Application in a biomonitoring context of three-spined stickleback immunomarker reference ranges

The relevance of a biomarker for biomonitoring programs was influenced both by the knowledge on biomarker natural inter-individual and site variabilities and by the sensitivity of the biomarker towards environmental perturbations. To minimize data misinterpretation, robustness reference values for biomarkers were important in biomonitoring programs. Specific three-spined stickleback, Gasterosteus aculeatus, immune reference ranges for field studies had been determined based on laboratory data and one reference station (Contentieuse river at Houdancourt). In this study, data obtained in one uncontaminated and three contaminated sites were compared to these reference ranges as a validation step before considering them for larger scale biomonitoring programs. When the field reference range were compared to data from the uncontaminated station (Béronelle), only few deviations were shown. In this way, data coming from uncontaminated station (Béronelle) was integrated in the field reference ranges to improve the evaluation of site variability. The new field reference ranges provided better discrimination of sites and spanned a larger range of fish lengths than the initial reference ranges. Furthermore, the results suggest lysosomal presence during several months and phagocytosis capacity in autumn may be the most relevant immunomarkers towards identifying contaminated sites. In the future, combining this reference value approach with active biomonitoring could facilitate the obtention of data in multiple stream conditions.