Americn Fisheries Society Symposium 76, 2011 2011 y the Americn Fisheries Society Long Term Retention, Survivl, Growth, nd Physiologicl Indictors of Juvenile Slmonids Mrked with Pssive Integrted Trnsponder Tgs Kenneth G. Os t r n d *, Gy l e B. Zy d l e w s k i, n d Willim L. G l e Aernthy Fish Techology Center, U.S. Fish nd Wildlife Service 1440 Aernthy Creek Rod, Longview, Wshington, 98632, USA Joseph D. Zy d l e w s k i c Columi River Fisheries Progrm Office, U.S. Fish nd Wildlife Service 1211 SE Crdinl Court, Suite 100, Vncouver, Wshington 98683, USA Astrct. To trck individuls in situ, over 12 million slmon nd trout hve een mrked with pssive integrted trnsponder (PIT) tgs in the Columi River Bsin, USA. However, few studies hve exmined long term tg retention s well s tg effects on juvenile slmon nd trout. We mrked juvenile coho slmon Oncorhynchus kisutch (N = 207), steelhed (ndromous rinow trout) O. mykiss (N = 221), cutthrot trout O. clrkii (N = 202) nd ull trout Slvelinus confluentus (N = 180) with 12, 19, or 23 mm PIT tgs nd exmined tg retention, survivl, growth, nd physiologicl performnce over six month period in lortory environment. PIT tg retention rtes were high for coho slmon (100%), steelhed (95%), cutthrot trout (97%), nd ull trout (99%), regrdless of tg size. Survivl ws lso high for coho (99%), steelhed (99%), cutthrot trout (97%), nd ull trout (88%) nd did not vry mong tg sizes. Short term individul growth rtes for coho slmon mrked with 12 mm tgs were significntly higher thn those mrked with 19 mm nd 23 mm PIT tgs. Likewise, steelhed trout individul growth rtes were lower for fish mrked with 23 mm PIT tgs followed y 19 nd 12 mm tgs. Conversely, long-term growth rtes were positive nd not ffected y tg size. There were no significnt effects of tg size or mrking on coho gill N+, K+, -ATPse ctivity (µmol ADP x mg protein 1 h 1 ) nd plsm osmollity (μmol kg 1 ) or ull trout heptosomtic indices. Our study suggests tht mrking juvenile slmonids with PIT tgs results in high retention with little effect upon their survivl, growth, nd importnt physiologicl indictors regrdless of tg size in lortory environment. * Corresponding uthor: Kenneth_Ostrnd@fws.gov Current ddress: School of Mrine Sciences, The University of Mine, 5741 Liy Hll, Orono, Mine 04469, USA Current ddress: Mid-Columi River Fishery Resource Office, 7501 Icicle Rod, Levenworth, Wshington 98826, USA c Current ddress: U.S. Geologicl Service Coopertive Fish nd Wildlife Reserch Unit, The University of Mine, Orono, Mine 04469, USA 1
2 Ostrnd et l. Introduction Since the 1980s, pssive integrted trnsponder (PIT) tgs hve een used to support the collection of vrious iologicl nd popultion demogrphic dt in vriety of niml models (Gions nd Andrews 2004). For exmple, this technology hs een used extensively in the Pcific Northwest for monitoring the ehvior nd survivl of juvenile nd dult slmonids in the Columi River Bsin (Zel et l. 2005). Over 15 million slmon nd trout hve een PIT tgged in the Columi River Bsin since 1987 (Pcific Sttes Mrine Fisheries Commission 2005). Though 12-mm PIT tgs re most commonly used, to mximize detection distnce mny reserchers employ vriety of tg sizes including 19-mm nd 23-mm PIT tgs (Roussel et l. 2000; Zydlewski et l. 2001; Hill et l. 2006). The distnce t which PIT tg cn e detected is prticulrly importnt in pplictions where fish re not recptured ut re remotely detected vi fixed or moile ntenn. Since dt collected from PIT tg detections is often used to determine stock identity (Jenkins nd Smith 1990; Achord et l. 1996), movements (Omredne et l. 1998; Zydlewski et l. 2001), migrtion rtes nd routes (Achord et l. 1996; Kennedy et l. 2007), undnce (Achord et l. 