If they are harmed by global warming it is because they do much of their hunting for seals that have breathing holes in the ice sheet. (dotearth.blogs.nytimes.com)
After walking across a frozen lake one morning, a boy and his grandfather make holes in the ice, drop their fishing lines into the water, and wait. (booklistonline.com)
If the ground had been blue the forms might have looked like islands in a sea but as some of the forms are themselves blue, maybe they more resemble fishing holes in ice. (patternsthatconnext.wordpress.com)