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Number: 

# 8)11-1-18 6 Docket Number: 

# A-83-2 2

Printed 4/21/2008 11:07:10 AM Sheet 8 of 198V

J . Grea t Lakes Res. , 197 9 Internat . Assoc . Grea

t Lakes Res . 5(l):84-89 . 

# Pr-f*r3Z>-

i EFFEC T O F FIS H AG E O N PREDICTE D AN D OBSERVE D CHRONI C TOXICIT Y O F \

LEA D T O RAINBOW TROU T I N LAK E ONTARI O WATER$ 

# I

V . Hodson , B . R . Blunt , D . Jensen , an d S . Morga n Great Lakes Biolimnology Laboratory Canada Centre for

Inland Waters 867 Lakeshore Rd., P.O. Box 5050 Burlington, Ontario L7R 4A6

ABSTRACT. Exposure of rainbow trout

/"Salm o gairdneri ^ starting at

the egg stage to water-borne lead in Lake Ontario water

(hardness of

135mg CaC0 3

/L) resulted

in black tails (early symptoms of

spinaldeformities) at lead concentrations as low as 22 yg/L. No black tails were observed

at 11 ng/L. Previous publications demonstrated

that the lowest

lead concentration causing black tails in trout

exposed from the fingerling stage in Lake Ontario water was 120(ig/L, suggesting that fish exposed

from the egg stage are 5times as sensitive as those exposed from the fingerling stage. Compared to previously published

data on fish exposed from the egg stage, blood lead offish exposed

from the egg stage was greater for a similar lead exposure. However, the relationship between blood lead and enzyme inhibition (erythrocyte 5 -amino levulinic acid dehydratase) was unchanged. Therefore the increased sensitivity of

trout exposed from the egg stage was probably due to enhanced lead accumulation rather

than to an enhanced

response to the lead

taken up. The incidence of

black tails at this hardness corresponded well to a prediction based

on published

lead toxicity at extremes of

water hardness. Thi s pape r

demonstrate s importan t subletha l effect s o f

lea do n rainbo w trou t

(Salmo gairdneri) a t lea dconcentration s o f 2 2 Mg/ Lo r greater . Th e subletha l toxicit y o f

lea di s show n t o var y wit hth e lif e stag e expose dan dca n b e predicte do n th e basi s o f wate r hardness . Chroni c exposur e o f

rainbo w trou t

t o water born e lea dresulte di n spina l deformitie s an dblac k tails , an earl y sympto mo f spina l deformities , a t concentration s a s lo w a s 8 Mg/ Li n sof t wate r (2 8 mg/ La s CaC0 3 ) (Davie s et al. 1976) . Th e duratio n o f exposur e befor e developmen t o f symptom s wa s longe r whe n th e exposur e starte di n th e fingerlin g stag e (averag e weigh t

= 6 g ) a s compare dt o an exposur e starte di n th e eg g stage . Hardnes s als o reduce dtoxicit y sinc e 36 0 Mg/ Ltota l lea dwa s require dt o produc e th e sam e symptom s i n wate r o f 35 3 mg/ Lhardnes s (Davie s et al. 1976) . A linea r interpolatio n o f

th e relationshi p betwee n hardnes s an dlogi o lea dconcentratio n suggeste dtha t th e lowes t lea dconcentratio n causin g thes e effect s shoul db e abou t

2 5 Mg/ L i n Lak e Ontari o wate r (13 5 mg/ Lhardness) . A n attemp t t o verif y thi s predictio n usin g fingerlin g rainbo w trou t (averag e weigh t =L6. 5 g ) demonstrate dtha t onl y fis h a t

12 0 Mg/L . lea dexhibite dsymptom s afte r 3 2 week s exposur e (Hodson , Blunt , an dSpr y 1978a) . Th e presen t experimen t

wa s conducte dt o determin e whethe r trou t expose dt o lea dfro mth e eg g stag e i n Lak e Ontari o wate r woul ddevelo p blac k

tail s a t aconcentratio n close r t o tha t predicte dfro m Davie s e f al. (1976) . MATERIAL S AN D METHOD S Rainbo w trou t

egg s wer e expose dt o nomina l lea d concentration s o f

0 (Control) , 10 , 32 , an d10 0 Mg / L . Afte r hatch , exposur e o f

th e fr y continue dfo r afurthe r 3 0 weeks . Eg g mortality , media n tim e t o hatch , hatchin g success , an dfr y mortalit y wer e measured . Incidenc e o f

blac k tails , th e firs t

sig n o f developin g spina l deformities , wa s recorde da t weekl y intervals . Afte r

