Mining and Aquatic Insects
Updated 12 Jan 21
Gunnison County Mine Information
Standard Mine Superfund site | West Elk Coal Mine | Gunnison Uranium Mill Site UMTRCA | NEPA projects on the GMUG Forest (some are mines) | Coal Creek Watershed Coalition | High Country Conservation Advocates
Standard Mine tailings pond remediated by the EPA. Photo from August of 2013 :-) Page down for a photo of the tailings pond before it was cleaned up.
Barbour,MT; Gerritsen,J; Snyder,BD; Stribling,JB (1999) Rapid Bioassessment Protocols for Use in Wadeable Streams and Rivers: Benthic Macroinvertebrates, and Fish. EPA 841-D-97-002 U.S. Environmental Protection Agency, Office of Water, Washington, D.C. http://www.epa.gov/owow/monitoring/rbp/
de Bisthoven,LJ; Postma,JF; Parren,P; Timmermans,KR and Ollevier,F 1998 Relations between heavy metals in aquatic sediments and in Chironomus larvae of Belgian lowland rivers and their morphological deformities. Can. J. Fish. Aquat. Sci 55(3): 688-703.
Abstract: Levels of Cd, Pb, Cu, and Zn were measured in fourth-instar Chironomus gr. thummi and in three sediment fractions of Belgian lowland rivers, extracted with 1 M NH4-acetate, 1 M HCl, and 70% HNO3 - 30% H2O2. The percentages of deformed larvae and the mean population severities (MPS) of deformity for the head structures were compared by means of Pearson and linear and polynomial regressions against the metal concentrations in the different compartments. All correlations found were positive. Mentum deformities correlated with all lead fractions (MPS) and the larval copper fraction (percent deformed), while the pecten epipharyngis deformities correlated with the sediment lead fractions and the HCl fraction of copper. Premandible deformities correlated with the copper sediment HNO3-H2O2 fraction and with extreme values of cadmium and zinc. The study demonstrated a variety of deformity response curves to trace metals. At one site, higher lead concentrations were found in larvae with a deformed mentum, compared with normal larvae. Mentum deformities appeared to be potential predictors of lead levels in the sediments and the larvae, while pecten epipharyngis deformities may be an indicator of lead and copper in the sediments.
Brinkman,SF and Johnston,WD 2012 Acute toxicity of zinc to several aquatic species native to the Rocky Mountains. Archives of Environmental Contamination and Toxicology, 62(2), 272-281.
Buchwalter,DB; Cain,DJ; Clements,WH and Luoma,SN 2007 Using biodynamic models to reconcile differences between laboratory toxicity tests and field biomonitoring with aquatic insects. Environmental Science & Technology. 41(13):4821-8.
Abstract: "Aquatic insects often dominate lotic ecosystems, yet these organisms are under-represented in trace metal toxicity databases. Furthermore, toxicity data for aquatic insects do not appear to reflect their actual sensitivities to metals in nature, because the concentrations required to elicit toxicity in the laboratory are considerably higher than those found to impact insect communities in the field. New approaches are therefore needed to better understand how and why insects are differentially susceptible to metal exposures. Biodynamic modeling is a powerful tool for understanding interspecific differences in trace metal bioaccumulation. Because bioaccumulation alone does not necessarily correlate with toxicity, we combined biokinetic parameters associated with dissolved cadmium exposures with studies of the subcellular compartmentalization of accumulated Cd. This combination of physiological traits allowed us to make predictions of susceptibility differences to dissolved Cd in three aquatic insect taxa: Ephemerella excrucians, Rhithrogena morrisoni, and Rhyacophila sp. We compared these predictions with long-term field monitoring data and toxicity tests with closely related taxa: Ephemerella infrequens, Rhithrogena hageni, and Rhyacophila brunnea. Kinetic parameters allowed us to estimate steady-state concentrations, the time required to reach steady state, and the concentrations of Cd projected to be in potentially toxic compartments for different species. Species-specific physiological traits identified using biodynamic models provided a means for better understanding why toxicity assays with insects have failed to provide meaningful estimates for metal concentrations that would be expected to be protective in nature. "
Buchwalter,DB; Cain,DJ; Martin,CA; Xie,L; Luoma,SN; Garland,JT 2008 Aquatic insect ecophysiological traits reveal phylogenetically based differences in dissolved cadmium susceptibility. Proceedings of the National Academy of Sciences 105 24, 8321-8326. html
Cadmus, P., Kotalik, C.J., Jefferson, A.L., Wheeler, S.H., McMahon, A.E. and Clements, W.H., 2019 Size-dependent sensitivity of aquatic insects to metals. Environmental Science & Technology. PDF
Abstract: " Laboratory assessments of aqueous metal toxicity generally demonstrate aquatic insects tolerate relatively high concentrations of metals in aqueous exposures; however, mesocosm experiments and field biomonitoring often indicate effects at relatively low metal concentrations. One hypothesis proposed to reconcile this discrepancy is an increased sensitivity of smaller size classes of organisms. We exposed field colonized benthic communities to aqueous metals in a series of mesocosm experiments. In addition, a novel single-species test system was used to expose first instar, mid-instar, and late instar mayflies (Ephemeroptera, Baetis tricaudatus) to Zn. These experimental approaches tested the hypothesis that small invertebrate size classes are more sensitive than large, mature size classes. Mesocosm results demonstrated strong size-dependent responses of aquatic insects to metals. Smaller organisms generally displayed greater mortality than large, mature individuals, and models were improved when size was included as a predictor of mortality. Size-dependent responses of Baetis spp. occurred in mesocosm experiments and in our single-species test system. The median lethal concentration (LC50) for early instar B. tricaudatus was less than 6% of the previously reported LC50 for late instars. Together, these results suggest that aquatic insect body size is an important predictor of susceptibility to aqueous metals. Toxicity models that account for insect phenology by integrating the natural size progression of organisms have the potential to improve accuracy in predicting effects of metals in the field."
Cain,DJ and Luoma,SN 1998 Metal exposures to native populations of the caddisfly Hydropsyche (Trichoptera: Hydropsychidae) determined from cytosolic and whole body metal concentrations. Hydrobiologia, 386(1-3) 103-117. PDF
Cain, D. J.; Luoma, S. N.; Wallace, W. G. 2004 Linking metal bioaccumulation of aquatic insects to their distribution patterns in a mining-impacted river. Environ. Toxicol. Chem. 23: 1463-1473.
