Effects of metal accumulation in the marine biota are of great concern due to their possible effects on ecosystem function and productivity. Species of high trophic levels provide integrated information about bioaccumulation trends within their distribution range. Nevertheless, two factors constrain their current use as bioindicators of metal contamination: i) the difficulty of getting samples without sacrificing the organism, and ii) the lack of knowledge about how factors derived from fish behavior (e.g. feeding or usual distribution in the water column) may contribute to bioaccumulation. Here, we assessed the use of blood samples as a biomonitoring tool of metal contamination in two top predator fish species (Epinephelus costae and Epinephelus marginatus). For this aim, we studied the relationship among metals concentrations of Fe, Cu, Hg, Pb, Zn, Se, Cd and As, as well as their levels among species and by size through analyzing blood samples following ICP-MS technique. Detectable concentrations of Cd were not found for any of the species. Significant Zn/As, As/Se and Pb/As correlations were found for E. costae, while for E. marginatus only Cu/Pb and Zn/Se were related. A strong positive relationship between mercury concentration and size was found in both species, while zinc and cooper levels were positive related to size only in E. marginatus. Selenium differed significantly between species, with higher concentrations in E. costae. Mercury concentrations found require further research in edible tissues (e.g. muscle) since there is no regulation establishing thresholds for mercury concentrations in blood. According to our results, the use of blood as a monitoring tool for metal contamination could be posed as an alternative to other techniques which need the sacrifice of the individuals, especially for those species that are in a critical state of conservation at local or/and global scale

VI Congreso Ibérico de Ictiología - VI Iberian Congress of Ichthyology (SIBIC2016), celebrado del 21 al 24 de junio de 2016 en Murcia.-- 1 page

Peer Reviewed