1996), growth (Peterson et l. 1994), mortlity (Kennedy et l. 2007), nd stocking success (Wills 2006), it is importnt tht the PIT tgs themselves do not directly or indirectly lter these dt. Although PIT tg retention rtes (Buzy nd Deegn 1999; Gries nd Letcher 2002; Peterson et l. 1994) nd short term post tgging survivl (Prentice et l. 1990; Peterson et l. 1994; Omredne et l. 1998; Gries nd Letcher 2002; Btemn nd Gresswell 2006) nd growth (Prentice et l. 1990; Peterson et l. 1994; Omredne et l. 1998; Btemn nd Gresswell 2006) hve een exmined nd commonly reported in the literture, the effects of tgs on long term growth nd importnt physiologicl processes for slmonids hve only een descried only preliminrily. Given the importnce of these processes on slmonid growth nd survivl it is importnt to understnd if PIT tg mrking imprts negtive effects upon smoltifiction, growth, nd energy storge. In ddition, the results from these erlier studies were often confounded y differences in environment, tg size, surgicl nd implnttion technique, study durtion, nd species nd fish life history stge (Btemn nd Gresswell 2006) mking it difficult to independently evlute the effect of mrking slmonids with PIT tgs. As result we exmined the long-term retention nd effect of different sized PIT tgs (12, 19, 23 mm) on the survivl, growth, nd physiologicl performnce of juvenile steelhed (ndromous rinow trout) Oncorhynchus mykiss, coho slmon O. kisutch, cutthrot trout O. clrkii, nd ull trout Slvelinus confluentus in lortory environment. Methods Coho slmon nd steelhed trout eggs were otined from Wshington Deprtment of Fish nd Wildlife (WDFW) Big Creek Htchery, cutthrot trout eggs were otined from WDFW Cowlitz Complex, nd dfluvil ull trout eggs were otined from the U.S. Fish nd Wildlife Service s Creston Ntionl Fish Htchery (NFH). Eggs were trnsported to Aernthy Fish Technology Center (AFTC) incuted nd htched in flow through trys mintined on well wter (12.5 C) nd nturl photoperiod. Juvenile coho slmon (N = 207), steelhed (N = 221), cutthrot (N = 202) nd ull trout (N = 180) were rered on rtificil slmonid feeds until they reched desired size (rnge = 100 150 mm, Fork Length, Florid). Individul fish were nesthetized, mesured, weighed, nd rndomly implnted with 12, 19, or 23 mm
PIT tg (134.2 khz ISO; Destron Fering Inc.) or left untgged (controls). The PIT tgs were inserted y cutting smll ( 5 mm) ventrl opening into the ody cvity just ehind the pectorl fin insertion (Gries nd Letcher 2002). A PIT tg ws plced into the ody cvity in lterl ventrl position ehind the pectorl fin insertion ut in front of the pelvic fin insertion. Coho nd steelhed were mrked with ll three differently sized tgs wheres ull trout were mrked with 12 nd 23 mm PIT tgs nd cutthrot trout with 23 mm tgs. Equl numers of fish were plced within three replicte circulr tnks (1.2 m dimeter) tht were supplied with pproximtely 1 l/min well wter t mient temperture (10 ± 2 C). Fish were fed Bio-Oregon dry pellets dily t 1% ody weight. Feeding levels were djusted ccording to totl iomss nd wter temperture monthly. Tnks were exmined dily for expelled tgs nd fish mortlity. During ech month, for up to 8 months, fish were nesthetized, mesured, weighed, nd identified vi PIT tg code to determine growth rtes. Growth rtes were determined etween ll smpling dtes y clculting specific growth (Buscker et l. 1990). During the spring (Mrch, April, nd My) coho slmon gill N +, K + -ATPse (AT- Pse) ctivity nd plsm osmollity (mosm Kg H 2 O 1 ) were determined s reltive indictors of sewter rediness nd smoltifiction. ATPse ctivity ws determined vi smll gill iopsy using the method of McCormick (1993) nd immeditely frozen on dry ice. Gill smples were stored t 