Chronic Sediment Toxicity Research Articles

Acute and chronic toxicity of rare earth elements-enriched sediments from a prospective mining area: Effects on life history traits, behavioural and physiological responses of Gammarus fossarum (Crustacea Amphipoda)

Rare earth elements (REE) have an essential role and growing importance in the world's economy. They are attracting interest from society, policymakers, and scientists. The rapidly growing global demand for REE in several strategic industrial and agricultural sectors led many countries to consider the (re)-opening of mining activities for REE extraction. Hence, their increasing use led to the disruption of their biogeochemical cycles with anthropic abnormalities already observed in aquatic ecosystems. Nonetheless, REE remain less studied, and their mechanisms of toxicity actions are not fully understood. As amphipods, Gammarus fossarum represent an important part of the aquatic macroinvertebrate assemblage and are generally used in ecotoxicological studies for their high ecological relevance. However, their use for the study of REE effects has been rather limited so far. The current study aims to assess the potential effects of two naturally REE-enriched sediments (N2 and B4) on G. fossarum. Effects on life history traits, behavioural and physiological responses have been evaluated. Exposing G. fossarum males for 72h to sediments N2 and B4 led to a decrease in haemolymph osmolality and locomotion while an increase in ventilatory activity was observed. Exposing G. fossarum pre-copula pairs with females at the same reproductive stage to the naturally REE-enriched sediments, for one moult cycle duration (∼30 days) showed that sediment B4 led to i) a significant uptake of REE, ii) a significant decrease in the proportion of females with oocytes and iii) a significant reduction in the total number of juveniles. The physicochemical analyses of sediments showed that B4 contains the highest amount of REE with a higher proportion of light REE. The present study gives the first insights into the potential toxicity of REE on G. fossarum as they may have deleterious effects on G. fossarum population's dynamics, which may alter the functioning of aquatic ecosystems.

Comparing 10- and 28-Day Sediment Toxicity and Bioaccumulation of Fluoranthene in Hyalella azteca Using Passive Sampling Techniques.

Understanding the changes in the temporal and spatial concentrations of chemical substances in sediment toxicity tests facilitates interpretation of their toxicity and accumulation in benthic organisms because benthic organisms are affected by chemicals via multiple exposure pathways. However, such investigations using chronic sediment toxicity tests have rarely been performed. To examine the concentration profiles of a hydrophobic organic chemical using chronic spiked-sediment toxicity tests, we performed 28-day sediment toxicity tests of fluoranthene with a freshwater amphipod, Hyalella azteca, using a semi-flow-through system and compared the results with those of 10-day tests. In these experiments, we measured various types of fluoranthene concentrations over the test periods: total dissolved (Cdiss ) and freely dissolved (Cfree ) concentrations in overlying water and porewater as well as sediment concentrations. We also examined which concentration correlated with the amphipod bioconcentration factor (BCF). We found that both overlying water and porewater Cfree did not differ significantly on days 10 and 28. Sediment concentrations remained almost stable for 28 days, whereas Cdiss in overlying water varied temporally. These results suggest that the 28-day test provides almost constant concentrations of fluoranthene, particularly in porewater, even in a semi-flow-through system. In addition, the comparison of BCF of fluoranthene on day 10 in the present study with that obtained from water-only tests reported in the literature suggested that Cfree in pore water was the most representative indicator of bioaccumulation in H. azteca. Our findings support the possible use of a water-exchange system in chronic spiked-sediment toxicity tests of hydrophobic organic chemicals. However, further studies using sediments and chemicals with different properties are warranted to generalize the findings of the present study. Environ Toxicol Chem 2022;41:2679-2687. © 2022 SETAC.

