BIOACCUMULATION OF HEAVY METALS BY BROWN TROUT (SALMO TRUTTA) IN THE ARKANSAS RIVER: IMPORTANCE OF FOOD CHAIN TRANSFER

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1 BIOACCUMULATION OF HEAVY METALS BY BROWN TROUT (SALMO TRUTTA) IN THE ARKANSAS RIVER: IMPORTANCE OF FOOD CHAIN TRANSFER by Willim H. Clements Completion Report No. 167

2 -_._--,---, _.. \, \ i BIOACCUMULATION OF HEAVY METALS BY BROWN TROUT(SALMO TRUTTA) IN THE ARKANSAS RIVER: IMPORTANCE OF FOOD CHAIN TRANSFER by Willim H. Clements, Ph.D. Deprtment of Fishery nd Wildlife Biology Grnt No Project No. 1 December, 1992 The reserch on which this report is bsed ws finnced in prt by the U.S. Deprtment of the Interior, Geologicl Survey, through the Colordo Wter Resources Reserch Institute; the contents of this publiction do not necessrily reflect the views nd policies of the U.S. Deprtment of the Interior, nor does the mention of trde nmes or commercil products constitute their endorsement by the United Sttes Government. COLORADO WATER RESOURCES RESEARCH INSTITUTE Colordo Stte University Fort Collins, CO 8523 Robert C. Wrd, Director

3 -!,----_...,--- ABSTRACT This study exmined uptke nd trnsfer of hevy metls (Cd, Cu, Zn) from benthic invertebrtes to brown trout (S/rn trutt) t the Arknss River, Colordo. Metls in wter, ufwuchs, benthic invertebrtes, nd fish were mesured t sttions locted upstrem nd downstrem from Cliforni Gulch (CG), U.S. EPA Superfund site. Field studies were conducted to estimte the reltive contribution of food nd wter to metl uptke by brown trout. Aufwuchs nd benthic invertebrtes were highly contminted by hevy metls t sttions locted downstrem from Cliforni Gulch. Significnt differences (p<.5) in metl concentrtions in ufwuchs nd benthic mcroinvertebrtes mong upstrem (reference) nd downstrem (impcted) sttions were observed. Metl concentrtions in ufwuchs nd benthic invertebrtes remined elevted t some downstrem sttions, despite decreses in wter concentrtions. Significnt vrition mong functionl groups ws lso observed, s metl levels in orgnisms directly ssocited with ufwuchs (collector-grzers nd collector gtherers) generlly hd the highest metl concentrtions. The diet of brown trout t the Arknss River ws dominted by benthic invertebrtes. Ephemeropter, Plecopter, Trichopter, nd Chironomide (primrily Orthocldiine) ccounted for between 4-95% of the diet of these orgnisms. Differences in prey vilbility between upstrem (AR1) nd downstrem (AR5) sttions resulted in differences in the diet of fish. Ephemeropter comprised greter portion of the diet of fish collected upstrem from CG, wheres metl-tolernt orgnisms, such s Trichopter nd Orthocldiine, were more common in the diet of fish from downstrem. Elevted metl levels in wter nd invertebrtes t sttion AR5 resulted in incresed metls in gill nd gut tissue; however, metl concentrtions in brown trout liver nd kidney tissue were generlly similr t sttions AR1 nd AR5. These dt suggest tht fish regulted metl ccumultion t the downstrem sttion. The implictions of these findings for the recovery of brown trout popultions t the Arknss River re discussed. 2