Abstract: "Although the differential responses of stream taxa to metal exposure have been exploited for bioassessment and monitoring, the mechanisms affecting these responses are not well understood. In this study, the subcellular partitioning of metals in operationally defined metal-sensitive and detoxified fractions were analyzed in five insect taxa. Samples were collected in two separate years along an extensive metal contamination gradient in the Clark Fork River (MT, USA) to determine if interspecific differences in the metal concentrations of metal-sensitive fractions and detoxified fractions were linked to the differences in distributions of taxa relative to the gradient. Most of the Cd, Cu, and Zn body burdens were internalized and potentially biologically active in all taxa, although all taxa appeared to detoxify metals (e.g., metal bound to cytosolic metal-binding proteins). Metal concentrations associated with metal-sensitive fractions were highest in the mayflies Epeorus albertae and Serratella tibialis, which were rare or absent from the most contaminated sites but occurred at less contaminated sites. Relatively low concentrations of Cu were common to the tolerant taxa Hydropsyche spp. and Baetis spp., which were widely distributed and dominant in the most contaminated sections of the river. This suggested that distributions of taxa along the contamination gradient were more closely related to the bioaccumulation of Cu than of other metals. Metal bioaccumulation did not appear to explain the spatial distribution of the caddisfly Arctopsyche grandis, considered to be a bioindicator of metal effects in the river. Thus, in this system the presence/ absence of most of these taxa from sites where metal exposure was elevated could be differentiated on the basis of differences in metal bioaccumulation."
Canadian Council of Ministers of the Environment 2002 Summary Tables for the Canadian Sediment Quality Guidelines for the Protection of Aquatic Life. Winnipeg. 7 pages.
Canton,SP and Ward,JV 1981 The aquatic insects, with emphasis on Trichoptera, of a Colorado stream affected by coal strip-mine drainage. Southwestern Naturalist 25 4, 453-460.
Carlisle,DM; Clements,WH 1999 Sensitivity and variability of metrics used in biological assessments of running waters. Environmental Toxicology and Chemistry 18, 285-291.
Carlisle,DM; Clements,WH 2003 Growth and secondary production of aquatic insects along a gradient of Zn contamination in Rocky Mountain streams. Journal of the North American Benthological Society 22 4, 582-597.
Abstract: "Secondary production estimates from several Rocky Mountain streams were used to test
hypotheses about the effects of chronic metal contamination on insect populations and ecosystem
processes. Quantitative samples of chemistry, habitat, and benthic insects were collected monthly
during the ice-free period (May-November) from five 2nd- to 3rd-order streams that varied primarily
in Zn contamination. Secondary production was estimated for the 19 dominant taxa using incrementsummation,
size-frequency, and P/B methods. Uncertainty was estimated by bootstrapping estimates
of mean abundance, biomass, and cohort production intervals. Secondary production of metal-sensitive
Heptageniidae (Rhithrogena robusta, Cinygmula spp., and Epeorus longimanus) was lower in lightly
to moderately contaminated streams than in reference streams. Experiments were done to determine
whether herbivore growth was influenced by food quality in contaminated streams. Growth estimates
from field and microcosm experiments revealed that low mayfly production in contaminated streams
was caused mostly by reduced population abundances. Production of predatory stoneflies was also
lower in contaminated streams than reference streams. Estimates of the trophic basis of production
revealed that, although the relative contribution to community production from various food sources
was similar among streams, total production attributable to algae and animal prey declined in contaminated
streams. Much of the reduction in herbivory in contaminated streams was the result of
lower production of heptageniids, especially R. robusta. Assemblage and taxon-specific estimates of
secondary production were sensitive to variation in metal contamination and indicated that relatively
low metal concentrations may have ecosystem-wide consequences for energy flow."
Carlisle,DM; Clements,WH 2005 Leaf litter breakdown, microbial respiration and shredder production in metal-polluted streams. Freshwater Biology 50, 380-390.
Chadwick,JW; Canton,SP 1984 Inadequacy of diversity indices in discerning metal mine drainage effects on a stream invertebrate community. Water, Air and Soil Pollution 22, 217-223.
Clements,WH 1991 Community responses of stream organisms to heavy metals: a review of observational and experimental approaches. In: Ecotoxicology of Metals: Current Concepts and Applications. 1st ed. Eds: Newman,MC; McIntosh,AW CRC press, Inc, Boca Raton, FL, 363-391.
Clements,WH 1994 Benthic invertebrate community responses to heavy metals in the Upper Arkansas River Basin, Colorado. Journal of the North American Benthological Society 13, 30-44.
Working in the Arkansas River of Colorado, the author saw lots of seasonal variation in heavy metal concentrations in the water, with the highest levels of total recoverable zinc in the water below California Gulch being above 3000 ug/l in the spring. He found mayflies dominated the communities at the clean reference sites, while moderately to highly polluted streams were dominated by Orthocladiinae chironomids and caddiflies. The distribution of caddisflies and blackflies was also affected by food availability. He found that the abundance of Heptageniidae was correlated with zinc levels but not elevation which makes them useful as indicators of heavy metal pollution. He also noted that species that enter the drift regularly such as Baetis may be affected by mine drainage, yet rapidly recolonize from upstream cleaner areas through drifting. As a result their numbers in samples below heavy metal inputs may not reflect their susceptibility to metals, but rather their excellent recolonization abilities.
Clements,WH 1999 Metal tolerance and predator-prey interactions in benthic macroinvertebrate stream communities. Ecological Applications 9, 1073-1084.
Clements,WH; Carlisle,DM; Courtney,LA; Harrahy,EA 2002 Integrating observational and experimental approaches to demonstate causation in stream biomonitoring studies. Environmental Toxicology and Chemistry 21, 1138-1146.
Clements,WH; Cherry,DS; Cairns,J 1988 Impact of heavy metals on insect communities in streams: a comparision of observational and experimental results. Canadian Journal of Fisheries and Aquatic Sciences 45 11, 2017-2025.
Working in the Clinch River of Russell County, Virginia and outdoor experimental streams, they measured population responses of macroinvertebrates to natural conditions and 12 µg of copper and zinc in the artifical streams. They used 6 replicates of substrate-filled trays everywhere and counted all the animals (no subsampling). Both stream mesocosm experiments and Clinch river sites showed similar results. They found abundance or total numbers of aquatic insects declined at all high effluent sites associated with the Clinch River coal-fired power plant, recovering 3- 4 kilometers downstream. Low levels of copper and zinc reduced species richness (number of different taxa) and total numbers as well as caused a shift in the species composition of dominant taxa. Metal contamination caused macroinvertebrate populations to shift from control (clean) sites dominated by Mayflies and Tanytarsini Midges to polluted sites dominated by Hydropsychidae caddisflies and Orthocladiinae midges.
