Shark tracks fish where small fry are gathered (7,6)
I believe the answer is:
nursery school
'small fry are gathered' is the definition.
I can't judge whether this definition defines the answer.
'shark tracks fish where' is the wordplay.
'shark' becomes 'nurse' (nurse shark is a kind of shark).
'tracks' becomes 'RY' (abbreviation for railway).
'fish where' becomes 'school' (I can't justify this - if you can you should believe this answer much more).
'nurse'+'ry'+'school'='NURSERY SCHOOL'
Can you help me to learn more?
(Other definitions for nursery school that I've seen before include "Primary education" , "Place for educating young children" , "Kindergarten" , "Educational establishment for the very young" , "Early stage of education" .)