A current issue on the coast (5)
I believe the answer is:
delta
'a current' is the definition.
(thesaurus)
'on the coast' is the wordplay.
'on' indicates putting letters inside (as in clothing 'on' a person).
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'coast' becomes 'dela' (I can't justify this - if you can you should believe this answer much more).
't' placed into 'dela' is 'DELTA'.
'issue' acts as a link.
Can you help me to learn more?
(Other definitions for delta that I've seen before include "Letter - where river divides" , "Divided river outlet" , "Fragmented estuary" , "Triangular river system" , "Area of alluvial deposit" .)