Bonneville Dam on the Columbia River

About a thousand miles after the Columbia's birth in Canada, it passed through the Columbia Gorge between Washington and Oregon. Because electrical power was desperately needed and because the river also was full of rapids that impaired navigation, Bonneville Dam was completed in 1937. One of the features became ever more important -- a fish ladder to help and protect spawning salmon returning to the miles of waterways of the Columbia River. Salmon varieties do this at different times and the numbers today are responding to greater care given to habitat and environmental issues. However, sea lions haven't read the rules and, being pretty smart, realized if they just hung out at the foot of the ladder, the salmon would follow the ladder, jumping up from one level to the next. Hey, a feast for an agile sea lion. For years these critters have become a real problem or enigma. They are protected from destruction, too, but increasing numbers found the the easy buffet of salmon at the ladders. Authorities have captured consistent eaters and removed them far down the Pacific, only to see them return as fast as their flippers can go. Can't win 'em all.  What to do. A real enigma for fish monitors. It's an ongoing puzzle.