4 INTRODUCTION Bioccumultion of Metls by Aqutic Orgnisms Bioccumultion of hevy metls in contminted strems hs been demonstrted in lge (Kelly nd Whitton 1989), mcroinvertebrtes (Krntzberg nd Stokes 1989; Kiffney nd Clements, in press) nd fish (Dllinger nd Kutzky 1985). Most of the evidence derived from lbortory studies indictes tht uptke from wter is the predominnt route of exposure, prticulrly for fish (Willims nd Giesy 1978). However, severl recent studies hve suggested tht dietry ccumultion my contribute significntly to totl body burdens of hevy metls in these orgnisms (Dllinger nd Kutzky 1985; Htkeym nd Ysuno 1987; Dllinger et l. 1987; Hrrison nd Klverkmp 1989; Douben 1989). Htkeym nd Ysuno (1987) reported tht 9% of cdmium ccumultion in the guppy, Poecili reticult, ws derived from feeding on contminted chironomids. Dllinger nd Kutzky (1985) demonstrted tht rinbow trout ccumulted metls primrily through the diet when levels in the wter were low. Hrrison nd Klverkmp (1989) lso found tht rinbow trout nd lke whitefish exposed to cdmium in continuous wter flowing system ccumulted significntly greter mounts of cdmium through food rther thn wter. These studies support the hypothesis tht some frction of hevy metls is elborted into fish tissue through the food chin. Sediments represent n importnt sink for hevy metls nd other contminnts in qutic systems. Levels of hevy metls in sediments re often severl orders of mgnitude greter thn those in overlying wter. Becuse of their close ssocition with sediments, benthic invertebrtes redily ccumulte metls from contminted sediments (Ttem 1986; Hre et l. 1989) nd therefore represent n importnt link to higher trophic levels. Although most metls show little tendency to biomgnify up food chins, concentrtions in fish cn rech hrmful levels owing to reduced prey diversity nd incresed consumption of contminted prey (Dllinger et l. 1987). Severl investigtors hve shown tht feeding hbits of fish t impcted sites my be modified to include tolernt prey types (Jefree nd Willims 198; Clements nd Livingston 1983; Livingston 1984). In strems polluted by mining effluents, Jefree nd Willims (198) reported tht fish switched from pollution-sensitive to pollution-tolernt prey types. 3

5 Hevy Metls in Strems of Colordo The upper Arknss River Bsin in Colordo hs been recognized s site of extremely poor wterqulity for mny yers. The Yk Tunnel (Ledville, CO), U.S. EPA Superfund site, releses lrge volumes of highly contminted wter into Cliforni Gulch, which flows directly into the Arknss River. Levels of zinc, copper, nd cdmium re gretly elevted in the Arknss River immeditely downstrem of Ledville, CO. Previous investigtions t the upper Arknss River hve demonstrted significnt effects of hevy metls on benthic mcroinvertebrte nd fish popultions. In prticulr, reduced density nd poor survivl of brown trout (S/rno trutt) t the Arknss River hs been ttributed to hevy metl contmintion. It hs been suggested tht bioccumultion of hevy metls, either from wter or from the food chin, contributes to the decline of S. trutt popultions in the Arknss River. Hevy metl contmintion in the Arknss River hs resulted in incresed bundnce of tolernt mcroinvertebrtes, prticulrly cddisflies, t sttions downstrem from Cliforni Gulch (Clements 1991). In prticulr, recent experiments conducted in our lbortory demonstrted tht the cddisfly Brchycentrus rnericnus is highly tolernt of hevy metls. These orgnisms re very bundnt t sttions immeditely downstrem from Cliforni Gulch nd comprise significnt portion of the diet of brown trout. Therefore it is likely tht dietry uptke of hevy metls my contribute to poor survivl of S. trutt in the Arknss River. I hypothesize tht incresed utiliztion of pollutiontolernt prey in the Arknss River will increse the potentil for food chin trnsfer of hevy metls. This reserch exmined the trnsfer of hevy metls (Cd, Cu, Zn) from benthic invertebrtes to brown trout (S/rno trutt) t the Arknss River, Colordo. The specific objectives of this reserch were to test the hypotheses tht: 1) concentrtions of hevy metls in benthic invertebrtes were elevted downstrem from Cliforni Gulch, U.S. EPA Superfund site; 2) feeding hbits of brown trout vried between upstrem nd downstrem sttions due to metl-induced chnges in prey vilbility; 3) metl levels in brown trout tissues re elevted downstrem from Cliforni Gulch; nd 4) benthic invertebrtes t the Arknss River re potentil source of hevy metls to brown trout. 4