80 C nd gill ATPse ctivity mesured spectrophotometriclly using the method of McCormick (1993). To mesure the reltive sewter tolernce, plsm osmollity ws determined fter 24 h slt wter exposures (32 ppt). Fish were killed y n overdose of nesthetic, nd lood collected using heprinized syringes. Plsm ws otined y centrifugtion t 10,000 rpm, 4 C for 5 min. Osmollity ws Performnce of Slmonids Mrked with PIT Tgs determined using n Osmette II osmometer. We determined the heptosomtic index (HSI) s n indictor of glycogen stores of dfluvil ulltrout. At the termintion of the experiment fish were mesured (FL), weighed, nd livers were dissected, removed from the viscer, weighed, nd HIS ws clculted s: HIS = (fish liver weight (g)/fish ody weight (g)) 100. Anlysis of Vrince (nlysis of vrince (ANOVA)) nd t-tests were used to test for differences mong the tretments for the response vriles (FL, weight, growth rte, ATPse, plsm osmollity, nd LR). Chisqure tests were used to compre differences (P < 0.05) in tg retention nd mortlity mong tretments for ech species. Sttisticl comprisons of growth rtes included only fish mrked with PIT tgs ecuse untgged control fish could not e individully identified. Dt were log trnsformed to meet ssumptions of normlity nd homogeneity of vrinces. Significnt ANOVAs (P < 0.05) were followed y Fisher LSD men seprtion tests for pirwise comprisons. Results All fish incresed in FL nd gined weight during the experiment regrdless of species or PIT tg size (Figure 1). There were no significnt differences in FL or weight mong tretment groups for ny species, excluding cutthrot trout. Although cutthrot trout mrked with 23 mm PIT tgs were similr in FL nd weight t the onset nd completion of the experiment they differed during Septemer (FL, P = 0.047; weight, P = 0.016) nd Octoer (FL, P = 0.014; weight, P = 0.007). Percent weight gin did not significntly differ etween the control fish nd those mrked with different sized tgs, in spite of species (Tle 1). Species specific growth rtes of fish mrked with PIT tgs my e negtively f- 3
4 Ostrnd et l. Fork Length (mm) 210 175 140 Coho Slmon Control 12mm 19mm 23mm Steelhed Trout Cuthrot Trout Bull Trout 150 Weight (g) 100 50 0 July Sept Nov Jn Mr Jn Apr My June July Aug Sept Oct Nov Jn Oct Nov Dec Jn Month Fi g u r e 1. Fork length (men ± 1 SE) nd weight (men ± 1 SE) of coho slmon, steelhed, cutthrot, nd ull trout unmrked or mrked with 12, 19, or 23 mm pssive integrted trnsponder tg. Letters denote significnt (P < 0.05) differences etween fish mrked with different sized PIT tgs on respective dte. fected following mrking event (Figure 2). The individul growth rtes for coho slmon during the first growth intervl were significntly lower for the fish mrked with 19 mm nd 23 mm PIT tgs s compred to those mrked with 12 mm PIT tgs. Individul growth rtes did not differ etween coho slmon mrked with 19 mm nd 23 mm PIT tgs during the first growth intervl. Likewise, steelhed trout individul growth rtes were slowest for fish mrked with 23 mm PIT tgs followed y 19 nd 12 mm tgs. During the third growth intervl (My to June) steelhed mrked with 23 mm PIT tgs grew significntly fster thn those mrked with 19 or 12 mm tgs tht did not significntly differ from ech other. Bull trout individul growth rtes did not differ mong fish mrked with different sized PIT tgs. All PIT tgged coho slmon sujected to 24 h sewter chllenges survived. Although ATPse ctivity ws significntly higher (P = 0.003) in April when compred to Mrch nd My, it did not differ mong the groups mrked with different sized tgs (Figure 3A). Plsm osmollity ws significntly higher in lter months (Figure 3B). Nevertheless, there were no significnt differences (P = 0.16) in plsm