Clements,WH; Kiffney,PM 1994a Assessing contaminant effects at higher levels of biological organization. Environmental Toxicology and Chemistry 13, 357-359.
Clements,WH; Kiffney,PM 1994b Integrated laboratory and field approach for assessing impacts of heavy metals at the Arkansas River, Colorado. Environmental Toxicology and Chemistry 13, 397-404. Abstract
In contrast to Clements research on the Clinch River in Virginia, this study of the Arkansas River near Leadville, Colorado found no change in the total numbers of aquatic insects above and below the Superfund site California Gulch. They did however note a shift in community structure as metal tolerant taxa (Orthocladiinae midges) replaced intolerant taxa (mayflies). "Benthic communities [below California Gulch] were were dominated by Orthocladiinae chironomids."
They ran chronic toxicity tests with Ceriodaphnia dubia and found significantly lower reproduction in water from the site 6 kilometers below California Gulch in the spring. In the fall the sites above California Gulch and the recovery site 45 km below had significantly worse reproduction.
Studying the concentrations of a few heavy metals in water from the Arkansas River they found: "Considerable seasonal variation in metal concentrations was observed at stations downstream from California Gulch. Levels of Cd, Cu and Zn were 7 to 9 times higher at [the station below California Gulch] in spring than in fall and remained elevated at [the recovery station 45 km below] in spring."
They also looked at bioaccumulation of Cadmium (Cd) Copper (Cu) and Zinc (Zn) in algae and the aquatic macroinvertebrates Baetis spp, Arctopsyche grandis and Rhyacophila in fall and spring. They found lots of variation as always but Baetis metal concentrations were usually higher than the other taxa studied. "Levels of Cd, Cu and Zn in periphyton and benthic macroinvertebrates were significntly elevated at stations downstream from California Gulch in both seasons. "
Clements,WH; Carlisle,DN; Lazorchak,JM; Johnson,PC 2000 Heavy metals structure benthic communities in Colorado mountain streams. Ecological Applications 10(2)626-638.
Clubb,RW; Gaufin,AR; Lords,JL 1975 Acute cadmium toxicity studies upon nine species of aquatic insects. Environmental Research 9, 332-341.
Clubb,RW; Gaufin,AR and Lords,JL 1975 Synergism between dissolved oxygen and cadmium toxicity in five species of aquatic insects. Environmental research, 9(3)285-289.
Abstract: " Continuous-flow bioassays were employed to determine the relationship between dissolved oxygen and cadmium upon five species of aquatic insects, as measured by survival and the amount of cadmium found within the insect. Results indicate the toxicity of cadmium increases as the dissolved oxygen concentration increases. This may be explained by an observed increase in the amount of cadmium found in the insect as the dissolved oxygen concentration increases. Oxygen consumption has been reported to increase as the dissolved oxygen concentration increases (Petty, 1967; Ericksen, 1963; Fox et al.. 1937). in this study, using a fixed cadmium concentration, the amount of cadmium found in the insect also increased with an increase in the dissolved oxygen. Therefore, cadmium absorption may be coupled to metabolism."
Colborn,T 1981 Aquatic Insects as measures of trace element presence: Cadmium and Molybdenum. MA Thesis, Western State College, Gunnison Colorado. 157 p.
Colburn,T 1982 Measurement of low levels of molybdenum in the environment by using aquatic insects. Bulletin of Environmental Contamination and Toxicology 29, 422-428.
Colburn,T 1986 The use of the stonefly Pteronarcys californica Newport as a measure of biologically available cadmium in a high altitude river system Colorado, USA. Water Quality Bulletin 11, 141-147.
Courtney,LA and Clements,WH 1998 Effects of acidic pH on benthic macroinvertebrate communities in stream microcosms. Hydrobiologia, 379(1-3), 135-145.
Abstract: " The effects of acid (HNO3) on drift and survival of benthic invertebrate communities were assessed in stream microcosms over a 7-day exposure period. Communities were obtained from the Cache la Poudre River, Colorado, using artificial substrates colonized in the stream for 30 days and then transferred to stream microcosms. Streams receiving the highest acid concentration (pH 4.0) contained significantly fewer individuals ( F = 378.42, p < 0.0001) and taxa ( F = 7.8, p = 0.0123) at the end of the experiment compared to the other two treatments (pH 5.5, 6.5) and the control (pH 7.4). Reduced macroinvertebrate abundance resulted primarily from reduced abundance of mayflies (Ephemeroptera) which were particularly sensitive. Comparisons of Plecoptera, Trichoptera, and Diptera abundances showed no statistically significant differences among treatments. Analysis of invertebrate drift samples, collected after 2, 6, 18, and 42 h exposure, revealed that percent drift in the most acidic streams was nine times that of control streams. Ephemeroptera was the only aquatic insect order to exhibit a significant drift response, and timing and magnitude of responses varied among mayfly taxa. Differences in sensitivity to acid among aquatic insect orders observed in our experimental streams were similar to those reported from field studies in other regions. Effects of acid on drift and survival of benthic invertebrate communities were also similar to effects of heavy metals, one of the primary water quality concerns in the Rocky Mountain region. These results suggest a general pattern of responses to chemical stressors in benthic communities from Rocky Mountain streams. "
Courtney,LA; Clements,WH 2000 Sensitivity to acidic pH in benthic invertebrate assemblages with different histories of exposure to metals. Journal of the North American Benthological Society 19 1, 112-127.
Standard Mine tailings pond before remediation.
Deacon,JR; Driver,NE 1999 Distribution of trace elements in streambed sediment associated with mining activities in the Upper Colorado River Basin, Colorado, USA. Arch. Environ. Contam. Toxicol. 37, 7-18.
Dowsett,FR Jr.; Ganster,MW; Ranta,RA; Baker,DJ and Stern,HJ 1981 Geology of the Mount Emmons Molybdenum Deposit, Crested Butte, Colorado. In: New Mexico Geological Society Guidebook, 32nd Field Conference, Western Slope, Colorado. PDF
Faith, D. P., Dostine, P. L. and Humphrey, C. L. 1995 Detection of mining impacts on aquatic macroinvertebrate communities: Results of a disturbance experiment and the design of a multivariate BACIP monitoring programme at Coronation Hill, Northern Territory.- Aust. J. Ecol. 20: 167-180.
Farag,AM; Nimick,DA; Kimball,BA; Church,SE; Harper,DD; Brumbaugh,WG. 2007Concentrations of metals in water, sediment, biofilm, benthic macroinvertebrates, and fish in the Boulder River watershed, Montana, and the role of colloids in metal uptake. Archives of Environmental Contamination and Toxicology.52(3):397-409.