6 MATERIALS AND METHODS Study Site The study site ws locted in vlley in centrl Colordo, between the Swtch nd Mosquito mountin rnges (Fig. 1). Dt reported in this study represent prt of long-term monitoring progrm (Clements, unpublished dt) to ssess the impcts of hevy metls from the Yk Tunnel, U.S. EPA Superfund site tht dischrges into Cliforni Gulch (CG) nd eventully into the Arknss River. The upper Arknss River is formed by the confluence of two min tributries, the Est Fork of the Arknss River nd Tennessee Creek. Smpling sttions were locted long 9 m elevtion grdient from Climx to Buen Vist, CO. Wter smples nd benthic invertebrtes were collected t sttions upstrem nd downstrem from CG. Three sttions (EF1, AR1, nd AR2) were locted upstrem from CG nd served s reference sites. Sttions AR3, AR5, nd AR8 were locted.3, 6., nd 45. Km downstrem from CG, respectively. Substrte consists of minly grvel-rubble with riffles nd runs comprising the mjority of strem hbitt. Flow is dependent upon snowmelt with high flow occurring during spring runoff. Riprin cnopy is scrce, consisting minly of willow (SliX spp.). Fish nd Invertebrte Smpling Brown trout (Slrn trutt) were collected from sttions AR1 nd AR5 using bckpck electroshocker on four smpling occsions: 2-21 April, 8-9 July, August, nd 5-6 September On ech occsion, smpling ws conducted on two consecutive dys. After fish hd been cptured, they were plced in live-bskets. Gut contents were removed with the use of hnd-held stomch pump. Smples were immeditely plced on dry ice nd frozen for metls nlysis. Stomch smples collected for identifiction of benthic invertebrtes were returned to the lbortory t Colordo Stte University. Feeding hbits hve been nlyzed for fish collected in April, July, nd August. Food items were identified to genus, species nd enumerted under dissecting microscope. Dry weights were recorded for ech smple to the nerest.1 mg using Sotoris Blnce ,-Ī

7 On two smpling occsions (July 1991 nd September 1991), brown trout collected from ech sttion were scrificed to determine the concentrtion of Cu, Cd, Zn in their gills, liver, gut, nd kidney. Whole fish were mesured, weighed, nd immeditely frozen on dry ice. In the lbortory, kidney, liver, gut, nd gill tissues were tken from ech fish nd plced in 16.5 ml glss test tubes. All brown trout tissue smples were digested nd nlyzed s described below. Benthic invertebrtes were collected for metls nlysis from ech sttion. Orgnisms were collected from riffle re using D-frme net. All orgnisms were sorted to genus in the field, except for chironomids which were sorted to tribe. Individul orgnisms were used for metls nlysis when possible, except for chironomids nd betid myflies, which were pooled becuse of their smll biomss. Ech vil ws treted s replicte smple. An effort ws mde to collect the sme species from reference nd contminted sites. All orgnisms were plced in 25-ml polypropylene scintilltion vils nd immeditely plced on dry ice. Metls Anlysis Concentrtions of Cd, Cu, nd Zn were nlyzed in wter smples collected from ll sttions. Wter smples were collected in 25 ml cid wshed nlgene continer nd cidified with 1 ml nlyticl grde HN 3 in the field. Totl metl concentrtions were mesured using Instrumenttion Lbortory Video 22 grphite furnce tomic bsorption spectrophotometer. Accurcy nd percent recovery were determined by nlyzing Ntionl Bureu of Stndrds bovine tissue, cid blnks, nd spikes. For metls nlysis, invertebrtes nd fish tissue smples were dried in n oven t 5 C nd then digested in 1 ml of 1:1 rtio of concentrted sulfuric nd nitric cid. All smples were llowed to predigest for period of no less thn 24 hours. Smples were then heted in wter bth t 5-6 C until digestion ws completed. Smples were diluted with 6 ml of distilled wter nd nlyzed for Cd, Cu, nd Zn s described bove

