Effect of Water Quality on the Volume of Freshwater Fish Production in Laguna

Author(s): Kathleen Joyce Austria
Email (s): kcaustria@cbzrc.pshs.edu.ph
Institution or organization of origin: Philippine Science High School- CALABARZON Region Campus
Country: Philippines


Laguna de Bay, the largest freshwater lake in the Philippines, accounts for about 17% and 44% of the national and municipal fisheries production. Several fish kill events have occurred in recent years, which according to the Laguna Lake and Development Authority (LLDA) were mainly caused by increased nitrate and decreased dissolved oxygen (DO) levels due to eutrophication and lake overturn. Different water quality (WQ) parameters have been suspected of affecting fish health and thereby the production volume. In this study, the relationship between different WQ parameters and the volume of freshwater fish production in Laguna was determined. Secondary WQ quarterly data were gathered from LLDA and were averaged to match the annual fisheries data from the Philippine Statistical Authority (PSA), both from years 2016 to 2019. To test the hypothesis that WQ may have a significant effect on fisheries production, the data were then analyzed through Pearson’s correlation coefficient and t-test.

Results revealed fecal coliform to have the only statistically significant correlation with fish volume. Nitrate and DO displayed moderate correlations, while other parameters showed little to no correlation. Related studies have shown that all parameters affect fish population in some way, either positive or negative. However, due to inadequate monthly data on fish production, averaged WQ parameter values may have influenced the study’s findings. Nevertheless, this suggests fecal coliform concentration may significantly affect fish health aside from the usual parameters analyzed in other studies. Hence, researchers assessing WQ should consider analyzing fecal coliform concentration, along with other external factors.

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