Restaurant with fish — about right by lake above Niagara (9)
I believe the answer is:
brasserie
'restaurant' is the definition.
(brasserie is a kind of restaurant)
'fish about right by lake above niagara' is the wordplay.
'fish' becomes 'bass' (bass is a kind of fish**).
'about' indicates putting letters inside.
'right' becomes 'r' (common abbreviation).
'by' says to put letters next to each other.
'lake above niagara' becomes 'erie' (Lake Erie).
'bass' going around 'r' is 'brass'.
'brass'+'erie'='BRASSERIE'
'with' acts as a link.
(Other definitions for brasserie that I've seen before include "bar serving food" , "French-style restaurant" , "Small restaurant serving alcohol as well as food" , "eatery" , "eating place" .)