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1 . DeForest, 8rix, and Adams Debate/Commentary for the dilTerenttissues, where possible, and also compared lhese resulls 10 lhe guidelines recommended by Lcmly (1993a) and Skorupa el ai. (1996). For consistency, all tissue concentrations are reponed OIL a dry weight (dw) basis. When selenium concentrations were reported on a wet weight (ww) basis in the original study, Lcmly assumed that the moisture content in lhe lissue was 75%.Jalvinen and Ankley (1999) reponed concentrations on a wet wcight basis, and assumed thatlhe percenlmoisture in lhe lissue was 80% if' it was nol reported. We convened the concentrations lhey reported back to a dl)' weigh I basis. In contrast to Lemly (l993a), we did not assume that the moisture content in every tissue was 75%. We ilssumed the moisture content in ovaries was slightly higher, at 85% (Gillepsie and Baumann, 1986). This assumplion was only needed for the Hermanulz et ai. (1992) study. Since lhe pcrcclll moisture in whole body fish tissue typically ranges from 75 to 80%, 75% was used conselvatively to adjust whole body conc~ntrations when neccssary. Each of the studies we reviewed is summarized below and, where appropri- ate, in Tables 2 to 4 relalive 10 interpretations by Lemly (1993a), Skorupa et al. (1996), andJalVinen and Ankley (1999). The review is divided into coldwaler and wannwater species because, as discussed later, there is evidence they may difTer in sensitivity. IlIlerpretatious of the studies by Lemly (I9!)Sa), Skorupa et ai, (1996), andJalVincn and Ankley (1999) are also provided for comparison when available. :z .. 0 ~ ~ .... ~ 0 ;t ~ ~ i .. .r ~ ~ i -.I :J ,~ -' " l.i '" .!! C\ a ;; ;; " " ;; ;; ,g ti Ii ~ Ii c -R ! I ,g '~ il :i: :i: 8 ;I: ~ ti .8 ,~ .~ ~ u ! 1 ~ ] III ';0 " tt:: ~ ~ ~ ~ M 1l III s: '" oS ! 'i Jl " "tl "0 ~ '" III i .c 0- M '" :z. i;i ~ ^ z '0 Q 0 ~ ! ~ 0 u u u i u ~ I g t UJ UJ UJ 9 v 0 0 0 e -' -' -' ~ i 8 !!. E " l " 1 1 1 i 1 I , I I Ii Ii ! I I u .f u M u :i ~ :i ! UJ a UJ UJ t ,'il 0 0 0 t ~ ~ ~ t ~ ~ " ~ 1 ~ :z. I I i " N Ii ... " " " a " 1 .... t ~ Ii " t Ii t Ii 1 I 1 I Ii III Ii Ii :a 13 t u 0 E E E I .13 '" fi .5 '6 '5 J! .~ j J! 1 ~ 8 OIl .g 1 i E i E ~ B E J ~ " .. I,) u .g 0 I,) 'l:j g Jl " C "0 r; ., III i J .. 0- r- ~ ::l '" .... u .. .0 .. N ^ C 0 Q u ~ 'a III 11 "ii lJ) 1 c t t " II> ~ :; :; E ,0 .e eN :3 g g -a B Ii ... ~ ~ " "8 11 11 III .8 .8 " ~ .0 C .s c c 11 11 ~ :c ro ~ ;;, u ... ... Coldwater Species Studies relating selenium residues tu toxic c1Tecls in colclw,llcr fish arc limited to rainbow trout (OncorhYllchus myk;ss) and chinook salmon (Oncorhynchus ts/iawytscllQ). Studies on each spccics are discusscd separately below. Raillbow Trout (Oncorhynchus mykiss) Goettl alld D(lV;es (/978). Rainhow twut were provided a diet spiked Wilh measured selenite concentrations of 9.0, 2,6, and 1.3 mg/kg dw, After 42 weeks, 2,1 % mortality occurred in trout fcd the 9.0 mg/kg dw dict, compared to 0% monality in the control /ish and in /ish fed thc 2.6 mg/kg dw diet. Trcatment replication was notl'cportcd so it was not possible to dctermine the NOEC and LOEC. Assuming that 21 % mortality is a signilicant response, the estimated die tal)' chrouic value for this study is 4.8 mg/kg dw Crable 2). I.cmly (l993a) reported that a dietal)' concentration of 9 mg/kg dw rcsultcd in mortality (Table 2), but he did not calculate a chronic valuc. Hodsoll, SP'y. alld lJlUllt (1980), Rainbow trout werc exposed to aqucous concentrations of selenile in the laboralOl)'. Somc clTccls on hluod ChClllisllY were obselvcd, but as stated b)' the authors, it is unlikely that the obsclved level of response would be dctrimentalto fish in a uatural situalion. Given ahe lack ofa link to potential population-Icvel effects and that dietary exposurc was litH evaluated, this study was not considered appropriate in evalualing wholc hody selenium thresholds. 1111111. Eml. Risk Assess, Vol. 5, Nu, 6, 1999 1193