pcxbox360ps3 Due to a misplaced condition, the Mirelurk Ecology perk has no effect. The perk is intended to check whether or not the creature being damaged is a mirelurk, but instead runs that check on the owner of the perk, i.e. the player, who is obviously not a mirelurk. [verified]
The Mirelurk Ecology perk was meant to be obtained after reading a book titled Marsh Hunting Tips Vol IV: Mirelurks. How the book was to be obtained is not indicated. The book still exists within the DLC's resources and, if somehow obtained, will grant the perk when used.