Effects of environmental pollution on microsatellite DNA diversity in wood mouse (Apodemus sylvaticus) populations

Ten microsatellite DNA loci were surveyed to investigate the effects of heavy metal pollution on the genetic diversity and population genetic structure of seven wood mouse (Apodemus sylvaticus) populations along a heavy metal pollution gradient away from a nonferrous smelter in the south of Antwerp (Flanders, Belgium). Analysis of soil heavy metal concentrations showed that soil Ag, As, Cd, Cu, and Pb decreased with increasing distance from the smelter. Genetic analyses revealed high levels of genetic variation in all populations, but populations from the most polluted sites in the gradient did not differ from those of less-polluted sites in terms of mean observed and expected heterozygosity level and mean allelic richness. No correlation was found between measures of genetic diversity and the degree of heavy metal pollution. However, an analysis of molecular variance and a neighbor-joining tree suggested a contamination-related pattern of genetic structuring between the most polluted and less polluted sites. Pairwise F(ST) values indicated that populations were significantly genetically differentiated, and assignment tests and direct estimates of recent migration rates suggested restricted gene flow among populations. Additionally, genetic differentiation increased significantly with geographical distance, which is consistent with an isolation-by-distance model. We conclude that, at least for our microsatellite DNA markers, genetic diversity in the studied wood mouse populations is not affected greatly by the heavy metal pollution.     

Metal-induced shifts in benthic macroinvertebrate community composition in Andean high altitude streams

High altitude creates unique challenging conditions to biota that limit the diversity of benthic communities. Because environmental pollution may add further stress to life at high altitude, the present study explored the effect of metal pollution on the macroinvertebrate community composition in Andean streams between 3,500 to 4,500 meters above sea level (masl) during wet and dry seasons. At polluted sites, showing a high conductivity and a low pH, metal concentrations (e.g., Al, 13.07 mg/L; As, 3.49 mg/L; Mn, 19.65 mg/L; Pb, 0.876 mg/L; Zn, 16.08 mg/L) ranged from 8-fold up to 3,500-fold higher than at reference sites. The cumulative criterion unit allowed quantifying the potential toxicity of metal mixtures at the contaminated sites. Principal component analysis of physical chemical variables showed that reference sites were more likely to be structured by transparency, water discharge, and current velocity, while polluted sites appeared to be determined by metals and conductivity. Canonical correspondence analysis indicated a strong influence of highly correlated metals in structuring invertebrate communities, which were dominated by dipterans, coleopterans, collembolans, and mites at polluted sites. At reference sites crustaceans, ephemeropterans, plecopterans, and trichopterans were the most representative taxa. We concluded that severe metal pollution induced changes in macroinvertebrate community composition in high-altitude Andean streams, with a replacement of sensitive taxa by more tolerant taxa. Yet relatively species-rich communities persisted under harsh conditions.     

Effects of Heavy Metal Exposure on Aggressive Behavior in a Small Territorial Songbird

Several studies have shown that elevated levels of certain heavy metals may affect the behavior of birds and mammals. However, most of these studies were carried out under controlled laboratory conditions; results from free-living populations are scarce. In this study we examined the possible effects of exposure to high heavy metal concentrations on the aggressive behavior of resident great tit (Parus major) males by means of simulated territorial intrusion experiments during the egg-laying and incubation period at a highly polluted and a reference site. We also examined the effects of heavy metal exposure on the breeding performance of the tested couples, and we examined the plasma testosterone concentrations of great tit males in both study sites. We found no significant differences in the aggressive behavior between great tits at the polluted and the reference site during the egg-laying period. During the incubation period, responding male great tits at the polluted site performed significantly more aggressive flights around the decoy than did males at the reference site. During this period, there was also a tendency that more responding males were out of sight of the observer for some time during the experiment at the reference site than at the polluted site and this also for a longer period of time. Other behavioral parameters did not differ significantly between the two sites. Although plasma testosterone levels were higher at the polluted site, they did not differ significantly between the two sites. The tested couples at the polluted site interrupted their laying sequence significantly more and hatching success was significantly reduced compared to the tested birds at the reference site. We found no significant difference in clutch size, the length of the laying interruptions, fledging success, and fledgling age between the two sites. Although our results showed only minor alterations in the territorial aggressive behavior of male great tits exposed to heavy metal pollution, these small changes may have an important influence on the breeding and survival of these birds.Received: 22 June 2002/Accepted: 1 December 2002     

