Stress plays an essential role in maintaining the fish health. Different stress agents' response initiates the hypothalamus's activation and subsequent changes in the neuroendocrine system, metabolism, and physiology. Fish are heavily influenced by their environment in various aquatic habitats. In the current study, zebrafish were exposed to varying pH levels, and the resulting stress responses were observed. The acute toxicity and chronic effects of extreme pH 4.2, 8.2, and 10.2 are effectively seen on zebrafish's gill. The current research primarily aims to shed light on the role of nonsense-mediated messenger RNA decay (NMD), a eukaryotic surveillance mechanism, explicitly focusing on the turnover of the core NMD transcripts in zebrafish exposed to extreme pH conditions. This study enlightens how water quality parameters like pH affect specific physiological and molecular events in zebrafish. In summary, exposure to sub-lethal pH concentrations influences zebrafish's physiological and NMD processes, resulting in zebrafish mortality.