Main drivers of mercury levels in Southern Ocean lantern fish Myctophidae

• Published in: Environmental Pollution
• Main Authors: Seco, José, Xavier, José C., Bustamante, Paco, Coelho, João P., Saunders, Ryan A., Ferreira, Nicole, Fielding, Sophie, Pardal, Miguel A., Stowasser, Gabriele, Viana, Thainara, Tarling, Geraint A., Pereira, Eduarda, Brierley, Andrew S.
• Other Authors: University of St Andrews. School of Biology, University of St Andrews. Scottish Oceans Institute, University of St Andrews. Centre for Research into Ecological & Environmental Modelling, University of St Andrews. Pelagic Ecology Research Group, University of St Andrews. Marine Alliance for Science & Technology Scotland
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2021
• Subjects: Trace element; Metal; Bioaccumulation; Mesopelagic fish; Antarctic; QH301 Biology; DAS; SDG 14 - Life Below Water; QH301; Southern Ocean; The Antarctic; Antarc*; British Antarctic Survey
• Online Access: http://hdl.handle.net/10023/23109; https://doi.org/10.1016/j.envpol.2020.114711

Authors acknowledge the Portuguese Foundation for the Science and Technology (FCT) for the PhD grant to JS (SRFH/PD/BD/113487). JPC is funded by CESAM (UID/AMB/50017/2019) and the Integrated Program of SR&TD ‘Smart Valorization of Endogenous Marine Biological Resources Under a Changing Climate’ (Centro-01-0145-FEDER-000018), co-funded by Centro 2020 program, Portugal 2020 and the European Regional Development Fund. The Institut Universitaire de France (IUF) is acknowledged for its support to PB as a Senior Member. We also thank MARE (MARE - UID/MAR/04292/2019) for the support to JX. Ecosystems Programme at the British Antarctic Survey supported GAT, GS, RAS and SF. Myctophids are the most abundant fish group in the Southern Ocean pelagic ecosystem and are an important link in the Antarctic marine food web. Due to their major ecological role, evaluating the level of mercury (Hg) contamination in myctophids is important as a step towards understanding the trophic pathway of this contaminant. The concentrations of total Hg were determined in muscle, gill, heart and liver tissue of 9 myctophid species to quantify tissue partitioning variability between species. Organic Hg concentration and proportion in muscle was also determined. Hg concentrations were higher in the liver and heart than in muscle and gills, but the proportion of organic Hg was almost 100% in muscle, indicating that the main uptake route for Hg is through the diet. Most of the species analysed have similar vertical and horizontal distributions, and similar feeding modes and prey. Geographical and temporal variability of Hg concentrations was examined using samples from 3 different years (2007/08, 2015/16 and 2016/17) and 2 locations (South Georgia and South Orkneys Islands). Our results appear to indicate a decreasing trend in Hg contamination over the last decade, particularly gill tissue, which is in agreement with a previous study on squid from the same region. There was no significant variability in Hg concentration between the different ...