Abstract: "To characterize the partitioning of metals in a stream ecosystem, concentrations of trace metals including As, Cd, Cu, Pb, and Zn were measured in water, colloids, sediment, biofilm (also referred to as aufwuchs), macroinvertebrates, and fish collected from the Boulder River watershed, Montana. Median concentrations of Cd, Cu, and Zn in water throughout the watershed exceeded the U.S. EPA acute and chronic criteria for protection of aquatic life. Concentrations of As, Cd, Cu, Pb, and Zn in sediment were sufficient in the tributaries to cause invertebrate toxicity. The concentrations of As, Cu, Cd, Pb, and Zn in invertebrates from lower Cataract Creek (63, 339, 59, 34, and 2,410 microg/g dry wt, respectively) were greater than the concentrations in invertebrates from the Clark Fork River watershed, Montana (19, 174, 2.3, 15, and 648 microg/g, respectively), that were associated with reduced survival, growth, and health of cutthroat trout fed diets composed of those invertebrates. Colloids and biofilm seem to play a critical role in the pathway of metals into the food chain and concentrations of As, Cu, Pb, and Zn in these two components are significantly correlated. We suggest that transfer of metals associated with Fe colloids to biological components of biofilm is an important pathway where metals associated with abiotic components are first available to biotic components. The significant correlations suggest that Cd, Cu, and Zn may move independently to biota (biofilm, invertebrates, or fish tissues) from water and sediment. The possibility exists that Cd, Cu, and Zn concentrations increase in fish tissues as a result of direct contact with water and sediment and indirect exposure through the food chain. However, uptake through the food chain to fish may be more important for As. Although As concentrations in colloids and biofilm were significantly correlated with As water concentrations, As concentrations in fish tissues were not correlated with water. The pathway for Pb into biological components seems to begin with sediment because concentrations of Pb in water were not significantly correlated with any other component and because concentrations of Pb in the water were often below detection limits. "
Fore,LS 2002 Biological assessment of mining disturbance on stream invertebrates in mineralized areas of Colorado. In: Biological Response Signatures: Indicator Patterns Using Aquatic Communities. Ed: Simon,TP CRC Press, Boca Raton, FL, 347-370.
The author tested a variety of metrics on data from mine-impacted streams in Colorado. Her data is from the EPA's Regional Environmental Monitoring and Assessment Program (REMAP) and was also collected from the Eagle River, Colorado for this paper. She concluded the following metrics decline consistently with mining impacts.
1) Species richness - Total Taxa
2) # Mayfly taxa
3) # Stonefly taxa
4) # Caddisfly taxa
5) # Metal Intolerant taxa
6) # Clinger Taxa
7) % Heptageniidae
These metrics can be combined into the Benthic Index of Biotic Integrity or B-IBI.
Gerhardt A; Bisthoven LJ de; Soares AMVM. 2004. Macroinvertebrate response to acid mine drainage: community metrics and on-line behavioural toxicity bioassay. Environ. Poll. 130: 263-274.
Gerhardt A; Bisthoven LJ de; Soares AMVM. 2005. Effects of acid mine drainage and acidity on the activity of Choroterpes picteti (Ephemeroptera: Leptophlebiidae). Archives of Environmental Contamination and Toxicology 48:450-458.
Goodyear,KL and McNeill,S 1999 Bioaccumulation of heavy metals by aquatic macro-invertebrates of different feeding guilds: a review. Science of the Total Environment, 229(1) 1-19. PDF
Hornberger,MI; Luoma,SN; Johnson,ML and Holyoak,M 2009 Influence of remediation in a mine-impacted river: Metal trends over large spatial and temporal scales. Ecological Applications, 19(6)1522-1535. PDF
Irving,EC; Baird,DJ; Culp,JM 2003 Ecotoxicological responses of the mayfly Baetis tricaudatus to dietary and waterborne cadmium: implications for toxicity testing. Environmental Toxicology and Chemistry 22, 1058-1064.
Iwasaki,Y; Kagaya,T; and Matsuda,H 2018 Comparing macroinvertebrate assemblages at organic-contaminated river sites with different zinc concentrations: Metal-sensitive taxa may already be absent. Environmental Pollution, 241:272-278.
Abstract: "We investigated responses of macroinvertebrates to different zinc concentrations in urban rivers contaminated with organic matter in a regional-scale monitoring survey and a smaller-scale field study. The present study was designed to test our prediction that total zinc concentrations of 60 µg/L (twice the Japanese environmental quality standard) do not lead to significant reductions in richness or abundance of macroinvertebrates in organic-contaminated rivers (biochemical oxygen demand of >3 mg/L). At the organic-contaminated sites in both surveys, very few species were present, and metal-sensitive heptageniid and ephemerellid mayflies were generally absent. In the regional-scale study, total zinc concentrations of up to 70 µg/L resulted in little reduction in macroinvertebrate richness. In the local-scale study, macroinvertebrate richness and abundance were not greatly reduced at the polluted downstream site with a total zinc concentration of 48 µg/L. Results from both surveys support our prediction. Therefore, an important implication of this study is that macroinvertebrate taxa that are susceptible to metal pollution should be sparse or absent in organic-contaminated rivers, so the impacts of metals such as zinc may be limited owing to the species-poor communities. Further research is required to evaluate the importance of reduced zinc bioavailability associated with increased organic matter and water hardness to the species-poor communities in organic-contaminated rivers."
Iwasaki,Y; Kagaya,T; Miyamoto,K.-i; Matsuda,H and Sakakibara, M 2011 Effect of zinc on diversity of riverine benthic macroinvertebrates: Estimation of safe concentrations from field data. Environmental Toxicology and Chemistry, 30: 2237-2243
Abstract: "We conducted field surveys at 25 sites in three Japanese catchments to provide conservative estimates of the safe concentration of zinc (Zn) for the protection of riverine macroinvertebrate diversity. The relationships between the Zn concentration and six macroinvertebrate metrics for taxon richness were determined by using regression analysis; this included a piecewise regression model, where two lines are joined at an unknown point. For each metric the piecewise regression model with a zero slope below a threshold concentration was selected as the best model to explain the influence of Zn. Under the assumption that macroinvertebrate diversity reductions of less than 10% are acceptable, the safe concentrations of Zn were estimated to be 84, 115, 84, 80, 85, and 70 µg/L for total taxon richness, Ephemeroptera, Plecoptera, and Trichoptera (EPT) richness, mayfly richness, caddisfly richness, chironomid richness, and estimated total taxon richness at the riffle scale, respectively. These concentrations are more than twice the water quality standard for Zn in Japan (30 µg/L), suggesting that the standard is likely overprotective for macroinvertebrate diversity. Field studies are useful for evaluating the level of protectiveness of safe concentrations (water quality standards) based on individual-level effects from laboratory toxicity tests, and this evaluation process will have a crucial role in implementing more purpose-driven ecological risk managements that aim to protect natural populations and communities. "
Johnston,RS; Brown,RW; Cravens,J 1975 Acid mine rehabilitation problems at high elevations. Watershed Management Symposium, ASCE Irrigation and Drainage Division. Logan Utah.
