Genotoxicity by Pahs In Shrimp (Litopenaeus Vannamei) and Its Impact on The Aquaculture of Two Coastal Ecosystems of The Gulf of California, Mexico

Abstract

During the lasts decades, aquaculture of several species have growth vertiginously around the world. In Mexico the shrimp aquaculture has been the most important. About 73-75 % of shrimp hatcheries are in coastal ecosystems of the states of Sonora and Sinaloa, located along the Gulf of California. In this States there is not oil industry; however, several industries and other activities discharge petroleum derivatives (imprudently or accidentally) into coastal waters; as happens in Teacapan estuary and Huizache-Caimanero lagoon. The aim of this work was to quantify the levels of PAHs in water of these ecosystems, and to evaluate the genotoxic damage to shrimp, under laboratory conditions. Water samples were taken during rainy and dry months from both coastal systems, and then analyzed by Gas Chromatography (GC). Once known the PAHs concentrations, lots of seven juvenile shrimp were exposed to sub-lethal concentrations of Naphthalene, Phenanthrene, Chrysene, Fluorene, Anthracene, Pyrene, Fluoranthene, Benzo(b)fluoranthene and Benzo(a)pyrene during 21 days, since these were the most frequently PAHs found. At end of exposure period, genotoxicity was evaluated by Comet assay, and presence of micro-nucleus in shrimp haemocytes. Results demonstrated genotoxic damage by presence of comets, and micro-nucleus more frequently in exposed shrimps than controls. Also, a growth decrease was observed in exposed shrimps. These results, indicate potential risk for shrimp aquaculture in Sinaloa and human health, since shrimp is exported and consumed locally, and because in some cases, experimental PAHs concentrations were lower than concentrations of some PAHs found in water of Teacapan estuary and Huizache–Caimanero lagoon.