I don't care what anyone thinks, an animal that weighs more than a car and can swim faster than Mark Phelps is a menace when they come up our rivers. They belong in the ocean--period. At least there the fish have a chance. In rivers like the Columbia, it is a killing ground (water) for the sea lions that decimate our fish runs.
The ignorant environmentalists who think that the seals and sea lions are just making a living have most likely not witnessed a pod of sea lions tearing fish apart, just for the fun of it when they've got their bellies full.
While attacks by sea lions may be rare, they are far from being unheard of and I think they will become more frequent as the animals become more familiar with people and the little boats we paddle. Just a few years ago, it was rare to see a seal, or sea lion up close. They were very shy and would go out of their way to stay clear. In the past few years the sea lions and seals have become very curious and now will go out of their way to check you out. I've had them follow me for some distances and a lot closer than I felt comfortable with. They most likely aren't contemplating any kind of attack, but they just might want to have a closer look at your kayak. I've seen pictures of small seals sitting on the bow of a kayak. I don't know about you, but I don't want a 3000 lb sea lion resting on any of my boats.
This might seem extreme to some, but I think the natural balance was much better when the commercial fishermen used to instill fear in the beasts when they came up the river and messed around with their nets.