Development and evaluation of test methods for benthic invertebrates and sediments: Effects of flow rate and feeding on water quality and exposure conditions (original) (raw)
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Environmental Toxicology and Chemistry, 1995
Manipulations of freshwater sediment were performed to remove indigenous organisms prior to conducting toxicity tests with three species of benthic invertebrates. The effects of these treatments on end points in bioassays were compared within and between two sediments, i.e., a "clean" sediment and a "contaminated" sediment. In addition, the effects of manipulations on the physicochemical structure of the two sediments and the presence of metals, PAHs, and PCBs in the contaminated sediment were examined. The amphipod Hyalella aztecu was most sensitive to the manipulations and had low survival in sediment that was sterilized. Growth (milligrams dry weight per individual) was affected by the presence of contaminants. Survival of Chironomus riparius was not affected by any manipulation but was reduced by contaminants as well as indigenous organisms. Growth of C. ripanus was higher in autoclaved sediment but lower in sediment containing endemic tubificid worms. Production of young by Tubifex tubifex increased in sediment that was irradiated, possibly due to increased detrital material. Particle size distribution, metals, nutrients, and PAHs varied little as a function of manipulation; however, sieving of sediment through 250-pm mesh did reduce percent total organic carbon (TOC), percent loss on ignition (LOI), and concentrations of some PCBs in either clean or contaminated sediment. Manipulation of sediments to remove endemic species should be determined on a caseby-case basis and is specific to the organisms used in toxicity tests.
Environmental Toxicology and Chemistry, 2011
In the field of sediment quality assessment, increased support has been expressed for using multiple species that represent different taxa, trophic levels, and potential routes of exposure. However, few studies have compared the bioaccumulation potential of various test species over a range of sediment contaminants (hydrophobic organics and metals). As part of the development and standardization of a laboratory bioaccumulation method for the Ontario Ministry of the Environment, the oligochaete Lumbriculus variegatus, mayfly nymph Hexagenia spp., and juvenile fathead minnow Pimephales promelas were exposed to a variety of fieldcontaminated sediments (n ¼ 10) to evaluate their relative effectiveness for accumulating different contaminants (e.g., dichlorodiphenyltrichloroethane [DDT] and metabolites, polychlorinated biphenyls [PCBs), polycyclic aromatic hydrocarbons [PAHs), polychlorinated dibenzo-p-dioxins and dibenzofurans [PCDD/Fs), and heavy metals). Bioaccumulation was usually highest in L. variegatus but also most variable within and (relative measures) between sediments. Bioaccumulation was similar between L. variegatus and Hexagenia spp. in most of the sediments tested. Significant differences in bioaccumulation between species were observed for DDT, dichlorodiphenyldichloroethane (DDD), PAHs, and PCDD/Fs. The present study indicates that species-specific differences in bioaccumulation may, but do not always, exist and can vary with contaminant and sediment type. The choice of test species or combination to use in a standard test method may depend on the objectives of the sediment quality assessment and data requirements of an ecological risk assessment. The results of the present study provide insight for selection of test species and validation of laboratory methods for assessing bioaccumulation with these species, as well as valuable information for interpreting results of bioaccumulation tests.
Environmental Toxicology and Chemistry, 1995
This paper reviews recent developments in methods for evaluating the toxicity and bioaccumulation of contaminants associated with freshwater sediments and summarizes example case studies demonstrating the application of these methods. Over the past decade, research has emphasized development of more specific testing procedures for conducting 10-d toxicity tests with the amphipod Hyalella azteca and the midge Chironomus tentans. Toxicity endpoints measured in these tests are survival for H. azteca and survival and growth for C. tentans. Guidance has also been developed for conducting 28-d bioaccumulation tests with the oligochaete Lumbriculus variegatus, including determination of bioaccumulation kinetics for different compound classes. These methods have been applied to a variety of sediments to address issues ranging from site assessments to bioavailability of organic and inorganic contaminants using field-collected and laboratory-spiked samples. Survival and growth of controls routinely meet or exceed test acceptability criteria. Results of laboratory bioaccumulation studies with L. variegatus have been confirmed with comparisons to residues (PCBs, PAHs, DDT) present from synoptically collected field populations of oligochaetes. Additional method development is currently underway to develop chronic toxicity tests and to provide additional data-confirming responses observed in laboratory sediment tests with natural benthic populations.
Environmental Toxicology and Chemistry, 1994
... JAMES C. BALOGH,~ TREFOR B. REYNOLDSON,§ KRISTIN E. DAY§ and ROBERT A. HOKEII tU S Environmental Protection Agency, 6201 Congdon Boulevard, Duluth, Minnesota 55804 SSpectrum Research, Inc , 31 South 60 Avenue E, Duluth, Minnesota 55804 §National ...
