Polycyclic aromatic hydrocarbons in clams Ruditapes decussatus (Linnaeus, 1758)

Abstract

The concentration of sixteen individual polycyclic aromatic hydrocarbons (PAHs) was measured in the clam Ruditapes decussatus whole soft tissues from several places of the Ria Formosa lagoon (Portugal). Total PAH (tPAH) concentrations were higher in the summer (August) and winter (January) than in the other months and the distribution pattern of the individual PAHs was generally dominated by the 4 aromatic ring PAHs, followed by the 2 + 3 aromatic rings PAHs. Benzo[a]anthracene and acenaphthene were the most representative PAHs of the two fractions. Principal components analysis (PCA) revealed that, in the Ria Formosa, seasonal variations are more important than spatial variations, due to changes in PAH source. These sources ranged from petrogenic to pyrolytic or a mixture of both. The origin of clam PAHs was also assessed by partial least squares (PLS) analysis using nineteen different PAH signatures, taken from the literature. It was possible to identify boat traffic, especially in the summer, as one of the most relevant PAH sources to the Ria Formosa. The influence of boat traffic was revealed by several signatures including diesel soot, oil and weathered oil and a mixture of different individual PAHs usually found in harbour sediments. Other relevant sources included combustion of organic matter such as forest fires and diverse domestic activities, occurring mainly in the summer. Most of the clams were considered safe for human consumption, except for some point samples, which presented unusually high PAH concentrations, suggesting the need for a regular survey of PAHs in clam tissues.

A multibiomarker approach in the clam Ruditapes decussatus to assess the impact of pollution in the Ria Formosa lagoon, South Coast of Portugal

“…It is known that TBT is highly persistent in the environment; however, values are lower than in previous studies in shellfish beds from the same region (Coelho et al, 2002). In what concerns PAHs, the maximum concentration was also in site 3 with levels similar to others from the same ecosystem (Barreira et al 2007a;Bebianno and Barreira, 2009).…”

“…It is extensively produced and harvested in the Ria Formosa lagoon where clam farming represents an important economical sector (Bebianno et al, 2004;Bebianno and Serafim, 2003). However, in the last decade clam production decreased as a result of the lagoon's water quality deterioration (Barreira et al, 2007a;Bebianno, 1995;Bebianno and Serafim, 2003;Bebianno et al, 2004;Coelho et al, 2002).…”

Interspecific variability of endocrine disruption and oxidative stress in two bivalve species from the Ria Formosa Lagoon (south coast of Portugal)

“…manly TBT) and polychlorinated byphenyls (PCBs) have been detected in M. galloprovincialis and R. decussatus as well as in water and sediments collected in the Lagoon (Table 1). The results of endocrine disruption and oxidative stress in this study reflect the results obtained in other studies on the presence of different contaminants in Ria Formosa waters, as well as the complex interactions between them (Coelho et al 2002, Bebianno and Serafim 2003, Barreira et al 2005, Díez et al 2005, Barreira et al 2007, Cravo et al 2009). The two determined biomarkers are not specific to a particular group of contaminants but could represent an integrated response to the impact of multiple toxic and/or environmental factors (Lafontaine et al 2000).…”

“…In environmental studies, bivalve molluscs such as mussels and clams have been widely used as bioindicators in biomonitoring and quality assessment programs. These ubiquitous and sessile organisms accumulate contaminants to a great extent and respond significantly to pollutant exposure , Barreira et al 2007. Mussels are sedentary filter-feeders that feed from the surrounding water (Bocchetti et al 2008) whereas clams are endobenthic suspension feeders that have the potential to accumulate bioavailable contaminants from both water and sediments .…”

Alkylphenols and polycyclic aromatic hydrocarbons in eastern Mediterranean Spanish coastal marine bivalves

“…The use of bivalve molluscs as sentinel organisms (biomonitors) of marine pollution is due to their ability to accumulate contaminants, their limited capacity for metabolizing them and their resistance to a wide range of pollutant levels (Francioni et al, 2007;Nesto et al, 2007). These organisms are able to bioaccumulate transient pollution present in the water column that sometimes is not recorded in the sediments (Baumard et al, 1999), being in these cases better pollution indicators (Barreira et al, 2007). Moreover, analysing the pollution content in bivalve tissues, where the contaminants are accumulated to noticeably higher concentrations than those in the water, provides information on the fraction of environmental water pollution bioavailable to aquatic organisms (Solé et al, 2000;Baumard et al, 1999).…”