osmollity mong the coho slmon mrked with PIT tgs of vrious sizes. Bull trout HSI did not differ mong controls nd the two mrked groups (Figure 4). Fish mrked with 23 mm PIT tgs hd lrger vrince of reltive liver weight thn fish mrked with either 12 mm PIT tgs or controls. We oserved low mortlity nd high PIT tg retention for ll the species, regrdless of tg size (Tle 1). Mortlity did not significntly differ within ech species mrked with different sized PIT tgs. Mortlity ws higher for ull trout (rnge = 10 15%) thn for the other species (rnge = 0 5%) we exmined. Likewise PIT tg retention ws high nd did
Performnce of Slmonids Mrked with PIT Tgs 5 T l e 1. Men (± 1 SE) initil fork length (FL), initil weight, finl weight gin, mortlity, nd pssive integrted trnsponder (PIT) tg retention for coho slmon nd steelhed, cutthrot, nd ull trout mrked with different sized PIT tgs. There were no sttisticl differences mong fish mrked with different sized PIT tgs regrdless of species. Species Tretment N FL (mm) Weight (g) Weight Mortlity (%) PIT tg Gin (%) Retention (%) Coho slmon Control 69 135 (1.24) 34 (0.82) 329.7 5.8 * 12 mm 69 132 (1.58) 32 (1.04) 355.5 0.0 100 19 mm 69 131 (1.47) 31 (1.00) 345.7 1.5 100 23 mm 69 132 (1.72) 32 (1.09) 337.2 2.9 100 Steelhed trout Control 75 125 (1.15) 20 (0.61) 468.9 1.3 * 12 mm 75 124 (1.17) 20 (0.59) 492.5 1.3 98.7 19 mm 75 124 (1.11) 20 (0.60) 477.7 0.0 97.3 23 mm 75 123 (1.20) 20 (0.64) 477.6 1.3 89.0 Cutthrot trout Control 101 136 (1.22) 31 (0.82) 131.9 5.0 * 12 mm * * * * * * 19 mm * * * * * * 23 mm 101 141 (1.29) 32 (0.96) 134.5 3.0 100 Bull trout Control 60 150 (2.56) 34 (1.80) 165.6 12.0 * 12 mm 60 149 (2.20) 34 (1.60) 164.3 15.0 99.5 19 mm * * * * * * 23 mm 60 149 (2.56) 34 (1.83) 153.9 10.0 100
6 Ostrnd et l. A. Coho Slmon 0.32 12 mm 19 mm 23 mm 0.24 0.16 Aug Oct Dec Fe Apr Growth Rte (%, ody weight) 0.54 0.45 0.36 0.08 0.06 Mr c Apr My June B. Steelhed Trout July Aug C. Cutthrot Trout 0.04 Aug Sept Jn 0.99 D. Bull Trout 0.90 0.81 Nov Dec Jn Month Fi g u r e 2. Individul growth rte (men ± 1 SE) of coho slmon (A), steelhed (B), cutthrot (C), nd ull trout (D) mrked with 12, 19, or 23 mm pssive integrted trnsponder tg (PIT). Letters denote significnt (P < 0.05) differences etween fish mrked with different sized PIT tgs.
Performnce of Slmonids Mrked with PIT Tgs 7 Gill N+,K+ ATPse ctivity (µmol ADP x mg protein -1 h -1 ) 4.5 4.0 3.5 3.0 2.5 2.0 A Control 12mm 19mm 23mm Osmollity (mmol kg -1 ) 1.5 336 328 320 B Control 12 mm 19 mm 23 mm 312 Mr Apr My Month Fi g u r e 3. Men (± 1 SE) Gill N +, K + -ATPse ctivity (A) nd plsm osmollity (B) of coho slmon mrked with 12, 19, or 23 mm pssive integrted trnsponder tgs (PIT). not differ mong the tretments, regrdless of species. PIT tg retention ws the lowest for steelhed mrked with 23 mm PIT tgs (89%) s compred to ll other tretments (rnge = 97 100%). Discussion Our results suggest tht there ppers to e little effect of tgging on long term juvenile fish growth, physiologicl indictors, mortlity, nd tg retention in lortory environment. Individul growth rtes pper to e somewht influenced y tg size shortly fter mrking. Therefore, reserchers exmining growth rtes soon fter tgging need to e cogniznt of this potentilly negtive effect. As technology continues to improve nd these tgs ecome smller, even short term effects on individul growth will likely ecome inconsequentil. Our results suggest tht the use of PIT tgged fish s indictors of stock identity (Jenkins nd