Toxicity of Mining-Contaminated Lake Sediments to Lumbriculus variegatus

Boreal lakes with soft water and low buffering capacity are susceptible to excess ion loading resulting from metal mining. The impact of two Finish mining sites in downstream lakes was assessed with a chronic sediment toxicity test using a laboratory-reared freshwater Lumbriculus variegatus (Oligochaeta). The test organisms were exposed to mining-contaminated natural lake sediments and hypolimnion water (HLW) or artificial freshwater (AFW) as overlying water in two independent experimental setups. In both test setups, growth and reproduction of L. variegatus were lower in sediments from the lakes receiving high amount of mining effluents from the mines nearby. In the biomining site, the main contaminants in the recipient lakes were the ore metals Ni and Zn, while in the lakes affected by the conventional underground mine, they were Cu and Zn. These metals accumulated in L. variegatus especially in the setup with natural HLW above the sediment. Growth and reproduction were lower in the HLW than in the AFW setup. The mining-contaminated sediments did not support optimum growth or reproduction of L. variegatus in comparison to the local reference sediments. Decline of pH in the unbuffered natural sediments brought up challenges in the assessment of metal-contaminated lake sediments with high sulfur content, and a need to develop new tools for their risk assessment.

Use of an Integrated Geochemical and Ecotoxicological Approach to Evaluate Sediment Metal Contamination in Three Protected Estuarine Areas Along the Coast of São Paulo State, Brazil.

We compared sediment quality in estuaries at three locations along the coast of São Paulo State, Brazil, using geochemical analyses and whole sediment toxicity tests, during the southern summer and winter of 2013. Each locality is afforded a distinct degree of legal protection, and exhibits a different level of metal pollution: overall, Rio Diana (RD, the most polluted, a Permanent Protection Area) > Rio Itapanhaú (RI, intermediate contamination, an Environmental Protection Area) > Rio Picinguaba (RP, pristine, a State Park). Chronic sediment toxicity tests evaluated reproductive rates of the copepod Nitokra sp. RI sediments showed the highest metal concentrations and toxicity in both seasons. Metal concentrations at RD were low but toxic in summer. RP sediments were not contaminated, suggesting effective legal protection from pollution at this locality. RI and RD, although provided some legal protection, showed clear signs of environmental degradation, emphasizing the need for more effective pollution control.

Acute waterborne and chronic sediment toxicity of silver and titanium dioxide nanomaterials towards the oligochaete, Lumbriculus variegatus

The use of silver (Ag) and titanium dioxide (TiO2) nanomaterials (NMs) in industrial processes and consumer products has experienced considerable growth since the late 20th century. Throughout their lifecycle, both Ag NM and TiO2NM are released into the environment, with benthic systems anticipated to be the final sink. Their potential toxicity towards benthic species is therefore of major concern. This study investigated the toxicity of silver (Ag; NM-300 K) and titanium dioxide (TiO2; NM-104) NMs to the freshwater oligochaete, Lumbriculus variegatus in acute (0–96-h) waterborne and chronic (28-d) sediment studies. Toxicity was investigated via assessment of mortality, behaviour, and antioxidant enzyme activity. The 96-h LC50 for Ag NMs in water was 0.51 mg/l (95% CI, 0.45–0.56), with L. variegatus displaying inhibited predation-avoidance behaviour compared to controls (6.66 ± 10%) successful response at 24-h), as well as significant increases (p < 0.05) in catalase (CAT) activity at sub-lethal concentrations at 24-h. Behavioural improvement and the return of antioxidant enzymes to control levels was observed after 48 and 72-h. AgNO3 exposure proved more toxic than Ag NM (96-h LC50 = 0.034 mg/l, 95% CI, 0.031–0.037) but resulted in no changes to antioxidant enzymes following sub-lethal exposure. Furthermore, Ag dissolution from Ag NM (~2–4%) could not account for the full extent of toxicity observed, suggesting a nano-specific effect. Increased environmental relevance via the inclusion of Suwannee River Humic Acid (SRHA, 5 mg/l) alleviated sub-lethal Ag NM toxicity despite a comparable 96-h LC50 (0.54 mg/l, 95% CI, 0.51–0.57). Significant effects of Ag NMs in formulated sediments (mortality, biomass) were only recorded according to OECD 225 at the highest test concentration (1333 mg/kg) for Ag NM indicating a potential attenuating effect of sediments towards toxicity. No toxicity was observed for TiO2 NM in aquatic or sediment exposures up to concentrations of 2000 mg/l and 1333 mg/kg, respectively.

