| Abstract Title: | Ruditapes sp. as bioindicators of mercury presence in Portuguese coastal lagoons |
| Presenter Name: | S¡lvia Pires |
| Company/Institution: | CESAM - Centro de Estudos do Ambiente e do Mar, Departamento de Biologia, Universidade de Aveiro, Portugal |
| Session: | Mercury in Marine Ecosystems |
| Co-Authors: | S¡lvia Pires,Teresa Baptista,Hugo Vieira,Amadeu Soares,Rui Rocha,Andreia Rodrigues |
Abstract Information :
Mercury (Hg) is a pollutant that requires particular attention due to its high toxicity, persistence and bioaccumulative properties. Although its anthropogenic emissions have been substantially reduced in Portugal, historical contamination leads to considerable burdens of Hg in the sediments of Ria de Aveiro and Ria Formosa lagoons. Therefore, it is expected that anthropogenic activities and seasonal storms and tides might resuspend bottom sediments, making Hg available to biota. Bivalves molluscs, in particular, are widely used as biomonitors of environmental metal concentrations due to their feeding behaviour, filtrating the Hg bioavailable from the water column. Besides, these organisms may act as vectors for the transfer of Hg to higher trophic levels. On the other hand, bivalve molluscs are traditionally used in gastronomy, and their harvesting represents an important activity in coastal communities. Therefore, monitoring Hg presence along the Portuguese coast is extremely relevant due to environmental but also food safety issues. This study aimed to assess Hg concentrations in bivalve molluscs collected monthly in aquaculture areas of three coastal lagoons (Ria Formosa, Ria de Aveiro and Lagoa de ?bidos, April 2019 ? January 2020). In this sense, samples of two species of clams (Ruditapes decussatus and/or Ruditapes philippinarum) were collected and, the total Hg quantification in the edible tissues of clams was carried out through the DMA-80 Evo Direct Mercury Analysis System. Clams proved to be good bioindicators of Hg presence. As expected, clams from Ria Formosa and Aveiro lagoons presented higher levels of Hg than ?bidos lagoon throughout the year. Nevertheless, values obtained for these clams are below the maximum levels established by European legislation of 0.5 mg/kg. Fluctuations on Hg accumulation due to seasonality will also be presented and discussed.
