Evaluation of Coded Wire Tag Loss in Brook Trout Tagged Using Automated Methods

Abstract

Automated coded‐wire‐tagging methods were recently applied to Brook Trout Salvelinus fontinalis for the first time, but information on tag loss and method efficiency is needed. We observed tag loss in Brook Trout over 210 d posttagging to determine the degree of tag loss and when tag loss stabilized for the 2015 year‐class. We also evaluated tag loss from two subsequent year‐classes. Brook Trout tag loss stabilized (i.e., reached the curve's inflection point) at 1.5% after 15 d posttagging and achieved its asymptotic maximum of 1.6% after 28 d. Tag loss rates for subsequent year‐classes were 1.7% and 2.3%. We also described throughput (fish tagged per hour) to evaluate method efficiency. Throughput ranged from 8,449 to 9,395 fish/h for Brook Trout and was comparable to observations on other salmonines; combined with the low rate of tag loss, this demonstrates the efficacy of automated methods for the marking and tagging of this species. In addition, rapid stabilization of tag loss in Brook Trout (15 d) was similar to that observed in Pacific salmonines but distinct from that recorded for other Salvelinus spp. (≥150 d), and underscored the need to directly measure species‐specific tag loss and its stabilization period and to avoid using closely related species as proxies.

PIT POP! Bursting the bubble on home-range bias with fine-scale PIT telemetry

“…Batch marking may be used when electronic tags are not appropriate and it is common for marking small fish, where a group of fish are marked with the same 'batch mark'. Popular marking techniques include fin clipping (Berra 1973;Lintermans 1998), injection of coloured dyes or elastomers (Cadwallader 1976a;Jungwirth et al 2019) and coded wire tags (Rash et al 2018;Lane et al 2019). Sample size is limited by the number of possible combinations of fin clips or colour markings, or the cost of marking and retrieving fish.…”