Pretty sure dead fish smell bad to us too. 
Maybe it's not that they *can't* eat seafood, but that they don't out of social taboo. I mean even a race of kleptomaniac carrion eaters probably frown on cannibalism. That or the sea life on Pak'ma *really* reacts badly to fishermen. Talk about your 'Galaxy's Deadliest Catch'!
Of course it's all academic since it's a fair bet that the rogue Vorlon fragment (or whatever that thing was) wasn't causing an actual emanation but psychically protecting the thought of an oppressive smell. Each race and individual's brain interpreting that implanted suggestion according to their own perceptions. Same with the fire and the funny voice and probably everything else.
Maybe it's not that they *can't* eat seafood, but that they don't out of social taboo. I mean even a race of kleptomaniac carrion eaters probably frown on cannibalism. That or the sea life on Pak'ma *really* reacts badly to fishermen. Talk about your 'Galaxy's Deadliest Catch'!
Of course it's all academic since it's a fair bet that the rogue Vorlon fragment (or whatever that thing was) wasn't causing an actual emanation but psychically protecting the thought of an oppressive smell. Each race and individual's brain interpreting that implanted suggestion according to their own perceptions. Same with the fire and the funny voice and probably everything else.