Baseline trace metals in gastropod mollusks from the Beagle Channel, Tierra del Fuego (Patagonia, Argentina)

Abstract

With the aim to evaluate the mollusk Nacella (P)magellanica as biomonitor of elemental pollution in seawater of the Beagle Channel, more than one hundred individuals of the gastropod were sampled, separated in viscera and muscle, and then examined with respect to the accumulation of Cd, Cr, Cu, Ni, Pb and Zn. Collection was performed in seven strategic locations along 170 km of the coastal area of the Beagle Channel (Tierra del Fuego, Argentina) in two campaigns during 2005 and 2007. Samples of surrounding seawater in the different sites were obtained and tested for the same metals as well. The accumulation capacity of Nacella (P)magellanica and thus its aptitude as biomonitor, was evaluated through the calculus of the preconcentration factors of the metals assayed. A discussion involving the comparison with other mollusks previously tested will be given. Several statistical approaches able to analyze data with environmental purposes were applied. Non parametric univariate tests such as Kruskal-Wallis and Mann-Whitney were carried out to assess the changes of the metal concentrations with time (2005 and 2007) in each location. Multivariate methods (linear discriminant analysis on PCA factors) were also applied to obtain a more reliable site classification. Johnson's probabilistic method was carried out for comparison between different geographical areas. The possibility of employing these results as heavy metals' background levels of seawater from the Beagle Channel will be debated.

Performance of two Patagonian molluscs as trace metal biomonitors: The overlap bioaccumulation index (OBI) as an integrative tool for the management of marine ecosystems

“…Our study concerns seven sites in the Beagle Channel, Tierra del Fuego, south Patagonia (Argentina) ( Figure 1). Tierra del Fuego has a unique ecosystem, and it is characterized by a wide range of wildlife and biodiversity (Pino et al 2010 (Pino et al, 2007;Conti et al 2011Conti et al , 2012b. Johnson's method (1949) was applied to heavy metal concentrations to generate frequency curve systems by translation.…”

“…including several factors such as salinity, water temperature, food availability and the reproductive phase of bivalves (Okumus and Stirling, 1998), while the well-known Metal Pollution Index (MPI) is applied to make comparisons of the total metal content in mussels among different sites (Usero et al, 1997 Going beyond classical biomonitoring studies (Conti et al, 2011;2012b) in this work we have built, for the first time, the control charts for the metals bioaccumulation in the selected biomonitors in the Beagle Channel. The first aim is to determine the range of overlaps of metal concentrations and the overlap bioaccumulation index (OBI) with respect to the upper (OBI-L) and lower (OBI-L1)…”

“…Metal concentrations in the selected biomonitors for the 2011-2012 sampling campaigns in seven sites of the Beagle Channel (mean ± sd, µg g -1 d.w.) a Data for N. magellanica in muscle and viscera were standardized by using the method reported inConti et al (2012a). Metal concentrations in the selected biomonitors for the 2005-2007 sampling campaigns in seven sites of the Beagle Channel (mean ± sd, µg g -1 d.w.) a(Conti et al, 2011;2012b) …”

High bioaccumulation of cadmium and other metals in Patagonian edible gastropods

“…On the marine coast of Patagonia Argentina, there have been many studies of metal accumulation in abiotic and biotic components (Gil et al 2006;Conti et al 2011;Giarratano et al 2013). However, metal content in marine gastropods has only been reported for the limpet Nacella magellanica (Gmelin, 1791) in the Beagle Channel, at the southernmost tip of Argentina (Conti et al 2012b).…”

Ecotoxicología y alteraciones morfo-funcionales en gasterópodos marinos expuestos a contaminación por Tributilestaño (TBT) y metales

“…A pesar de su gran abundancia en el ambiente, no todas las formas de un metal pueden ser asimiladas dentro de los organismos, lo cual depende principalmente de la fisiología (Blackmore 2000) y de la función del elemento dentro del organismo (Rainbow 2007 (Conti et al 2012b). La información sobre concentraciones de metales en sedimentos y biota a lo largo de la zona costera patagónica incluye algas, invertebrados y vertebrados (Gil et al 1988;Harvey y Gil 1988;Gil et al 1989;Muse et al 1995;Gil et al 1996;Gil et al 1999;Gaiero et al 2002;Pérez et al 2005;Gil et al 2006;Pérez et al 2007;Vázquez et al 2007;Mohamed 2008 Valores de FBA mayores a 1 indican que el elemento se bioacumula en los gasterópodos, y valores menores a 1 indican que si bien existen niveles del metal en los organismos, la concentración no supera la de la fuente con la cual se lo relacionó, en este caso, los sedimentos o los bivalvos.…”