Sea Otter Facts

  • California’s southern sea otter has been listed as a threatened species under the Endangered Species Act since 1977.
  • Currently the southern sea otter population is estimated at just above 3,000 animals.
  • Sea otters play a vital role in the health and stability of the nearshore marine ecosystem as a keystone species
  • Sea otter fur is the densest of any mammal at about 1 million hairs per square inch. (We have 100,000 hairs on our entire head)
  • Wild sea otters typically have a lifespan between 15 and 20 years.
  • A group of sea otters resting together is called a raft.
  • Sea otters are one of the few animals that use tools.
  • Sea otters have no blubber so they constantly groom themselves to maintain the insulating & water repellant properties of their fur.
  • An otter must consume 25% of its bodyweight in prey each day just to stay alive (for a 75 lb kid, that’s 75 1/4 lb burgers!).
  • Sea otters eat many kinds of invertebrates, including sea urchins, abalone, clams, crabs, snails, sea stars, squid & octopuses.
  • Unlike northern sea otters found in Alaska, southern sea otters here in California don’t eat fish.
  • Sea otter moms typically nurse their pups for about 6 months before weaning them.
  • Newborn sea otter pups are so buoyant they can’t immediately dive for food. Pups begin to dive and forage at about 2 months.
  • Sea otters can hold their breath over 6 minutes. Average dive = 60 feet but have been known to dive to depths of nearly 300 feet.
  • Sea otters have built in pouches of loose skin under their forearms to stash extra prey when diving.
  • Sea otters eat sea urchins & other invertebrates that graze on giant kelp. No sea otters, no kelp forests.
  • White shark bites are now the leading cause of sea otter mortality in California.
  • Large percentage of southern sea otter mortality is due to infectious diseases, many of which are known to have anthropogenic causes.
  • Threats to population recovery include white sharks, pathogens & parasites, food limitation, coastal pollutants and oil spills.
  • Sea otters are equally active both night and day.