Sediment toxicity assessment: Comparison of standard and new testing designs
2000
Standard methods of sediment toxicity testing are fairly well accepted; however, as with all else, evolution of these methods is inevitable. We compared a standard ASTM 10-day amphipod toxicity testing method with smaller, 48-and 96-h test methods using very toxic and reference sediments. In addition we compared parallel exposures of single species, either the amphipod Ampelisca abdita or the mysid Americamysis bahia, to multiple species, mysid, and amphipod, cohabiting the same types of chambers. These comparisons were performed for both water-only and sediment-water tests. Results of the comparison of the standard ASTM 10-day amphipod test with the smaller, 48-and 96-h test chambers indicate that survival was high in both test designs using the reference sediment. With toxic sediments, complete mortality occurred in less than 48 h using the smaller experimental chambers and only after 96 h in the larger experimental chambers. We concluded that although time to death is shorter in the smaller, shorter exposure chambers, there was no overall change in mortality for the organisms, and that the smaller chambers were predictive of the results obtained with larger chambers and longer exposures. For multiple species testing in whole sediment exposures there was no change in toxicity to either the amphipod or the mysid when they cohabited the same chamber. In contrast, for water-only exposures, A. bahia demonstrated less sensitivity when cohabiting the same chamber as A. abdita. Therefore, during whole sediment testing we can add A. bahia and A. abdita to the same test chamber without changing the toxicity to either species; however, in our 10-ml water-only exposures, the species should be tested separately. We compared the standard ASTM exposure chambers (ASTM 1999) to our smaller, shorter-duration exposure chambers using amphipods.
Confounding Factors in Sediment Toxicology
2000
Whole sediment tests are the standard when testing sediments for the obvious reason that organisms need to be exposed to the bulk sediment so that effects in survival and growth can be monitored. Water only tests have become standard laboratory practices as 96-hr reference tests. Ammonia is one of the most common reference toxicants used, followed by cadmium. Good control survival in the reference tests indicates that the animals should give a reasonable response when exposed to toxicants. The objective of running concurrent reference tests is to determine the health of the test population by observing the response from potentially confounding toxicants such as ammonia (Kohn et al., 1994; Gardiner et al., 1995). Porewater is assumed to have common characteristics as the surrounding sediment primarily because of its physical proximity. Pore waters are known to contain elevated levels of ammonia and nitrites, as a result of biological decomposition activities from marine bacteria. Both ammonia and nitrites can be toxic to a wide variety of marine organisms (shrimp, fish, amphipods, and phytoplankton) and are normally found in all marine sediments. Some sediments, high in organic matter with a large percentage of fine grain sizes, contain high levels of ammonia (>2 PPM) while other marine sediments may contain low levels of total ammonia (<0.5 PPM) because of low organic content and large grain size (Middle Loch, Pearl Harbor, Hawaii). Porewaters can act as a pathway for chemicals in the water that eventually bind to the sediment. Some researchers have observed a strong relationship between toxicant levels in porewater and observed mortality in test organisms (Whiteman et al., 1996). There is also evidence that porewater, overlying water, and the sediment can be chemically different from each other which may indicate that porewater may not be in equilibrium with sediment or overlying water (Nipper et al., 1998). Salinity, dissolved oxygen, pH, and sulfide have also been observed to be different in porewater than in overlying water. Yet, others have observed the ability of porewater contaminants to bind to organics and become non-bioavailable resulting in little or no toxicity to test organisms (DeWitt et al., 1997). Most Common Confounding Factors Ammonia Ammonia is usually reported as total ammonia and is the combination of the ammonium ion and un-ionized ammonia. Ammonia in sediments is a direct result of bacterial action on decaying organic matter and is a totally natural process. Because biological material sinks to the benthos, this is a major site for these natural degradation processes to occur. As the nitrifying bacteria degrade nitrogen into ammonia and nitrites, toxicity to other live biota also increases. Subsequently, only the hardiest of animals can tolerate these conditions within the sediments (amphipods, worms). Toxicity tests have been developed around these organisms to measure their response to "other" contaminants of concern while still being tolerant of high ammonia conditions.
