Abstract

ARANDA-COELLO, José Manuel; MENDOZA-VELAZQUEZ, Oscar Miguel  and  GUTIERREZ-OLVERA, Carlos. Heavy metals in caudal scales of Crocodylus moreletii in the southern portion of the Lacandona jungle, Chiapas, Mexico. Rev. Int. Contam. Ambient [online]. 2023, vol.39, 54454.  Epub June 05, 2023. ISSN 0188-4999.  https://doi.org/10.20937/rica.54454.

Heavy metals are the main contaminants of aquifers due to their high toxicity, persistence, and mobility; they affect important hydraulic loads, such as lagoons and irrigation canals, and due to their physical and chemical properties, they are not biodegradable and can become toxic to vertebrates and invertebrates. The objective of this study was to determine the presence of heavy metals in the population of Crocodylus moreletii inhabiting the southern portion of the Lacantun River in the Lacandon jungle. Samples of caudal scales were collected by manual captures and with Thompson snares from March 2018 to February 2019 in 23 km of the middle sub-basin of the Lacantún River in the Montes Azules Biosphere Reserve (REBIMA). Subsequently, the presence of heavy metals such as lead (Pb), cadmium (Cd), copper (Cu) and zinc (Zn) was determined using the atomic absorption spectroscopy by flame technique, while for mercury (Hg) and the metalloid arsenic (As) by atomic absorption spectroscopy by hydride generation. With these results, we infer that the pollutants present in the caudal scales of C. moreletii at the three sites sampled are indicative of point sources of contamination for the southern border zone of the REBIMA within the complex known as Selva Lacandona.

Keywords : conservation; Morelet’s crocodile; pollutants; bioaccumulation; environmental pollution; ecotoxicology.

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