Source : Webster's Revised Unabridged Dictionary (1913)

Bloater \Bloat"er\ (-[~e]r), n. [See {Bloat}, {Blote}.]
   The common herring, esp. when of large size, smoked, and half
   dried; -- called also {bloat herring}.

Source : WordNet®

bloater
     n : large fatty herring lightly salted and briefly smoked