Estudi dels metalls pesants en sargs (Diplodus sargus, L.) procedents de dues àrees pesqueres de la Costa Brava

Abstract

Because of the frenetic anthropic activity, mainly the industrial one, oceans and seas all over the world have been suffering the huge impact, rising the levels of contamination every year. The Mediterranean Sea is not an exception and heavy metal ions dissolved in water are the most common form of pollution. Furthermore, the fact that it has several aquaculture infrastructures in open sea, has become one of the factors known to increase the metallic contamination of coastal areas, affecting especially marine fauna. In this study, we expose the effects of heavy metal contamination in different specimens of Diplodus sargus (L.) in two coastal areas of the Costa Brava (north-eastern of Catalonia) due to the fact that white seabream is known to have omnivorous diet and it does not present a prey specialization, is used in this research as a bioindicator. We analysed the concentrations of arsenic (As), cadmium (Cd), chromium (Cr), cooper (Cu), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), selenium (Se), tin (Sn) and zinc (Zn) found in muscular tissue. Most of the toxic elements did not show a well-defined linear regression with the total length and the weight (both are morphometric parameters), the exception was Hg. It was the only pollutant that showed bioaccumulation. The presence of more Cu in the fishing area with a marine farm indicated the contamination effects that the installations produced. Excluding arsenic, chromium, mercury and selenium, the rest of heavy metals were not considered a health risk. Arsenic was the metal with the highest number of highly polluted individuals of white seabream (68,1%), followed by Hg (39,65%) and finally by Cr and Se (21,55%). Although As was the most abundant heavy metal, Hg and Cr were those with the higher potential danger for health, especially for the most vulnerable ones, such as children and pregnant women. Despite that, Costa-Brava white seabreams can be eaten without much concern if its consumption is moderated, considering D. sargus as other bioaccumulator fishes like tuna or swordfish