Assessment of Potentially Toxic Elements in Technosols by Tailings Derived from Pb–Zn–Ag Mining Activities at San Quintín (Ciudad Real, Spain): Some Insights into the Importance of Integral Studies to Evaluate Metal Contamination Pollution Hazards

This work presents an integral methodological approach to assess the environmental potential hazards posed by metals and metalloids hosted by spolic technosols derived from old tailings from a mining operation for galena (PbS, with high Ag contents)-sphalerite (ZnS, with a varied cohort of trace elements contents) in central Spain. We studied the total and soluble concentrations and spatial distribution of Pb, Zn, Cd, As, and Fe and the mineralogy of these soils, as well as an ecotoxicological evaluation by means of bioassays. The indices assessing soil contamination such as pollution load index (PI) and natural mobility index (NMI) have been calculated. Furthermore, the phytotoxic effect of the soil samples has been determined and a chronic sediment toxicity test using the benthic ostracod Heterocypris incongruens was applied. The geochemical study of 33 spolic technosols samples indicates large to extremely large metal and metalloid total contents: up to 48,600 mg kg−1 Pb, 34,000 mg kg−1 Zn, 500 mg kg−1 Cd, and 1000 mg kg−1 As. Given that sphalerite is usually the most important host mineral for cadmium in hydrothermal mineral deposits, there is a high correlation (R = 0.75) between this element and Zn. On the other hand, despite being two metallogenically intertwined elements in ore deposits, Pb and Zn show a less significant relationship, which can be attributed both to heterogeneities in the mineralogical composition of the veins, and to the complex history of the mineral concentration process: In the older process, the interest was only for Pb, meanwhile in the late period, the interest was focused in Zn. The Phytotoxkit® bioassay showed that soils with high PTEs presented very high toxicity, particularly the inhibition germination is related to Pb, As, and Cd content and root inhibition with Pb content. Both indexes were correlated with pH and electrical conductivity; samples with lower pH and higher soluble salt content are those with higher seed germination inhibition and root growth inhibition. On the other hand, the Ostracodtoxkit® bioassay showed very high sensitivity, with 100% mortality. The applied bioassays confirmed the soil toxicity and it is highly recommended to complement the results from environmental chemistry with results from bioassays, in order to provide a more complete and relevant information on the bioavailability of contaminants and to characterize the risk of contaminated areas.

Development of a chronic sediment toxicity test using the benthic ostracod Heterocypris incongruens and their application to toxicity assessments of urban road dust

This study reports on the development and application of a chronic sediment toxicity test using the benthic ostracod Heterocypris incongruens. H. incongruens reproduction parameters such as egg production, first day of brooding, egg-laying ratio, and hatching ratio were examined in this study. The test was first validated by determining the repeatability of the test method under seven control performances. The results showed good test repeatability of most endpoints, with coefficient of variation (CV) results below 15%. However, lifetime egg production, hatching ratio, and the reproductive rate were highly variable, with CVs ranging from 29.5% to 51.9%. Next, an application example of the proposed chronic method was performed using a series of urban road dust (URD) samples diluted with a reference sediment and compared to a 6 d H. incongruens toxicity test. The results of the proposed chronic test showed a statistically significant difference in the first day of brooding at 6.25% URD which did not exhibit significant mortality and growth inhibition in 6 d toxicity test.

Assessment of Sediment Risk in the North End of Tai Lake, China: Integrating Chemical Analysis and Chronic Toxicity Testing with Chironomus dilutus.

