Mink raiding pond
Hi, I have used this site many times over the past 5 years to help with the operation of my 12K gallon pond, Koi and goldfish, inherited with the home I bought. I have been very lucky, till now, that the pond runs smoothly and rather easily given the size. Over the past two weeks, I have not been so fortune. A mink has discovered the pond and has raided 100% of my 4-12" koi, 80% 12-24" and totally mangled a 30+" koi. I have since moved my large koi, including the damaged koi, to a 200 gallon tempoary pond in the garage while I try to trap the mink. I am looking for help and advice after a very stressful week or two (for me and the koi).
I have 9 30" koi and 3 20" koi in the temporary pond. Currently there is just an aerator and I am trying to switch out buckets of water everyday. I cannot keep this up all winter and the ammonia level is already dangerously high.
So have 3 options I am looking for urgent help with:
a) board the koi somewhere, disadvantage being the cost ($70-100/mth)
b) buy a filter system and heater and try keep them in the garage. I don't know the cost of this yet but am concerned that the temporary pond isn't big enough for a long term solution. They are still very agitated when I go in the garage but settle after a few minutes. The white koi are showing distress via pink coloring. The water has been lightly salted.
c) the mink does not seem to have been around for the past week, from what I can tell... I can put them back in the pond and keep the trap operation + try to electrify the perimeter. This won't be easy as the pond goes underneath some decking and is rather large, I think I would likely accomplish 70-80% coverage. To top it off, I also have a dog and cat to worry about.
Has anyone been challenged with this sort of situation or decison before? Any suggestion or opinions would be much appreciated. It has been awful to watch this happen.