Pollution-induced community tolerance and functional redundancy in a decomposer food web in metal-stressed soil

Pollution may lead to the development of pollution-induced community tolerance (PICT) in a stressed community. We studied the presence of PICT in soil food webs using soil microcosms. Soil microcosms containing soil invertebrates and microbes were collected from polluted and unpolluted areas and exposed to a range of soil zinc concentrations. A pine seedling was planted in each microcosm to measure the effects of the origin of the community and Zn pollution on above-ground plant production. The effects of the treatments on nutrient content in the soil were also measured. The diversity of soil microarthropods and the soil's mineral nutrient content were low at the Zn-polluted site. We did not observe an increasing Zn tolerance among the soil organisms in the polluted soil. However, low population growth rates of soil invertebrates from the polluted site may indicate the deleterious effects on fitness of long-lasting pollution. In the soil from the nonpolluted site, Zn additions caused changes in the invertebrate food web structure. These changes were explained by the good physiological condition of the animals and their insensitivity to Zn. The fact that the food web structure in soil from the polluted site did not change can be used as a rough indicator of PICT. Structural stability is presumed by the lack of Zn-sensitive species at this site and the inability of populations to acclimate by altering their growth or reproduction patterns in response to changing soil conditions. Although microbial-based soil decomposer systems may have a high functional redundancy, our results indicate that metal stress at the polluted site exceeds the tolerance limits of the system. As a consequence, ecosystem function at this site is endangered. This study also shows that the evolution of metal tolerance by soil decomposer organisms may not be a common reaction to soil pollution, although changes of population and community structure indicated severe metal stress on organisms.     

Influence of metal (Cd and Zn) waterborne exposure on radionuclide (134Cs, 110Ag, and 57Co) bioaccumulation by rainbow trout (Oncorhynchus mykiss): a field and laboratory study

Field and laboratory experiments were carried out to assess the influence of Cd and Zn on the contamination levels of 110Ag, 57Co, and 134Cs in rainbow trout. During a four-week prior exposure phase, two fish groups were held in tanks in the Lot River (France) at a reference (<0.05 microg Cd/L and 68 microg Zn/L) and at a polluted site (1.5 microg Cd/L and 152 microg Zn/L). During a subsequent phase, organisms were brought back to the laboratory, where the radionuclide accumulation and depuration were studied for 14 and 7 d, respectively. During this second phase, the water used in the experiments was brought back from the two sites on the Lot River in order to work under the same chemical conditions. The potential effect of chronic exposure to stable metals on several biomarkers has been explored: Plasma analysis indicated the disruption of certain variables linked to the energetic metabolism and to the maintenance of the ionic balance. In contrast, no significant disruption of the measured enzyme activities was observed. With regard to the bioaccumulation of radionuclides, concentrations in fish exposed to metals are much lower than those in fish from the control group. Various hypotheses are proposed to link fish metabolic profiles due to metal exposure to the radiocontamination of organisms.     

Spatial distribution of trace metals in sediments from urban streams of Semarang, Central Java, Indonesia

Elevated environmental concentrations of metals are usually associated with the impact of urbanization. The present study is focused on metal contamination in urban sediments. A field survey was carried out to determine the distribution of four metals, i.e., cadmium (Cd), lead (Pb), copper (Cu), and zinc (Zn), in the coastal urban area of Semarang, Central Java, Indonesia. Sediment samples were collected from 101 grids of 2x2 km. To map the spatial distribution of these metals, concentrations of each metal were plotted against the corresponding grid coordinate. Cd was below the detection limit (<0.03 microg/g) in all samples, whereas concentrations of Pb, Zn, and Cu fell into a wide range. Frequency distributions of Pb, Zn, and Cu concentrations indicated a similar pattern, in which the major proportion of the sites had a low metal concentration. Some sites, however, had extremely high metal concentrations, Zn up to 1257 microg/g, Pb up to 2666 microg/g, and Cu up to 448 microg/g. The data were used to define background concentrations for sediments in coastal zones of Indonesia ("reference values"). The proposed reference values are 25.6 microg/g, 132.2 microg/g, and 40.7 microg/g, respectively, for Pb, Zn, and Cu. The degree of metal contamination of each individual site was classified according to the calculated value of a combined pollution index, W. Four categories of the degree of metal contamination were proposed, i.e., unpolluted, slightly polluted, polluted, and heavily polluted. Based on this classification, from 101 sites investigated in the greater Semarang area, 51 are unpolluted, 36 slightly polluted, 9 polluted, and 5 heavily polluted.     