Whole life-cycle bioassays with Chironomus dilutus were performed to evaluate sediment toxicity in Tai Lake, a typical freshwater lake in China. Meanwhile, contaminants of concern were analyzed in sediment. The sediments in Tai Lake showed no acute mortality in 10-day testing to C. dilutus. After chronic exposure to the sediments, however, adverse effects-including decreased survival and sublethal impairments of growth, emergence, and fecundity-were observed at most sites in Tai Lake. A variety of contaminants were detected in sediment with the total concentrations in the range of 504-889ng/g dry weight (dw) for polycyclic aromatic hydrocarbons, 0.56-1.81ng/g dw for polychlorinated biphenyls, 38.6-87.8ng/g dw for polybrominated diphenyl ethers, 8.34-14.2ng/g dw for organochlorine pesticides, 1.27-2.95ng/g dw for organophosphate pesticides, 0.11-0.21ng/g dw for pyrethroid pesticides, and 332-609µg/g dw for metals. Finally, a canonical correlation analysis was applied to link chronic sediment toxicity to the toxic units of individual contaminants. Results suggested that two pesticides (hexachlorocyclohexane and chlorpyrifos) and two metals (chromium and nickel) in sediments from Tai Lake were the potential contributors to the noted toxicity in C. dilutus in the life-cycle toxicity testing. In conclusion, acute bioassays with the benthos were not sensitive enough to assess sediment toxicity in freshwater lakes in China, and it is desirable to integrate chronic toxicity testing with chemical analysis to better understand sediment risk.

Chaetoceros gracilis AS A BIOINDICATOR OF SEDIMENT QUALITY

&lt;p&gt;Chronic sediment toxicity tests could be used to evaluate the effects of sediment on critical stages in the life of an organism like invertebrate larvae and microalgae. Microalgae play an important role in aquatic ecosystem due to their role as producer in food chain producing organic matter and oxygen through photosynthesis process. This paper aimed to assess sediment quality of Semarang water using chronic sediment toxicity test. Research was conducted by testing 13 sediment samples from Semarang coastal region in August, 2010. Results showed that sediments exposed for 96 hours were still able to stimulate the growth of &lt;span style="text-decoration: underline;"&gt;C&lt;/span&gt;. &lt;span style="text-decoration: underline;"&gt;gracilis&lt;/span&gt; eventhough the copper concentration was above standard value provided by the CCME. The conclusion from this research was that sediment in Semarang still in good condition and can support growth of C. gracilis as primary producer. Chronic sediment toxicity test using C. gracilis could be combined with heavy metal measurement for sediment quality asessment.&lt;/p&gt; &lt;p&gt;Keywords: sediment, bioindicator, diatomae, &lt;span style="text-decoration: underline;"&gt;C.&lt;/span&gt; &lt;span style="text-decoration: underline;"&gt;gracilis&lt;/span&gt;, chronic toxicity, Semarang&lt;/p&gt;

Chaetoceros gracilis AS A BIOINDICATOR OF SEDIMENT QUALITY

Chronic sediment toxicity tests could be used to evaluate the effects of sediment on critical stages in the life of an organism like invertebrate larvae and microalgae. Microalgae play an important role in aquatic ecosystem due to their role as producer in food chain producing organic matter and oxygen through photosynthesis process. This paper aimed to assess sediment quality of Semarang water using chronic sediment toxicity test. Research was conducted by testing 13 sediment samples from Semarang coastal region in August, 2010. Results showed that sediments exposed for 96 hours were still able to stimulate the growth of C. gracilis eventhough the copper concentration was above standard value provided by the CCME. The conclusion from this research was that sediment in Semarang still in good condition and can support growth of C. gracilis as primary producer. Chronic sediment toxicity test using C. gracilis could be combined with heavy metal measurement for sediment quality asessment. Keywords: sediment, bioindicator, diatomae, C. gracilis, chronic toxicity, Semarang

Chronic Toxicity Thresholds for Sediment-Associated Benzo[a]pyrene in the Midge (Chironomus dilutus)

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in aquatic ecosystems and have been shown to be one of the causes of sediment toxicity to benthic invertebrates. Benzo[a]pyrene (BaP) was selected as a representative for the PAH family of compounds for developing chronic sediment toxicity thresholds for Chironomus dilutus. Life-cycle toxicity testing was initiated using newly hatched midge larvae and terminated until hatch of the second generation. Median lethal concentrations were 92.5±19.6 and 56.9±1.76μg/g organic carbon (OC) after exposing midges to sediment-associated BaP for 20days (before pupation) and 43days (end of test), respectively. Sublethal toxicity was described as 5 and 50% effect concentrations (EC5 and EC50), and these were 6.63±0.82 and 41.1±1.61μg/g OC for growth reduction at 20days, respectively. Impairments of emergence and reproduction of C. dilutus were also assessed at the end of the testing, and the EC5 and EC50 values were 3.41±0.53 and 26.9±1.43μg/g OC for emergence and 2.18±0.34 and 13.4±1.13μg/g OC for reproduction, respectively. In addition, bioavailability-based chronic toxicity thresholds were also established using Tenax-extractable BaP concentrations. Although more environmentally relevant, data regarding chronic toxicity are less available than those regarding acute toxicity. Therefore, establishing numeric chronic toxicity thresholds for sediment-associated BaP with the consideration of the bioavailability would improve the accuracy of assessing PAH-related sediment toxicity.

