Chemical Use and Its Determinants in Commercial Tilapia Farming in Bangladesh: A Cross-sectional Study

Abstract

Chemicals used in aquaculture, including antibiotics, disinfectants, biocides, and other therapeutic agents, can significantly affect the surrounding environment and disrupt the interconnected One Health sectors, encompassing human, animal, and environmental health, as well as food safety. However, there is limited understanding of the extent and key factors influencing chemical use in aquaculture farms in Bangladesh. To address this knowledge gap, we conducted a retrospective cross-sectional study in November 2022, surveying 116 commercial tilapia farms in Mymensingh, a major tilapia production hub in Bangladesh. The pond-level questionnaire was deployed to collect data from one randomly chosen pond per farm where tilapia farming was conducted during the last production cycle. A total of 68.1% of farmers reported 251 instances of aquamedicine administration involving 61 different products, with the majority (54.6%) being antimicrobial agents, including antibiotics, antiparasitics, and disinfectants, applied in the selected ponds. Approximately 46.6% of the farmers interviewed experienced fish mortality in their ponds and the two primary causes of fish mortality identified by respondents were water quality issues (85.2%) and pathogen infections (66.7%). Univariate logistic regression analysis revealed that the likelihood of using any chemical inputs was approximately twenty-four times higher (OR 23.8, 95% CI: 4.9–116.3, p<0.05) on the ponds where clinical signs of illness were present and five times higher in polyculture commercial tilapia farming techniques (OR 5.3, 95% CI: 1.1–26.2, p<0.05). Frequent use of chemical products, particularly antimicrobial agents, could have significant risks to both environmental, animal, and human health. This practice may contribute to the development of antimicrobial resistance (AMR) and the contamination of aquatic ecosystems with harmful residues. To mitigate these impacts, it is essential to promote preventive measures such as improved water quality management and biosecurity practices, while ensuring the responsible and judicious use of antimicrobials in aquaculture.