New methodology for extraction of total metals from macroalgae and its application to selected samples collected in pristine zones from Baja California, Mexico

摘要

One of the main problems to adequately evaluate natural and anthropogenic contributions of trace metals to the oceans, is the inherent variability in their concentrations caused by the continuous change in the conditions of the marine environment, and by the dynamics of currents and upwelling processes. Mollusk bivalves, together with other filter-feeding organisms can be used as bioindicators of contamination, but they incorporate metals associated to the microscopic organisms that constitute their food, as well as from the ingestion of inorganic particulates (e.g., Struck et al. 1997, Paez-Osuna et al. 2000). An alternative that recently has been explored is the possibility of using macroalgae as bioindicators of metal concentrations in seawater(Leal et al., 1997; Haritonidis and Malea, 1999; Muse et al., 1999; Paez-Osuna et al., 2000; Sanchez-Rodrfguez et al., 2001). One of the main advantages of analyzing metals in seaweed tissues is their capacity of accumulate trace metals in concentrations that, generally, are several orders of magnitude higher than their respective concentrations in seawater (e.g., Sanchez-Rodriguez et al. 2001). However, and contrary to filter-feeding organisms, metal concentrations in algal tissue are proportional only to the concentrations of dissolved metals in the water surrounding the macroalgae (Luoma et al. 1982).