Food for Thought

If you suddenly had nothing to eat but popcorn and chips, you might enjoy your meals for a while, but sooner or later that junk food diet would take its toll on your body. Your immune system wouldn’t be as effective at fighting off diseases. You’d become tired more quickly. You wouldn’t have the energy to do much of anything.

Travel with sea lion researchers as they collect evidence to help determine what Steller sea lions
are eating.

Video screenshot of sea lion researchers in an aluminum boat. Click to watch the video

Steller sea lions in Alaska may have the same problem. As the amount of Steller “health food” in the North Pacific decreases, they have to turn more and more to their version of “junk food”. Instead of eating their usual diet of nutrient-rich salmon and herring, they are now eating the less nourishing pollock and cod. As a result, they may not be getting the nutrition they need to grow, keep healthy, have babies, or escape from danger. Scientists call this the “junk food hypothesis”.

Scientists are not sure why the quantity of different types of fish living in the North Pacific has changed so much. This change might be due to global warming, overfishing, or other changes in the ecosystem. Whatever the reason, diet may be playing a great part in the mysterious decline of the Steller sea lion.