The most common and most likely answer to this crossword clue is the 8 letter word SCALLOPS
I've seen this crossword clue in Financial Times
S
C
A
L
L
O
P
S
More clues leading to the result SCALLOPS
Buddy explains!

The straight part
We know that "Seafood" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case seafood = scallops.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SCALLOPS mean?
SCALLOPS noun- Any of various marine bivalve molluscs of the family Pectinidae which are free-swimming.
- One of a series of curves, forming an edge similar to a scallop shell.
- A fillet of meat, escalope.
- A form of fried potato.
- A dish shaped like a scallop shell.