MEPS prepress abstract  -  DOI: https://doi.org/10.3354/meps12452

Overview of trace elements trophic transfer in fish through the concept of assimilation efficiency

Simon Pouil*, Paco Bustamante, Michel Warnau, Marc Metian

*Email: simon.pouil1@gmail.com

ABSTRACT: Fish mainly bioaccumulate trace elements from the water (across the gills) and through the diet (along the gastrointestinal tract). It is, nevertheless, acknowledged that the diet is generally the major contributor to trace element uptake in fish. The laboratory-based approach is currently the most appropriate way to precisely quantify the trophic transfer of trace elements in fish. Thus, the assimilation efficiency (AE) of trace elements from ingested food is a commonly-determined parameter. However, there are still some discrepancies in the literature regarding the definition and the determination of AE in aquatic organisms and especially in fish. In this context, this review gathers first the information to provide a consolidated definition of this concept as well as a description of the methods and protocols used to quantify the AE of trace elements. It also looks over the main results concerning trace element AE in fish from the available literature. Most studies reporting AE considered the effects of biotic factors, especially the influence of the quality of food. Abiotic factors have received less attention although they affect fish physiology and, by extension. potentially affect AE of trace elements. The need for further investigations is thus rising from the review, especially looking at the influence of abiotic factors such as temperature, salinity or pH on trace element AE or in the context of multiple stressors co-occurrence; this will help better understanding trophic transfer of trace elements in fish and thus their overall bioaccumulation in fish.