Toxicity of Metals Associated with Sediments from the Columbia River to Early Life Stages of White Sturgeon

In the Upper Columbia River (UCR) between Trail, BC, and Grand Coulee Dam, WA, it has been hypothesized that metals associated with sediments might be contributing to poor recruitment of white sturgeon. Accordingly, the present study employed laboratory flow-through tests to characterize chronic toxicity of UCR sediments to early life stages of white sturgeon (Acipenser transmontanus). Sediments were collected from areas of the UCR known to be sturgeon spawning- and/or nursing-grounds and contained a range of concentrations of metals of primary interest, including copper (Cu), cadmium (Cd), lead (Pb), and zinc (Zn). Early life stage white sturgeon were exposed for 60 days and survival and growth were related to concentrations of metals in bulk sediment, pore water, overlying water, and water at the sediment-water interface. Based on probable effect concentrations (PECs) and excess simultaneously extracted metals (SEMX), site sediments in the present study had the potential to elicit adverse effects to sediment-dwelling organisms. In addition, the Biotic Ligand Model (BLM) was used to allow for more explicit consideration of bioavailability of metals to white sturgeon. BLM predictions indicated that concentrations of Cu in pore water slightly exceeded the threshold for effects (up to a factor of 2.2) for two of the five site sediments, while concentrations of metals in overlying water and at the sediment-water interface were below the threshold for effects. No effects were observed, however, in survival or growth of white sturgeon exposed to site sediments that were relatable to concentrations of metals. Of the methods used to characterize potential effects due to exposure to metals associated with sediments, BLM predictions corresponded best with the observed results.

Chronic toxicity of nickel‐spiked freshwater sediments: Variation in toxicity among eight invertebrate taxa and eight sediments

This study evaluated the chronic toxicity of Ni-spiked freshwater sediments to benthic invertebrates. A 2-step spiking procedure (spiking and sediment dilution) and a 2-stage equilibration period (10 wk anaerobic and 1 wk aerobic) were used to spike 8 freshwater sediments with wide ranges of acid-volatile sulfide (AVS; 0.94-38 µmol/g) and total organic carbon (TOC; 0.42-10%). Chronic sediment toxicity tests were conducted with 8 invertebrates (Hyalella azteca, Gammarus pseudolimnaeus, Chironomus riparius, Chironomus dilutus, Hexagenia sp., Lumbriculus variegatus, Tubifex tubifex, and Lampsilis siliquoidea) in 2 spiked sediments. Nickel toxicity thresholds estimated from species-sensitivity distributions were 97 µg/g and 752 µg/g (total recoverable Ni; dry wt basis) for sediments with low and high concentrations of AVS and TOC, respectively. Sensitive species were tested with 6 additional sediments. The 20% effect concentrations (EC20s) for Hyalella and Gammarus, but not Hexagenia, were consistent with US Environmental Protection Agency benchmarks based on Ni in porewater and in simultaneously extracted metals (SEM) normalized to AVS and TOC. For Hexagenia, sediment EC20s increased at less than an equimolar basis with increased AVS, and toxicity occurred in several sediments with Ni concentrations in SEM less than AVS. The authors hypothesize that circulation of oxygenated water by Hexagenia led to oxidation of AVS in burrows, creating microenvironments with high Ni exposure. Despite these unexpected results, a strong relationship between Hexagenia EC20s and AVS could provide a basis for conservative site-specific sediment quality guidelines for Ni.