3 0 week s post-hatc h (mea n weigh t = 2 9 g) , bloo dlead , erythrocyt e 6-amin o levulini c aci ddehydratas e (ALA-D) , hematocrit , an dconditio n facto r

wer e measure daccordin g t o th e method s o f

Hodso n et

al. (1977) . Al l lea dcon centration s wer e replicate dfou r time s fo r

atota l o f 1 6 tanks . Result s wer e subjecte dt o analyse s o f var ianc e a t th e 95 % confidenc e leve l (Stee l an dTorri e * 1960) . o f co r tionim ; regres s Th e d descri b th e eg : tio n b< pcrat u irycle , of 11. ' an dd < mum• stand a al l 1 6 overal l L . Av e Abou t from were « lizati o flleal t an dd were i la r in t transf f x 3 0 ; lea dc fe da siz e a t perat i appr o eac h 1 i n eac -mu m seda s vatio r Th e A fe db eac h . four \ rat e g 0. 1 g , t o 1 2 capa c avera j min p wa s C

-P. 3

EFFEC T O FFIS H AG E O N LEA D TOXICIT Y 8 5

12 0 -ek s Th e tin e :ag e :ail s o m

ea d Mg / fo r 3 t o /er e i o f a t ea n .in o ;rit , 5 t o ;on o f var rri e i960) . Significanc e o f difference s betwee n mean s 0 f contro l an dtreate dfis hwer e teste db y parti

tionin g th e treatmen t

sum s o f squares . Slope s o f regressio n line s wer e compare db y t-tests .

Wate r The dilutio n wate r

wa s fro mLak e Ontari o a s describe db y Hodso n et

al. (1977) . Temperatur e i n th e eg g incubato r

wa s 11. 9 ± .68° C an dth e variatio n betwee n tray s wa s les s tha n 0.9 C C . Th e tem peratur e i n th e exposur e tank s followe daseasona l cycle , increasin g fro mth e incubatio n temperatur e o f 11.9° C t o amaximu mo f 22.5° C ove r

4 month s anddecreasin g t o 10° C ove r 3 months . Th e maxi

mu mo f variatio n betwee n tank s wa s 1. 1 °C . Th e standar ddeviatio n o f

oxyge n measurement s acros s al l 1 6 tank s range dfro m0.2 9 t o 0.7 7 mg/ L an d overall oxyge n concentration s wer e 8. 5 ± 0. 7 mg / L . Averag e p H wa s 8.1 6 ± 0.25 .

Fis h Abou t 10 0 m l (70 0 eggs ) o f rainbo w trou t

egg s fro mNorfol k

Trou t Fisheries , Simcoe , Ontario , wer e expose dt o lea dwithi n 3 1 / 2 hour s o f ferti

lizatio n i n eac ho f

sixtee n 10- L eg g incubato r tray s (Healt hTechn aCorp.) , modifie dfo r separat e inlet s an ddrains . N o prophylacti c tratment s fo r fungu s wer e use dothe r

tha n remova l o f

dea degg s a t

regu la r intervals . Durin g swim-up , 50 0 fr y pe r tra y wer e transferre dt o separat e polyethylen e tank s (3 0 x 3 0 x 3 0 cm ) containin g 2 0 Lo f wate r wit h th e sam e lea dconcentratio n a s th e origina l tray . The y wer e fe dacommercia l trou t

fee da t aratio n an dgranul e size adjuste dweekl y fo r

averag e fis hsiz e an dtem perature . Th e fis hwer e thinne dwhe n th e biomas s approache dth e loadin g limitation s o f th e flo w o f each tan k (se e below) . Consequently , sampl e siz e i n eac htan k

decrease dwit htim e bu t wa s amaxi

mu mfo r an y give n fis hsize . Result s wer e expres se da s apercentag e o f

th e fis ha t

th e tim e o f

obser

vation . Lea dExposur e Syste m Th e 4-stag e dilute r

(Moun t an dBrung s 1967 ) wa s fe db y adose r

describe db y Hodso n (1979) . A t eac h concentration , i t

delivere d68 0 ml/mi n spli t fou r way s t o giv e 17 0 mL/mi n pe r tank . Th e flo w rat e gav e 3. 5 L/da y fo r

ever y gramo f

egg s (abou t 0. 1 g each ) an dlimite dbiomas s o f fis hi n eac htan k to 12 2 g a t

