Retention of Large‐Format, Soft Visible Implant Alphanumeric Tags in Walleye

Abstract

We evaluated the effects of fish length, fish sex, and number of days posttagging on retention of large‐format, soft visible implant (VI) alphanumeric tags that were injected underneath the clear tissue on the lower mandible of Walleyes Sander vitreus. We also evaluated whether the direction of insertion or the application of surgical‐grade tissue adhesive to the tag incision site would affect tag retention. Adult Walleyes were collected with gill nets from natural lakes in Iowa during spring and then were transported to a hatchery, where they were measured, sexed, and tagged. One worker injected 752 Walleyes (mean TL = 21.8 in; SE = 0.16) with two identical VI tags; each side (left and right) of the lower mandible received one tag. Incisions were dried with a cloth, and tissue adhesive was applied to one of the two tag injection sites. Walleyes were released back into the lake and were recaptured with gill nets and by anglers. Of the 129 Walleyes recaptured up to 5 years posttagging, 80 fish (62%) had retained both tags and the remaining 49 fish had retained one of the tags. Retention adjusted for fish that lost both tags (n = 8; probability = 0.09) was 58% (80 of 137). Tag retention was significantly related to fish size at the time of tagging, as smaller fish lost more tags. Consequently, males (mean TL = 20.5 in; SE = 0.39) were more likely to lose tags than females (mean TL = 24.3 in; SE = 0.26). Insertion direction, adhesive application, or the number of days posttagging at recapture did not influence VI tag retention. We recommend that in studies requiring high tag retention in Walleyes, the injection of large‐format, soft VI tags into the clear tissue underneath the mandible should not be considered. Received February 16, 2012; accepted October 3, 2012

Relative Effects of Mortality versus Emigration on a Reservoir Walleye Population

“…Annual Walleye survival estimates were then corrected for annual tag loss (16%; Meerbeek et al. ) by dividing the estimates by the probability that a Walleye retained a tag (Pollock et al. ).…”

Retention of visible implant alphanumeric tags in adult Walleye

“…Walleye were collected from a chain of lakes in northwestern Iowa during March-April 2012 and 2013 and transported to the Spirit Lake Fish Hatchery using the same procedures as described in Meerbeek et al (2013). Walleye were measured (TL; in), sexed (determined by extrusion of gametes [Walleye that did not excrete gametes were classified as immature females]), and two identical VIA tags (0.106 £ 0.047 £ 0.004 in; NMT) were injected via a single-shot syringe just below the soft, clear tissue on the underside of the lower mandible, with each side (left and right) receiving one tag each.…”

“…Tag retention of VIA tags has been extensively documented for salmonids tagged in post-orbital or fin ray tissue with variable results (see Turek et al 2014). Channel Catfish Ictalurus punctatus and Walleye Sander vitreus injected with VIA tags into clear tissue had retention rates ranging from 0% to 76% (Buckmeier and Irwin 2000;Meerbeek et al 2013). In general, VIA tag retention has been highly associated with fish length at tagging, with larger fish having higher retention rates (McMahon et al 1996;Shepard et al 1996;Meerbeek et al 2013).…”

“…In Iowa, large-format VIA tags were injected in the lower mandible of Walleye from 1990 through 2009 to estimate population parameters. Large-format VIA retention rate for this species in this location was 76% and resulted in erroneous estimates of Walleye abundance, survival, and recruitment (Meerbeek et al 2013). In 2010, the Iowa Department of Natural Resources (DNR) began injecting current standard VIA tags in Walleye.…”

A Standardized Technique to Back‐Calculate Length at Age from Unsectioned Walleye Spines

“…Walleye (n = 2,794) were collected via gill nets (6 ft × 320 ft × 2.5-in bar mesh) in April 2011 from three natural lakes in northwest Iowa and were transported to a hatchery facility where they were measured to the nearest 0.1 in (TL), sexed (determined by extrusion of gametes), and individually tagged (Meerbeek et al 2013). Additionally, the first two dorsal spines of each Walleye were removed (for age estimation) from the point of attachment with a pair of side cutters before being released back to the lake of capture.…”