8 Ostrnd et l. 2.0 Heptosomtic Index (%) 1.6 1.2 0.8 Control 12 mm 23 mm Tg Size Fi g u r e 4. Reltive liver weight (men ± 1 SE) for ull trout mrked with either 12, or 23 mm pssive integrted trnsponder tgs (PIT). The length specific stndrd weight (Ws) developed y Hytt nd Huert in (2000) ws used to determine ull trout reltive liver weight. Smith1990; Achord et l. 1996), movements (Omredne et l. 1998; Zydlewski et l. 2001), migrtion rtes nd routes (Achord et l. 1996; Kennedy et l. 2007), undnce (Achord et l. 1996), growth (Peterson et l. 1994), mortlity (Kennedy et l. 2007), nd stocking success (Wills 2006) do not directly or indirectly influence or is these dt during juvenile life history stges. Nevertheless, it is importnt to note tht PIT tg loss my e much higher during lter life history stges (e.g., sltwter phse). PIT tgged fish pper to hve higher mortlity nd lower smolt-to-dult recruit survivl (SARS) thn nonpit tgged fish (see Knudsen et l. 2009; Willims et l. 2005). Thus our study results should e restricted to or cutiously extrpolted eyond juvenile life history stges. Growth rtes of fish, prticulrly coho slmon nd steelhed, were negtively ffected y PIT tgging shortly fter tgging. Our results re similr to those oserved for Chinook slmon Oncorhynchus tshwytsch (Prentice et l. 1990), rown trout Slmo trutt (Omredne et l. 1998), Eursin perch Perc fluvitilis (Brs et l. 2000), mottled sculpin Cottus irdii (Ruetz et l. 2006), nd steelhed trout (Btemn nd Gresswell 2006). Furthermore, our results suggest tht the negtive influence on short term growth rtes ppers to e excerted s PIT tg size to ody weight rtios increse. Growth rtes hve een reported to e negtively ffected when PIT tg to ody weight rtios exceed 4% (Brs et l. 2000; Ruetz et l. 2006). In our study, PIT tg to ody weight rtios were less (rnge = 2% to 0.5%) thn those previ-
ously reported, yet individul growth rtes were still negtively effected in oservtions shortly fter tgging. Fish tht were implnted with hevier nd lrger sized tgs hd significntly slower growth shortly fter tgging thn controls or those implnted with smller tgs. This suggests tht tg size, s well s the tgging event (Kennedy et l. 2007) contriutes to the oserved growth ptterns we oserved following mrking. Interestingly, it ppers tht once fish hve recovered they re le to compenste for short term reductions in growth nd resume growth ptterns similr to tht of control fish. Nevertheless, our results tken together with those of pst studies suggest tht short period of reduced growth fter tgging my e expected nd should e considered when response vriles re collected nd mesured shortly fter tgging. Our results suggest tht PIT tgging does not imprt significntly negtive effects on coho smoltifiction or juvenile dfluvil ull trout glycogen stores. There were no significnt differences in ATPse ctivity or plsm osmollity mong coho slmon controls nd those mrked with different sized tgs. In our study coho slmon were tgged prior to the initition of smoltifiction. We suspect tht the stress of the tgging event nd the tg itself were miniml nd therefore did not significntly ffect the prr smolt trnsformtion. Our results for ATPse ctivity nd plsm osmollity were similr to those reported for other slmonids rered under htchery conditions (Hor 1988; Hill et l. 2006; Kennedy et l. 2007). Although PIT tg mrking fish did not pper to ffect smoltifiction, fish tht re mrked t the onset or during the smoltifiction process my e negtively influenced possily slowing emigrtion, encourging residulism, or incresing mortlity (Kennedy et l. 2007); however, dditionl reserch will e needed to exmine this hypothesis. Likewise, ull trout HSI did not differ mong controls nd the two tretment groups. Nevertheless, the incresed vrince Performnce of Slmonids Mrked with PIT Tgs ssocited with fish PIT tgged with 23 mm tgs suggests tht proportion of our tretment popultion my hve fired worse thn the rest. Given ull trout