Does anyone know anything about the origins of the haunting fishermen's wives song, Caller Ou? Lyrics are:

CALLER O'U

When winter winds howl and the sea rolling high
Our boatmen sae brave, all dangers defy
Their last haul on board, they steer for the shore
Their live cargo landed is soon at our door

Chorus:
Caller o'u, caller o'u, caller o'u
Frae the Forth, caller o'u, caller o'u

At nicht roon the ingle sae canty are we
The fisher lass brings in her treat frae the sea
Wi' music and sang as time passes by
We hear in the distance the creel lassies cry

Chorus

So here's to the boatman, at hame and awa'
At kirk and at fair there's nane gaes sae braw
And weel be their dames sae blythesome and fair
They're voices in evening is music to hear.

Chorus

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Jean Redpath used to sing it beautifully. I presume from the references in it to the Forth that it originates from around Leith or Edinburgh, but does anyone know any more than that?