Depends on the seal. I don't know if any of the Arctic seal populations are significantly endangered. The only one that I can think of that is showing a significant decline is the Steller's sea lion, and that's probably due to alteration in fish availability in the Bering Sea and north Pacific Ocean. (And I remember reading that the decline in the Steller's sea lion, a favorite orca repast, is causing orcas to target smaller morsels, like sea otters.)