2 L pe r g fishpe r

day . Th e carryin g capacity wa s increase dt o 16 0 g/tan k whe n th e fish averaged1. 6 g b y increasin g th e flo w t o 22 2 mL / mi n pe r tank . Th e 95 % molecula r replacemen t

tim e wa s 3 hi n th e eg g trays , an d6 an d4. 8 hfo r th e lo w an dhig hflo w rates , respectively , i n th e expo sur e tank s (Spragu e 1969) . Solven t extractabl e lea d wa s measure ddail y o n a n unfiltere dsampl e b y atomi c absorptio n spectrophotometr y (IWD 1974 ) a t eac hconcentratio n o f

on e replicate . Extractabl e lea di n laborator y wate r wa s foun dt o b e th e sam e a s tota l lea dmeasure dafte r aci ddigestio n o f

th e wate r sample . RESULT S Lea dconcentration s i n th e eg g tray s wer e fairl y constan t durin g th e eg g incubatio n period , bu t mea n measure dconcentration s wer e somewha t les s tha n nomina l (Tabl e 1) . I n th e exposur e tanks , concentration s wer e fairl y constan t fro mmont h t o mont hexcep t

fo r Septembe r

whe n average s fel l b y abou t 20 % fro mth e overal l average . Measure dcon centration s wer e withi n 15 % o f th e measure dval

ue s i n th e eg g trays . Biologica l result s ar e compare d t o th e mea n measure dlea dconcentration s (Tabl e 2) . Eg g developmen t

wa s norma l i n th e presenc e o f lea dan dfew egg s die dbefor e o r durin g th e eye d stag e (Tabl e 1) . Ther e wa s asligh t bu t nonsigni

can t elevatio n i n eye deg g mortalit y an dadecreas e i n overal l hatc ha t

th e highes t

lea dconcentration . Afte r hatc hther e wa s n o differenc e betwee n treat ment s i n sac fry , swim-u p fry , o r fingerlin g mortal

ity . A t 3 week s post-hatch , adilute r malfunctio n cause dextensiv e mortalit y i n som e reps . Th e sur ivor s fro munaffecte dtank s wer e redistribute d withi n eac htreatmen t

t o equaliz e th e numbe r o f fishpe r tank . B y 3 0 week s exposure , th e incidenc e o f blac k tail s wa s 0 % a t

5. 8 an d1 1 Mg/L , 5.5 % a t 2 2 M g/L , an d88 % a t

6 5 Mg/ L (Tabl e 2) . Bloo dlea d concentration s wer e significantl y inhibite dat al l lea dconcentration s abov e control . Th e bloo d lea dconcentration s correspondin g t o th e occur renc e o f blac k tail s wa s 170 0 Mg/

L whil e th e ALA

D activit y wa s 6 4 n

M PBG/m L RBC' s / h (nano

mole s porphobilinge n pe r millitr e o f

re dbloo dcell s pe r hour ) (equivalen t

t o 74 % inhibition) . Ther e wa s n o effec t

o f lea do n conditio n facto r an d hematocrit . DISCUSSIO N Thi s experimen t

demonstrate dtha t

symptom s o f lea dtoxicit y i n rainbo w trou t occurre da t

concen tration s o f

2 2 Mg/ L o f highe r afte r 3 0 week s post hatc hi n contras t

t o apreviou s experimen t i n whic hsimilar

toxi c effect s i n rainbo w trou t occur re dafte r 3 2 week s exposur e onl y a t aconcentra -8 6

TABLE 1. Summary of

egg development

data. HODSO N et

al.

