Volume turned up after seabird bites head of injured auk (9)
I believe the answer is:
guillemot
'auk' is the definition.
(guillemot is a kind of auk)
I cannot understand how the remainder of the clue works.
(Other definitions for guillemot that I've seen before include "cliff-ledge nester" , "Seabird" , "An auk" , "Fisher" , "Diving bird" .)