Author(s):
Seixas, Sónia 
; Bustamante, Paco ; Pierce, Graham J.
Date: 2005
Persistent ID: http://hdl.handle.net/10400.2/1516
Origin: Repositório Aberto da Universidade Aberta
Subject(s): Toxic element; Marine pollution; Cephalopods; Mercury; Octopus
Description
Mercury concentrations were measured in tissues of 12 individuals of Octopus vulgaris, captured by the commercial fishery
at two points along the Portuguese coast, Viana do Castelo and Cascais, in spring 2002. Concentrations were determined in six
tissues (digestive gland, branchial hearts, gills, mantle, arms, and gonads). Correlations between mercury concentrations in different tissues were examined as were correlations between mercury levels and total length, mantle length, weight, gonadosomatic index, digestive gland index, and state of maturation. Differences between sexes and localities were analysed.
The concentration of mercury in the digestive gland (Viana, 0.58F0.08, and Cascais, 3.43F2.57 mg/kg dry weight) was
higher than in the other tissues, and values were generally similar to those recorded in previous studies on octopods. Arm
muscle contained most of the mercury with 56% of the total body burden followed by the digestive gland with 31%, mantle with 11%, gills with 0.8%, gonad with 0.5%, and branchial heart with 0.2%. In all tissues, mercury concentrations were slightly higher in samples from Cascais than in Viana do Castelo, which is consistent with higher concentrations recorded in seawater at
Cascais. Levels of mercury determined in octopus were within the range of values legally defined as safe for human consumption.