* S = pooledstandar

ddeviation-calculate dfro

mthe erro r mea n squar e o f th e analysi s o

f variance Sj^ = pooledstandar

derro r o f the mea n R= numbe

r o f replicat e exposur e tray s TABLE 2. Summary of

physiological

measurements at

week 30. Paramete r Measure dlea di n wate r G*g/L±S ) No . o f egg s teste d Media n tim e t o hatc h(h ) Percen t egg s no t developin g t o th e eye dstag e Percen t egg s dyin g i n th e eye dstag e Percen t hatc h Percen t mortalit y o f

sac fr y Percen t mortalit y o f swim-up fr

y 0 (Control )

4.2+1. 7 264 6 67 3 3.0 3 1.2 6 95.7 2 2.0 6 2.9 2 1 0

12± 5 242 8 68 6 3.4 6 1.0 7 95.4 8 1.8 2 3.7 5 Nominal lea dconcentratio n (Mg/L ) 3 2 10 0 S * 26±8 246 5 67 6 3.86 . 1.2 4 94.9 3 2.0 6 1.4 2 76±2 3

206 6 67 0 3.1 8 2.1 4 94.6 7 2.1 7 1.67 8

0.9 2 0.8 7 1.4 8 0.4 6 1.5 3 S X

4 0.4 6 0.4 4 0.7 4 0.2 3 0.7 7 R | 

# J 1 i < ; 4 

## 4 J 4 J 

# 4 

# I 4 ]

• i

Paramete r Measure dleadconcentratio n i n wate r (jug/LtS ) Conditio n facto r Hematocri t

(% ) Bloo dlea d(Mg/L

) Whole bloo d ALA-D ! (n

M PBG/mL RBCs/h ) Percen t inhibitio n o f

ALA- D Percen t blac k tail s 0 (Control )

5.8±4. 8 1.58 3 31. 4 15 0 24 2 0 0 1 0

11± 7 1.56 4 29. 2 420 * 166 * 3 2 0 Nominal lea dconcentratio n

3 2 22+ 9 1.49 5 . 32. 4 1700 * 64 * 7 4 5. 5 10 0

65±2 6

- : 1.50 6 31. 2 1800 * 87 * 6 4 88. 0 (Mg/L

) S

0.24 0 3. 9 5 2 5 2

—

- S X

0.1 2 2. 0 2 6 2 6

—

- - i l



## R J

4 1 4 1 " 4 | 4 1



## - i 4 1 R= numbe

r of replicat e exposur e tank s *Significantl

y differen t fro mcontrol s a

t the 95 % confidence leve

l •ALA- D = erythrocyt

e deltaamin

o levulinic aci

ddehydratas e (nanoMole s Porphobilinoge n synthesizedpe

r m L re dbloo dcell

s pe r hour ) tio n o f 12 0 Mg/ L (Hodso n et

al. 1978a) . Sinc e th e dilutio n water , specie s an dexposur e tim e wer e th e same , th e differenc e wa s du e eithe r t o th e fluctuat

in g temperatur e regim e o f th e presen t

experimen t o r th e lif e stag e a t

whic hth e exposur e wa s started . Sinc e Davie s et

al. (1976 ) observe dtha t trou t expose da s sac fr

y wer e mor e sensitiv e tha n thos e expose dstartin g a s fingerlings , an dsinc e bot hthei r test s employe dfluctuatin g temeratur e regimes , th e lif e stag e hypothesi s i s probabl y correct . Sa c fr y ar e probabl y th e stag e mos t sensitiv e t o lea dsinc e onl y th e chorion s o f

egg s tak e u p lea dan dno t th e embry o (Holcomb e et

al. 1976) . Ther e ar e tw o possibl e explanation s fo r th e increase dsensitivit y o f fingerling s expose dfro m th e eg g stage . Eithe r

thes e fis htak e u p mor e lea d fo r agive n lea dexposure , o r agive n amoun t

o f lea dtake n u p exert s agreate r toxicity ; i.e. , th eP. 5

EFFEC T O F FIS H AG E O N LEA D TOXICIT Y 8 7

4 4 4 4 toooo

^ log r o BL = 1.9730 + .609 9 tog, 0 W L log* , B L = 2.063 9 + .4434 log wW L log* , BL * 1.6407+593 5 logioW L log r o BL ' 1.4745+1.0805log, 0 W L

