Significance and Use
5.1 Protection of a species requires the prevention of detrimental effects of chemicals on the survival, growth, reproduction, health, and uses of individuals of that species. Behavioral toxicity tests provide information concerning the sublethal effects of chemicals and signal the presence of toxic test substances.
5.1.1 The locomotory, feeding, and social responses of fish are adaptive and essential to survival. Major changes in these responses may result in a diminished ability to survive, grow, avoid predation, or reproduce and cause significant changes in the natural population (8). Fish behavioral responses are known to be highly sensitive to environmental variables as well as toxic substances.
5.2 Results from behavioral toxicity tests may be useful for measuring injury resulting from the release of hazardous materials (9).
5.3 Behavioral responses can also be qualitatively assessed in a systematic manner during toxicity tests to discern trends in sublethal contaminant effects (5).
5.4 The assessment of locomotory, feeding, and social behaviors is useful for monitoring effluents and sediments from contaminated field sites as well as for defining no-effect concentrations in the laboratory or under controlled field conditions. Such behavioral modifications provide an index of sublethal toxicity and also indicate the potential for subsequent mortality.
5.5 Behavioral toxicity data can be used to predict the effects of exposure likely to occur in the natural environment (10).
5.6 Results from behavioral toxicity tests might be an important consideration when assessing the hazard of materials to aquatic organisms. Such results might also be used when deriving water quality criteria for fish and aquatic invertebrate organisms.
5.7 Results from behavioral toxicity tests can be used to compare the sensitivities of different species, the relative toxicity of different chemical substances on the same organism, or the effect of various environmental variables on the toxicity of a chemical substance.
5.8 Results of behavioral toxicity tests can be useful in guiding decisions regarding the extent of remedial action needed for contaminated aquatic and terrestrial sites.
5.9 The behavioral characteristics of a particular organism need to be understood and defined before a response can be used as a measure of toxicity (11). Swimming, feeding, and social behavior varies among species as well as among life stages within a species; the most effective test methods are therefore those tailored to a particular life stage of a single species. The range of variability of any behavioral response of unexposed organisms is influenced by genetic, experiential, physiological, and environmental factors. It is thus important to avoid selecting test organisms from populations that may vary in these factors.
5.10 Results of behavioral toxicity tests will depend on the behavioral response measured, testing conditions, water quality, species, genetic strain, life stage, health, and condition of test organisms. The behavioral response may therefore be affected by the test environment.
5.11 No numerical value or range of values has been defined as the norm for swimming, feeding, or social behavior for any fish; the detection of abnormal activity is therefore based on comparisons of the responses of exposed fish, either with activity measured during a baseline or pre-exposure period or observations of fish under a control treatment (10).
5.12 These measures are incorporated readily into standard toxicity test protocols, with minimal stress to the test organism.
Scope
1.1 This guide covers some general information on methods for qualitative and quantitative assessment of the behavioral responses of fish during standard laboratory toxicity tests to measure the sublethal effects of exposure to chemical substances. This guide is meant to be an adjunct to toxicity tests and should not interfere with those test procedures.
1.2 Behavioral toxicosis occurs when chemical or other stressful conditions, such as changes in water quality or temperature, induce a behavioral change that exceeds the normal range of variability (1). Behavior includes all of the observable, recordable, or measurable activities of a living organism and reflects genetic, neurobiological, physiological, and environmental determinants (2).
1.3 Behavioral methods can be used in biomonitoring, in the determination of no-observed-effect and lowest-observed-effect concentrations, and in the prediction of hazardous chemical impacts on natural populations (3).
1.4 The behavioral methods described in this guide include locomotory activity, feeding, and social responses, which are critical to the survival of fish (4).
1.5 This guide is arranged as follows:
Section Number
Scope
1
Referenced Documents
2
Terminology
3
Summary of Guide
4
Significance and Use
5
Interferences
6
Safety Precautions
7
Responses Measured
8
Test Organisms
9
Facility
10
Qualitative Behavioral Assessment Method
11
Quantitative Behavioral Measurements
12
Experimental Design
13
Calculation of Test Results
14
Report
15
1.6 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. For an explanation of units and symbols, refer to IEEE/ASTM SI 10.
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. While some safety considerations are included in this guide, it is beyond the scope of this guide to encompass all safety requirements necessary to conduct behavioral toxicity tests. Specific hazards statements are given in Section 7.
1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.