Kashian DR, Prusha BA, Clements WH. 2004 Influence of total organic carbon and UV-B radiation on zinc toxicity and bioaccumulation in aquatic communities. Environmental Science & Technology. 38(23):6371-6376.
Abstract: "The effects of total organic carbon (TOC) and UV-B radiation on Zn toxicity and bioaccumulation in a Rocky Mountain stream community were assessed in a 10-d microcosm experiment. We predicted that TOC would mitigate Zn toxicity and that the combined effects of Zn and UV-B would be greater than Zn alone. However, TOC did not mitigate Zn toxicity in this study. In fact, treatments with TOC plus Zn had significantly lower community respiration as compared with the controls and Zn concentrations associated with the periphyton increased in the presence of TOC. UV-B had no additive effect on periphyton Zn accumulation or community respiration. Heptageniid mayflies (Ephemeroptera) were particularly sensitive to Zn, and reduced abundances were observed in all Zn treatments. UV-B did not additionally impact Heptageniid abundances; however UV-B did have a greater effect on macroinvertebrate drift than Zn alone. Ephemeroptera, Plecoptera, and Trichoptera (groups typically classified as sensitive to disturbance) were found in highest numbers in the drift of UV-B + Zn treatments. Measures of Zn accumulation in the caddisfly Arctopsyche grandis, periphyton biomass, and total macroinvertebrate abundance were not sufficiently sensitive to differentiate effects of TOC, UV-B, and Zn. These results indicate that UV-B and TOC affect Zn bioavailability and toxicity by impacting species abundance, behavior, and ecosystem processes. "
Kiffney,PM 1996a Main and interactive effects of invertebrate density, predation and metals on a Rocky Mountain stream macroinvertebrate community. Canadian Journal of Fisheries and Aquatic Sciences 53 7, 1595-1601.
Kiffney,PM; Clements,WH 1993 Bioaccumulation of heavy metals by benthic invertebrates at the Arkansas River, Colorado. Environmental Toxicology and Chemistry 12, 1507-1517.
The authors studied concentrations of the metals Zinc, Copper and Cadmium in benthic macroinvertebrates, aufwuchs and water in the Arkansas river of Colorado. This is part of their continuing studies near the Superfund site called California Gulch. They focused their collections on the mayfly Baetis, caddisflies Arctopsyche grandis and Rhyacophila as well as the stoneflies Pteronarcella badia and Skwala americana. Quote from abstract: " Elevated concentrations of metals in the water were paralleled by higher concentrations in benthic organisms. Significant differences (p<.05) in metal concentrations in aufwuchs and enthic macroinvertebrates among upstream (reference) and downstream (impacted) stations were observed. Metals concentrations in aufwuchs and benthic invertebrates remained elevated at some downstream stations, despite decreases in water concentrations. Time of year and functional group contributed to the variation in metal bioaccumulation in benthic macroinvertebrates. Monitoring metal concentrations in aquatic macroinvertebrates was a better indicator of metal bioavailability in the Arkansas River than ambient (water) metal concentraions." They also found that metal concentrations in the insects and aufwuchs were more similar than insects and water.
Kiffney,PM; Clements,WH 1994 Effects of heavy metals on a macroinvertebrate assemblage from a Rocky Mountain stream in experimental microcosms. Journal of the North American Benthological Society 13 4, 511-523.
Kiffney,PM; Clements,WH 1996 Effects of metals on stream macroinvertebrate assemblages from different altitudes. Ecological Applications 6 2, 472-481.
Mostly about Zinc in natural streams. Also lab experiments with Cd and Cu. Higher altitudes have smaller bugs which are more sensitive than the same bugs at lower elevations. They recommend lower chronic metal standards at higher elevations.
Leland,HV 1985 Drift response of aquatic insects to copper. Verhandlungen der Internationalen Vereinigung für Theoretische und Angewandte Limnologie 22: 2413-2419.
Manning,AH; Verplanck,PL; Mast,MA; Marsik,J and McCleskey,RB 2011 Spring runoff water-chemistry data from the Standard Mine and Elk Creek, Gunnison County, Colorado, 2010: U.S. Geological Survey Open-File Report 2011-1159, 20 p. PDF and tables
Maret,TR; Cain,DJ; MacCoy,DE; Short,TM 2003 Response of benthic invertebrate asseblages to metal exposure and bioaccumulation associated with hard-rock mining in northwestern streams, USA. Journal of the North American Benthological Society 22 4, 598-620.
Martin,HW 1976 Water pollution caused by inactive ore and mineral mines. EPA-600/2-76-298 185 pages.
Martin, C.A., Luoma, S.N., Cain, D.J. and Buchwalter, D.B., 2007 Cadmium ecophysiology in seven stonefly (Plecoptera) species: delineating sources and estimating susceptibility. Environmental science & technology, 41(20), pp.7171-7177. PDF
Abstract: "A major challenge in ecotoxicology lies in generating data under experimental conditions that are relevant to understanding contaminant effects in nature. Biodynamic modeling combines species-specific physiological traits to make predictions of metal bioaccumulation that fare well when tested in the field. We generated biodynamic models for seven predatory stonefly (Plecoptera) species representing the families Perlidae (5) and Perlodidae (2). Each taxon was exposed to cadmium independently via diet and via solution. Species varied approximately 2.6 fold in predicted steady-state cadmium concentrations. Diet was the predominant source of accumulated cadmium in five of the seven species and averaged 53.2 ± 9.6% and 90.2 ± 3.7% of net Cd accumulation in perlids and perlodids, respectively. Differences in Cd bioaccumulation between the two families were largely driven by differences in dissolved accumulation rates, which were considerably slower in perlodids than in perlids. We further examined the subcellular compartmentalization of Cd accumulated from independent aqueous and dietary exposures. Predicted steady-state concentrations were modified to only consider Cd accumulated in metal-sensitive subcellular compartments. These values ranged 5.3 fold. We discuss this variability within a phylogenetic context and its implications for bioassessment. "
Mebane,CA; Dillon,FS and Hennessy,DP 2012 Acute toxicity of cadmium, lead, zinc, and their mixtures to stream-resident fish and invertebrates. Environmental Toxicology and Chemistry, 31(6), 1334-1348. PDF
Milani, D., Reynoldson, T. B. and Kirby, S. 1997a. Whole sediment toxicity tests and their application in determining the relative sensitivity of 4 benthic invertebrates to different classes of compounds in spiked and natural sediments.- Can. tech. Rep. Fish. Aquat. Sci. 2192: 33.
