Tricky Capture-Mark-Capture/Resight Situation

[tspaulding]

Hello,
I have been conducting a capture-mark-recapture study to estimate population size of 2 independent populations for the past 5 years using two primary methods of capture: electrofishing and minnow traps, and marking with PIT tags. Unfortunately recaptures have been incredibly rare (usually < 10% of captures), especially in one of our pond environments.

We are attempting to explore new ways to "resight" individuals, and one that we are interested in is "wanding" where we would wave a detecting wand through the pond, which would pick up any tags, including those which have been shed or otherwise are no longer in live fish, "dead" tags.

Assuming we can identify "live" tags from "dead" tags, could I include these resights into my Robust Design model to improve parameter estimates, and if so, how would you go about it? My intuition says that this provides information on capture probability and maybe should be used to fix the capture probability to # Captured Tags/# Total "Live" Tags within each session. Is this the appropriate way to incorporate this?