1. Killer Whales (Orcas): Killer whales are considered apex predators and are known to prey on seals. They are highly intelligent and hunt in coordinated groups, making them formidable predators of seals.
2. Sharks: Several shark species, such as great white sharks, tiger sharks, and Greenland sharks, are known to prey on seals. Seals often share habitats with these sharks, and encounters between them can lead to predation.
3. Polar Bears: In Arctic regions, polar bears pose a significant threat to seals. Polar bears are skilled hunters that actively prey on seals, especially during periods when seals haul out on ice or give birth on ice floes.
4. Sea Lions and Fur Seals: Some sea lion and fur seal species are known to hunt and prey on smaller seal species. For example, the Antarctic fur seal preys on crabeater seals and Antarctic fur seals.
5. Humans: Unfortunately, humans have also been significant predators of seals historically and continue to pose threats through hunting and overexploitation in some areas.
It's important to note that the specific predator-prey relationships and the level of predation can vary depending on the seal species, geographic location, and environmental factors.