不同种类食品中镉含量水平及污染评价

目的：通过简单随机抽样，探讨了L市区各菜市场和大型超市不同种类食品中Cd的污染程度。方法：采用重金属单因子污染指数法对其不同种类食品中Cd的污染程度进行评价。结果：不同种类的食品中，Cd的单项污染指数值大小顺序为：食用菌类（1．35）〉薯类（0．97）〉蛋类（0．86）〉茄果类蔬菜（0．82）〉鱼类（0．81）〉禽畜肝脏（0．78）〉块茎类蔬菜（0．77）〉瓜菜类蔬菜（0．76）〉禽畜肉类（0．73）〉禽畜肾脏（0．63）〉叶菜类蔬菜（0．55）〉大豆（0．43）〉大米（0．42）〉水果类（0．22），可知食用菌类已经受到Cd的污染。结论：部分食品受到Cd的污染。     

Determination of Heavy Metal (Zn, Pb, Cd and Cr) Concentration in Benthic Fauna Tissues Collected from the Southeast Caspian Sea, Iran

The aim of the present study was to determine zinc (Zn), chromium (Cr), cadmium (Cd) and lead (Pb) content of benthic fauna in the southeast coast of the Caspian Sea, where the major fish restocking programs are conducted. Seasonal sampling was performed in three sampling sites: north Miankaleh (NM), south Miankaleh (SM) and Gharesoo coast (GC). Results showed that sampling sites, sampling seasons and sampling sites × sampling seasons interaction had a significant effect on the heavy metal levels (p < 0.05). The yearly heavy metal concentration order was as follows: Zn > Pb > Cd > Cr. Yearly Pb levels of the NM site were significantly higher than the other sites. Also, yearly Cr levels of the SM site were significantly higher than site GC. Comparison of the benthos heavy metal levels with the available reference values suggests that the benthos tissues might be highly polluted which can intoxicate the fish feeding on them.     

Effects of Acclimation on the Toxicity of Stream Water Contaminated with Zinc and Cadmium to Juvenile Cutthroat Trout

We investigated the influence of acclimation on results of in situ bioassays with cutthroat trout in metal-contaminated streams. Cutthroat trout (Oncorhynchus clarki) were held for 21 days (1) in live containers at a reference or "clean" site having dissolved metals near detection limits (0.01 microg/L cadmium [Cd] and 2.8 microg/L zinc [Zn]; hardness 32 mg/L as CaCO(3)) and (2) at a site in a mining-impacted watershed having moderately increased metals (0.07 microg/L Cd and 38 to 40 microg/L Zn; hardness 50 mg/L as CaCO(3)). The 96-hour survival of each treatment group was then tested in situ at five sites from September 5 to 9, 2002, and each group exhibited a range of metal concentrations (0.44 to 39 microg/L arsenic [As], 0.01 to 2.2 microg/L Cd, and 0.49 to 856 microg/L Zn). Survival was 100% at three sites for both treatments. However, a higher percentage of metal-acclimated fish survived at the site with the second highest concentrations of Cd and Zn (0.90 and 238 microg/L, respectively) compared with fish acclimated at the reference site (100% vs. 55%, respectively). Survival was 65% for acclimated fish and 0% for metal-na?ve fish at the site with the largest metal concentrations (2.2 microg/L Cd and 856 microg/L Zn). Water collected from the site with the largest concentrations of dissolved metals (on October 30, 2002) was used in a laboratory serial dilution to determine 96-hour LC(50) values. The 96-hour LC(50) estimates of na?ve fish during the in situ and laboratory experiments were similar (0.60 mug Cd/L and 226 microg Zn/L for in situ and 0.64 microg Cd/L and 201 microg Zn/L for laboratory serial dilutions). However, mortality of na?ve cutthroat trout tested under laboratory conditions was more rapid in dilutions of 100%, 75%, and 38% site water than in situ experiments.     