8 '.., I Sttisticl Anlyses Becuse of non-homogeneity of vrinces ll metl concentrtions were logtrnsformed. Anlysis of vrince (ANOVA) nd Tukey's Honest Significnt Difference (HSD) multiple rnge test were performed to determine differences in metl concentrtions in invertebrtes. Tukey's HSD test controls mximum experiment error rte nd is suitble for unequl smples sizes. Student's t-tests were employed to test for differences in metl levels in fish tissue mong loctions. All sttisticl nlyses were performed using PC-version of Sttisticl Anlysis System (SAS). A significnt difference ws determined to exist t p<.5 level. RESULTS Concentrtions of Hevy Metls in Wter Concentrtions of Cd, Cu, nd Zn t the Arknss River vried mong loctions nd mong sesons (Fig. 2). Zinc ws the dominnt metl mesured t ll sttions on ll smpling occsions. Levels of Zn t sttions immeditely downstrem from LMDT (EF5, EF6) nd CG (AR3) rnged from 25 ug/l to 8624 ug/l. Levels of Cd were lso elevted downstrem from both sources of metls; however, Cu concentrtions were not influenced by input from LMDT. Concentrtions of Cd, Cu, nd Zn t sttion EF1 were generlly higher thn EF2. The source of metls t sttion EF1 is not known. Metl concentrtions t sttions AR1 nd AR2 were elevted bove bckground levels due to input from LMDT. Becuse of dilution provided by Tennessee Creek, levels of Cd nd Zn were generlly lower t these two sttions compred to EF5 nd EF6. Concentrtions of most metls were reduced t sttion AR8, but generlly remined bove reference sttion vlues. An exception to this pttern occurred during spring 1991 when levels of ll metls remined elevted t this downstrem site. Sesonl vrition in metl concentrtions ws observed t ll sttions. In prticulr, during spring 1991 levels of metls were gretly elevted t ll sttions downstrem from CG. The gretest sesonl vrition ws observed t sttion AR3, where levels of Cd, Cu, nd Zn were 48X, 17X, nd 24X greter in spring 1991 compred to fll

9 T Metl Concentrtions in Aufwuchs nd Benthic Invertebrtes The order of metl concentrtions in ufwuchs (defined s periphyton, lge, nd ssocited biotic mteril) nd mcroinvertebrtes prlleled those in wter (Fig. 3). Zn levels were highest in ll orgnisms, followed by Cu nd Cd. Metl levels were highest in ufwuchs nd in orgnisms directly ssocited with this mteril (e.g., Betis spp. nd Pteronrcell bdi). Metls in benthic orgnisms were higher t downstrem contminted sttions (AR3 nd AR5) compred to upstrem reference sttions (EF1, AR1, nd AR2). Despite gretly reduced levels in wter t sttion AR5 compred to AR3, concentrtions of metls in ufwuchs nd most invertebrte tx remined elevted nd often incresed t sttion AR5. Metl concentrtions in some tx remined elevted t AR8, the furthest downstrem sttion. For exmple, concentrtions of Zn nd Cd in Betis spp. were significntly higher t sttion AR8 compred to AR1 during My 1991 nd September 199, respectively. In ddition, concentrtions of copper were higher in Arctopsyche grndis t AR8 during September 199. On few occsions metl levels were higher t upstrem sttions compred to downstrem sttions. This ws most frequently observed in the spring, when levels in wter were generlly gretest. Most notble were the elevted levels of Zn in Betis spp. nd ufwuchs t AR1 (spring), Cd nd Cu in ufwuchs t EF1 (spring), Cu in Pteronrcell bdi t AR2 (spring), nd Cd in Rhycophil spp. t AR2 (fll). As with concentrtions of metls in wter, there ws considerble sesonl vribility in Cd, Cu, nd Zn concentrtions in ufwuchs nd mcroinvertebrtes (Fig. 3). Although results of one-wy ANOVA indicted tht metl levels in benthic communities were generlly elevted in the spring, this ws dependent on sttion, tx, nd metls. For exmple, while Cd levels in ufwuchs were higher in spring, Zn nd Cu were generlly gretest t downstrem sttions during fll. As noted bove, Cd nd Cu levels t EF1 were elevted during spring compred to summer nd fll. Feeding Hbits of Brown Trout Aqutic insects were the dominnt prey in the diet of brown trout collected from sttions AR1 nd AR5 t the Arknss River on ll smpling occsions (Fig. 4). 8

