Seafood found in different storeys (7)
I believe the answer is:
oysters
'seafood' is the definition.
(I know that oysters is a type of seafood)
'different storeys' is the wordplay.
'different' indicates an anagram.
'storeys' is an anagram of 'OYSTERS'.
'found in' is the link.
(Other definitions for oysters that I've seen before include "Yet Ross can find the marine creatures" , "Edible bivalve molluscs" , "Yet Ross, strangely, has the marine creatures" , "Yet Ross finds these marine creatures" , "Sources of pearls" .)