies to improve their detection capabilities as as under Trump drilling will not be stopped.