Water quality dynamics and their association with bacterial pathogen prevalence in Litopenaeus vannamei aquaculture ponds in Haryana, India

Aquaculture of Litopenaeus vannamei (Pacific white shrimp) has rapidly expanded in Haryana, India, due to its high economic potential. However, disease outbreaks, particularly those caused by bacterial pathogens, remain a major constraint, often linked to fluctuating water quality parameters. This study aimed to analyze the dynamics of key water quality variables and evaluate their association with the prevalence of major bacterial pathogens in L. vannamei ponds across selected sites in Haryana. Water and shrimp samples were collected over a six-month culture period from ten representative ponds. Physicochemical parameters including temperature, pH, salinity, dissolved oxygen (DO), ammonia, nitrite, and turbidity were measured bi-weekly. Simultaneously, bacterial pathogens such as Vibrio spp., Aeromonas hydrophila, and Pseudomonas spp. were isolated and quantified using standard microbiological techniques. The results demonstrated that elevated ammonia and nitrite levels, low DO, and fluctuating pH were significantly correlated (p < 0.05) with increased pathogen loads. Vibrio spp. was the most prevalent, followed by A. hydrophila. The study underscores the critical role of water quality management in minimizing bacterial infections and improving shrimp health and yield.