Shellfish harvesting in intertidal areas is a widespread and economically important activity in many countries across West Africa. However, in some areas, there is virtually no information concerning the levels of contaminants (and other elements related to nutritional aspects) in the harvested species. We collected sediments and several individuals of the West African bloody cockle Senilia senilis and of the razor clam Tagelus adansoni during the dry season of 2015 nearby three islands in the Bijagós archipelago, Guinea-Bissau. Aluminium, Ca, Fe, Mg, As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn were determined in sediments and whole soft tissues of the two bivalves. Sediments showed uniformly low trace element concentrations, pointing to an ecosystem with low levels of trace element contamination. T. adansoni presented higher concentrations of most elements than S. senilis, with the exception of Cd that showed up to 40 times higher values in S. senilis than in T. adansoni from the same sites. Furthermore, Cd concentrations (25±8.7 mg kg−1, dw) in S. senilis are clearly above the maximum level established for human consumption. Future studies should clarify whether biological factors are the major responsible for this unusual situation.
Trace elements Bivalves Sediments West Africa
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This research was partially supported by the Strategic Funding UID/AMB/50017 (CESAM), UID/CTM/50011/2013 (CICECO), UID/Multi/04423/2013 (CIIMAR) and UID/MAR/04292/2013 (MARE) through national funds provided by FCT–Foundation for Science and Technology and European Regional Development Fund (ERDF), in the framework of the program PT2020. Further funds were provided by the MAVA Foundation through a project granted to IBAP (Guinea-Bissau) - 11-070 Evaluation et conservation de la biodiversité dans le Parc National Marin de Joao Vieira e Poilao. We thank IBAP sailors for important help during fieldwork. Thanks are also due to Alfredo da Silva, Aissa Regalla, Castro Barbosa and Justino Biai for granting permissions for work in the protected areas and for all facilities and logistical support. Rui Monteiro (SFRH/BD/108535/2015), Pedro Coelho (BPD/102870/2014), Pedro M. Lourenço (SFRH/BPD/84237/2012) and Inês Catry (SFRH/BPD/102637/ 2014) were supported by national funds through doctoral and post-doctoral grants from FCT.
Ardovini R, Cossignani T (2004) West African seashells (including Azores, Madeira and Canary Is. Conchiglie dell’Africa Occidentalle. L’Informatore Piceno: AnconaGoogle Scholar
Auger PA, Machu E, Gorgues T et al (2015) Comparative study of potential transfer of natural and anthropogenic cadmium to plankton communities in the North-West African upwelling. Sci Total Environ 505:870–888. doi:10.1016/j.scitotenv.2014.10.045CrossRefGoogle Scholar
Boyden CR, Phillips DJH (1981) Seasonal variation and inherent variability of trace elements in oysters and their implications for indicator studies. Mar Ecol Prog Ser 5:29–40. doi:10.3354/meps005029CrossRefGoogle Scholar
Broom MJ (1985) The biology and culture of marine bivalve molluscs of the genus Anadara. International Center for Living Aquatic Resources Management, ManilaGoogle Scholar
Long ER, Macdonald DD, Smith SL, Calder FD (1995) Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuarine sediments. Environ Manag 19:81–97. doi:10.1007/BF02472006CrossRefGoogle Scholar
Otchere FA (2003) Heavy metals concentrations and burden in the bivalves (Anadara (Senilia) senilis, Crassostrea tulipa and Perna perna) from lagoons in Ghana: model to describe mechanism of accumulation/excretion. African J Biotechnol 2:280–287CrossRefGoogle Scholar
Phillips DJH (1976) Common mussel Mytilus edulis as an indicator of pollution by zinc, cadmium, lead and copper. 1. Effects of environmental variables on uptake of metals. Mar Biol 38:59–69. doi:10.1017/S0025315404009312hCrossRefGoogle Scholar
Reinfelder JR, Wang WX, Luoma SN, Fisher NS (1997) Assimilation efficiencies and turnover rates of trace elements in marine bivalves: a comparison of oysters, clams and mussels. Mar Biol 129:443–452. doi:10.1007/s002270050185CrossRefGoogle Scholar
Rudnick RL, Gao S (2003) Composition of the continental crust. In: Treatise in geochemistry volume 3. Pergamon, Oxford, pp 1–64Google Scholar
Vale C, Sundby B (1998) The interactions between living organisms and metals in intertidal and subtidal sediments. In: Langston WJ, Bebianno MJ (eds) Metal metabolism in aquatic environments. Springer US, Boston, MA, pp 19–29CrossRefGoogle Scholar
Williams P (1985) Pactical estuarine chemistry—a handbook. Cambridge University PressGoogle Scholar
Windom HL, Schropp SJ, Calder FD et al (1989) Natural trace metal concentrations in estuarine and coastal marine sediments of the southeastern United States. Environ Sci Technol 23:314–320. doi:10.1021/es00180a008CrossRefGoogle Scholar
Wolff WJ, Gueye A, Meijboom A et al (1987) Distribution, biomass, recruitment and productivity of Anadaria Senilis (L.) (Mollusca: Bivalvia) on the Banc D’Arguin, Mauritania. Netherlands J Sea Res 21:243–253CrossRefGoogle Scholar