10 Ephemeropter (Betis spp., Ephemerel/ sp.), Plecopter (Prostoi besmets, Skw/ mericn), Trichopter (Arctopsyche grndis, Rhycophil spp.), nd Chironomide (Orthocldiine) dominted the diet nd ccounted for between 4-95% of ll prey. In prticulr, Betis spp. ws frequently found in the diet of fish from both sttions nd on ll dtes. Differences in feeding hbits of S/mo trutt between upstrem nd downstrem sttions were observed (Fig. 5). In prticulr, myflies were more common in the diet of fish collected from AR1 compred to AR5. In contrst, cddisflies nd Orthocldiine were more common in the diet of fish collected downstrem from CG. Differences in feeding hbits of S. trutt between sttions were direct result of differences in prey vilbility. Abundnce of Ephemeropter ws gretert the upstrem reference sttion, wheres Trichopter nd Orthocldiine were more bundnt downstrem of Cliforni Gulch. Metl Concentrtions in Brown Trout Concentrtions of Cd, Cu, nd Zn in brown trout tissue vried between sttions nd dtes (Fig. 6). Cd nd Cu levels were generlly higher in liver nd kidney, wheres concentrtions of Zn were higher in gill nd gut tissue. Differences in metl concentrtions between sttions were dependent on tissue type. Metl concentrtions in liver nd kidney tissue were generlly similr or significntly higher t the upstrem sttion. In contrst, metl concentrtions in gill nd gut tissue were often greter t the downstrem sttion. The order of metl concentrtions in certin brown trout tissue ws not the sme s tht observed for wter smples nd benthic invertebrtes. For exmple, Cu concentrtions were much greter thn Zn in liver tissue, despite the fct tht mbient Zn levels in wter were much higher. Similrly, Cd levels were higher thn Cu in kidney tissue. 9

11 ,-----,---, I DISCUSSION Results of this study indicte tht brown trout collected from the Arknss River consumed prey tht with high levels of hevy metls. In prticulr, Betis spp. nd Orthocldiine chironomids, which comprised lrge portion of the diet t both sttions, were highly contminted. Levels of metls in wter, gill tissue, benthic orgnisms, nd gut tissue re shown in Figure 7. Metl levels in ech comprtment were elevted t the downstrem sttion. In generl, metl concentrtions in wter nd brown trout gill tissue were reltively low compred to other comprtments. Of the three metls exmined, Cd ppered to hve the gretest ffinity for gill tissue. Metl concentrtions in ufwuchs were gretly elevted, suggesting tht this mteril is mjor source of metls t the Arknss River. This hypothesis is supported by the high levels of metls mesured in the myfly Betis spp., which feeds directly on ufwuchs. Metl concentrtions in other dominnt brown trout prey were elevted t sttion AR5 compred to AR1. Metl levels in brown trout gut tissue were generlly lower thn in prey items. Although these dt indicte tht food chin trnsfer of metls is reltively inefficient, they show tht some frction of these metls re vilble through the diet. Differences gut tissue concentrtions between sttions vried mong the three metls. Levels of Cd in gut tissue were similr between sttions AR1 nd AR5, wheres Cu nd Zn were elevted t the downstrem sttion. In generl, levels of metls in wter nd food were greter t sttion AR5 compred to AR1. As expected, brown trout tissues tht were directly exposed to metls in food nd wter (e.g., gut nd gill tissue) generlly hd higher levels of metls t sttion AR5 compred to AR1. In prticulr, Zn ws significntly elevted in gill nd gut tissue t AR5 on both smpling dtes. In contrst to these findings, levels of Cd, Cu, nd Zn in liver nd kidney tissue were either similr t upstrem nd downstrem sttions or elevted t the upstrem sttion. Despite similr metl levels mesured in brown trout storge tissue t sttions AR1 nd AR5, I suggest tht fish from the downstrem sttion were potentilly stressed by metl exposure. Fish t sttion AR5 re clerly exposed to higher metls in wter nd 1

