Background Info

For two million years, the world's largest sea lions have survived along Alaska's rocky coastline, but now the population is declining at an alarming rate. Wild Chronicles joins a team of scientists using Crittercam® to investigate theories about the Steller sea lions' mysterious disappearance, and uncover clues that could save the species.



Why does Richard, a biologist, call the declining population of Steller sea lions "a great mystery"?

Show Answer

The population of Steller sea lions has shrunk radically, but, as Richard says, "there are no bodies." Without bodies, biologists are unable to analyze the health or circumstances surrounding the animals' deaths.


Don, another biologist, studies the health of Steller sea lions. What does he find?

Show Answer

Steller sea lions weigh less today than they did 20 years ago.


What is the primary food source for Steller sea lions?

Show Answer

Walleye pollock (also called Alaska pollock) accounts for more than half of a Steller sea lion's diet.


What other predator hunts this food source?

Show Answer

People have developed an enormous pollock fishery in Alaska.


Competition for food may contribute tothe declining population of Steller sea lions. What may be other contributing factors?

Show Answer

Scientists are researching the effects of pollution and changing water temperatures on Steller sea lions.

For Further Exploration


Term Part of Speech Definition Encyclopedic Entry



edge of land along the sea or other large body of water.

Encyclopedic Entry: coast



camera designed to be worn on a wild animal, providing a "critter-eye view" of the animal's environment.



to reduce or go down in number.



total number of people or organisms in a particular area.

sea lion


marine mammal.


Media Credits

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Caryl-Sue, National Geographic Society

Page Producer

Tom Kist

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