Evaluation of the mayfly Ephoron virgo for European sediment toxicity assessment

The mayfly Ephoron virgo plays a key role in the ecological recovery in large European rivers. The larvae spend their life in the sediment and are therefore exposed to contaminants in various ways. In this study, the use of E. virgo as a test species for whole sediment bioassays was evaluated. The sensitivity was compared with Hexagenia limbata (a North American mayfly recommended for standard sediment testing). Lead (Pb) was used as a model contaminant. Seven Pb concentrations (range, 100–3,200 μg g−1) were spiked to uncontaminated natural sediment. Prior to the bioassays, spiked sediments were equilibrated for 35 days to ensure the partitioning of Pb among overlying water, pore water and sediment. E. virgo and H. limbata were exposed to Pb-contaminated sediments for 21 days in the test jars containing 250 mg sediment (i.e. 4 cm deep; 250 ml test medium). The exposure was performed as a semi-static system of which overlying water was renewed twice per week. Pb concentrations in pore water and sediment were measured at the beginning and the end of the assays. Pb bioavailability in the sediment was assessed using the equilibrium partitioning model based on acid volatile sulphide (AVS) and simultaneously extracted metal (SEM). A clear dose–response relationship between E. virgo survival and Pb toxicity/bioavailability in the sediment was obtained, with the lowest observed effect concentration of 2,071 μg Pb g−1 treatment [(SEMPb–AVS)/fraction of organic carbon (OC) = 168.9 μmol g−1 OC]. The results also confirmed the SEM–AVS model as no Pb toxicity occurred at (SEMPb–AVS) ≤0 μmol g−1. Comparing the responses of the two mayfly species exposed to the same Pb-contaminated sediment, E. virgo showed a higher sensitivity. The difference in sensitivity to Pb of the two mayflies could be related to intrinsic species sensitivity. Some factors which might influence sensitivity, i.e. the developmental stage and homogeneity of the larval age at exposure, should also be considered. Comprehensive data for the risk assessment of European sediments may be obtained from sediment bioassays with indigenous species. In this study, a chronic sediment toxicity assay using larvae of E. virgo has been demonstrated. Considering the sensitivity and the need to incorporate more ecologically relevant data, it can be concluded that the 21-day whole sediment toxicity test with E. virgo is a good bioassay for testing sediment toxicity.

The effects of engineered nanoparticles on survival, reproduction, and behaviour of freshwater snail, Physa acuta (Draparnaud, 1805)

Increasing uses of engineered nanoparticles (ENPs) in commercial products and industrial applications has eventually resulted to their releases into atmospheric, terrestrial, and aquatic environments. However, knowledge gaps in ENPs toxicity, fate, and behaviour currently limit our ability to quantify risk assessment of materials with nanoscale dimensions, and therefore, the extent of the resultant environmental impacts remains unknown. In the present study, we evaluated the effects of γ-alumina, α-alumina, modified TiO 2 (M-TiO 2), and commercial TiO 2 (C-TiO 2) ENPs on the survival, behaviour, and early life stages of the freshwater snail Physa acuta (Draparnaud). The toxicity evaluation was carried out after spiking commercial sand with ENPs concentrations of 0.005, 0.05, or 0.5 g kg −1. Our findings suggest that increases of γ-alumina and α-alumina concentrations at sub-lethal level concentrations caused significant reduction in the embryo growth rate and embryo hatchability. In addition, these ENPs induced observable developmental deformities of the embryos. In addition, toxicity evaluations using acute 96-h and chronic 28-d tests showed exposure duration may be a significant factor in ENPs-induced toxicity. Therefore, long-term exposure of aquatic organisms to ENPs – potentially can alter certain ecological populations at different trophic levels – and may compromise the entire aquatic ecological functionality. The percentage hatchlings in test chambers containing 0.5 g kg −1 γ-alumina and α-alumina concentration was 50% less to those observed in the controls. Our results suggest the embryonic growth and hatchability tests are useful endpoints in chronic sediment toxicity tests for determining the toxic thresholds of ENPs in sediment environment. Although no snail mortalities were observed during the static 96-h test containing sediment spiked with different concentrations of M-TiO 2, C-TiO 2, γ-alumina and α-alumina – the antioxidant enzymatic assay results indicated a significant change in antioxidant levels which altered peroxidation at 0.05 or 0.5 g kg −1concentrations for both γ-alumina and α-alumina.