I I I I I 1 1

10O O Lead Concentratio n i n Wate r(u.g/L ) ft flG. 1. Blood

lead (BL) of rainbow trout

exposed to waterborne lead

(WL). *The slope forline D was significantly different from that

of the otherlines at

the 95% confidence level dose-respons e relationshi p o f th e targe t

sit e ha s changed . I n th e firs t

case , th e rat e o f

uptak e o r

ex cretio n ha s changed , resultin g i n ahighe r equilib

riu mconcentratio n a t

th e targe t

sit e an dhenc e a greate r response . I n th e secon dcase , lea duptak e dynamic s hav e remaine dconstan t bu t th e respons e t o agive n leve l o f

lea dtake n u p i s muc hgreater . fi Thes e hypothese s wer e teste db y examinin g th e relationshi p betwee n lea di n wate r an dbloo dlea d (uptake ) an dbetwee n lea dtake n u p an drespons e (toxicity ) fo r

trou t expose donl y a s fingerlings (publishe ddata ) an dfo r trou t expose dfro mth e eg g stag e (thi s experiment ) (Figure s 1 , 2 , an d3) . Th e dat afo r

thes e figure s wer e take n o r calculate d fromHodso n et

al. (1977 ) fo r

lin e A i n eac hfigure , Hodso n et al. (1978a ) fo r

lin e B i n eac hfigure , Hodson , Blunt , an dSpr y (1978b ) a t p H 8. 0 fo r Kne e C i n Figur e 1 , an dthi s experimen t fo r lin e D i n eac hfigure . Equation s fo r eac hlin e ar e give n I i cell s o n eac hfigur e an dth e statistic s fo r th e regressio n lines ar e give n i n Tabl e 3 . •£ Th e slop e o f

alin e relatin g log 1 0 [bloo dlead ] t o log ! 0 [lea di n water ] i s relativel y constan t ove r ; fr y three separat e experiment s wit hrainbo w trou t •ince 'exposedonl y a s fingerling s (lines , A , B , an dC , Fig

I I th e ur

e 1) . I n contrast , th e slop e fo r trou t expose d fromth e eg g stag e i s muc hgreate r (lin e D , Figur e th e 1) , indicatin g ahighe r tha n expecte dbloo dlea d ro mfo

r agive n lea dexposur e abov e 1 0 Mg/ Llead . Th e leadwate

r temperatur e a t

th e tim e o f

samplin g i n thi s t of experimen t

wa s 10°C . Th e experimenta l tempera th e ture s o f

line s A , B , an dC wer e 11 , 11 , an d15° C 320- t

. c > O 0 3 OAnr r 240 - 

### o 0 0 0 - 160 - c 

### I 80 H ( 0 Q I <

_ l 

### < „ ALA- D = 320-102log 1 0 W L 1 0 W L log 1 0 W L

1 — I I I I I |

1 0 I I I I I I 10 0 Lea d Concentratio n i n Wate r(u.g/L ) FIG. 2,Erythrocyte 8-amino levulinic acid dehydratase activity (ALA-D) of

rainbow trout

exposed to water-borne lead (WL). Line B is an unpublished analysis from Hodson et al. (1978a). *The slope of line D was significantly different from that

of line A but

not from that of line B at the 95% confidence level.

320- 1 JO O C O Q C 240 - o c o Q . 160 - c '_> o TO 

### a i < 8 0 - ALA- D = 547 - 12 8 log 1 0 B L ALA-D = 590-14 6 log 1 0 BL B L

T | 10 0 I I I I I | — 100 0 Lea d Concentratio n i n Bloo d (u.g/L ) FIG. 3. The relationship between erythrocyte 8-amino levulinic acid

dehydratase activity (ALA-D) and blood lead (BL) forrainbow trout

exposed to water-borne lead. Line B is an unpublished

analysis from Hodson et al. (1978a). *There were no statistically significant differences between the slopes of

these lines at

the 95% confidence level. respectively . Thes e result s ar e supporte db y th e relationshi p betwee n ALA- D activit y an dwaterborn e lead . Th e negativ e slop e relatin g ALA- D t o waterborn e lea d8 8 HODSO N et al. TABLE 3. Statistics describing the regression lines shown in Figures 1, 2 and

