Evaluation of metals and their teratogenic effects in Lepidochelys olivacea in Puerto Arista, Chiapas, Mexico

Abstract

Metals in high concentrations cause harmful effects on ecosystems, affecting organisms that have wide-ranging migrations and specific eating habits such as sea turtles. These reptiles have limited metal elimination routes, including excretion through eggs, which contributes to the appearance of malformations in offsprings and embryos. Therefore, the objective of this research was to evaluate the concentrations of Pb, Cr, Cu, and Cd in neonates dead and unborn of the turtle Lepidochelys olivacea, as well as the identification of body regions with a higher malformation index (MI) and its possible relationship with teratogenic effects due to exposure to said contaminants. 24 embryos and 11 hatchlings were collected and analyzed from a turtle camp in Tonala, Chiapas, Mexico. 21 malformations were identified, to which a lethality level was assigned; also, the intensity and incidence rates were calculated. The region with the highest IM was the shell (60.7%). The most frequent malformations were irregular plates (18%) and compressed shell (11.2%). The intensity was 2.5 (m/organism) and 0.2 (m/nest), with an incidence of 1.3. The metals were analyzed by atomic absorption spectrophotometry, and metal concentrations were Pb>Cr>Cu>Cd in both groups. The average concentrations in neonates were 38.5 mg kg ^-1 Pb, 8.5 mg kg ^-1 Cr, 3.7 mg kg ^-1 Cu, and 3.1 mg kg ^-1 Cd, while in offspring they were 32.1 mg kg ^-1 Pb, 7.2 mg kg ^-1 Cr, 4.1 mg kg ^-1 Cu and 4.0 mg kg ^-1 Cd. No correlation was found between malformations and metals.