Each one catching salmon in the drink (7)
I believe the answer is:
alcohol
'the drink' is the definition.
(alcohol is a kind of drink)
'each one catching salmon' is the wordplay.
'each' becomes 'all' ('all' can be similar in meaning to 'each').
'one catching' is an insertion indicator.
'salmon' becomes 'coho' (type of salmon).
'all' placed around 'coho' is 'ALCOHOL'.
'in' acts as a link.
(Other definitions for alcohol that I've seen before include "The intoxicant in drink" , "To a position aboard" , "Spirits etc" , "lager, perhaps" , "wine, say" .)