Mize,SV; Deacon,JR (2002) Relations of benthic macroinvertebrates to concentrations of trace elements in water, streambed sediments, and tronsplanted bryophytes and stream habitat conditions in nonmining and mining areas of the Upper Colorado River Basin, Colorado, 1995-98. United States Geological Survey Water Investigations Report 02-4139. 54 pages.
Mogren,CL and Trumble,JT 2010 The impacts of metals and metalloids on insect behavior. Entomologia Experimentalis et Applicata, 135: 1-17. Full Text
Abstract: " In toxicology studies, the use of death as an endpoint often fails to capture the effects a pollutant has on disruptions of ecosystem services by changing an animal’s behavior. Many toxicants can cause population extinctions of insect species at concentrations well below the EC25, EC50, or EC90 concentrations traditionally reported from short-term bioassays. A surprising number of species cannot detect metal and metalloid contamination, and do not always avoid food with significant metal concentrations. This frequently leads to modified ingestion, locomotor, and reproductive behaviors. For example, some species show a tendency to increase locomotor behaviors to escape from locations with elevated metal pollution, whereas other insects greatly decrease all movements unrelated to feeding. Still others exhibit behaviors resulting in increased susceptibility to predation, including a positive phototaxis causing immatures to move to exposed positions. For purposes of reproduction, the inability to avoid even moderately polluted sites when ovipositing can lead to egg loss and reduced fitness of offspring. Ultimately, impaired behaviors result in a general reduction in population sizes and species diversity at contaminated sites, the exceptions being those species tolerating contamination that become dominant. Regardless, ecosystem services, such as herbivory, detritus reduction, or food production for higher trophic levels, are disrupted. This review evaluates the effects of metal and metalloid pollution on insect behaviors in both terrestrial and aquatic systems reported in a diverse literature scattered across many scientific disciplines. Behaviors are grouped by ingestion, taxis, and oviposition. We conclude that understanding how insect behavior is modified is necessary to assess the full scope and importance of metal and metalloid contamination. "
Moran,RE; Wentz,DA (1974) Effects of metal-mine drainage on water quality in selected areas of Colorado, 1972-1973. Colorado Water Resources Circular No. 25 151 pages.
Discusses mine pollution near Crested Butte among other places.
Nehring,RB 1976 Aquatic insects as biological monitors of heavy metal pollution. Bulletin of Environmental Contamination and Toxicology 15 2, 147-154.
Nelson,SM 1994 Observed field tolerance of caddisfly larvae (Hesperophylax sp.) to high metal concentrations and low pH.
Abstract: " Tolerance of Hesperophylax sp. to a low pH mine tailings seep which contained high concentrations of heavy metals was documented in Lake County, Colorado. "
Nelson,SM and Roline,RA 1996 Recovery of stream macroinvertebrates community from mine drainage disturbance. Hydrobiologia 339, 73-84.
Nelson,SM and Roline,RA 1999 Relationships between metals and hyporheic invertebrate community structure in a river recovering from metals contamination. Hydrobiologia 397, 211-226.
Parkhurst,BR; Elder,RG; Meyer,JS; Sanchez,DA; Pennak,RW and Waller,WT 1984 An environmental hazard evaluation of uranium in a Rocky Mountain stream. Environmental Toxicology and Chemistry, 3(1), 113-124.
Abstract: " Uranium mining is an important industry in the Rocky Mountain region; however, little is known about the environmental hazards of uranium to fish and other aquatic organisms.
Indian Creek, a hard-water stream (200 mg/L as CaCO3) near Gunnison, Colorado, receives periodic discharges of runoff from a uranium mine. In addition, natural springs contribute uranium to the creek. As a result, uranium concentrations in the creek range up to 4 mg/L, concentrations which are potentially toxic to trout based on published toxicity data. Therefore, we conducted a series of studies to analyze the potential toxicity and bioaccumulation of uranium in Indian Creek and downstream waters.
A 60-d post-hatch, early life stage toxicity test was conducted with brook trout in water of hardness and alkalinity similar to Indian Creek. Additional tests were performed in soft and hard water (96-h acute toxicity tests) and in water of Indian Creek's quality (48-h acute toxicity tests). Trout from the 60-d test were also analyzed for uranium bioaccumulation. To confirm the results of the laboratory studies, these data were compared with on-site field study data, including surveys of fish and benthic invertebrates, and analyses of uranium levels in trout. The laboratory results indicated that the high hardness and alkalinity of the test water greatly reduced the potential toxicity of uranium to trout. Concentrations estimated to be chronically toxic from the early life stage test were greater than 9 mg/L; whereas the 48-h LC50 was 59 mg/L. Bioconcentration factors for uranium were low, ranging from 1.9 to 4.3.
Benthic invertebrate and fish studies conducted in Indian Creek confirmed that current uranium concentrations are not significantly toxic to resident aquatic biota. In-stream bioaccumulation of uranium is also very low, and is comparable to the laboratory-derived values.
Our study demonstrated that laboratory toxicity and bioaccumulation tests can accurately evaluate potential in-stream hazards of uranium. To accurately estimate in-stream toxicity and bioaccumulation of metals, it is important that laboratory tests simulate in-stream water quality."
Peckarsky,BL; Cook,KZ 1981 Effect of Keystone mine effluent on colonization of stream benthos. Environmental Entomology 10, 864-871.
