I have a series of layers that are linked through relationship classes. When the user clicks on a watershed (HUC = Hyrdologic Unit Code) with the identify tool a list of species and impaired rivers/streams is brought up.

The problem is the field that ArcMap decided to show for the impaired river/stream is not helpful at all in this context (some permanent ID). I'd like it to show the actual impairment as defined by the Clean Water Act 303(d) dataset, which is in this same table.
Is there a way to define the field that ArcMap displays in the identify box??