s ggressive nture, the effect of socil sttus comined with tg size my explin the oserved vrince. Thus PIT tgging conducted during criticl periods of ull trout energy storge or utiliztion such s migrtory or overwintering periods (Berry 1994; Rtcliff et l. 1996) my ffect survivl rtes following mrking events. We encourge reserchers to consider the timing of PIT tg mrking events s to void potentilly ffecting criticl physiologicl processes. Juvenile fish survivl nd PIT tg retention rtes in this lortory study were high nd comprle to those reported in the literture. Although most studies on juvenile fish hve een much shorter in durtion thn our study, our mortlity rtes were similr to those reported for Atlntic slmon Smo slr (5.7%, 12 mm PIT tgs, Gries nd Letcher 2002; 21.2%, 23 mm PIT tgs, Roussel et l. 2000), Chinook slmon (1%, 12 mm PIT tgs, Achord et l. 1996; 12 mm PIT tgs, 3.6%, Prentice et l. 1990), sockeye slmon Oncorhynchus nerk (3.6%, 12 mm PIT tgs, Prentice et l. 1990), nd steelhed (2%, 23 mm PIT tgs, Hill et l. 2006; 14%, 23 mm PIT tgs, Btmn nd Gresswell 2006). Like our results, previously reported tg retention rtes (rnge = 30 100%) were reltively high for juveniles (Prentice et l. 1990; Peterson et l. 1994; Omredne et l. 1998; Btmn nd Gresswell 2006; Knudsen et l. 2009). Collectively, these results nd our study indicte tht low mortlity nd high retention rtes will occur if good fish hndling prctices re employed nd fish re llowed to fully recover prior to relese. Acknowledgments We thnk J. Holmes, J. Poole, nd P. Lrson of the U.S. Fish nd Wildlife Service. 9
10 Ostrnd et l. This informtion is distriuted solely for the purpose of predissemintion peer review under pplicle informtion qulity guidelines. It hs not een disseminted y the Service. It does not represent nd should not e construed to represent ny Service determintion or policy. References Achord, S., G. M. Mtthews, O. W. Johnson, nd D. M. Mrsh. 1996. Use of pssive integrted trnsponder (PIT) tgs to monitor migrtion timing of Snke River Chinook slmon smolts. North Americn Journl of Fisheries Mngement 16:302 313. Brs, E., C. Mlrouck, M. Hourt, P. Kestemont, nd C. Mélrd. 2000. The effect of PIT tgs on growth nd physiology of ge-0 cultured Eursin perch Perc fluvitilis of vrile size. Aquculture 185:159 173. Btemn, D. S., nd R. E. Gresswell. 2006. Survivl nd growth of ge-0 steelhed fter surgicl implnttion of 23-mm pssive integrted trnsponders. North Americn Journl of Fisheries Mngement 26:545 550. Berry, D. K. 1994. Alert s ull trout mngement nd recovery pln. Alert Environmentl Protection Fish nd Wildlife Service Mngement Division, Edmonton, Alert 22p. Buscker G., I. Adelmn, nd E. Goolish. 1990. Growth. Pges 363 387 in C. B. Schreck nd P. B. Moyle, editors. Methods for fish iology. Americn Fisheries Society, Bethesd, Mrylnd. Buzy, K., nd L. Deegn. 1999. Retention of nchor nd pssive integrted trnsponder tgs y Arctic gryling. North Americn Journl of Fisheries Mngement 19:1147 1150. Gries, G., nd B. H. Letcher. 2002. Tg retention nd survivl of ge-0 Atlntic slmon following surgicl implnttion with pssive integrted trnsponder tgs. North Americn Journl of Fisheries Mngement 22:219 222. Gions, J. W., nd K. M. Andrews. 2004. PIT tgging: simple technology t its est. Bio- Science 54:447 454. Hill, M. S., Zydlewski, G. B., Zydlewski, J. D., nd J. M Gsvod. 2006. Development nd evlution of portle PIT tg detection units: PITpcks. Fisheries Reserch 77:102 109. Hor, W. S. 1998. The physiology of smolting slmonids. Pges 275 343 in W. S. Hor nd D. Rndll, editors. Fish Physiology. Volume XIB. Acdemic Press, New York. Jenkins, W. E. nd T. I. J. Smith. 