Cephalopod beak sections used to trace mercury levels throughout the life of cephalopods: the Giant Warty squid Moroteuthopsis longimana as a case study

• Published in: Marine Environmental Research
• Main Authors: Queirós, José, Bustamante, Paco, Cherel, Yves, Coelho, Joao, Seco, José, Roberts, Jim, Pereira, Eduarda, Xavier, José
• Other Authors: Marine and Environmental Sciences Centre (MARE UC), Universidade de Coimbra Coimbra, LIttoral ENvironnement et Sociétés - UMR 7266 (LIENSs), Institut national des sciences de l'Univers (INSU - CNRS)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centro de Estudos do Ambiente e do Mar, Departamento de Biologia, Universidade de Aveiro, Centro de Estudos do Ambiante e do Mar (CESAM), Scottish Oceans Institute, University of St Andrews Scotland, National Institute of Water and Atmospheric Research Wellington (NIWA), British Antarctic Survey (BAS), Natural Environment Research Council (NERC)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: Southern Ocean; Ontogenetic shifts; Mercury; Trace elements; Bioaccumulation; [SDV.TOX.ECO]Life Sciences [q-bio]/Toxicology/Ecotoxicology; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDV.BA.ZI]Life Sciences [q-bio]/Animal biology/Invertebrate Zoology
• Online Access: https://hal.science/hal-02904190; https://hal.science/hal-02904190/document; https://hal.science/hal-02904190/file/Queiros%20et%20al%202020%20MER.pdf; https://doi.org/10.1016/j.marenvres.2020.105049

International audience Cephalopods represent an important pathway for mercury transfer through food-webs. Due to the general difficulties in capturing oceanic squid, beaks found in the diet of top predators can be used to study their life-cycles and ecological role. Using upper beaks of the giant warty squid Moroteuthopsis longimana (major prey in the Southern Ocean), we describe a method to assess mercury concentrations along the life of cephalopods through the segmentary analysis of beak sections (i.e. rostrum’s tip and subsections along the hood). Distinct total mercury concentrations in the different subsections support that beaks can be used to study mercury levels in different periods of cephalopods’ life-cycle. Mercury values in the anterior (1.3 to 7.9 μg kg-1 dw) and posterior (7.8 to 12.5 μg kg-1 dw) subsections reflect juvenile and adult stages, respectively. Furthermore, these results confirm that mercury bioaccumulates continuously throughout the individuals’ life, with adults doubling their mercury concentrations to juveniles.