How does the poet use refrain in the poem, The Milkfish Gatherers?

The repetition of the first line of the poem later in the narrative along with the line "But the spine lives when the brain dies / In a convulsive misery" is called a refrain. The word refrain is derived from the Latin refrangere, "to break." The refrain is a line that is broken off from the main part of the poem and keeps coming back. The refrain also breaks the way a wave breaks, echoing the idea of the sea once again.