Journal of Great Lakes Research, 1995
There have been few comparative assessments of the relative sensitivities of microorganisms in short-term (l to 20 min.) screening bioassays and benthic invertebrates exposed for longer periods of time (l0-to 28-d) to contaminated sediments. In this paper, the responses offour species of benthic invertebrates (Chironomus riparius, Hyalella azteca, Hexagenia spp., and Tubifex tubifex) and three microorganisms (Escherichia coli, Photobacterium phosphoreum, and Bacillus spp.) were compared using rank correlation (Spearman's r s)' for sediments collected from 46 nearshore sites «3 km) in the Laurentian Great Lakes. At a subset of sites (n = 27), data on the benthic invertebrate community structure were obtained and these sites were ranked and compared to the responses in each of the laboratory tests. The results indicate that two of the microbial screening tests, specifically, the Sediment-Chromotest®, which measures inhibition of the inducible enzyme, {3-galactosidase, in E. coli, and the Microtox® Solid-Phase Test (measures inhibition of bioluminescence), correlated with results from tests with invertebrates, particularly decreased survival of e. riparius (r s = 0.545 and 0.463, respectively), reduced growth of H. azteca (r s = 0.347 and 0.467, respectively) and Hexagenia (r s = 0.307 and 0.385, respectively) and lower production of cocoons by T. tubifex (r s = 0.347 and 0.416, respectively). In addition, reduced growth of e. riparius was positively correlated with reduced growth of the mayfly, Hexagenia spp. (r s = 0.655), survival and growth of the amphipod, H. azteca (r s = 0.416 and 0.570) and decreased production of cocoons (r s = 0.703) or live young (r s = 0.658) by T. tubifex. When information on the structure of the benthic invertebrate community was included as a subset of the data (n = 27), two microbial tests (Microtox® SPT and Sediment-Chromotest®) and several invertebrate tests (e.g., growth ofe. riparius, H. azteca, and Hexagenia and reproduction by T. tubifex) were strongly correlated with a degradation of the benthic community composition.
Estuaries, 2005
An integrated approach for ecological and ecotoxicological sediment assessments along the freshwater saltwater interface (FSI) and estuarine areas in general was developed, through the adaptation of recently proposed methods for the midge larvaChironomus riparius (an in situ assay based on post-exposure feeding for sediment toxicity assessments in freshwater systems) and the development of new techniques for the polychaeteHediste (Nereis) diversicolor (an in situ post-exposure feeding assay). Based on the previously proposed methods, improvements were made to the feeding quantification ofC. riparius fourth instar larvae. A method to quantify the post-exposure feeding ofH. diversicolor was developed and optimized under laboratory conditions using newly hatchedArtemia franciscana nauplii as a food source. Assay chambers and procedures fromC. riparius assays were easily adapted forH. diversicolor in situ exposures. Sediment assays using this integrated approach were successfully performed at an uncontaminated river-estuarine system. They consisted of a 48-h exposure followed by a 1-h post-exposure feeding for chironomids and a 2-h post-exposure feeding for polychaetes. Good recovery rates were obtained after the 48-h field exposure. Fluctuations in various physicochemical variables at the FSI, due to the tidal regime, did not significantly influenceC. riparius larval post-exposure feeding rates, suggesting that uncontaminated freshwater sites located upstream of FSI areas can be used as reference sites forC. riparius in situ evaluations in estuaries. Adapted assay chambers and procedures were suitable forH. diversicolor in situ exposures.
A Short-Term Sublethal In Situ Sediment Assay with Chironomus riparius Based on Postexposure Feeding
Archives of Environmental Contamination and Toxicology, 2005
A short-term, sublethal, and cost-effective in situ sediment toxicity assay for routine assessments with the midge Chironomus riparius Meigen, based on postexposure feeding, was developed and evaluated. An inexpensive and easy-to-use assay chamber was designed. A sediment toxicity assay was successfully performed at a lentic system impacted by acid mine drainage, at sites with different types of sediment. It consisted of a 48-h exposure period followed by a 1-h postexposure feeding during which the larvae were fed on Artemia franciscana nauplii. Methodologies for feeding quantification of fourth-instar larvae (10-d old) were first developed and optimized under laboratory conditions. A. franciscana nauplii were shown to be more suited than fish flake food for postexposure feeding quantification, allowing higher precision and cost-effectiveness. It also required a shorter postexposure feeding period, thus minimizing the chances for an eventual organism physiological recovery from toxicant exposure. The influence of several environmental conditions during exposure on postexposure feeding was also evaluated: temperature, dissolved oxygen, pH, salinity, hardness, substrate, humic acids, light, and food availability. Only temperature was found to significantly influence postexposure feeding rates; exposure at 5°C led to reduced feeding activity compared to 30°C. Recovery rates of 87% were obtained after the 48-h field exposure at all sites (except site R2). A statistically significant postexposure feeding depression was observed at the three sites impacted by acid mine drainage. Therefore, the proposed short-term in situ assay is a potentially useful tool to assess sediment sublethal toxicity on a routine basis.