Ecological relevance of a chlorophyll a fluorescence ecotoxicological endpoint

Abstract

With the increasing use of new techniques to assess toxic stress and the effects of pollution, it is important to ensure that any “new” endpoint employed is able to demonstrate a level of eco-relevance. Though recent application of chlorophyll a fluorescence parameters to macroalgal bioassays has been successful, a level of eco-relevance for such use has not been experimentally shown. As such, this article presents a series of experiments designed to establish a link between fluorescence parameters and higher-level effects (supra-individual level). The results show that fluorescence parameters are capable of predicting germination success of macroalgal gametes and can do so much sooner than the actual event of germination. Furthermore, a decline in is shown to be strongly associated with a reduced germination success. Thus, a level of eco-relevance has been established for the fluorescence endpoint that is at least equal to that of the widely accepted germination-based macroalgal bioassays.

Keywords:

• eco-relevance
• chlorophyll a fluorescence
• toxicity bioassay
• macroalgae
• Hormosira banksii

Acknowledgments

This research is supported by a SPIRT grant with support from Australian Research Council and Primary Industries Research, Victoria.