Sea area next to the Spanish lines (8)
I believe the answer is:
doggerel
'lines' is the definition.
(lines of poor quality poetry)
'sea area next to the spanish' is the wordplay.
'sea area' becomes 'dogger' (Dogger Bank, area of the North Sea).
'next to' says to put letters next to each other.
'the spanish' becomes 'el' ('the' in Spanish).
'dogger'+'el'='DOGGEREL'
(Other definitions for doggerel that I've seen before include "Burlesque verse" , "Unpretentious verses" , "Bad verse - of canine beginnings?" , "Verse lacking artistry" , "Unpretentious verse" .)