12 through the diet. The similr levels in fish from these two sttions suggest tht brown trout regulted metls in these storge tissues. Severl reserchers hve demonstrted tht fish regulte metl concentrtions in criticl orgns using metl-binding proteins such s metllothionein (Roch et l. 1982). Since production of these proteins comes t some metbolic cost to the orgnism, fish from the downstrem sttion must divert energy from other importnt physiologicl processes (e.g., growth, reproduction) to metl regultion. Reduced density, growth, nd survivl of brown trout beyond 3-4 yers t loctions downstrem from Cliforni Gulch supports the hypothesis tht these fish re stressed by chronic metl exposure. Bsed on mbient metl levels, metls in benthic orgnisms, nd feeding hbits of brown trout, I propose conceptul model to explin the distribution nd trnsfer of hevy metls t the upper Arknss River (Fig. 8). Levels of metls in ufwuchs were much higher thn ny other comprtment. I suggest tht dissolved metls nd metls ssocited with prticulte mterils in the wter column were most likely the primry source of contminnts to this mteril. Levels in orgnisms directly ssocited with ufwuchs (e.g. Betis, nd Orthocldiine chironomids) were lso gretly elevted. I suggest tht this route (wter----->ufwuchs----->betis nd Orthocldiine) ws primry pthwy for the movement of metls in the Arknss River system. Becuse of the high levels of metls in Betis nd Orthocldiine, nd becuse these orgnisms comprised significnt portion of the diet of brown trout, I suggest tht these orgnisms were n importnt source of metls to S/rno trutte. Aufwuchs communities nd sediments represent mjor sinks for metls t the Arknss River nd my dely recovery of this system. Current remedil ctivities t Cliforni Gulch re expected to reduce concentrtions of hevy metls in wter. Despite lower mbient concentrtions, metls present in contminted sediments nd periphyton will be biovilble nd will continue to impct this system. Consequently, bioccumultion of hevy metls by benthic invertebrtes nd subsequent trnsfer to brown trout my continue following these clenup ctivities. Continued reserch on the reltive importnce of diet nd wter s sources of metls to Setmo trutte will be necessry to evlute the effectiveness of remedition t the Arknss River. 11

13 LITERATURE CITED Clements, W.H Fte nd effects of hevy metls on the Arknss River. Colordo Wter Resources Reserch Institute Completion Report No Project Number G Clements, W.H. nd R.J. Livingston Overlp nd pollution-induced feeding hbits of filefish (Pisces:Moncnthide) from Aplchee By, Florid. Copei 1983: Dllinger, R., nd H. Kutzky The importnce of contminted food uptke for the hevy metls by rinbow trout (Slmo girdneri): field study. Oecologi (Berl.) 67: Dllinger, R., F. Prosi, nd H. Bck Contminted food nd uptke of hevy metls by fish: review nd proposl for further reserch. Oecologi (Berl.) 73: Douben, P.E.T Metbolic rte nd uptke nd loss of cdmium from food by the fish Noemccheilus brbtulus L. (stone loch). Environ. Pollut. 59: Hre, L., P.G.C. Cmpbell, A. Tessier, nd N. Belzile Gut sediments in burrowing myfly (Ephemeropter, Hexgeni Iimbt): their contribution to niml trce element burdens, their removl, nd the efficcy of correction for their presence. Cn. J. Fish. Aqut. Sci. 46: Hrrison, S.E. nd J.F. Klverkmp Uptke, elimintion nd tissue distribution of dietry nd queous cdmium by rinbow trout (Slmo girdneri Richrdson) nd lke whitefish (Coregonus clupeformis Mitchell) Environ. Tox. Chern. 8: Htkeym, S. nd M. Ysuno Chronic effects of Cd on the reproduction of the guppy (Poecili reticult) through Cd-ccumulted midge lrve (Chironomus yoshimtsui). Ecotox. Environ. St. 14: Jefree, R.A. nd N.J. Willims 198. Mining pollution nd the diet of the purple-striped gudgeon Mogurnd mogurnd Richrdson (Eleotride) in the Finniss River, Northern Territory, Austrli. Ecol. Monogr. 5: Kelly, M.G. nd B.A. Whitton Interspecific differences in Zn, Cd, nd Pb ccumultion by freshwter lge nd bryophytes. Hydrobiologi 175: T ,------

