Standard Guide for Conducting Laboratory Toxicity Tests with Freshwater Mussels

Importancia y uso:

5.1 Protection of a species requires prevention of unacceptable effects on the number, weight, health, and uses of the individuals of that species. Toxicity tests can be used provide information about the toxicity of a test material to a specific life stage of a particular species of mussel. The primary adverse effects studied are reduced survival or growth.

5.2 Results of toxicity tests might be used to predict effects likely to occur on mussels in field situations as a result of an exposure under comparable conditions.

5.3 Results of toxicity tests might be used to compare the sensitivities of different mussel species and the toxicity of different test materials, and to study the effects of various environmental factors on results of such tests.

5.4 Results of toxicity tests conducted with mussels might be an important consideration when assessing the risks of test materials to aquatic organisms or when deriving environmental guideline values for toxicants.

5.5 An acute toxicity test is conducted to obtain information concerning the immediate effects on mussels of a short exposure to a test material under specific experimental conditions. An acute toxicity test does not provide information about whether delayed effects will occur, although a post-exposure observation period, with appropriate feeding, if necessary, might provide such information (Guide E729).

5.6 Results of chronic (at least 28 d) toxicity tests with mussels might be used to predict chronic or partial chronic effects on species in field situations as a result of exposure under comparable conditions.

5.7 Short-term chronic toxicity tests are conducted for 7 d, a complementary test duration in the USEPA shot-term methods for estimating the chronic toxicity of effluents and receiving waters to fathead minnow (Pimephales promelas; USEPA 2002) (31) and provides a more direct estimate of the safe concentrations of effluents and receiving waters than acute toxicity tests, at a slightly lower level of effort compared to chronic 28 d toxicity test.

5.8 Results of toxicity tests might be useful for studying the biological availability of, and structure-activity relationships between, test materials.

5.9 Results of toxicity tests will depend on temperature, composition of the dilution water, condition of the test organisms, and other factors.

5.10 Interferences—A number of factors can impede or prevent selection and use of freshwater mussels for toxicity testing (Guide E1850). The following should be considered when selecting a test species and measuring the sensitivity of the test species during toxicity tests.

5.10.1 Handling of field-collected adult mussels resulting from collection or transport to the laboratory might cause excessive mortality or sublethal effects.

5.10.2 The age, health, and physical condition of adult mussels (for example, the presence of parasites, bacteria, and disease) collected from a resident population might not be adequately known.

5.10.3 The physical characteristics of the testing environment (such as water quality, temperature, water flow, light) and food requirements might affect the ability of the test organisms to acclimate, recover from handling, or adapt to the laboratory environment conditions.

5.10.4 The degree of contamination and the history of contamination at the collection of the adult mussels might not be adequately known.

5.10.5 In the field, mussels may be exposed to contaminants in water, sediment, or food. This standard only addresses effects associated with exposure of mussels to contaminants in water. Methods for conducting sediment toxicity tests with juvenile mussels are included in Guide E1706.

5.10.6 There are insufficient data available to determine if juvenile mussels are able to avoid exposure to chemicals by valve closure. If it is suspected that juvenile mussels are avoiding exposure to a chemical in a toxicity test, it may be desirable to place the suspected live test organisms into dilution water that does not contain any added test material for 1 d to 2 d after the end of the toxicity test to determine whether these test organisms are alive or dead (section A1.4.7; Guide E729).

Subcomité:

E50.47

Referida por:

E0729-23E01, E2122-22, E1022-22, E1706-25

Volúmen:

11.09

Número ICS:

67.120.30 (Fish and fishery products)

Palabras clave:

acute toxicity test; bivalve; chronic toxicity test; freshwater; glochidia; juvenile mussels; Margaritiferidae; Margaritiferid mussels; mollusc; mollusk; mussels; short-term chronic toxicity test; Unionidae; Unionid mussels; Unionoidea;