Seafood board not for turning (8)
I believe the answer is:
plankton
'seafood' is the definition.
(I've seen this before)
'board not for turning' is the wordplay.
I cannot quite see how this works, but
'board' could be 'plank' ('plank' can be a synonym of 'board') and 'plank' is located in the answer.
an anagram of 'not' is 'ton' which is located in the answer.
This accounts for all the letters.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for plankton that I've seen before include "Diminutive drifter" , "Marine organism" , "Whale food" , "Seafood diet" , "Microscopic organisms that float on the surface of water" .)