Heavy Metals in Oysters, Shrimps and Crabs from Lagoon Systems in the Southern Gulf of México

Lagoon systems in the southern Gulf of Mexico are highly productive. These aquatic systems have been severely negatively impacted by anthropogenic and industrial activities. The objective of this research was to estimate the concentration of heavy metals Pb, Cu, Cd and Zn in oysters, shrimp and crabs from the Carmen-Pajonal-Machona and Mecoacán lagoon systems in Tabasco, México. Samples were collected from fishing zones within these lagoon systems and included oysters Crassostrea virginica, and crustaceans such as Litopenaeus setiferus (shrimp) and Callinectes sapidus (crab). Concentrations of Pb, Cu, Cd and Zn were determined by atomic absorption using flame spectrophotometry. The heavy metal concentration pattern in oysters, shrimp and crab in the Carmen-Pajonal-Machona system was Cu > Pb > Cd. The maximum average concentration of Cu was 259.12 ± 12.312 in oyster; 0.516 ± 0.154 in shrimp, and in crab 0.907 ± 0.273 µg g-1. Pb had a maximum concentration of 1.37 ± 0.77 in oyster, in shrimp was 0.059 ± 0.044, and for crab was 0.0055 µg g-1 (p>0.05), while in the Mecoacán lagoon system the pattern showed Pb > Cd > Zn. The maximum average concentration of Pb was 321.15 ± 28.828 µg g-1, the minimum was 84.70 ± 8.612 µg g-1. The highest concentration of Cd was 63.74 ± 8.446 µg g-1, and the minimum 13.00 ± 0.64 µg g-1. For Zn the maximum average concentration obtained was 24.42 ± 2.665 µg g-1.