Genotoxicity Risk Assessment in Nile tilapia (Oreochromis niloticus) from a Hatchery Exposed to Pesticides in the Haut-Sassandra Region, Côte d’Ivoire

Fish is a primary protein source in Côte d'Ivoire, accounting for 39% of animal protein intake. However, the current local production from fisheries is insufficient to meet the annual national demand. Fish farming could address this gap, but the production of high-quality fry remains a key challenge. Water quality plays a crucial role in fry production, yet many tilapia farms in the country are susceptible to agrochemical contamination from nearby agricultural activities, which can affect both fish health and reproduction. This study aims to assess genotoxicity of a hatchery water in tilapia using the alkaline comet assay. Water samples from Modern Hatchery of Gonaté in the Haut-Sassandra Region of Côte d'Ivoire were collected in November 2021 and October 2022 for pesticides analysis. Simultaneously, fish broodstock samples were collected for genotoxicity assessment. Our results show that in 2021, when pesticides were used in the surrounding area, DNA damage in the erythrocytes of tilapia broodstock (41.6 ± 6.7% tail DNA) was significantly higher (ANOVA, F(3,31) = 222.9, P < 0.001) compared to individuals sampled in 2022 (15.5 ± 4.4%) after pesticide use in the adjacent food crops ceased. Pesticide residues, including glyphosate, acetamiprid, and mancozeb, were detected in water samples from 2021 but were absent in 2022, coinciding with the cessation of pesticide use near the hatchery. These findings underscore the impact of agrochemical exposure on DNA damage in tilapia, which may have detrimental effects on fry production.