The song seems to be about some actual incident and a search for spanish trawlers and Newfoundland turns up quite a bit including the following song which is not what we were looking for but it is related.
^^
Tribute To Brian Tobin

Oh, my name is Brian Tobin and I'm here to work me plan,
And keep the fishing trawlers off the Banks of Newfoundland;
The Spanish fleet and all the foreign vessels will be banned,
From fishing in the waters on the Banks of Newfoundland.

Refrain:
Oh, the Portuguese, the Japanese, the Norwegians, and the French,
And all the Spanish trawlers fishing there upon the Banks,
You're breaking all our fishing laws, I hope you understand,
And the ocean's done away with on the Banks of Newfoundland.

Oh, the horns they sound on the fishing ground and they tried to reach its side,
The baby turbot swims away, but they got no place to hide;
And the old wharf-cutter goes to work, and just the way we planned,
No ifs and buts, their trawls are cut on the Banks of Newfoundland.

Oh, we don't need tanks out on the Banks, 'cause there won't be a fight,
So start to haul your fishing trawls, 'cause what you're doing ain't right;
For years and years, the baby fish were caught and boxed and canned,
I should have done this years ago on the Banks of Newfoundland.

Oh, ten years from now you'll wonder how we made it all work out,
And the younger ones would wonder what this song was all about;
Well, it's just their obligation to remember my command,
And keep the Spanish trawlers off the Banks of Newfoundland.