Now sea otters are in the news as the center of an ecological mystery.
Orcas appear to have developed a taste for sea otters in parts of Alaska.
Hunger may be the cause. The longer answer to why the otters are disappearing, or why the whales have suddenly started eating them, may be as complex as the coastal ecosystem itself. The more complete explanation of the orcas' sudden interest in otters appears to be overfishing by humans. Seals, in turn, need oil-rich fish such as salmon and herring to survive in the cold northern waters, but these fish are also prized by humans, and their populations have dropped as a result of improving fishing technology and strong world markets for fish. Fish catches both near shore and off-shore have climbed steadily in recent decades, even as fish numbers have fallen.