1990. Use of PIT tgs to individully identify striped ss nd red drum rood stocks. Pges 341 345 in N. C. Prker, A. E. Giorgi, R. C. Heidinger, D. B. Jester, Jr., E. D. Prince, nd G. A. Winns, editors. Fish-mrking techniques. Americn Fisheries Society, Symposium 7, Bethesd, Mrylnd Mrylnd. Kennedy, B. M., W. L. Gle, nd K. G. Ostrnd. 2007. Evlution of clove oil concentrtions for use s n nesthetic during field processing nd pssive integrted trnsponder implnttion of juvenile rinow steelhed. Northwest Science 81:147 154. Kennedy, B. M., W. L. Gle, nd K. G. Ostrnd. 2007. The reltionship etween smolt development nd migrtion timing to vin predtion risk of steelhed (Oncorhynchus mykiss) in lrge estury. Cndin Journl of Fisheries nd Aqutic Sciences 64:1506 1516. Knudsen, C. M., M. V. Johnston, S. L. Schroder, W. J. Bosch, nd D. E. Fst. 2009. Effects of pssive integrted trnsponder tgs on smoltto-dult recruit survivl, growth, nd ehvior of htchery spring Chinook slmon. North Americn Journl of Fisheries Mngement 29:658 669. McCormick, S. D. 1993. Methods for non-lethl gill iopsy nd mesurement of N +, K+ -ATPse ctivity Cndin Journl of Fisheries nd Aqutic Sciences 50:656 658. Omredne, D., J. Bgliniere, nd F. Mrchnd. 1998. The effects of pssive integrted trnsponder tgs on survivl nd growth of juvenile rown trout (Slmo trutt L.) nd their use for studying movement in smll river. Hydroiologi. 371 372:99 106. Peterson, P., E. Prentice, nd T. Quinn. 1994. Comprison of sequentil coded wire nd pssive integrted trnsponder tgs for ssessing overwinter growth nd survivl of ju-
venile coho slmon. North Americn Journl of Fisheries Mngement 14:870 873. Prentice E., T. Flgg, nd C. McCutcheon. 1990. Fesiility of using implntle pssive integrted trnsponder (PIT) tgs in slmonids. Pges 317 322 in N. C. Prker, A. E. Giorgi, R. C. Heidinger, D. B. Jester, Jr., E. D. Prince, nd G. A. Winns, editors. Fish mrking techniques. Americn Fisheries Society, Symposium 7, Bethesd, Mrylnd. Pcific Sttes Mrine Fisheries Commission (PSMFC). 2005. PIT tg informtion system (PTAGIS). Pcific Sttes Mrine Fishereis Commission, Gldstone, Oregon. Rtcliff, D. E., S. L. Thiesfeld, W. G. Weer, A. M. Sturt, M. D. Riehle, nd D. V. Buchnn. 1996. Distriution, life history, undnce, hrvest, hitt, nd limiting fctors of ull trout in the Metolius River nd Lke Billy Chinook, Oregon, 1983 1994. Oregon Deprtment of Fish nd Wildlife Fisheries Division, Informtion Report No. 96 97. Roussel, J. M., A. Hro, nd R. A. Cunjk. 2000. Field test of new method for trcking smll fishes in shllow rivers using pssive integrted trnsponder (PIT) technology. Cndin Journl of Fisheries nd Aqutic Sciences 57:1326 1329. Performnce of Slmonids Mrked with PIT Tgs Ruetz, C. R., B. M. Erl, nd S. L. Kohler. 2006. Evluting pssive integrted trnsponder tgs for mrking mottled sculpins: effects on growth nd mortlity. Trnsctions of the Americn Fisheries Society 135:1456 1461. Willims, J. G., S. G. Smith, R. W. Zel, W. D. Muir, M. D. Scheuerell, B. P. Sndford, D. M. Mrsh, R. A. McNtt, nd S. Achord. 2005. Effects of the federl Columi River power system on slmonid popultions. U.S. Deprtment of Commerce, NOAA Tech. Memo. NMFS-NWFSC-63. Wills, T. C. 2006. Comprtive undnce, survivl, nd growth of one wild nd two domestic rown trout strins stocked in Michign rivers. North Americn Journl of Fisheries Mngement 26:535 544. Zel, R. W., Wgner, T., Congleton, J. L., Smith, S. G., nd J. G. Willims. 2005. Survivl nd selection of migrting slmon from cpturerecpture models with individul trits. Ecologicl Applictions 15:1427 1439. Zydlewski, G. B., Hro, A., Whlen, K. G., nd S. D. McCormick. 2001. Performnce of sttionry nd portle pssive trnsponder detection systems for monitoring of fish movements. Journl of Fish Biology 58:1471 14. 11