I was amazed to discover a number of crayfish in the outflow between my two ponds. I never looked for them in my pond but assumed there were none. I guess I was wrong. I had intended to stock some but hadn’t gotten that far yet. So my question is how to determine whether there are a lot of crayfish in the pond or was it just a few in the discharge between ponds? And for the record the ponds were originally lined with shale so the habitat would be well suited for them. So anyway how do I figure out if there are crayfish in larger numbers ? Trapping? Any suggestions appreciated.

If you have lots of crayfish a minnow trap with a slightly expanded opening and baited with scrap meat, pet food or fish fillet will catch crayfish. If several over night trap sets each catches more than 10 crays then you have a good number of them.

Finding the young crayfish in May under rocks about 1/2" long will indicate a number of crayfish and that they are populating.