Your explanation makes more sense, but that's not what the quoted text is saying. The text makes it seem that if the chicks don't grow up on (sufficient) sea ic

Your explanation makes more sense, but that's not what the quoted text is saying. The text makes it seem that if the chicks don't grow up on (sufficient) sea ice, they may not develop waterproof feathers at all. Or is there some Australian-specific meaning of "impacts" that I'm unaware of?