For once I'm going to disagree with you Radriano, this certainly has a refrain, the same 2nd and 4th lines throughout, which would admirably qualify it as a chantey, whether it was ever so used or not (the latter IMHO).

My best guess would be (agreeing with MMario) that this is a rewrite of High Barbary, in an attempt to make it more suitable for a book of children's poetry - and probably to qualify for author's royalties.