Biomarkers inRuditapes decussatus: a potential bioindicator species

Abstract

The clam Ruditapes decussatus is distributed worldwide and due to its ecological and economical interest has been proposed as a bioindicator in areas where mussels are not available. The accumulation of several anthropogenic compounds in their tissues suggests that they possess mechanisms that allow them to cope with the toxic effects of these contaminants. Besides pollutant uptake, the use of biomarkers is pointed out in this paper since it is a promising approach to monitor the effect of these contaminants in the marine environment. Biomarkers complement the information of the direct chemical characterization of different types of contaminants. Therefore, the aim of this paper is to review the role of several biomarkers: (metallothioneins (MT), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidases (GPx) (total and selenium-dependent), lipid peroxidation (measured as MDA, one of the final products of lipid peroxidation), glutathione S-transferase (GST) and acetylcholinesterase (AChE), measured in different tissues of the clam R. decussatus, in laboratory conditions and under various environmental stresses, in two ecosystems (Ria Formosa lagoon- Portugal) and Bizerta lagoon (Tunisia) in a perspective of a multibiomarker approach to assess environmental changes. Experiment and field studies are in good agreement since MT levels, especially in the gills, the first target tissue of these contaminants, can be used as biomarker of exposure to Cd. GPx and MDA may also be determined in this respect. AChE activity is inhibited by pesticide and, to a less extent, by metal exposure in the gills and whole soft body of clams. However, the induction of GST isoforms experimentally demonstrated is not observed in the field because only global GST activity was determined. The whole set of results opens new research perspectives for the use of this species to assess the effect of mixtures of pollutants in the aquatic environment.

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

“…The clam Ruditapes decussatus has a widespread distribution in European and Mediterranean coastal waters and a great ecological and econom--ical importance. 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).…”

“…Field studies that include a multibiomarker approach allow measurements of the impact of several environ--mental stressors. This approach has been very successful with invertebrates and nowadays it is a recommended tool for envi--ronmental monitoring programs (Bebianno et al, 2004;Cravo et al, 2009;Maria et al, 2009;Porte et al, 2001;Viarengo et al, 2007). Therefore, the aim of this study was to apply a suite of biomarkers in an attempt to understand the time and space contamination trend within this ecosystem and its potential adverse effect on clams.…”

“…Exposure to organophosphorus compounds, substances widely used as pesti--cides in agriculture, was diagnosed through the inhibition of acetylcholinesterase (AChE) activity in the gills (Bebianno et al, 2004;Cajaraville et al, 2000). Additionally, a nonspecific response associated with disruption in the lipid component of cellular membranes that reflects exposure and toxicity to pollut--ants was assessed through lipid peroxidation (LPO) determined in the gills (Cajaraville et al, 2000;Viarengo et al, 2007).…”

“…The use of a battery of different biomarkers enables the assess--ment of a variety of responses but it does not completely replace the chemical approach (Bebianno et al, 2004;Cravo et al, 2009). There--fore, in this study selected contaminants were also analyzed in clams tissues: metals (cadmium, copper, nickel, lead, zinc), Tributyltin (TBT) and PAHs (mostly associated with boat traffic).…”

Establishment of functional primary cultures of heart cells from the clam Ruditapes decussatus

“…It has been demonstrated for example that clam, an economically important bivalve in many countries, such as in France, Tunisia and Portugal could be submitted to various pollutants of anthropogenic origin (Bebianno et al 2004). Therefore, it was interesting to attempt to establish cell cultures from this species.…”