Abstract: "Colonization cages were filled with organism-free, standardized, stone substrate and placed in the stream bed above and below the effluent from an inactive lead and zinc mine in western Colorado. A significantly higher proportion of the total individuals colonizing cages from an upstream direction were dead below the effluent compared with the controls above the effluent. The percent “mortality” of the mayfly, Baetis bicaudatus, the dominant species in Coal Creek, was also consistently higher below the effluent. Total numbers of live insects colonizing cages were generally higher above the effluent; but results were not as consistent as “mortality” data. A diversity index (H'), species richness, and equitability (J') of the samplers were not reliable indices of responses to stress by the benthic community. Given cages with contaminated substrate in uncontaminated water, the community recovered remarkably quickly. Colonizing populations were indistinguishable from those of control cages with uncontaminated substrate within 9 days. We conclude that the substrate habitat below the mine effluent is unsuitable for most benthic invertebrates and that the colonization technique that allows determination of percent mortality is more consistent and reliable than conventional measures of diversity for assessing the response of benthic invertebrates to stress. If water quality can be restored to a pristine state, the benthos may rapidly recover from the effects of previous acid mine drainage stress. "
Petrin,Z 2011 Species traits predict assembly of mayfly and stonefly communities along pH gradients. Oecologia, 167(2), 513-524. Abstract
Pollard,AI and Yuan,L 2006 Community response patterns: evaluating benthic invertebrate composition in metal-polluted streams. Ecological Applications, 16(2), 645-655.
Prairie, R 1994 Evaluation of sediment quality near mining sites and effects on benthic organisms.- Can. tech. Rep. Fish. aquatic Sci.1989: 26-27.
Prusha,BA and Clements,WH 2004 Landscape attributes, dissolved organic C, and metal bioaccumulation in aquatic macroinvertebrates (Arkansas River Basin, Colorado). Journal of the North American Benthological Society 23 2, 327-339.
Quinn, M.R., Feng, X., Folt, C.L. and Chamberlain, C.P., 2003 Analyzing trophic transfer of metals in stream food webs using nitrogen isotopes. Science of the Total Environment, 317(1-3), pp.73-89. PDF
Abstract: " This study examines detrimental effects of acid mine drainage (AMD) on stream invertebrate communities and tests for a direct relationship between trophic position and accumulation of three metals (Fe, Cu, Zn) by stream invertebrates in situ. On two dates in each of seven stream sites, we measured food chain length, mean trophic level, taxa richness, and trophic position of stream macroinvertebrates comprising the food webs using stable nitrogen isotope ratios. Metals in tissue of representatives of 35 taxa were measured by ICP-OES. Our results are the first direct comparison of uptake of these metals in stream invertebrate taxa according to trophic position as identified by δ15N. As predicted, metal concentrations were generally greater in water and insects from sites adjacent to mining activity and invertebrate taxa richness was significantly lower. Taxa richness increased with distance away from contaminated headwaters. Despite reductions in diversity at sites nearest AMD, food chain length and mean trophic level did not differ between streams. The relationship between trophic position and metal accumulation differed considerably among metals. Specifically, Fe declined (biodilution) and Zn increased (biomagnification) with trophic level, but trophic position had no effect on Cu levels in these insects. Our results highlight fundamental differences in trophic transfer of specific metals through aquatic food webs and identify ecologically important impacts of AMD on stream invertebrates."
Reisman,D; Rutkowski,T; Smart,P and Gusek,J 2008 The construction and instrumentation of a pilot treatment system at the Standard Mine Superfund Site, Crested Butte, Co. In Proceedings of the 2008 National Meeting of the American Society of Mining and Reclamation. Richmond, Virginia pgs 892-909 PDF
Reynolds,SK and Ferrington LC,J 2002 Differential morphological responses of Chironomid larvae to severe heavy metal exposure (Diptera: Chironomidae). Journal of the Kansas Entomological Society 75 3, 172-184.
Riddell DJ, Culp JM and Baird,DJ 2005 Behavioral responses to sublethal cadmium exposure within an experimental aquatic food web. Environmental Toxicology and Chemistry 24: 431-441.
Rumburg,CB; Gery,BH and Butcher,K 1978 Gunnison County Stream Water Quality Study. USEPA 68-01-3589 85 Pages.
Standard Mine Trestle before the Superfund Cleanup.
Ruse,LP and Herrmann,SJ 2000 Plecoptera and Trichoptera species distribution related to environmental characteristics of the metal-polluted Arkansas River, Colorado. Western North American Naturalist 60 (1) 57-65.
Abstract: The Upper Arkansas catchment has been polluted with heavy metals from mining for almost 140 yr. Adult Plecoptera and Trichoptera species distributions were recorded from 22 stations along 259 km of main river during 1984-85 so that these could be related to metal deposition and other environmental characteristics. Chemically or physically perturbed sites had poor species richness compared with adjacent sites. There was no sequential downstream increase in species numbers. Filter-feeders proportionally increased downstream as predators declined; these proportions were reset at a high-energy site before the trend resumed. Using canonical correspondence analysis, we found that species composition was most strongly related to changes in distance/altitude and to temperature, particularly after regulatory flows entered the river. The proportion of biological variation explained by river measurements indicated that collected adults were largely derived from the main Arkansas River. Species tolerant of high sedimentary metal concentrations were identified while some other species appeared to be sensitive. The study provides a disturbed-state reference for monitoring effects of remedial actions begun in 1991, and for comparisons with other Colorado rivers.
Ruse,LP; Herrmann,SJ; Sublette,JE 2000 Chironomidae (Diptera) species distribution related to environmental charateristics of the metal-polluted Arkansas River, Colorado. Western North American Naturalist 60, 34-56. PDF
Reynolds,SK; Ferrington LC,J 2002 Differential morphological responses of Chironomid larvae to severe heavy metal exposure (Diptera: Chironomidae). Journal of the Kansas Entomological Society 75 3, 172-184.
Rumburg,CB; Gery,BerthaAnn,H; Butcher,K (1978) Gunnison County Stream Water Quality Study. USEPA 68-01-3589 85 Pages.
Discusses Coal Creek, Uh Be Joyful, Slate and East Rivers. The Keystone Mine up Coal Creek is identified as the source of heavy metals. The Mount Emmons Project is a proposed molybdenum mine at the Keystone mine site now funded by Thompson Creek Metals.
Ruse,LP and Herrmann,SJ 2000 Plecoptera and Trichoptera species distribution related to environmental characteristics of the metal-polluted Arkansas River, Colorado. Western North American Naturalist 60 1, 57-65.
Ruse,LP; Herrmann,SJ; Sublette,JE 2000 Chironomidae (Diptera) species distribution related to environmental charateristics of the metal-polluted Arkansas River, Colorado. Western North American Naturalist 60, 34-56.
Saiki,MK; Jennings,MR and Brumbaugh,WG 1993 Boron, molybdenum, and selenium in aquatic food chains from the lower San Joaquin River and its tributaries, California. Archives of Environmental Contamination and Toxicology, 24(3), 307-319.
