Bioaccumulation and biochemical patterns of Ruditapes philippinarum clams: Responses to seasonality and low contamination levels. (30th September 2020)

• Record Type: Journal Article
• Authors: Costa, Silvana; Lopes, Joel; Coppola, Francesca; Correia, Simão; Henriques, Bruno; Leite, Carla; Soares, Amadeu M.V.M.; Zengjie, Jiang; Pereira, Eduarda; Chiesa, Stefania; Freitas, Rosa
• Is Part Of: Estuarine, coastal and shelf science. Volume 243(2020)
• Publication Date: 2020-09-30
• Subjects: Clams -- Metal contamination -- Safety consumption -- Seasons -- Biochemical performance; Estuarine oceanography -- Periodicals; Coasts -- Periodicals; Estuarine biology -- Periodicals; Seashore biology -- Periodicals; Coasts; Estuarine biology; Estuarine oceanography; Seashore biology; Periodicals; 551.461805
• DOI: 10.1016/j.ecss.2020.106883
• Languages: English
• ISSNs: 0272-7714

Abstract

Abstract: Shellfish farming and shellfish harvesting have been practiced for a long time in the Ria de Aveiro coastal lagoon (Portugal). Among commercial bivalves, Manila clam Ruditapes philippinarum represents one of the most important species inhabiting this coastal system. Introduced in Portugal in 1984, naturalised R. philippinarum clam populations have been subjected to several pressures that may threaten this resource sustainable management: illegal fishing, harvesting in chemically polluted sites with impacts on human health and lack of control in terms of productivity with the risk of a progressive decline of the biomass. On behalf of the ASARISAFE project (with the title Safety and sustainable management of valuable clam product in Portugal and China) the environmental quality of Manila clam harvesting sites was evaluated, focusing on inorganic pollution and health status of clams in terms of bioaccumulation as well as biochemical performance. Seasonal sampling campaigns were conducted in six R. philippinarum harvesting areas evaluating inorganic pollution levels, in clam's tissues, sediment and water. Clams biochemical performance in terms of metabolism, energy reserves and oxidative stress was also assessed. The results obtained showed that mercury (Hg) and arsenic (As) were the elements with the highest BAF (Bioaccumulation factor) values, but contamination levels in tissues and sediments varied among sampling areas and seasonal campaigns. The amount of clams consumed per week to exceed Provisional Tolerable Week Intake (PTWI, kg) was the lowest for As, revealing that less 0.05 kg of clams was enough to exceed PTWI. However, the results obtained further demonstrated that the clam's biochemical performance was not responding to tissues contamination levels but were closely related to seasons, with distinct metabolic capacity and oxidative stress levels among distinct sampling periods during the year. Highlights: Seasonal changes overlaps pollution levels effects on clam's biochemical machinery. Cu, Cr and As are the elements with higher concentrations in sediments, water and tissues, respectively. As is the element of most concern in terms of human health, with values as lower as 0.05 kg to exceed PTWI. Higher LPO levels and GSH/GSSG ratio during Summer and Spring. Membranes' integrity prevention during Winter and Autumn due to antioxidant defences.