There's generally not a big risk of bears overfishing salmon into near extinction in the massive fishing vessels that they don't possess, nor do they feed antibiotics to the salmon that they don't farm, so that's also not an issue for the bears. When bears go to the super market, they rarely have the choice between buying vegetables or salmon, because humans are generally reluctant to let bears in there, and even if they got in, most of them wouldn't have any cash.

Regardless, there aren't many bears reading HN, so it would be a waste of time trying to discuss these issues with them here anyway.

I think it'll be possible for humans to discuss the ethics of eating salmon without necessarily getting the bears on board with their decision. Most humans tend to generally not involve bears that much in their day-to-day decision making.

We can acknowledge the suffering caused by the bear.

Perhaps the overall utility of having a happy bear in your ecosystem beats not having a bear, or a starving one. Since we can't know for sure, the precautionary principle tells us to just let the bear be a bear. But it still sucks for the salmon, and therefore a human capable of forgoing the salmon clearly should at least consider it.