Boron (B), molybdenum (Mo), and selenium (Se) were measured in water, sediment, particulate organic detritus, and in various biota—filamentous algae, net plankton, macroinvertebrates, and fishes—to determine if concentrations were elevated from exposure to agricultural subsurface (tile) drainage during the spring and fall 1987, in the San Joaquin River, California. Concentrations of B and Se, but not Mo, were higher in most samples from reaches receiving tile drainage than in samples from reaches receiving no tile drainage. Maximum concentrations of Se in water (0.025 ?g/mL), sediment (3.0 ?g/g), invertebrates (14 ?g/g), and fishes (17 ?g/g) measured during this study exceeded concentrations that are detrimental to sensitive warmwater fishes. Toxic threshold concentrations of B and Mo in fishes and their foods have not been identified. Boron and Mo were not biomagnified in the aquatic food chain, because concentrations of these two elements were usually higher in filamentous algae and detritus than in invertebrates and fishes. Concentrations of Se were lower in filamentous algae than in invertebrates and fishes; however, concentrations of Se in or on detritus were similar to or higher than in invertebrates and fishes. These observations suggest that high concentrations of Se accumulated in invertebrates and fishes through food-chain transfer from Se-enriched detritus rather than from filamentous algae. "
Smart,P; Rutkowski,T; Todd,L and Progess,C 2010 Case Study: Evaluating the Feasibility
of Co-Treating Biochemical Reactor Effluent and Mining Influenced Water. In: Proceedings of the 2010 National Meeting of the American Society of Mining and Reclamation (Pittsburg, PA, June 5-11, 2010). PDF
Sonderegger DL, Wang H, Huang Y, Clements WH. 2009 Effects of measurement error on the strength of concentration-response relationships in aquatic toxicology. Ecotoxicology (London, England). 18(7):824-828.
Abstract: "The effect that measurement error of predictor variables has on regression inference is well known in the statistical literature. However, the influence of measurement error on the ability to quantify relationships between chemical stressors and biological responses has received little attention in ecotoxicology. We present a common data-collection scenario and demonstrate that the relationship between explanatory and response variables is consistently underestimated when measurement error is ignored. A straightforward extension of the regression calibration method is to use a nonparametric method to smooth the predictor variable with respect to another covariate (e.g., time) and using the smoothed predictor to estimate the response variable. We conducted a simulation study to compare the effectiveness of the proposed method to the naive analysis that ignores measurement error. We conclude that the method satisfactorily addresses the problem when measurement error is moderate to large, and does not result in a noticeable loss of power in the case where measurement error is absent. "
Spehar,RL; Anderson,RL; Fiandt,JT 1978 Toxicity and bioaccumulation of cadmium and lead in aquatic invertebrates. Environmental Pollution 15, 195-208.
Steele,TD; Coughlin,TH 1982 Bottom sediment chemistry and water quality near Mount Emmons, Colorado. Effects of Waste Disposal on Groundwater and Surface Water (Proceedings of the Exeter Symposium, July 1982) IAHS Publ.no. 139:63-78.
[The mine they mention is the Keystone mine, the property is now owned by the Mt Emmons Project.] Abstract: "Reconnaissance surveys of selected trace-metal concentrations of bottom sediments of two streams in the vicinity of Mount Emmons in south-central Colorado were made during August 1980 and July 1981. Mineral mining has occurred in the study area in the past, and development of a new molybdenum mine is planned. Associated treatment of existing and projected mine drainage along with the construction and operate mine facilities may alter the streamflow and water quality regimes. The data from the reconnaissance surveys were compared to recent water quality data at sites along the same stream reaches. The largest concentrations of arsenic in both water and bottom sediments in both surveys were measured for samples near the headwater reach of Coal Creek, which is approximately 3 miles upstream from the proposed mining activity. Iron concentrations in bottom sediments were slightly greater at sampling sites near the head-waters of both streams and were substantially greater at sites downstream from an old mine discharge into Coal Creek. Stream profiles for manganese and zinc concentrations in bottom sediments gradually increased in a downstream direction along Coal Creek, in contrast to the abrupt increase in concentrations of these trace metals for water samples collected downstream from the old mine discharge. Trace-metal concentrations in bottom sediments tended, in general, to be greater for the 1981 survey compared to the 1980 survey, which may have reflected both the below-normal streamflow which occurred during 1981 relative to above-normal streamflows during 1980, as well as the influence of a sequestriant agent or possibly a residual polymer introduced with the discharge of a heavy metals treatment plant. Profiles of bottom sediment trace-metal concentrations tend to depict a more integrated description of lithological factors affecting water chemistry in contrast to the more highly variable concentrations with season in water."
Stitt,RP Rockwell,RW Legg,DE and Lockwood,JA 2006 Evaluation of Cinygmula (Ephemeroptera: Heptageniidae) drift behavior as an indicator of aqueous copper contamination. Journal of the Kentucky Academy of Science 67(2) 102-108. Abstract
Velleux ML, Julien PY, Rojas-Sanchez R, Clements WH, England,JF. 2006 Simulation of metals transport and toxicity at a mine-impacted watershed: California Gulch, Colorado. Environmental Science & Technology. 40(22):6996-7004.
Abstract: "The transport and toxicity of metals at the California Gulch, Colorado mine-impacted watershed were simulated with a spatially distributed watershed model. Using a database of observations for the period 1984-2004, hydrology, sediment transport, and metals transport were simulated for a June 2003 calibration event and a September 2003 validation event. Simulated flow volumes were within approximately 10% of observed conditions. Observed ranges of total suspended solids, cadmium, copper, and zinc concentrations were also successfully simulated. The model was then used to simulate the potential impacts of a 1-in-100-year rainfall event. Driven by large flows and corresponding soil and sediment erosion for the 1-in-100-year event, estimated solids and metals export from the watershed is 10,000 metric tons for solids, 215 kg for Cu, 520 kg for Cu, and 15,300 kg for Zn. As expressed by the cumulative criterion unit (CCU) index, metals concentrations far exceed toxic effects thresholds, suggesting a high probability of toxic effects downstream of the gulch. More detailed Zn source analyses suggest that much of the Zn exported from the gulch originates from slag piles adjacent to the lower gulch floodplain and an old mining site located near the head of the lower gulch. "
Warnick,SL; Bell,HL 1969 The acute toxicity of some heavy metals to different insects. Journal WPCF 41 2, 280-284.
Wentz,DA (1974) Effect of mine drainage on the quality of streams in Colorado 1971-1972. Colorado Water Resources Cicular No. 21. 119 pages.
Zuellig,RE; Kashian,DR; Brooks,ML; Kiffney,PM and Clements,WH 2008 The influence of metal exposure history and ultraviolet-B radiation on benthic communities in Colorado Rocky Mountain streams. Journal of the North American Benthological Society, 27(1), 120-134. PDF