Direct threats to Caspian seals include hunting, accidental capture in sturgeon fishing nets, periodic outbreaks of canine distemper virus, and water pollution. However, the Caspian seal population is also threatened by declines in herring, sturgeon, kilka, and other prey due to commercial fishing and the establishment in the Caspian Sea of comb jellyfish, which consume the zooplankton these fishes eat.
