Total and extractable elemental composition of the intertidal estuarine biofilm of the Río de la Plata: Disentangling natural and anthropogenic influences

Historic variation of trace elements in pinnipeds with spatially segregated trophic habits reveals differences in exposure to pollution

“…In human bone, the concentration of Zn varied from 60 to 310 μg g −1 dry weight between and is considered to have a strong physiological regulation (Shafer et al, 2008). Thus, the concentration range found in our study could be considered normal in the dentin of pinnipeds despite the presence of Zn enrichment in Montevideo sediments, where this element can reach concentrations 8 times higher than the earth's crust average (García-Alonso et al, 2017). Aluminum is the third most abundant element in the Earth's crust (Martin, 2006) and the main form of uptake by mammals is through the diet.…”

“…Since 1993, the Cr effluent from tanneries has decreased to only 2% of the historic loads in rivers (Feola et al, 2013;Rafaelle, 2012) after wastewater treatment systems were installed (Lacerda et al, 1998). The concentration found in dentin of pinnipeds is below what is considered the average for environmentally exposed humans (50 ± 22 μg g −1 ) (Nowak and Chmielnicka, 2000), despite the fact that the enrichment factor for Uruguayan coastline sediments could reach values up to 4.6 times when compared to the average concentration in the Earth's crust (García-Alonso et al, 2017).…”

“…In comparison with other species, A. australis and O. byronia showed high Fe concentrations than, e.g., Leptonychotes weddellii in the Antarctic (Table 1, Yamamoto et al, 1987). This could be related to the high bioavailability of this element in the Uruguayan coastline where it can present concentrations between 2 and 12 mg g −1 dry weight (García-Alonso et al, 2017).…”

“…A higher concentration of Cu can be found in lakes, rivers and estuaries than in the ocean (Georgopoulos et al, 2001). Sediments with up to 135 μg g −1 dry weight concentrations of Cu in Montevideo Bay are considered to be highly polluted (Muniz et al, 2004a), and Cu was also found in the intertidal sediments (Castiglioni et al, 2018;García-Alonso et al, 2017). The external area of Rio de la Plata estuary also has levels of Cu that could toxic for the resident biota (Carsen et al, 2003).…”

Floración excepcional de cianobacterias tóxicas en la costa de Uruguay, verano 2019

“…En ella habitan cerca de 150 millones de personas distribuidas en cinco países y se ubican cuatro grandes capitales (Achkar, et al, 2015). La cuenca se caracteriza por drenar zonas con intensa producción agroindustrial asociada a un uso elevado de fertilizantes y plaguicidas (García-Alonso, et al, 2017). Durante los últimos 50 años en esta cuenca se ha registrado un incremento en las lluvias, lo que sumado a las modificaciones en los usos del suelo ha determinado un aumento importante en los caudales de sus tributarios (Barros, et al, 2014).…”