Measures of Environmental Performance and Ecosystem Condition (1999) / Chapter Skim
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Insights from Ambient Toxicity Testing
Insights from Ambient Toxicity Testing
Pages 199-216
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From page 199... ...
The performance of organisms in ambient toxicity tests can thus be used to directly assess the biological quality of waters that receive industrial or other effluents. This paper examines the types of insights that can be derived from ambient toxicity testing, based on lessons learned from several large-scale ambient toxicity testing programs established for streams that receive effluent from U.S.
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From page 200... ...
. For regulatory purposes, effluent testing is used to establish a reliable estimate of an effluent's NOEC, LOEC, or LC50 (concentration of effluent that is lethal to half of the test organisms in a specified period of time)
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From page 201... ...
Equal number of replicates? FIGURE 2 Legend analysis flow path for reproduction data from Ceriodaphnia efflu Statistical NOEC = no-observed-effect concentration ent toxicity tests (redrawn from Weber et al., 1989)
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From page 202... ...
The nutritional benefits of the "extra food" can be important. For ambient toxicity tests of water samples from two sites in East Fork Poplar Creek (EFPC)
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From page 203... ...
It is through adherence to an expected dose-response relationship that effluent toxicity testing gains predictive value. Therefore, much effort in the development of toxicity tests has gone into the selection of test procedures that generate smooth dose-response curves.
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From page 204... ...
We also measured the pH, conductivity, alkalinity, hardness, and total residual chlorine of all freshly collected water samples. Ambient toxicity tests were run on water from as many as 10 sites per stream, but in some cases one site was sufficient for effective monitoring.
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From page 205... ...
When using toxicity test methods to assess ambient water quality, a bioassay should simultaneously meet two key objectives: It should discriminate readily among sites, and it should exhibit little variation from test period to test period, when applied to noncontaminated control water or to water from a noncontaminated reference site. An ANOVA-based analysis of results of 285 site and test-period combinations was used to determine which test organism -- Ceriodaphnia or fathead minnow larvae -- best fulfilled these objectives (Boston et al., 1994)
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From page 206... ...
The procedure is simple and practical in concept and its computation is similar to Fisher's Exact Test, which EPA recommends for assessing Ceriodaphnia survival in effluent toxicity tests. The main drawback of contingency-based methods is that generating strong conclusions requires data from a large number of ambient tests at one or more reference sites.
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From page 207... ...
A contingency-table analysis method also could be used to establish a lower pass-or-fail criterion for Ceriodaphnia reproduction or fathead minnow survival or growth. Using data for reference sites in the three streams near Oak Ridge National Laboratory, we found that Ceriodaphnia mean reproduction values were less than or equal to 10 offspring per surviving female in only 6 of 121 tests (Table 2)
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From page 208... ...
One simple method for using concordance ranks sites according to responses for each species separately, then tabulates the number of cases in which each site is best or worst for each species, for either species, or for both species together. Table 3 shows an example of this approach, using Ceriodaphnia and fathead minnow toxicity test results for eight test periods and six sites in East Fork Poplar Creek.
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From page 209... ...
Chemical water-quality parameters measured for each site-date TABLE 3 Results of Ambient Toxicity Tests of Water from Six Sites on East Fork Poplar Creek Site Water Quality 22.8 21.9 20.5 18.2 13.8 10.9 Best for minnow growth 2 1 3 1 2 1 Best for Ceriodaphnia 1 1 0 1 4 1 Best for both speciesa 0 1 0 0 2 0 Best for either species 3 2 3 2 6 2 Worst for minnow growth 1 3 2 0 0 2 Worst for Ceriodaphnia 2 1 1 3 0 2 Worst for both speciesa 0 1 0 0 0 1 Worst for either species 3 3 3 3 0 3 aIn all cases Ceriodaphnia dubia and Pimephales promelas were tested con currently. NOTE: Numerals specifying sites refer to distances (km)
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From page 210... ...
Logistic regression analysis was used to relate chemical conditions to Ceriodaphnia mortality patterns in water samples from East Fork Poplar Creek. When using 7-day static-renewal toxicity test methods to assess ambient water quality, the water in the test chambers is replaced daily with freshly collected water.
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From page 211... ...
may change strongly in response to waste-water discharges. These two issues were explored by using Ceriodaphnia tests to evaluate water-quality conditions in upper East Fork Poplar Creek, where TRC was suspected of causing or contributing to fish kills.
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From page 212... ...
Concurrent with the routine ambient toxicity monitoring tests for upper East Fork Poplar Creek, we conducted diagnostic toxicity tests to demonstrate that TRC (or related oxidants) accounted for the observed toxicity.
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From page 213... ...
Comparison with an appropriate suite of reference sites is critical to derive the correct answer for the correct reasons. In ambient toxicity testing, and in biological monitoring generally, one must be constantly alert to the difference between biological importance and statistical significance (Cairns and Smith, 1994; Yoccoz, 1991)
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From page 214... ...
toxicity testing program. Data pruning by date can be used to help identify sites where water quality is suspect, and a representative suite of reference sites should be included in every ambient testing program to help place suspect sites into appropriate perspective.
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From page 215... ...
Pp. 37–108 in Second Report on the Oak Ridge Y-12 Plant Biological Monitoring and Abatement Program for East Fork Poplar Creek, R
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From page 216... ...
1990. Ambient toxicity dynamics: Assessments using Ceriodaphnia dubia and fathead minnow (Pimephales promelas)
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