Influence of pond water total alkalinity on disease dynamics in Indian tropical freshwater aquaculture: Evidence from case studies.

Abstract

The study was conducted in the freshwater aquaculture&#xa0;farms for a period of 5&#xa0;years where pond water samples (N&#x2009;=&#x2009;831) were subjected to an estimation of the total alkalinity which is one of the important parameters for the fish culture system. Further, the collection of pond water total&#xa0;alkalinity and fish health status was recorded upon each sampling. After metadata analysis, it was found that there is a significant correlation between the total alkalinity of pond water and the prevalence of various&#xa0;infectious diseases in farmed food fish while other water quality parameters were at an optimal range. In addition, the correlation values were found to be&#x2009;+&#x2009;0.95,&#x2009;+&#x2009;0.32, and&#x2009;-&#x2009;0.77 while the total alkalinity of that pond water was&#x2009;&#x2264;&#x2009;40&#xa0;ppm,&#x2009;&#x2264;&#x2009;100&#xa0;ppm, and&#x2009;&#x2265;&#x2009;100&#xa0;ppm respectively. The results of the study infer that lower alkalinity favors the incidence of infectious diseases in farm food fish. The fish health-related data revealed that the occurrence of infectious diseases&#xa0;(presence of&#xa0;etiological agents) significantly (p&#x2009;<&#x2009;0.05) reduced in farmed food fish while the total alkalinity range of pond water was &#x2009;&#x2265;&#x2009;100&#xa0;ppm (mg/L). Hence, it could be concluded that the variations in total alkalinity ranges of pond water considerably affect the&#xa0;fish health and occurences of&#xa0;infectious disease in freshwater aquaculture systems in Indian tropical climates.