Genetic damage in Rhinella marina populations in habitats affected by agriculture in the middle region of the Sinú River, Colombia

Abstract

Contamination with pesticide residues affects the environmental health of agroecosystems, especially the amphibian fauna that lives in these environments. The objective of the present study was to determine pesticides concentrations in sediments of agroecosystems and to evaluate genetic damage in Rhinella marina populations living in these zones. A total of 91 individuals were collected, 51 in the group exposed in different areas of the middle region of the Sinú River (Irrigation District of Mocari 16, Irrigation District of Aguas Negras 21, Irrigation District of Cerete 14) and 40 in a control group; at the same time, 36 subsamples of sediments were taken at each sampled station to determine pesticides organochlorine by means of chromatography coupled with ISQ Thermo Scientific mass spectrometer. The micronucleus test was applied in erythrocytes of the individuals collected. Results showed the presence of persistent organochlorine pesticides (POPs) in the sediment samples (p,p'-DDT, p,p'-DDE, and p,p'-DDD) of agricultural soils. Two individuals were registered with abnormalities in their limbs at the Mocari station, representing 12.5% of the morphological malformations to this sector. Micronucleus analysis revealed statistically significant genetic damage in exposed individuals (Mocari 9.87 ± 5.1, Cerete 7.7 ± 1.7, Aguas Negras 5.6 ± 3.6) with respect to the control group (2.4 ± 1.9) (p < 0.05). Spearman correlation analysis revealed a positive association between genetic damage and POP concentrations (p < 0.05). In addition, cellular alterations such as nuclear buds, and pyknosis (cell death), were statistically significant in the exposed group compared to the control group (p < 0.05). This study suggests that there is evidence for morphological and genotoxic effects in R. marina populations inhabiting areas influenced by agriculture, possibly associated with the presence of p,p'-DDT, p,p'-DDD, and p,p'-DDE.

Habitat differences affect the nuclear morphology of the erythrocytes and the hepatic melanin in Leptodactylus fuscus (Anura) in the Brazilian Cerrado savanna

“…The formation of MN is known to be a result of the action of genotoxic agents that generate lesions in the DNA (Fenech 2000;Pollo et al 2015) or as a product of the removal of excess material from the main nucleus, leading to genomic instability (Prieto- García et al 2007;Pollo et al 2015). A similar pattern has been recorded in previous in situ studies of anurans, both larvae and adults, in habitats disturbed by agricultural practises (Pollo et al 2015;Babini et al 2015;Cruz-Esquivel 2017;Borges et al 2019b). These ndings highlight the importance of this type of study for the assessment of the health of populations inhabiting disturbed environments (Hoffman et al 2003).…”

“…The micronucleus (MN) test in ecotoxicological studies has become a standard procedure due to its simplicity, high sensitivity, and reliability, with the results becoming available rapidly (Fenech 2000;Cruz-Esquivel et al 2017). In addition to micronuclei, other erythrocyte nuclear abnormalities (ENAs) have been associated with the processes of cell division and death (Pollo et al 2015).…”

Habitat Differences Affect the Nuclear Morphology of the Erythrocytes and the Hepatic Melanin in Leptodactylus Fuscus (Anura) in the Brazilian Cerrado Savanna

“…Multiple stressors for amphibians may arise simultaneously in agricultural environments, including habitat fragmentation (Prado and Rossa-Feres 2014) and the loss of vegetation cover from the margins of bodies of water (Silva et al 2012a), which results in an increase in UV radiation (Lipinski et al 2016) and the distance between forest fragments and the ponds in which many amphibian species breed (Silva et al 2012b). The application of pesticides contaminates not only the soil, but also bodies of water, either directly or indirectly (Lajmanovich et al 2014) The micronucleus (MN) test in ecotoxicological studies has become a standard procedure due to its simplicity, high sensitivity, and reliability, with the results becoming available rapidly (Fenech 2000;Cruz-Esquivel et al 2017). In addition to micronuclei, other erythrocyte nuclear abnormalities (ENAs) have been associated with the processes of cell division and death (Pollo et al 2015).…”