Associations between trace metals in sediment, water, and guppy, Poecilia reticulata (Peters), from urban streams of Semarang, Indonesia

The present study aims to answer the question whether the amount of metal in aquatic biota reflects the concentrations in the sediment and water, and whether the physico-chemical properties of the water and sediment have any influence on the suspected relationship. A study was made of 101 small streams in the city of Semarang, Central Java, Indonesia. Data on fish occurrence in 63 streams of the greater Semarang indicated that the guppies did not avoid the highly polluted sites. No significant difference in body weight between sites was found. Significant differences were found in metal body concentrations (Pb and Zn) between fish collected from sites with different degrees of pollution. A significant declining trend of Pb concentrations with increasing organism size was observed, whereas for two other metals, Zn and Cu, the concentrations did not depend on the body weight. Apparently, body concentrations of these two metals are regulated and maintained at a certain concentration. For the relationships between metal concentrations in water, sediment and fish, water and sediment parameters, and fish dry weight, the presence of significant multiple correlations and bivariate correlation (in 17 of 91 pairs of variables) indicated that, in general, abiotic parameters and body size had no influence on the metal flux from sediment to water, and into fish. Results of partial correlation analyses further suggested that metal concentrations in the sediments were the most important factor governing the metal body concentrations of fish. The present study indicates that the guppy Poecilia reticulata from urban streams is a potential bioindicator for urban metal pollution, especially with respect to their (1) spatial distribution over sites of all pollution regimes and (2) variation in metal accumulation levels reflecting the degree of pollution.     

Metallothionein as bioindicator of freshwater metal pollution: European eel and brown trout

The aim of this work was to evaluate the potential of metallothionein (MT) as a bioindicator of heavy metal pollution in brown trout and European eel in the field situation. River Ferrerias (North Spain) provided a good gradient of metal contamination: concentrations of heavy metals were elevated both in water and in sediments at the downstream (polluted) site and were low at the upstream (unpolluted) site. MT levels of brown trout exhibited statistically significant differences between sites. Although European eel at the polluted site had a higher MT content, differences were not significant. It is concluded that MT is a good bioindicator of heavy metal pollution in brown trout.     

刁江沿岸土壤重金属污染状况及土地的合理利用模式

目的了解刁江沿岸土壤重金属污染区分布,寻求安全的污染区土地利用模式。方法于2003年在刁江沿岸设置了12个采样断面,采样分析土壤中重金属含量,分析了污染区大米、玉米和桑叶中的重金属(As,Pb,Cd、Zn)含量。结果土壤中的主要污染物为As(19.6～7441mg/kg)、Pb(53.4～1823mg/kg)、Cd(0.35～39.2mg/kg)、Zn(110～4199mg/kg)等,污染区范围与洪水淹没区一致。污染耕地上产出的大米中Cd和Pb含量超过国家食品卫生标准,尤其是大米中Cd的含量超标4.9倍,Pb超标0.905倍;玉米中Pb、Cd和Zn的含量分别超标1.345倍,0.56倍和0.598倍。结论受上游矿山开发影响,刁江沿岸土壤重金属污染十分严重,建议将污染区耕地划定为食用农作物禁止种植区,在污染区开展种桑养蚕试验,将严重尾砂覆盖污染区作为尾砂库并进行植被恢复与重建。     

High concentrations of heavy metals in neighborhoods near ore smelters in northern Mexico

In developing countries, rapid industrialization without environmental controls has resulted in heavy metal contamination of communities. We hypothesized that residential neighborhoods located near ore industries in three northern Mexican cities would be heavily polluted with multiple contaminants (arsenic, cadmium, and lead) and that these sites would be point sources for the heavy metals. To evaluate these hypotheses, we obtained samples of roadside surface dust from residential neighborhoods within 2 m of metal smelters [Torreón (n = 19)] and Chihuahua (n = 19)] and a metal refinery [Monterrey (n = 23)]. Heavy metal concentrations in dust were mapped with respect to distance from the industrial sites. Correlation between dust metal concentration and distance was estimated with least-squares regression using log-transformed data. Median dust arsenic, cadmium, and lead concentrations were 32, 10, and 277 microg/g, respectively, in Chihuahua; 42, 2, and 467 microg/g, respectively, in Monterrey, and 113, 112, and 2,448 microg/g, respectively, in Torreón. Dust concentrations of all heavy metals were significantly higher around the active smelter in Torreón, where more than 90% of samples exceeded Superfund cleanup goals. At all sites, dust concentrations were inversely related to distance from the industrial source, implicating these industries as the likely source of the contamination. We concluded that residential neighborhoods around metal smelting and refining sites in these three cities are contaminated by heavy metals at concentrations likely to pose a health threat to people living nearby. Evaluations of human exposure near these sites should be conducted. Because multiple heavy metal pollutants may exist near smelter sites, researchers should avoid attributing toxicity to one heavy metal unless others have been measured and shown not to coexist.     

