Further to my post above, thinking about it I reckon I can still remember this song, or quite a lot of it anyway, without fishing out the tape. It went something like this:

Oh the herring loves the moonlight
And the mackeral loves the wind
But the oyster loves the dredging sand
For they come o' a gentler kin/kind

Djey-ee-oorie-addie
Weel rowed five men
As good as your ten
The oysters are a gentle kin
And they willna 'ttack unless you sing
'Come buy my oysters: that's the thing
To serve the sheriff and the king
And the commons o' the land,
And the commons o' the sea'.