Maulvault Ana Luísa, Custódio Ana, Anacleto Patrícia, Repolho Tiago, Pousão Pedro, Nunes Maria Leonor, Diniz Mário, Rosa Rui, Marques António
Division of Aquaculture and Seafood Upgrading, Portuguese Institute for the Sea and Atmosphere, I.P. (IPMA), Avenida de Brasília, 1449-006 Lisboa, Portugal; Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto, Portugal; MARE - Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo, 939, 2750-374 Cascais, Portugal.
Division of Aquaculture and Seafood Upgrading, Portuguese Institute for the Sea and Atmosphere, I.P. (IPMA), Avenida de Brasília, 1449-006 Lisboa, Portugal; Instituto Superior de Agronomia (ISA), School of Agriculture, University of Lisbon, Tapada da Ajuda, 1349-017 Lisboa, Portugal.
Environ Res. 2016 Aug;149:77-85. doi: 10.1016/j.envres.2016.04.035. Epub 2016 May 13.
Warming is an expected impact of climate change that will affect coastal areas in the future. These areas are also subjected to strong anthropogenic pressures leading to chemical contamination. Yet, the consequences of both factors for marine ecosystems, biota and consumers are still unknown. The present work aims to investigate, for the first time, the effect of temperature increase on bioaccumulation and elimination of mercury [(total mercury (THg) and methylmercury (MeHg)] in three tissues (muscle, liver, and brain) of a commercially important seafood species - European seabass (Dicentrarchus labrax). Fish were exposed to the ambient temperature currently used in seabass rearing (18°C) and to the expected ocean warming (+4°C, i.e. 22°C), as well as dietary MeHg during 28 days, followed by a depuration period of 28 days fed with a control diet. In both temperature exposures, higher MeHg contents were observed in the brain, followed by the muscle and liver. Liver registered the highest elimination percentages (EF; up to 64% in the liver, 20% in the brain, and 3% in the muscle). Overall, the results clearly indicate that a warming environment promotes MeHg bioaccumulation in all tissues (e.g. highest levels in brain: 8.1mgkg(-1) ww at 22°C against 6.2mgkg(-1) ww at 18°C after 28 days of MeHg exposure) and hampers MeHg elimination (e.g. liver EF decreases after 28 days of depuration: from 64.2% at 18°C to 50.3% at 22°C). These findings suggest that seafood safety may be compromised in a warming context, particularly for seafood species with contaminant concentrations close to the current regulatory levels. Hence, results point out the need to strengthen research in this area and to revise and/or adapt the current recommendations regarding human exposure to chemical contaminants through seafood consumption, in order to integrate the expected effects of climate change.
气候变暖是气候变化的一个预期影响，未来将影响沿海地区。这些地区还受到强大的人为压力，导致化学污染。然而，这两个因素对海洋生态系统、生物群和消费者的影响仍然未知。目前的工作旨在首次研究温度升高对一种具有商业重要性的海鲜品种——欧洲海鲈（Dicentrarchus labrax）的三种组织（肌肉、肝脏和大脑）中汞（总汞（THg）和甲基汞（MeHg））生物累积和消除的影响。将鱼暴露于目前用于海鲈养殖的环境温度（18°C）和预期的海洋变暖温度（+4°C，即22°C）下，并在28天内投喂含甲基汞的饲料，随后在28天的净化期内投喂对照饲料。在两种温度暴露条件下，大脑中的甲基汞含量最高，其次是肌肉和肝脏。肝脏的消除百分比最高（消除率；肝脏高达64%，大脑为20%，肌肉为3%）。总体而言，结果清楚地表明，变暖环境会促进甲基汞在所有组织中的生物累积（例如，在甲基汞暴露28天后，大脑中的最高水平：22°C时为8.1mgkg(-1)湿重，而18°C时为6.2mgkg(-1)湿重），并阻碍甲基汞的消除（例如，净化28天后肝脏的消除率下降：从18°C时的64.2%降至22°C时的50.3%）。这些发现表明，在气候变暖的情况下，海鲜安全可能会受到影响，特别是对于污染物浓度接近当前监管水平的海鲜品种。因此，结果指出需要加强该领域的研究，并修订和/或调整当前关于人类通过食用海鲜接触化学污染物的建议，以便纳入气候变化的预期影响。