Lysosomal membrane stability in laboratory- and field-exposed terrestrial isopods Porcellio scaber (Isopoda, Crustacea)

Two established methods for assessment of the cytotoxicity of contaminants, the lysosomal latency (LL) assay and the neutral red retention (NRR) assay, were successfully applied to in toto digestive gland tubes (hepatopancreas) of the terrestrial isopod Porcellio scaber (Isopoda, Crustacea). In vitro exposure of isolated gland tubes to copper was used as a positive control to determine the performance of the two methods. Lysosomal latency and the NRR assay were then used on in vivo (via food) laboratory-exposed animals and on field populations. Arbitrarily selected criteria for determination of the fitness of P. scaber were set on the basis of lysosomal membrane stability (LMS) as assessed with in toto digestive gland tubes. Decreased LMS was detected in animals from all polluted sites, but cytotoxicity data were not in agreement with concentrations of pollutants. Lysosomal membrane stability in the digestive gland tubes of animals from an environment in Idrija, Slovenia that was highly polluted with mercury (260 microg/g dry wt food and 1,600 microg/g dry wt soil) was less affected than LMS in laboratory animals fed with 5 and 50 microg Hg/g dry weight for 3 d. This probably indicates tolerance of P. scaber to mercury in the mercury-polluted environment and/or lower bioavailability of environmental mercury. In animals from the vicinity of a thermal power plant with environmental mercury concentrations three to four orders of magnitude lower than those in Idrija, LMS was severely affected. In general, the LL assay was more sensitive than the NRR assay. The LMS assay conducted on digestive gland tubes of terrestrial isopods is highly recommended for integrated biomarker studies.     

The use of in situ and stream microcosm experiments to assess population- and community-level responses to metals

We conducted field and stream microcosm experiments to assess population-level (density, size distribution) and community-level (species richness metrics, multivariate analysis of community composition) responses of macroinvertebrates to heavy metals in the Arkansas River, a mining-polluted stream in Colorado, USA. Experiments were conducted in spring and summer to coincide with early and late developmental stages (i.e., instars) of the mayfly Rhithrogena hageni. Results of field experiments showed significant mortality at metal-contaminated sites during summer when mayfly populations were dominated by small, early instars (mean dry wt = 0.13 mg). In contrast, no significant mortality was observed in spring when organisms were larger (mean dry wt = 1.78 mg). Multivariate analyses based on abundance of dominant taxa clearly separated reference and metal-impacted stations in summer experiments but showed little separation in spring. We observed no significant effects of metals on species richness, number of mayfly species, or EPT (species richness of Ephemeroptera, Plecoptera, and Trichoptera) in.either field experiment. Using stream microcosms, we established concentration-response relationships between heavy metals and R. hageni density, species richness, mayfly richness, and EPT. Density of R. hageni was generally more sensitive to metals than measures of species richness, and summer populations of R. hageni were more sensitive to metals than spring populations. Because the presence of large, relatively tolerant individuals in spring coincided with periods of higher metal concentrations, R. hageni was protected from toxic effects in this system. We conclude that phenology and developmental stage are important factors influencing responses of some aquatic macroinvertebrates to metals. Thus, timing bioassessments to coincide with the presence of these sensitive life stages can improve our ability to detect subtle contaminant effects.     

2007年成都市食品化学污染物监测结果分析

目的 了解成都市食品中重金属的污染状况和食品添加剂的使用情况,为政府相关部门制定食品安全对策,构建食品安全体系提供科学依据.方法 在成都市20个区(市)县建立食品化学污染物定期监测网点,采用随机采样原则,采集粮食、散装熟肉制品、即食性豆制品、散装糕点、水产品、皮蛋及生猪肉7类食品,按照国家标准方法进行铅、镉、亚硝酸盐、脱氢乙酸、丙酸盐等指标的检测.结果 采集7类食品共1 004.件.食品中铅合格率为95.6%,其中粮食的合格率最低,为80.0%;食品中镉合格率为96.1%,其中,水产品的合格率最低,为93.2%;散装熟肉制品亚硝酸盐的合格率为89.9%;腐乳中脱氢乙酸的合格率仅为78.9%,散装糕点中丙酸盐合格率100%.结论 成都市粮食中铅的超标情况较严重,散装熟肉制品中亚硝酸盐残留量的超标率较严重,新型食品添加剂如脱氢乙酸在腐乳中滥用情况较严重,提示有关部门应加大对粮食、熟肉制品、各类新型食品添加剂的检测和监管力度.     