14 ._ ,-- I Kiffney, P.M. nd W.H. Clements (in press) Bioccumultion of hevy metls by benthic invertebrtes t the Arknss River, CO, USA. Environ. Tox. Chem. Krntzberg, G. nd P.M. Stokes Metl regultion, tolernce, nd body burdens in the lrve of the genus Chironomus. Cn. J. Fish. Aqut. Sci. 46: Livingston, R.J Trophic responses of fishes to hbitt vribility in costl segrss systems. Ecology 65: Roch M., J.A. McCrter, A.T. Mtheson, M.J.R. Clrk, nd R.W. Olfson Heptic metllothionein in rinbow trout (Slmo girdneri) s n indictor of hevy metl pollution in the Cmpbell River system. Cn J. Fish Aqut Sci. 39: Ttem, H.E Bioccumultion of polychlorinted biphenyls nd metls from contminted sediments by freshwter prwns, Mcrobrchium rosenbergii nd clms, Corbicul flumine. Arch. Environ. Contm. Tox. 15: Willims, D.R. nd J.P. Giesy, Jr Reltive importnce of food nd wter sources to cdmium uptke by Gmbusi ffinis (Poecilide). Environ. Res. 16:

15 FIGURE LEGENDS Figure 1. Mp of smpling sttions t the upper Arknss River, CO. Figure 2. Metl concentrtions in wter t smpling sttions t the Arknss River. Arrows indicte sources of metls from Ledville Tunnel nd Cliforni Gulch. Figure 3. Men concentrtions of Cd, Cu, nd Zn in ufwuchs nd dominnt mcroinvertebrte tx t the Arknss River. Brs with the sme letter were not significntly different (p<o.5). Figure 5. Feeding hbits of brown trout (Slmo trutt) t sttions AR1 nd AR5. Figure 6. Percent composition of dominnt mcroinvertebrte groups in brown trout diet nd in the field t sttions AR1 nd AR5. Figure 7. Metl concentrtions in liver, kidney, gill nd gut tissue of brown trout tissue collected from sttions AR1 nd AR5 during July, 1991 nd September, Figure 8. Men concentrtions of metls in wter, gills, ufwuchs, prey, nd brown trout gut tissue t sttions AR1 nd AR5. Figure 9. Conceptul model of hevy metl trnsfer t the Arknss River. The size of the rrows indictes the reltive importnce of different pthwys. 14

16 Upper Arknss River Bsin EF 1 Est For Ledville Drin ( Cliforni Gulch ) Arknss River EF 5 Ledville AR7 Lke Creek f I v- Tennessee Creek AR5 Lke Fork Hlfmoon Creek -n -l. <. C -s CD... Z<C] I 5 L--J Scle of Kilometers

17 3 Cd 1-3! * I I I I I...J EF1 EF2 EF5 EF6 AR1 AR2 AR3 AR5 AR7 ARB """"- C) ::J 3 Cu --..,... Fll 1989 Z 1 Spring Summer 199 : 1...! Fll 199 I Z II Spring 1991 W * o Summer 1991 Z 6..A-.3 I I I EF1 EF2 EF5 EF6 AR1 AR2 AR3 AR5 AR7 ARB o,ooo Zn 3, 1, 3 6.!! 1... t f?j 3 I I I I I I I I EF1 EF2iEF5 EF6 AR1 AR2 iar3 AR5 AR7 ARB STATION Figure 2. / i -, -

18 p=.1 Aufwuchs P=.9 p=.2 P=.1 p=.1 P=.4 25, , P =.1 p=.19 p=.1 2, 15, Ol :::t &1, 5, o '---.l..:::::a..-'..a:>.."::'" October 199 My 1991 August 1991 IZSJ EF 1 E:2J AR 1 E:] AR 2 AR 3 II AR 5 IITJ AR 8 Figure 3. f? -"---

19 5 4 Betis s P=.1 P=.1 p=.4 3 :::J..!Q Q P=.2 P=.3 P=.4 15 OJ -OJ :::J.. 1 S' Q. 5 12,, p=.5 P =.1 p=.3 1, 8, OJ >..:: 6, & 4, 2, o ' October 199 [2l EF 1 rz:j AR 1 My :3 AR2 AR3 August 1991 [II AR 5 illlti AR 8 Fi gure 3 (cont, ) ll _ ,--

20 25 p=,46 P=.15 bdi 2 C) 15 -C) ::::l..... "' o , P=.7 P =.8 8 C) 6 -C) ::::l.. S" b b 5, 4, P =.15 P =.2 C) 3, -C) ::::l.. C N... 2, 1, October 199 EF 1 r2l AR 1 My 1991 lsj AR2 AR 3 August 1991 AR 5 []J AR 8 i '1 Fi gure 3. (cnt.) l

21 '.., P=.5 P =.2 p=.7 ) Ol 15 :::l.!q p=.2 P =.1 p=.7 15 ) Ol :::l. 1 S' 5 o -l.<:l..a.l4."":" 2, , p=.3 P =.3 p=.1 1,5.=: 1, S. 5 OL...-..:.:J..I:"':" October 199 My 1991 August 1991 EF1AR1AR2.AR3AR5AR8 Figure 3 (cnt.)

