Mercury in surface sediments and benthic organisms from Guaymas Bay, east coast of the Gulf of California

Abstract

In order to know the concentration of mercury in surface sediments, macroalgae and clams from Guaymas Bay, Mexico, 20 surface sediment samples and several individuals of Codium amplivesciculatum (3), Enteromorpha clathrata (4), Gracilaria subsecundata (2), Ulva lactuca (2), Chione subrugosa (80) and Crassostrea gigas (40) were collected and their Hg concentration was measured by a cold vapor Hg analyzer, after acid digestion. In addition, granulometric analysis and quantification of total organic carbon, aluminum, iron and manganese contents in sediments were performed. A Pearsons correlation matrix was determined and, the enrichment factor, the geoaccumulation index and the biota-sediment accumulation factor were calculated. Mercury concentrations in sediments ranged from 0.3 to 2.3 microg g(-1), with the central and northern portions showing the highest values. Macroalgae had a content of Hg that oscillated from 0.058 to 0.134 microg g(-1), while the average concentrations of this metal for clams and oysters were 0.063 and 0.230 microg g(-1), respectively. A clear effect of Guaymas City and the anthropogenic activities carried out around the Guaymas Bay has been observed and the enrichment factor and the geochemical index suggest that sediments from this coastal ecosystem are moderately to strongly contaminated with Hg. However, according to the figure of the maximum human consumption of Hg per week recommended by the World Health Organization, people can ingest clams without risk to their health.

Mercury in Biota and Surficial Sediments from Coatzacoalcos Estuary, Gulf of Mexico: Distribution and Seasonal Variation

“…3). Similar patterns of Hg distribution (higher levels in sediments from the vicinity of metal sources) have been reported in Patos lagoon, Brazil (Mirlean et al 2003) and Guaymas lagoon, Mexico (Green-Ruiz et al 2005). On the other hand, in a previous study in Coatzacoalcos estuary, lowest values of Cd, Cr and Pb were detected in sediments from sites located upstream of Minatitlán (Páez-Osuna et al 1986).…”

The Importance of Analytical Chemistry in Environmental Geochemistry Studies in Mexico

“…In addition, Green-Ruiz at al. [27] found moderate to strong contamination of Hg (measured by cold vapor AAS) via ER and geochemical index values of sediments collected in the same bay.…”

Strong Acid Mixture and Sequential Geochemical Arsenic Extractions in Surface Sediments from the Santa Maria La Reforma Coastal Lagoon, Mexico: A Bioavailability Assessment

“…Several studies have observed significant correlations between metal(oid) contents and fine-grain sediments (silts and clays), which is due to the high specific surface area and the TOC content of the sediments (r silt-TOC = 0.84; r clay-TOC = 0.68). These factors lead to metal(oid)s being trapped in sediments and natural soils (Horowitz and Elrick 1987;Moore et al 1989;Ergin et al 1996;FernandezCaliani et al 1997;Tam and Wong 2000;Zhang et al 2002;Reddy et al 2004;Green-Ruiz et al 2005).…”