Salt from deserted sea channel (6)
I believe the answer is:
saline
'salt' is the definition.
('saline' can be similar in meaning to 'salt')
'deserted sea channel' is the wordplay.
'deserted' says to hollow out the word (remove centre letters).
'channel' becomes 'line' (line is a kind of channel**).
'sea' with its middle taken out is 'sa'.
'sa'+'line'='SALINE'
'from' acts as a link.
(Other definitions for saline that I've seen before include "Containing or tasting of salt" , "Salty to aliens" , "Intravenous feeding" , "Containing salt for aliens" , "Salty like sea water" .)