Combination of kelp, rice and fish (8)
I believe the answer is:
pickerel
'fish' is the definition.
(I have seen 'American fish' mean 'pickerel' so perhaps 'fish' could also mean 'pickerel')
'combination of kelp rice' is the wordplay.
'combination of' is an anagram indicator (I've seen this in other clues).
'kelp'+'rice'='kelprice'
'kelprice' anagrammed gives 'PICKEREL'.
'and' acts as a link.
(Other definitions for pickerel that I've seen before include "Young or small pike; prick eel (anag.)" , "freshwater fish" , "American fish" .)