Nitrogen and Phosphorus Fertilizer Increases the Uptake of Soil Heavy Metal Pollutants by Plant Community

Soil heavy metal pollution is widespread around the world. Compared with hyperaccumulation plants, non-hyperaccumulator plant communities have many advantages in the remediation of heavy metals pollution in soil. The application of nitrogen (N) and phosphorus (P) is inexpensive and convenient, which can promote the growth of plant. N and P fertilizer might increase plant community remediation of heavy metal polluted soils. In our study, the effects of N and P fertilizer on remediation of soil Cd, Cu, Pb pollution by plant community were studied through a greenhouse experiment. Our results indicated that addition of N, P and N?+?P fertilizer increased plant community aboveground biomass. Simultaneously, addition of N and P fertilizer increased the accumulation of heavy metals in aboveground of the plant community and accelerated plants absorption soil heavy metals. Among them, N fertilizer had the best effect. Our results provide an inexpensive method for remediation heavy metal pollution of contaminated farmland, abandoned land and mine tailings, etc.

     

Indirect Effects of Heavy Metals on Parasites May Cause Shifts in Snail Species Compositions

We studied the direct and indirect effects of pollution on the distributions and abundances of two closely related species of pulmonate freshwater snails. Physella columbiana is more numerous at heavy metal–polluted lakes, and Lymnaea palustris is more numerous at reference lakes. Both species are present at all sites, as are predatory bluegill sunfish (Lepomis macrochirus). The direct effects examined included the snails' growth and reproduction in both the presence and absence of heavy metals and their short-term survival when exposed to large concentrations of heavy metals. The indirect effects were the species' ability to elude capture by sunfish and the diversity and abundance of parasites within the snails. We found that heavy metals had little direct effect on growth and reproduction and that both species acquired similar levels of metals in their tissues. Interestingly, P. columbiana (the more abundant species in polluted lakes) actually exhibited higher recruitment in the absence of metals than did L. palustris (reference lakes). L. palustris has life history characteristics that favor increased growth and reduced reproduction. These characteristics resulted in decreased predation of adults by gape-limited predators and a greater ability to cope with heavy parasite burdens. P. columbiana exhibited slower growth, which resulted in increased predation although higher reproduction rates may compensate. The major effect of heavy metals on species distributions was indirect on the snails' parasites. Parasites appeared to be very susceptible to metals, and this resulted in lower parasite diversity and intensities at polluted sites for both species of snails. P. columbiana may only be able to outcompete L. palustris at polluted sites due to the indirect effects of heavy metals; the negative effect of heavy metals on parasites, and a proposed negative effect of metals on the foraging ability of sunfish that favors the faster-reproducing P. columbiana. Received: 13 August 2001/Accepted: 19 January 2002     

Selenium impacts on razorback sucker, Colorado River, Colorado I. Adults

Adult razorback sucker (Xyrauchen texanus) were exposed to various selenium concentrations in ponds and isolated river channels of the Colorado River near Grand Junction, CO, to determine effects on their growth and residue accumulation over an 11-month period. Adults at Horsethief ponds were fed a commercial diet, whereas fish at Adobe Creek channel and North Pond foraged on natural food items. Selenium concentrations at Horsethief were 2.2 microg/L in water, 0.1-1.4 microg/g in sediment, and 2.3-3.1 microg/g in food organisms (1.1 microg/g in commercial fish food), at Adobe Creek were 3.8 microg/L in water, 0.5-2.1 microg/g in sediment, and 4-56 microg/g in food organisms, and at North Pond were 9.5 microg/L in water, 7-55 microg/g in sediment, and 20-81 microg/g in food organisms. The selenium concentrations in muscle plugs from adults at Adobe Creek (11.7 microg/g, SD = 0.4, n = 6) and North Pond (16.6 microg/g, SD = 1.0, n = 6) were greater than at Horsethief (4.5 microg/g, SD = 0.2, n = 6). During a depuration period adults from Adobe Creek and North Pond lost 1-2% of their selenium burden in 32 days and 14-19% in 66 days. Selenium accumulated in razorback sucker above toxic thresholds reported in other studies, yet those residues were less than those reported in muscle plugs of 40% of wild razorback sucker caught in the Green River, Utah.