Scientist’s beginning work to preserve observation (8)
I believe the answer is:
scanning
'observation' is the definition.
'scientist's beginning work to preserve' is the wordplay.
'beginning' says to take the initial letters.
'work to preserve' becomes 'canning'.
The initial letter of 'scientists' is 's'.
's'+'canning'='SCANNING'
(Other definitions for scanning that I've seen before include "Examining" , "Glancing over, skimming" , "Reading in document to computer" .)