Ecological impacts of lead mining on Ozark streams: Toxicity of sediment and pore water

We studied the toxicity of sediments downstream of lead–zinc mining areas in southeast Missouri, using chronic sediment toxicity tests with the amphipod, Hyalella azteca, and pore-water toxicity tests with the daphnid, Ceriodaphnia dubia. Tests conducted in 2002 documented reduced survival of amphipods in stream sediments collected near mining areas and reduced survival and reproduction of daphnids in most pore waters tested. Additional amphipod tests conducted in 2004 documented significant toxic effects of sediments from three streams downstream of mining areas: Strother Creek, West Fork Black River, and Bee Fork. Greatest toxicity occurred in sediments from a 6-km reach of upper Strother Creek, but significant toxic effects occurred in sediments collected at least 14 km downstream of mining in all three watersheds. Toxic effects were significantly correlated with metal concentrations (nickel, zinc, cadmium, and lead) in sediments and pore waters and were generally consistent with predictions of metal toxicity risks based on sediment quality guidelines, although ammonia and manganese may also have contributed to toxicity at a few sites. Responses of amphipods in sediment toxicity tests were significantly correlated with characteristics of benthic invertebrate communities in study streams. These results indicate that toxicity of metals associated with sediments contributes to adverse ecological effects in streams draining the Viburnum Trend mining district.

Biological and Chemical Characterization of Metal Bioavailability in Sediments from Lake Roosevelt, Columbia River, Washington, USA

We studied the bioavailability and toxicity of copper, zinc, arsenic, cadmium, and lead in sediments from Lake Roosevelt (LR), a reservoir on the Columbia River in Washington, USA that receives inputs of metals from an upstream smelter facility. We characterized chronic sediment toxicity, metal bioaccumulation, and metal concentrations in sediment and pore water from eight study sites: one site upstream in the Columbia River, six sites in the reservoir, and a reference site in an uncontaminated tributary. Total recoverable metal concentrations in LR sediments generally decreased from upstream to downstream in the study area, but sediments from two sites in the reservoir had metal concentrations much lower than adjacent reservoir sites and similar to the reference site, apparently due to erosion of uncontaminated bank soils. Concentrations of acid-volatile sulfide in LR sediments were too low to provide strong controls on metal bioavailability, and selective sediment extractions indicated that metals in most LR sediments were primarily associated with iron and manganese oxides. Oligochaetes (Lumbriculus variegatus) accumulated greatest concentrations of copper from the river sediment, and greatest concentrations of arsenic, cadmium, and lead from reservoir sediments. Chronic toxic effects on amphipods (Hyalella azteca; reduced survival) and midge larvae (Chironomus dilutus; reduced growth) in whole-sediment exposures were generally consistent with predictions of metal toxicity based on empirical and equilibrium partitioning-based sediment quality guidelines. Elevated metal concentrations in pore waters of some LR sediments suggested that metals released from iron and manganese oxides under anoxic conditions contributed to metal bioaccumulation and toxicity. Results of both chemical and biological assays indicate that metals in sediments from both riverine and reservoir habitats of Lake Roosevelt are available to benthic invertebrates. These findings will be used as part of an ongoing ecological risk assessment to determine remedial actions for contaminated sediments in Lake Roosevelt.

Relative sensitivities of toxicity test protocols with the amphipods Eohaustorius estuarius and Ampelisca abdita

