Undoubtedly, but I imagine it would be hard to do more than speculate without observing it happen. Emperors eat fish and crustaceans like krill. Krill are predated on by many animals, most notably whales, but the types of fish these guys eat I don't know much about. Effect of the penguins being gone, hard to say. Sadly, the krill which are so important to many, many, many species are also at risk due to acidification among other things.