One former fisheries enforcement officer told me that a captured sea lion can be so belligerent that fishermen sometimes have to kill it before trying to remove it from the deck of the boat. For years Canada sanctioned killing sea lions to keep their numbers in check. A decade ago the Steller sea lion, which is about twice the size of its cousin, the California sea lion, was placed on the endangered species list. What's at stake here is not just the sea lion, but the health of a robust fisheries industry. About half the fish landed in the United States comes from the Gulf of Alaska and the Bering Sea.
Males can weigh more than a ton and, when captured, are known to be belligerent.
Most experts believe competition for the resource is what's killing off the sea lions, but Horning says that's not necessarily so. Horning is less than a year into a multi-year effort to attach devices to sea lions that will allow his team to study up to 100 animals from adolescence to death. Inside Tracking Other scientists have already used satellite-tracking devices on sea lions, but these were glued to the hair of the sea lion. When the animal molts, as it does each year, it sheds the hair as well as the device, limiting the research to less than a single year. The devices will collect data throughout the lifetime of the animal.