3. Figure 1

2
3 Lin e

A B C D A B D A B D s a

*y. x 0.235 0 0.181 7 0.101 7 0.265 1 3 3 4 1 4 6 3 7 7 0 5 4 % b

0.083 8 0.061 2 0.038 8 0.170 3 13. 4 13. 8 29. 4 12. 1 15. 7 14. 4 r c

0.8 4 0.7 8 0.9 7 0.8 6 -0.8 5 -0.8 2 -0.8 3

. -0.8 5 -0.5 8 -0.8 3
a Standarddeviatio

n o f the regressio

n o f y on x "Standar ddeviation o

f the slope Correlatio n coefficien

t i s similar i n tw o previou s experiment s (line s A an d B , Figur e 2 ) startin g wit hfingerlings . I n th e pre sen t experimen t

startin g wit heggs , th e slop e i s agai n greate r

(lin e D , Figur e 2) , indicatin g agreate r tha n expecte dlea duptake . Th e consistenc y o f respons e show n b y line s A , B , an dC i n Figur e 1 an d2 , develope dwit hdifferen t lot s o f fish , sug gest s tha t th e differenc e show n b y lin e D i s experi

menta l an dno t

du e t o rando mfluctuation . Therefore , Figure s 1 an d2 suppor t th e first hypothesi s tha t

th e rate s o f

uptak e o r

excretio n o f lea dvary betwee n fishexpose da s fingerling s an d fishexpose da s eggs . Th e ne t resul t i s a n increas e i n th e apparent

premeabilit y o f

lea db y fis hexpose d fro mth e eg g stage . I n contrast , th e enzymati c respons e t o lea d take n u p (ALA- D inhibition ) indicate s tha t thi s dose-respons e relationshi p remain s unchanged . Figur e 3 illustrate s tha t th e slope s o f

line s relatin g ALA- D activit y t o bloo dlea dar e th e sam e fo r fis h expose donl y a s fingerhngs an dfis hexpose dfro m th e eg g stage ; ie. , lea dtake n u p exert s th e sam e effec t i n bot hgroups . Therefore , increase dsensitivit y t o lea di n rain

bo w trou t

expose da s egg s appear s t o b e afunctio n o f increase dlea daccumulatio n rathe r tha n incre

ase dtoxicit y o f

th e lea dtake n up . Thi s chang e i n lea daccumulatio n ma y represen t a n alteratio n o f gil l membran e structure s acros s whic hlea di s take n up , o r a n alteratio n o f

th e rat e o f

som e depuratio n mechanism . Sinc e bloo dlea di s i n equilibriu mwit h lea di n wate r

withi n 4 8 h(Hodso n et al. 1978b) , i t i s no t possibl e t o distinguis hbetwee n th e tw o mechanism s withou t

furthe r uptake-depuratio n studies . Th e differenc e i n permeabilit y t o lea d betwee n fingerling-expose dan degg-expose dfish" i s probabl y lon g lastin g sinc e th e half-tim e fo r depuratio n fro mbloo di s abou t 4 week s (Hodson et al 1977) . Consequentl y i f permeabilit y wa

s affecte donl y temporaril y i n ver y youn g fish ^ bloo dlea dwoul db e th e sam e a s tha t o f fis f expose da s fingerhng s b y 3 0 week s post-hatch . Thes e result s agre e well with , thos e predicte " fo r Lak e Ontari o wate r

fro mDavie s et

al. (197 $ A linea r interpolatio n o f

lea dtoxicity , base do

n tota l lead , agains t

wate r hardness , indicate s tha t IS Mg/ L lea dshoul dcaus e n o developmen t o f blac k tail s whil e abou t

2 5 Mg/ L should . Thi s experimen t demonstrate dtha t

2 2 Mg/ L cause d5.5 % blac k

tail s whil e 1 1 Mg/

L cause dnone . Recen t

studie s i n ou

r la b sugges t

tha t organi c particulate s i n wate r ma y reduc e lea daccumulatio n a s doe s increase dp H (Hodso n et

al 1978b) . Consequentl y prediction s o f th e variatio n o f

lea dtoxicit y wit hhardnes s wi D b e mos t vali dwher e p H an dparticulate s ar e constant . ' '% Davie s et al. (1976 ) measure dtota l lea din a settle dwate r

sampl e b y atomi c absorptio n spectro photometr y an d"free " lea db y puls e polaro

graphy . The y fel t

tha t "free " lea dmor e closel y describe dlea dtoxicity ; bu t the y di dno t

specif y th e for mo f

lea dinclude di n th e measuremen t However , monitorin g "free " lea db y puls e polan * graph y i s no t