22 25 r l , p=.4 P =.1 P = ::::t. Q p=.1 p=.1 p= Ol Oi ::::t. 8 S' Q , r , P=.4 P =.2 p=.2 8, 6, ::::t. : 4, 2, October 199 My 1991 August 1991 t?:ql EF 1 12l AR 1 E:S] AR 2 AR 3 AR 5 IlillI AR 8 Figure 3 (cont.) :) _._--

23 1,4 p=.4 p=.6 1,2 1, 8 N_ 6 4 b 2 o L...-.l.- October 199 IS2l EF 1 E2l AR 1 My 1991 lsj AR2 AR3 August 1991 Ii AR5 GIl AR8 I T._---_._- II Figure 3 (cnt.)

24 T FEEDING HABITS OF BROWN TROUT APRIL 1991 AR1 III Betis II Orthocldiine IQ$l Skw/ mericn Prostoi bssmets AR5 Other Chironomide JULY 1991 AR1 AR5 Betis 83 Ephemerell D Brchycentrus r2 Rhycophil f2?j Arctopsyche II Orthocldiini August 1991 AR1 AR5 Betis 18 Orthocldiine Simulium D G/ossosom Terrestrils Figure 4.

25 o ABUNDANCE OF DOMmANT GROUPS 1r , 8 CiS o 6 o o 4 s.. () 2 12 o 1 CiS o 8 s o 6 o '" '" "..... //j.// ,..... '" '" I , , rrii::i:}}} =J=U' llil j:';l 1.'.l.I.I.I.'.I.'.I.,.'.).J.I.!.I. igi ::::;:::::::::;:;:., , , , :-:-:-:-:-:-:-:-:. -:-:-:-:.:-:-:<-: AR1 AR5 AR1 AR5 AR1 AR5 STATION FEEDING HABITS OF BROWN TROUT Apr. o '---J AR1 AR5 Jul..:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.: , '". AR1 AR5 STATION AR1 AR5 k::::1 Ephemeropter Plecopter Eillill Trichopter [:::::\::::1 Orthocldiini Figure 5. -r '

26 4, , 3 Cdmium 2 C) :::s z o - : I Z W o Z o ọ.j j:!: w :! o LIVER LIVER KIDNEY KIDNEY GILLS GUT 1,., , AR1. AR5 GILLS September, 1991 Zinc Copper GUT 1, , 1,2 1, o LNER KIDNEY GILLS ORGAN GUT Figure 6. T,._---_._- II

27 Cdmium 4 C) 3 C) 2 1 Z - 3, 1, : 3 I- 1 Z W 3 LIVER KIDNEY GILLS GUT b AR1. AR5 Copper (J 1 Z 3 1 (J LIVER KIDNEY GILLS GUT..I 8 6 July, 1991 W :E 4 Zinc 2 o LIVER KIDNEY GILLS ORGAN GUT Figure 6 (cnt.)

28 J :> -..::,....." l.cl s::::: -s CD "-J " CD :J r-+ Wter Gills Brchycentrus Arctopsyche Gut o.. Concentrtion of Zn g 1'> b '" s g!1' I II;I $> g Wter Aufwuchs BetIs Orthocldllne Brchycentrus Arctopsyche Gut o Ul f1l Orthocledllne Brchycentrus Arctopsyche Gut o 8 8 Concentrtion of Cd l!!j D Concentrtion of Cu '" g 8 Aufwuchs o o3 Betls 3 Orthocldllne

29 1! J I... -n I.Cl s:: -s CD i HEAVY METALS IN THE ARKANSAS RIVER A CONCEPTUAL MODEL BAETIS 'ORTHOCLADIINAE SKWALA RHYACOPHILA WATER BRACHYCENTRUS ARCTOPSYCHE IBROWN TROUT I -I