Testing in Aquatic Ecotoxicology: What Are the Scientific Conditions for the ‘3R’ Concept?

In this chapter, we will evaluate how and if a 3R based approach can be applied in testing of ecotoxicity of chemicals. The 3R approach (reduce-refine-replace) is a strategy to reduce or totally abolish the use of experimental animals in favour of alternative methods. We review the current status of alternatives in aquatic ecotoxicology and how well they perform in comparison with current in vivo methods. We will conclude that theoretically can alternative methods and approaches replace animal based testing but the way to reach this goal is long. A strong development of more sophisticated alternative methods is needed focusing on specific and physiologically/toxicologically relevant ­endpoints. We underline the importance to gain more information on toxic mechanisms of chemicals. New exciting biochemical techniques are waiting around the corner, e.g. in the genomics area and they need to be integrated in future test paradigms.