Have to comment the bull trout in our local waters. While it is true that they are definitely a major fish eater they are part of the natural ecosystem and play a healthy role in the system. In fact they are an excellent indicator of the over all health of a river system. They require high quality habitats in the headwaters for spawning and early rearing, access to the estaury and near shore marine waters as well as a health forage base.
When caught on appropriate sized tackle they provide a spunky fight and have supply an interesting diversion many otherwise slow days on the river.
Bob -
You said "That being said, if we try to manage one population and not the others (this could be seen both in few numbers - bulls/dollies or big numbers - seals/sea lions), there's gonna be problems!" I could not agree more. That is one reason I find it so surprising that many anglers are willing to harvest salmon (chinook, coho, pinks, etc) from a health population but insist on mandatory wild steelhead release everywhere. Isn't targeting harvest on most species (salmon) found an ecosystem while protecting another (steelhead) just another example manage one population and not the others? Are there only problems when the protected species is not one we care about?
Tight lines
Smalma