A series of dose–response experiments was conducted to compare the relative sensitivities of toxicity test protocols using the amphipods Ampelisca abdita and Eohaustorius estuarius. A. abdita is one of the dominant infaunal species in the San Francisco Estuary, and E. estuarius is the primary sediment toxicity species used in the San Francisco Estuary Regional Monitoring Program. Experiments were conducted with a formulated sediment spiked with copper, fluoranthene, chlorpyrifos, and the three pyrethroid pesticides permethrin, bifenthrin, and cypermethrin, all chemicals of concern in this Estuary. The results showed that the protocol with A. abdita was more sensitive to fluoranthene and much more sensitive to copper, while E. estuarius was more sensitive to chlorpyrifos, and much more sensitive to the pyrethroid pesticides. These results, considered in conjunction with those from previous spiking studies [Weston, D.P., 1995. Further development of a chronic Ampelisca abdita bioassay as an indicator of sediment toxicity: summary and conclusions. In: Regional Monitoring Program for Trace Substances Annual Report. San Francisco Estuary Institute, Oakland, CA, pp 108–115; DeWitt, T.E., Swartz, R.C., Lamberson, J.O., 1989. Measuring the acute toxicity of estuarine sediments. Environ. Toxicol. Chem. 8: 1035–1048; DeWitt, T.H.E., Pinza, M.R., Niewolny, L.A., Cullinan, V.I., Gruendell, B.D., 1997. Development and evaluation of a standard marine/estuarine chronic sediment toxicity method using Leptocheirus plumulosus. Draft report prepared for the US Environmental Protection Agency, Office of Science and Technology, Washington DC, under contract DE-AC06-76RLO 1830 by Batelle Marine Science Laboratory, Battelle Memorial Institute, Pacific Northwest Division, Richland, WA], suggest that, in general, A. abdita is more sensitive to metals, E. estuarius is more sensitive to pesticides, and both protocols have roughly comparable sensitivities to hydrocarbons. The preponderance of evidence from previous field studies indicate that E. estuarius is considerably more responsive to ambient sediment samples [Bay, S.M., Gries, T.H., Anderson, B.S., Phillips, B.M., Field, J.L., Moore, D.W., Greenstein, D.J., 2005. Comparison of marine amphipod test species responsiveness to contaminated sediments. In: Conference Proceeding: Annual Meeting of the Society of Environmental Toxicology and Chemistry. SETAC, Baltimore, Maryland; Anderson, B.S., Hunt, B.M., Thompson, B., Lowe, S., Taberski, K., Carr, R.S., in press. Patterns and trends in sediment toxicity in the San Francisco estuary. Environ. Res.]. One reason for this may be that tube building behavior of A. abdita isolates this species from contaminants in pore water, and results from the current experiments partially support this hypothesis.

Can Amphipod Behavior Help to Predict Chronic Toxicity of Sediments?

ABSTRACT Amphipods are widely used in both acute and chronic (sub-lethal) sediment tests. Acute sediment tests provide relatively rapid results, but may fail to detect moderately toxic contaminants that are bound to the sediment, whereas chronic life-cycle tests are rarely performed as they are time consuming and expensive. Observations during chronic testing of oil-contaminated sediment suggested that there may be a link between the behavior of the marine amphipod Corophium volutator and reduction in growth rate. Behavior tests were performed with six individual amphipods per treatment using sediment spiked with weathered Forties oil with burrowing time, re-emergence from sediment, and activity prior to burrowing as endpoints. Further behavior tests were used to predict the chronic toxicity of sediments spiked with three crude oils each with a dominant unresolved complex mixture of hydrocarbons (UCM). The effect of sediment type on behavior was also investigated. The results suggested that although the behavior test could not be used alone as a viable alternative to sediment toxicity tests, it could prove useful as an adjunct to acute tests, and help select sediments that deserve further investigation.

A chronic bioassay with the estuarine amphipod Corophium volutator: Test method description and confounding factors

Methods of conducting a chronic sediment toxicity test with the estuarine amphipod Corophium volutator are described. They consist of a 49-day exposure, after which mortality, growth and reproduction are determined. Pilot experiments were used to optimize test design parameters such as temperature, duration, feeding and refreshing regimes, and effects of indigenous organisms. By way of further validation, the present study focused on the effects of four different parameters: oxygen saturation, salinity, ammonium and nitrite. These confounding factors might play an important role especially if the test is used for risk assessment of field-contaminated sediments. It is concluded that the present experimental design is well suited for chronic sediment exposures with C. volutator. The test can be performed at a broad range of salinity values, provided that controls are performed at the same salinity. Results further demonstrate that with the endpoints growth and reproduction this chronic test procedure is a factor 7–18 more sensitive to ammonium and nitrate than the standardized acute bioassay (endpoint mortality).