The Mink used to be in the area for just a few weeks a year.
just a few weeks a year? what time of year was that? where did they go during the other time?
Ibiza?
Tennerife?
Benedorm?

No but theriously. Do you think they where roaming onto your patch during a specific season. I'm told they can cover a long stretch of river. The mallards on our stretch has been seriously depleted this year.

Our local council loans traps out. can't remember which dept.
It might be worth checking to see if there is a mink eradication program in your area. When I lived in Aberdeen (3 or 4 years ago) I know there were 2 full time mink trappers in Aberdeenshire paid for by the government as part of some program or other.
The guy that I met who did this job was always keen to hear from people who thought they knew where mink were and would come out, set traps and give advice.
Phoning fife council might be a very good idea!
I wonder which the mink would prefer, left writhing caught in the jaws of Fenn trap for an hour or so while one finds a vet, or being dispatched asap?
Shotgun pellets catching and bouncing of a fenn trap would be interesting as well
Once shot something with a .410 in a 12x8 hen hut, pellets bouncing everywhere! (I was much younger and I've learned a lot since then
)
No sense in animals suffering ( even if they are murdering b*******ds ). Shotgun is out of the question in this location. My shooting buddy suggested one of these
http://www.airgundepot.com/colt-air-pistols.html for quick quiet humane dispatch. I wonder how effective my welding gloves would be against its teeth!
I cut down a 12gauge cartridge back to the brass cap and set it off with a nail when i was a kid. I learned how stupid this idea is milliseconds after the hammer connected. Ma wee pinky hurt like hell, no lasting damage but lesson learned... Doh!