Short‐Term Passive Integrated Transponder Tag Retention in Wild Populations of Bluehead and Flannelmouth Suckers

Abstract

Passive integrated transponder (PIT) tags, commonly used to individually identify fish, are assumed to not hinder survival or alter the behavior of the fish and to be retained throughout the duration of the study. While these assumptions have been verified for many species, other species have exhibited poor retention or survival, or altered behavior. In this study, we evaluated short‐term PIT tag retention and recapturability of PIT‐tagged fish in wild populations of migrating and spawning Bluehead Sucker Catostomus discobolus and Flannelmouth Sucker C. latipinnis. We trapped fish as they entered a spawning tributary of the Gunnison River near Delta, Colorado, USA. We abdominally injected 12.5 × 2.1 mm PIT tags and externally marked 2,645 fish; another 2,660 fish were given an alternative external mark but were not PIT‐tagged. When we recaptured fish as they exited the tributary, we found a PIT tag retention rate >99% and recaptured a greater proportion of PIT‐tagged fish than of control fish for both species. We did not identify any tag loss in females, suggesting that tags were not expelled with eggs while spawning. Abdominally injected PIT tags are an effective way of marking these species. Received November 22, 2016; accepted February 26, 2017 Published online April 18, 2017

Suitability of surgically implanted 8‐mm passive integrated transponder tags for small‐bodied fishes

“…Short-term survival of the other PIT-tagged fishes evaluated was high (> 90%) and well aligned with literature values for other small-bodied fishes (range: 50%-100%; Bangs et al, 2013;Clark, 2016;Dixon & Mesa, 2011;Pennock, 2017;Pennock et al, 2016). We tagged smaller individuals than previous researchers but observed higher survival for creek chub and white sucker by using smaller PIT tags (Ficke et al, 2012;Johnston & Smithson, 1999). Consistent with other research of surgically implanted PIT tags, mortality was rare after 28-d (Archdeacon et al, 2009;Bangs et al, 2013;Pennock, 2017).…”

An Intermittent Stream Supports Extensive Spawning of Large‐River Native Fishes

“…Hooley‐Underwood et al. () observed ≥98% retention rates of newly implanted PIT tags during the spawning season and potential short‐term tagging mortality of just 0.3% using this method for spawning suckers in this stream. In 2015 we had an excess of tags and were able to tag all healthy suckers and many chub (651 tags deployed in total), but in 2016 and 2017 we deployed all available tags (2,644 and 1,646, respectively).…”

“…We installed a picket weir and trap boxes designed to separately capture and hold upstream‐ and downstream‐bound fish (as described in Hooley‐Underwood et al. ) in Cottonwood Creek 130 m above its mouth. The 22‐mm spacing of weir pickets was selected to prevent the passage of suckers (our primary target) longer than 210 mm in 2015 and 2016, but after experiencing difficulties associated with debris accumulation in 2016, we expanded the spaces to 28.6 mm to limit only suckers greater than 250 mm in 2017.…”

“…We implanted a 12.5‐mm, 134.2‐kHz, full‐duplex PIT tag abdominally in every native sucker (our primary species of interest) and some Roundtail Chub ≥150 mm TL not previously tagged and in apparent good health, as described in Hooley‐Underwood et al. (), until available tags were depleted for each year. Hooley‐Underwood et al.…”

“…Each fish captured was identified to species using morphological characteristics (Baxter and Stone 1995;Snyder et al 2004), measured (TL, mm), weighed (g), and scanned for a PIT tag using a hand-held portable reader (Biomark model 601 or Biomark model HPR Plus, Boise, Idaho). We implanted a 12.5-mm, 134.2-kHz, full-duplex PIT tag abdominally in every native sucker (our primary species of interest) and some Roundtail Chub ≥150 mm TL not previously tagged and in apparent good health, as described in Hooley-Underwood et al (2017), until available tags were depleted for each year. Hooley-Underwood et al (2017) observed ≥98% retention rates of newly implanted PIT tags during the spawning season and potential short-term tagging mortality of just 0.3% using this method for spawning suckers in this stream.…”