ye t practica l o n asurveillanc e basi s (IJ C 1976) . Th e successfu l predictio n o f sublethal toxicit y base do n tota l lea dindicate s tha t tota l lead , afte r

filtratio n t o remov e particulates , ma £ provid e apractica l basi s fo r wate r pollutio n stand : ards . j § I n summary , fou r

importan t

result s o f

thi s stud y ar e tha t sensitivit y o f

fis ht o lea di s relate dt o th e lif e stag e expose dt o lead , tha t increase dsensitivit

y t o lea dresult s fro magreate r apparen t permeabilit y t o lea drathe r

tha n fro ma n enhance drespons e t o th e lea dtake n up , tha t predictio n o f

hardnes s effect s o n subletha l lea dtoxicit y betwee n me * sure dextreme s appear s valid , an dtha t measure ; ment s o f tota l lea dma y provid e areasonabl e bas k fo r predictin g lea dtoxicity . i ?

ACKNOWLEDGMENT S Th e author s than k

th e Wate r

QuaUt y LaboratoO ' Network , Inlan dWater s Directorate , Canad aCen

tr e fo r Inlan dWaters , fo r

lea danalyse s o f

wate r an dfis htissues . 4P. 7

n i tro ir o >el \ -if y :nt . .tro asi i tha i •Jta l na \ .nd

EFFEC T O FFIS H AG E O N LEA D TOXICIT Y 8 9

^ : -SO ; is h Hi: . te c 7 G , or. I f aci : •en : ail . Ou : na \ Pl i Oll i wi n •onDanes , 

### REFERENCE S

„ „ , - - H- , Goettl , J . P . Jr. , Sinley , J . R. , an dSmith , N . c 1976 . Acute an dchroni c toxicit y o f lea dt o rainbo w i/out , Salmo gairdneri, i n har dan dsof t water . Water Res . 10:199-206 . Ilodson , P

- V . 1979 . A meterin g devic e for toxicant s use d i n bi'oassay s withaquati c organisms . Prog. Fish Cult. I n press . , Blunt , B . R. , Spry , D . J. , an dAusten , K . 1977 . —Evaluation o f

erythrocyt e 5-amin o levulini c aci ddehy

dratas e activit

y a s ashort-ter mindicato r in fisho f

a harmfu l exposur e t o lead. /

Fish. Res. Board

Can. 34 : 501-508 . , Blunt , B . R. , an dSpry , D . J . 1978a . Chroni c toxi

cit y o f water-born e an ddietary lea dt o rainbo w trou t (Salmo gairdneri) i n Lake Ontari o water . Water Res. 12:869-878 . ^ 1978b . pH-induce dchange s i n bloo d lea do f lead-expose drainbo w trou t (Salmo gairdneri). J.Fish. Res. Board

Can. 35:437445 . Holcome , G . W. , Benoit , D . A. , Leonard , E . N. , an dMcKim , J . M . 1976 . Long-ter

meffect s o f

lea dexposur e o n thre e generation s o f

broo k trou t (Salvelinus fontinalis). J. Fish. Res. Board

Can. 33:1731-1741 . IJC . 1976 . Toxicity t o Biot ao f Meta l Form s i n Natura l Water . Proceeding s o f

aworksho p hel di n Duluth , Min

nesota , Oct . 7-8 , 1976 . Edite db y R . W . Andrew , P . V . Hodson , an dD . E . Konasewich . Internationa l Join t Commission , Windsor , Ontario . IWD . 1974 . Analytical

Methods Manual. Wate r Quality Branch , Inlan dWater s Directorate , Environmen t Canada , Ottawa , Canada . Mount , D . I. , an dBrungs , W. A . 1967 . A simplifie ddosin g apparatu s fo

r fish toxicolog y studies . Water Res. 1:21

- 29 : Sprague , J . B . 1969 . Measurement o f pollutan t

toxicit y t o fish. 1 . Bioassa

y method s fo

r acut e toxicity . Water

Res. 3:793-821 . Steel , R . G . D. , an dTorrie , J . H . 1960 . Principles andprocedures of

statistics. McGraw-Hill , New York .

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- /ity ilit y i l o les s neaure asi s •-if.

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