Look for the white scar tissue or a pink muzzle on a recently bred female. Mom will carry the pup on her chest while at the surface and leave the pup floating like a cork in the water while she hunts for food. The pup will make a shrill cry calling for the mother. Pups learn to dive at 6 weeks and are weaned by the mother at 5 to 8 months. Otters have few natural predators, although attacks by white sharks and killer whales have been documented.
Humans are by far the most effective predators.
Some otters are lost each year to gill net fishing and gunshot wounds. When an oil spill coats the fur, an otter is kept from effectively grooming, and the animal can die in a short time from exposure and the inhalation and ingestion of the toxic oil and fumes. More About Cetaceans Whales and dolphins are the most highly adapted of the marine mammals. Most are fast-swimming predators with many adaptations for finding food. They can dive to great depths and hold their breath for a long time.